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Abstract
Electroplating: Basic Principles, Processes and Practice offers an understanding of the theoretical background to electroplating, which is essential if the practical results are to be as required. This book is different in that it explains HOW the electrodeposition processes work, covering such topics as the elctrodeposition of composites, multilayers, whisker formation and giant magnetoresistive effects. The section on R & D approaches will be especially useful for organisations in the field. This is the first English language version of a well-known German language book from a prestigious author of international repute.'Electroplating' is an invaluable resource for manufacturers of coatings, electrochemists, metal finishers and their customers and academics in surface engineering. • Offers an understanding of the theoretical background to electroplating • Explains how the electrodeposition processes work • Prestigious author of international repute.
... This hybrid approach enables selective metal coating on conductive polymer substrates, expanding the potential applications of electroplating. As a widely used surface treatment technique, electroplating allows the deposition of one or more layers of metals or alloys onto a variety of substrates, enhancing surface properties such as conductivity, corrosion resistance, and mechanical strength 61,62 . This technique employs chemical or electrochemical methods to deposit a thin metal film on the surface of metals or other conductive materials, thereby enhancing their physical and chemical properties 63 . ...
... This metallic film can be pure metals, such as copper 64,65 , nickel 66 , silver 67 , or gold 67 , or alloys like zinc-nickel alloy 68 , tailored to meet diverse application needs. The fundamental principle of electroplating is based on electrolytic reactions 61,62 . During the electroplating process, the item to be plated serves as the cathode, while the plating solution is enriched with the metal cations to be deposited. ...
... To sum up, electroplating and electroless plating offer distinct advantages and trade-offs for the metallization of 3D-printed polymer substrates. Electroplating utilizes an external power source and necessitates a conductive substrate, facilitating accelerated deposition rates and enhanced thickness control, thus rendering it appropriate for applications that require durable and uniform metal layers 61,62 . Nonetheless, its reliance on surface conductivity and the necessity for more complex masking procedures may restrict its applicability to intricate, non-conductive geometries. ...
... For active metals (e.g., Al, Mg, and Be) and metals that are difficult to electrodeposit from aqueous solution (e.g., Ti, Mo, and W), it is possible to achieve electrodeposition or co-electrodeposition in organic solvents. [24] In the case of alkali and alkaline-earth metals, they cannot be electrodeposited individually from aqueous solution at the cathode. Molten salt electrodeposition can be employed to obtain alloys, for example, electrodeposition of Al-Mn alloys from AlCl 3 -NaCl-MnCl 2 molten salt system, electrodeposition of Li-Pd alloys from LiCl-KCl-PdCl 2 molten salt system, electrodeposition of Ti and its alloys from NaCl-KCl molten salt system. ...
... Molten salt electrodeposition can be employed to obtain alloys, for example, electrodeposition of Al-Mn alloys from AlCl 3 -NaCl-MnCl 2 molten salt system, electrodeposition of Li-Pd alloys from LiCl-KCl-PdCl 2 molten salt system, electrodeposition of Ti and its alloys from NaCl-KCl molten salt system. [24] Ionic liquids are liquids composed of ions of materials at or near room temperature, with numerous advantages such as a wide temperature range, wide solubility range, extremely low vapor pressure, good stability, strong polarity, adjustable acidity, electrochemical window, and so on. Compared with traditional organic solvents, room temperature ionic liquids have a wider electrochemical window, excellent electrical conductivity, nonvolatility, and enhanced thermal stability, which can be widely used in aluminum ion batteries and magnesium ion batteries. ...
... Compared with traditional organic solvents, room temperature ionic liquids have a wider electrochemical window, excellent electrical conductivity, nonvolatility, and enhanced thermal stability, which can be widely used in aluminum ion batteries and magnesium ion batteries. [24] Electrodeposition is typically conducted in two-or threeelectrode systems (Figure 1b), with three-electrode electrodeposition as the primary example in the following discussion. A representative electrodeposition device is illustrated in Figure 1b. ...
Developing “beyond lithium‐ion ” batteries with reduced cost per unit of stored energy, high safety, and good electrochemistry performance is regarded to be an urgent task for rechargeable battery systems ascribing to the coming technical bottleneck of the state‐of‐the‐art commercial Li‐ion batteries. Rechargeable multivalent ion batteries (RMIBs), such as Zn²⁺, Mg²⁺, Ca²⁺, and Al³⁺ ion batteries, have attracted intensive attention due to their low cost, high safety, high energy density, and operating availability. However, the development of high‐performance RMIBs, is severely hindered due to the lack of appropriate cathode materials, electrolytes with wide electrochemical windows, and highly reversible and stable anodes.Therefore, some research progress on RMIBs is reviewed and summarized However, most of the reported reviews mainly focus on the cathode and electrolyte of RMIBs. A comprehensive review of anode chemistry is not reported yet. In particular, the fundamental electrodeposition chemistry of RMIBs is not fully understood. This review summarizes the recent advances and the basic mechanism in researching anode electrodeposition chemistry for RMIBs. The understanding of the anode electrodeposition chemistry can accelerate the development of the application of practical RMIBs is hoped.
... At equilibrium, Ia and Ic are equal. So, there is no net I flow [2,17]. Commercial additives came as two separate solutions: leveler and brightener. ...
... This phenomenon should not in any way be confused with the processes of ions diffusion in solutions. The growth process begins after the nuclei have reached a critical size [2]. When additives are adsorbed onto the electrode surface, Zn ions diffusion is partially impaired, thus causing a 10-fold decrease in Ic. ...
... Hydrophilic groups are attracted to the aqueous phase, while the hydrophobic end is weakly adsorbed onto the steel surface. The degree of ordering at the interface causes a reduction in tension, thus enabling the release of gas bubbles that may otherwise adhere to the electrode surface, causing pitting or deposit porosity [2]. Moreover, the substrate coverage by the surfactant molecules causes the reduction shift in E to more negative values, along with the decrease in Ic [8]. ...
This work presents a set of electrochemical techniques applied to investigate the effect of Zn baths with additives on steel surfaces coating by EP. The form and intensity of the reduction in I were analyzed as a function of the applied E, using LSV. In this way, different stages of the EP process involved in Zn deposition on steel surfaces, and the effect of each additive, were identified. First, commercial additives produced by a local company, with highly complex compositions, were studied to understand their Ct effects on the different stages of steel coating in Zn baths by the EP process. Based on the ability to replicate those results, C7H6O2 and Triton X-100, previously reported as brightener and leveler, respectively, were proposed as a simple additive mix. Very strong synergetic effects were present, even in this simplified bath. The effect of different additives Ct on the steel coatings grain size or morphology was also evaluated using SEM images, in the final stage. A correspondence between optimal Ct of the commercial additives and the proposed bath (1 x 10-2 M Triton X-100 and 3 x 10-9 M C7H6O2) was found. Finally, EIS experiments were carried out for the different bath compositions, with this simplified additive mix. The results were interpreted through an equivalent electrical circuit represented by Rct, with two parallel CPE, which evidenced Zn deposits inhomogeneities.
... Along those lines, is it now important to highlight another class of additives known as surfactants, not only as dispersing agents but also as a medium for coatings with enhanced surface properties. In this way, surfactants are mostly used as wetting agents, due to their chemical properties (specifically their hydrophobic and hydrophilic ends) that allow the reduction of surface tension between the liquid and the substrate, and ultimately prevent the interference of the hydrogen bubbles that form during the electrodeposition process [31]. These bubbles usually hold onto the surface of the pieces subject to coating and eventually lead to porosity and the formation of pits, this being the most frequent reason why surfactants are added to the baths [22]. ...
... These bubbles usually hold onto the surface of the pieces subject to coating and eventually lead to porosity and the formation of pits, this being the most frequent reason why surfactants are added to the baths [22]. On the other hand, the most relevant role of surfactants in this work happens to be the less frequent one, for instance, the way these agents improve the uniform distribution of solid and insoluble compounds, such as nanoparticles, and even prevent agglomeration and sedimentation of the same [31,32]. Thus, there are many wetting agents, and it is possible to classify them into different groups such as anionic, cationic, and non-ionic, being the surfactant subject to study in this work, cetyltrimethylammonium bromide (CTAB), classified as a cationic one. ...
... Thus, there are many wetting agents, and it is possible to classify them into different groups such as anionic, cationic, and non-ionic, being the surfactant subject to study in this work, cetyltrimethylammonium bromide (CTAB), classified as a cationic one. Nevertheless, as with any other surfactant, CTAB is a complex additive to work with, since it needs optimal concentrations to benefit from the above advantages, and when those concentrations are not met, it may compromise the electrodeposition process and the properties of the coatings [31,33]. ...
Coatings can be created using various technologies and serve different roles, including protection, functionality, and decorative purposes. Among these technologies, electrodeposition has emerged as a low-cost, versatile, and straightforward process with remarkable scalability and manufacturability. Nickel, extensively studied in the context of electrodeposition, has many applications ranging from decorative to functional. The main objective of the present work is the electrodeposition of double-layer nickel coatings, consisting of a bright nickel pre-coating followed by a black nickel layer with enhanced properties, onto steel substrates. The influence of deposition parameters on colour, morphology, adhesion, roughness, and coefficient of friction was studied. The effects of cetyltrimethylammonium bromide (CTAB) and WS2 nanoparticles on the coatings’ properties and performance were also investigated. Additionally, the influence of the steel substrate’s pre-treatment, consisting of immersion in an HCl solution, prior to the electrodeposition, to etch the surface and activate it, was evaluated and optimized. The characterization of the pre-coating revealed a homogeneous surface with a medium superficial feature of 2.56 μm. Energy dispersive X-ray spectroscopy (EDS) results showed a high content of Ni, and X-ray diffraction (XRD) confirmed its crystallinity. In contrast, the black films’ characterization revealed their amorphous nature. The BN10 sample, which corresponds to a black nickel layer with a deposition time of 10 min, showed the best results for colour and roughness, presenting the lowest brightness (L*) value (closest to absolute black) and the most homogeneous roughness. EDS analysis confirmed the incorporation of WS2, but all samples with CTAB exhibited signs of corrosion and cracks, along with higher coefficient of friction (COF) values.
... At equilibrium, Ia and Ic are equal. So, there is no net I flow [2,17]. Commercial additives came as two separate solutions: leveler and brightener. ...
... This phenomenon should not in any way be confused with the processes of ions diffusion in solutions. The growth process begins after the nuclei have reached a critical size [2]. When additives are adsorbed onto the electrode surface, Zn ions diffusion is partially impaired, thus causing a 10-fold decrease in Ic. ...
... Hydrophilic groups are attracted to the aqueous phase, while the hydrophobic end is weakly adsorbed onto the steel surface. The degree of ordering at the interface causes a reduction in tension, thus enabling the release of gas bubbles that may otherwise adhere to the electrode surface, causing pitting or deposit porosity [2]. Moreover, the substrate coverage by the surfactant molecules causes the reduction shift in E to more negative values, along with the decrease in Ic [8]. ...
... It will be explicitly concentrated on the points that are of interest for the coating of APT tips, and the practical aspects of the deposition will be discussed. For further information, the reader is referred to literature, that describes the electroplating process in detail (Giurlani et al., 2018;Hanson & Hanson, 2019;Kanani, 2006;Paunovic & Schlesinger, 2006;Schlesinger & Paunovic, 2010). ...
... Concerning the preparation of a bulk work piece, in-line plating processes require several cleaning steps before the ED-process (Kanani, 2006). Transferred to the tip preparation, thoroughly cleaning of the W-tip with distilled water and clean isopropyl, preceding to the DEP-step proved to be important. ...
... The anode at the bottom of the electrolyte vat and the cathodically polarized specimen inserted from the top are in contact with the Ni-electrolyte. After applying a DC current, the Ni-cations electrode posit on the negatively charged cathode (Hanson & Hanson, 2019;Kanani, 2006). Apart from the Ni-anode in our setup, another typical electrode material, employable for various electrolytes, is platinum (Kanani, 2006). ...
The behavior of catalytic particles depends on their chemical structure and morphology. To reveal this information, the characterization with atom probe tomography has huge potential. Despite progresses and papers proposing various approaches towards the incorporation of particles inside atom probe tips, no single approach has been broadly applicable to date. In this paper, we introduce a workflow that allowed us to prepare atom probe specimens from Ga particles in suspension in the size range of 50 nm up to 2 μm. By combining dielectrophoresis and electrodeposition in a suitable way, we achieve a near‐tip shape geometry, without a time‐consuming FIB lift‐out. This workflow is a simple and quick method to prepare atom probe tips and allows for a high preparation throughput. Also, not using a lift‐out allowed us to use a cryo‐stage, avoiding melting of the Ga particles, while ensuring a mechanical stable atom probe tip. The specimen prepared by this workflow enable a stable measurement and low fracture rates.
Research Highlights
Enabling cryo‐preparation of (nano)particles for the atom probe.
Characterization of surface and bulk elemental distribution of GaPt model SCALMS.
... Under these conditions, the charge transfer resistance at the oxide/Ni coating interface is significantly high, indicating superior performance and quality of NiO compared to the annealed and electroplated samples. This improvement can be attributed to the combined effect of the high-density submicron twins and low-energy planes, such as (111) and (100), in the surface microstructure of the temper-rolled sample, which collectively enhances the protective performance of the passive layer. The (111) planes typically exhibit lower surface energy than other planes, such as (110), making them more stable and less reactive. ...
... Localized corrosion preferentially initiates in granular areas where pores are more likely to exist. Typically, these pores form during the electroplating process [100]. Annealing helps eliminate pores and defects, reducing vulnerable sites for localized corrosion. ...
... At this time, the steel mill stopped producing steel and started manufacturing metallic artifacts (CLA 2014). It is possible that they started to work with electroplating processes because Co, Cu, and Ni are used in this process to protect metallic artifacts (Kanani 2004). ...
... In this time, the steel mill stopped producing steel and started to manufacture metallic artifacts (CLA 2014). Maybe they started to work with electroplating processes, since Co, Cu, and Ni are very used in this process in a sense to protect metallic artifacts (Kanani 2004). We notice strong Pearson's correlation among Co, Cu, and Ni (r > 0.7), but weak correlation between Co and Fe. ...
In this study, we evaluated the pollution history by metals over the twentieth century in an urban reservoir (Garças Reservoir, Metropolitan Region of São Paulo, Southeast Brazil) by the paleolimnological approach. The concentrations of eight metals (Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) were determined in a ²¹⁰Pb-dated sediment core (~ 100 years of information). Metal’s enrichment and pollution degree were assessed using the Consensus-Based Sediment Quality Guidelines (CBSQG), enrichment factor (EF), Geoaccumulation Index (Igeo), and Potential Ecological Risk Index (RI). Local background values were used to calculate metal enrichment indexes. Principal component analysis (PCA) was performed to analyze metal variability across samples. Overall heavily to extremely contamination was determined mainly after ~ 1975, particularly to Pb, Ni, and Fe, whereas moderately to heavily Cu, Zn, Mn, and Co pollution levels were detected by Igeo. Very high EF values (> 2 ≤ 24) were found, suggesting mainly anthropogenic sources for these elements. However, Pb concentrations declined considerably towards the top of the core, reflecting the prohibition of leaded gasoline since 1986. The long-term metal enrichment in the Garças Reservoir was related mainly to vehicular traffic emissions and industrial activities. Further anthropogenic stressors such as untreated sewage inputs and surface runoff contributed significantly to metal pollution, particularly from the late 1950s, reflecting the most populous region socio-economic development in Brazil.
... [23] Electrodeposition is a method already applied on industrial scales especially for functional or protective coatings of various assemblies, enhancing lubricant properties, electrical conductance or corrosion, wear and thermal resistance. [20,24] In addition to scalability, this process does not require high process temperatures or highly specialized equipment. [20] Furthermore, electrodeposited layers are metallically bonded to the substrate, offering enhanced adhesion [25,26] and improved electrical conductivity due to reduced contact resistances. ...
... During electrodeposition, the deposition charge is consumed partly for the cathodic hydrogen evolution and the reduction of the metal species. As the electrolyte pH is known to influence the co-evolution of hydrogen during electrodeposition, [24] shifting the pH towards acidic conditions causes more cathodic hydrogen evolution. Hence, the deposition current efficiency is found to be reduced for the herein obtained NiFe layers, as the deposited amount of NiFe catalyst decreased while the electrolyte pH was shifted towards 0. A similar effect was reported by Su et al. for fluorborate NiFe electrolytes. ...
This study presents the correlation between electrolyte pH, surface morphology, chemical speciation and electro‐catalytic oxygen evolution activity of additive‐free electrodeposited NiFe catalysts for application in anion exchange membrane water electrolysis. Spherical morphologies were identified at pH 0, shifting towards honey‐combed structures at pH 4 with increasing surface area, especially at pH 3. Further, the electrolyte pH was found to influence the NiFe composition and electro‐catalytic activity. Enhanced OER activity was noted at pH 2 with overpotentials of 214 mV at 10 mA cm⁻² and 267 mV at 100 mA cm⁻². The results reveal that the electrolyte pH is a parameter not only influencing the morphology but also tailoring the surface area, Fe oxide and Fe hydroxide composition and consequently the catalytic activity. Further, the outcomes highlight the electrolyte pH as a key process parameter that should be adjusted according to the application, and may substitute the addition of electrolyte‐additives, proposing a simpler method for improving catalyst electrodeposition.
... Electroplating, or electrodeposition is the most fascinating method for materials synthesis, through electro-crystallization of metal atoms by reducing metal ions due to impressed potential/current. 1 Electrodeposition is more advantageous compared to other methods of materials synthesis in terms of their ease of fabrication, cost, time, etc. In this direction, among many electrodeposited Nickel-based alloy coatings, (Ni-Fe) alloy coating is an important class of material due to its distinctive properties, like good corrosion resistance, low coefficient of thermal expansion, and soft magnetic properties etc. [2][3][4] As a result, (Ni-Fe) alloy coatings are widely employed in industries for various applications. ...
... 23 Generally, corrosion study of electrodeposited (Ni-Fe) alloy coatings reveals that their corrosion protection efficacy mainly depends on their deposition behaviour with variation of plating parameters, like metal ion concentrations, complexing agent, operating temperature, pH and composition on the final properties of the films formed. 1 In addition, the role of additives on the crystallographic structure and hence properties of the coatings are widely recognized. Thus, guided by the above facts a new lowconcentration bath of (Ni-Fe) alloy has been proposed using sulphamic acid, as the additive. ...
Here, we report the development of high corrosion-resistant (Ni-Fe) alloy coatings from a low-concentration bath through multilayer approach. The corrosion analysis of (Ni-Fe) alloys electrodeposited at different current densities (2.0–5.0 A/dm ² ) revealed that the coating developed at 2.0 A/dm ² , represented as (Ni-Fe) 2.0 A/dm ² is highly anticorrosive. The corrosion resistance of monolayer (Ni-Fe) 2.0 A/dm ² coating, showing a corrosion rate of 14.71 × 10 ⁻² mm/y was further improved by utilizing multilayer approach. Corrosion study revealed that multilayer coating having 120 layers, represented as (Ni-Fe) 2.0/4.0/120 was six times more anticorrosive (with corrosion rate = 2.33 × 10 ⁻² mm/y), compared to its monolayer counterpart. The improved anticorrosion performance of multilayered coatings was explained in the light of advanced instrumental techniques.
... [1] Electroplating is often called "Electrodeposition". [3] Electroplatingcan be considered to occur by the process of electrodeposition and is a specific type of surface finishing. [4] The benefits of such process is to Improve appearance , Slow or prevent corrosion (rust) and Increase strength and resistance to wear for engineering finishes. [5] The kinetics of the electrodeposition of metals involves mainly two steps, Mass transfer step where the metal ions reach the cathode surface from the bulk solution and Charge transfer step where the metal ions combine with electrons at the cathode surface to form metal atoms. ...
... The negative values of ∆S٭ pointed to a greater order produced during the process of activation.4. ∆G٭ values of the inhibited systems were more positive than that for the uninhibited systems revealing that in cores of inhibitor addition the activated electrodeposition complex becomes less stable as compared to its absence. ...
A polymer (or polymer) Is a high molecular weight compound composed of repeating subunits, these materials may be organic, inorganic, or mineral-organic, and may be natural or synthetic in origin. "". Nanopolymers have come to play an essential and holistic role in everyday life due to their unique properties Electrodepositionis the process of producing a coating, usually metallic a surface by the action of electric current as a thin layer. Electroplating is often called "Electrodeposition". Electroplatingcan be considered to occur by the process of electrodeposition and is a specific type of surface finishing. The benefits of such process is to Improve appearance, Slow or prevent corrosion (rust) and Increase strength and resistance to wear for engineering finishes. The kinetics of the electrodeposition of metals involves mainly two steps, Mass transfer step where the metal ions reach the cathode surface from the bulk solution and Charge transfer step where the metal ions combine with electrons at the cathode surface to form metal atoms. The mass transfer of copper ions occurs through the following primary mechanisms, electric migration under a potential gradient, adiffusion by ion density difference. A convective motion of solution. Different organic substances are used as additives in electrodeposition to modify the physical properties of the deposit. In this study Nano Polymers are used as additives and Nano Polymers are a high molecular weight substances some of them perform important functions in livening organisms and some of them have an important function in industry, Nano Polymers are classified to natural Nano Polymers for example (Protiens and Carbohydrates) and synthetic Nano Polymers for example (Poly ethylene glycol and Poly vinyl alcohol). Adsorption of such organic compounds on the cathode surface may block a part of the active electrode area and therefore, reduce the mass transfer coefficient and the limiting current. Additives inhibit electrode reactions, primary inhibition,caused by substances whose molecular composition doesn't change during electrodeposition process andsecondary inhibition, caused by substances whose generated during electrode reaction by chemical reaction which competes with the electrodeposition of metals. Additives accelerate electrode reactions, they accelerate the copper electrodeposition through the formation of ion-complex in solution, Electrodeposition of metals is used widely in industry to perform the following technical processes, electroplating, electroforming electrorefining of metals, electrowinning of metals from their natural ores, recovery of heavy metals e.g. Cu, Cd, Hg, Pb, Ag from waste solutions discharged from metal finishing industries Effect of Inhibitors on electrodeposition.
... Point contact leads to higher insertion loss and poor performance. 7,8 These dog-bone structures and non-uniformity are the two major obstacles in the thick electroplating of structures [9][10][11] which need to be resolved for proper response. In contrast, uniform thickness results in proper cantilever contact in the on-state, as shown in Fig. 1c. ...
... The Helmholtz or electrical double and diffuse layers control the bone structure. [9][10][11] This type of distribution is given by Maxwell-Boltzmann statistics as where ρ i is the charge density per unit area, n i is the number of ions per unit volume in the bulk, and Ѱ(x) is the potential distribution function with respect to distance from the electrode. ...
Most microelectromechanical systems (MEMS) devices require suspended structures with high metallic thickness, which is not possible with standard sputtering techniques. Electroplating-based UV LIGA is a cost-effective technique preferred for fabricating thick metallic structures. Gold is preferred as a structural material for MEMS devices such as RF switches, among other metals, due to its high conductivity and low reactivity. For electroplating, a constant current supply is applied between the cathode (electroplating wafers) and the anode (metallic mesh) dipped in gold electrolyte. The value of electric potential is determined by the constant current supply, which is determined by the plating area/current density. The standard DC current supply produces bone structures and non-uniform deposition across the wafer. The Helmholtz or electrical double layer plays a vital role in controlling the profile of the electroplated film. This paper addresses the issues of non-uniform deposition and bone structures with agitation, wafer rotation and bipolar pulsed power supply.
... Tungsten with its unusual properties such as highest melting point ( 3410 o C) of all metals, lowest coefficient of linear thermal expansion ( 4.3 / o C) , highest tensile strength of ( 410 kg/mm 2 ) and one of the highest young's modulus of elasticity ( 3500 kg/ mm 2 ), can render excellent properties to its alloy [4]. The presence of tungsten in amorphous alloys increases the corrosion resistance of such alloys and it has good resistance of strong oxidizing acids at high temperatures and may compete even with ceramics and graphite by virtue of high thermal resistance [4,5]. ...
... Tungsten with its unusual properties such as highest melting point ( 3410 o C) of all metals, lowest coefficient of linear thermal expansion ( 4.3 / o C) , highest tensile strength of ( 410 kg/mm 2 ) and one of the highest young's modulus of elasticity ( 3500 kg/ mm 2 ), can render excellent properties to its alloy [4]. The presence of tungsten in amorphous alloys increases the corrosion resistance of such alloys and it has good resistance of strong oxidizing acids at high temperatures and may compete even with ceramics and graphite by virtue of high thermal resistance [4,5]. Nickel and tungsten are insoluble in the solid and liquid phase because of the high difference in diameter, higher than 15% [6]. ...
This study describes the effects of the bath parameters (temperature, current density, additive concentrations and stirring) on tungsten content and microstructures of Ni-W deposits prepared from thiourea-containing bath, on graphite substrate to protect it from oxidation at high temperature. The morphology of the deposits was studied by optical microscope (TEM) and the approximate composition by energy dispersive spectroscopy (EDS).Increasing the concentration of thiourea refining the structure of the deposits, while the increasing in the current density and temperature led to increase the W content with and without stirring.
... A wide range of metals can be deposited electrochemically, including high-temperature materials such as nickel and biocompatible alloys like Co-Cr [3]. In this study, copper was selected as the coating material due to its ease of deposition from aqueous electrolytes at room temperature and its straightforward handling [4]. This choice facilitates a systematic investigation of the electrochemical deposition process and its mechanical impact on the polymer structure. ...
Additive manufacturing (AM) of metallic lattice structures enables lightweight, high-performance components for structural and multifunctional applications. However, direct metal AM processes are costly and resource-intensive. This study investigates a hybrid approach that combines the geometric flexibility of polymer AM with the mechanical performance of electroplated metals. Polymer lattice templates with fine features were fabricated via stereolithography and subsequently coated with thick copper layers through a 48-h electroplating process. The resulting hybrid structures achieved a copper mass fraction exceeding 98% and exhibited a relative density of 18.9%, comparable to fully metallic lattice materials. Mechanical testing under uniaxial compression revealed substantial improvements in structural performance: while absolute stiffness and strength increased by up to 500 times compared to the uncoated polymer lattice, the relative density also increased significantly. To account for this, the relative effective modulus, defined as the ratio of relative modulus to relative density, was evaluated, demonstrating a 30-fold improvement through metallization. Failure analysis revealed stretch-dominated deformation and brittle collapse modes, closely resembling those observed in hollow metallic lattices. These results highlight the potential of thick-film electroplating as a scalable and versatile route to fabricate mechanically efficient, predominantly metallic lattice structures. This approach paves the way for multifunctional applications in lightweight and energy-absorbing systems.
... During the electroplating process, the silver particles deposited on the working electrode are initially sparse and discrete. As more silver is reduced and electrodeposited, the silver nuclei begin to reach the percolation threshold, [30] the individual particles merge into an interconnected metallic mesh, resulting in a sudden drop in emissivity. This explains why a decrease in emissivity is observed when the charge density reaches 12.5 mC cm −2 . ...
This paper presents the development of an electrochemically‐driven variable emission thermoregulating device designed for efficient radiative heat management across various temperature environments. Utilizing the ionic liquid 1‐butyl‐3‐methylimidazolium tetrafluoroborate (BMIMBF4), the study explores its thermal and electrochemical stability, low vapor pressure, and excellent performance over a wide operational temperature range, making it an ideal electrolyte. The device uses mid‐infrared electrochromic technology, employing ultra‐wideband transparent conductive electrodes and reversible metal electrodeposition to dynamically adjust thermal emissivity between 0.06 and 0.89. This capability allows for significant improvements in heat management, offering a responsive and adaptable solution compared to current systems. The findings suggest that such advanced materials and mechanisms can enhance energy management in spacecraft, potentially extending to other space fields requiring precise thermal control.
... The main mechanism of electroless plating is an autocatalytic reaction that deposits metal through the interaction between catalyst ions, reducing agents, metal ions, and additives in the plating solution. [1,425] Unlike electroplating, [426][427][428] which is capable of instantaneous plating in response to an external energy supply, the chemical reaction in electroless plating is initiated by the diffusion and movement of ions in the bath, resulting in a relatively low plating rate. [163,284] In general, when electroless plating is performed at low or room temperature, ions diffuse slowly toward the substrate, which can result in a long plating time to achieve the target thickness. ...
Electroless plating is a solution‐based metal deposition technique through redox reaction, without external power. Due to its simple, versatile, and low‐cost process, coupled with high compatibility with various metals, electroless plating has become a key technology in many industrial fields such as electronics, automotive, aerospace, and biomedical engineering. Recent advances in electroless plating have enabled sophisticated plating on polymers and three‐dimensional surfaces, making it a prominent technology in emerging fields such as selective laser sintering, additive manufacturing, and wearable technology. This review provides a comprehensive overview of electroless plating, from its core theory to the latest research trends. Initially, the detailed mechanism of electroless plating is described, followed by an examination of the plating process. Then, the compositions of a typical electroless plating bath are introduced, and the critical operating parameters are categorized. Next, the evaluation factors of electroless plated surfaces are discussed, along with the current limitations of electroless plating technology. Finally, the various applications of electroless plating studied to date are presented, and future directions for this technology are suggested.
... The metallic layer in produced on the cathode surface through redox reactions in the electrolyte [3]. This process can be performed using both pulsed and direct currents [4]. Today, electrochemical deposition of nickel on various surfaces is one of the most common surface treatments. ...
Nickel coatings are widely used in various engineering applications due to their excellent corrosion resistance as well as adequate wear and erosion resistance. The coating process is generally performed by electroplating, which is simple and economical. However, one of the challenges of the electroplating process is the non-uniformity of coating thickness on substrates with sharp points and recesses. In this study, the effect of the substrate geometry on the non-uniformity of coating thickness was investigated and quantified. For this purpose, a screw, one of the most commonly used components in various industries, was coated in a Watts bath. Nickel coating was applied for different durations ranging from 2 to 25 minutes, and the thickness distribution on the threads was examined. The average thickness in three regions, meaning the tip, middle, and depth of the threads, was measured using scanning electron microscope images of the longitudinal section of the screws. The results showed that the coating thickness at the convex tip of the threads was on average three times greater than at the concave depth. The ratio of maximum to minimum thicknesses did not show a meaningful consistency with the deposition time.
... The electrochemical term for the partial molar Gibbs energy is written as follows [1,[51][52][53][54][55][56][57]: ...
The phase rule of Gibbs is one of the basic equations in phase equilibria. Although it has been with us for 150 years, discussions, interpretations and extensions have been published. Here, the following new content is provided: (i). the choice of independent components is discussed, and the component rule is introduced, (ii). independent state variables are divided into compositional and non-compositional ones, (iii). the generalized phase rule is derived replacing number two in the original phase rule by the number of independent non-compositional state variables introduced above, (iv). the degree of freedom is decreased by the number of compositional constraints in special points (azeotrope and congruent melting) of phase diagrams, (v). a rule is derived connecting the maximum number of coexisting phases with the dimensions of the phase diagram, (vi). examples show how to apply the phase rule to unary, binary and ternary phase diagrams and their sections, (vii). the same is extended with the discussion of calculable and not calculable phase fractions, (viii). it is shown that the current definition of the degree of freedom is not sufficient in the number of cases, (ix). the current definition of the degree of freedom is extended, (x). the application of the generalized phase rule is demonstrated when other non-compositional state variables are applied for nano-phase diagrams, and/or for phase diagrams under the influence of electric potential difference, external magnetic field, mechanical strain or the gravitational field.
... 1. Knowledge elicitation: After a short analysis of standard literature in the subject area of electroplating (e.g. from textbooks and overview papers such as Kanani, 2004or Leiden et al., 2020, the main knowledge hierarchy levels including declarative knowledge concepts were specified. An illustration of this preliminary specification was used as basis for the 2. Knowledge analysis and visualisation: In an iterative process using structured interviews, the first presentation was discussed with two electroplating experts (scientists that work more than 10 years in the electroplating field). ...
Many cyber-physical systems face the challenge of appropriately integrating domain-specific human expert knowledge into the cyber part to create a shared sphere of knowledge and intelligent interactions between humans and the semi-autonomous technical system. Cognitive engineering contributes methods and insights into higher-order cognition that help to embed human knowledge in an appropriate way. The original research introduces a novel transdisciplinary framework called Human-CoMo, which demonstrates a systematic modelling process, different human perspectives, and the integration of expert knowledge at multiple hierarchical levels. Fundamental principles inspired by human cognition, such as conceptual chunking and knowledge precision, are characterised. Furthermore, it is shown how knowledge hierarchies can be methodically reflected in appropriate data analysis and modelling levels for small and big data applications including artificial intelligence approaches. Combined knowledge- and data-based modelling approaches offer more flexibility to integrate the strengths of humans and technology in a complementary way. The cognitive foundations and their computational reflections are outlined for the technical example process electroplating from the field of materials and surface engineering. The possibilities and limitations of integrating human knowledge through formalisation and implications for future forms of human-machine interaction are discussed.
... Electroplating is typically used to modify the surface of electrically conductive metals by adding a layer of metal particles of interest using an electrochemical process to enhance interfacial characteristics and visual appeal [1]. This method finds extensive applications in various industries, ranging from decorative finishes to enhancing corrosion resistance, wear resistance, and electrical conductivity of components [2]. ...
This study investigates the synergistic effects of electrolyte flow velocity and magnetic fields on the surface quality of nickel electroplated onto copper substrates. Nickel coatings protect copper from oxidation and fouling, prolonging component life. An electroplating apparatus with a Watts bath and copper electrode was used to compare three deposition methods: static bath, flowing electrolyte, and flowing electrolyte under a magnetic field. Our investigation indicates a direct relationship between current density and deposition thickness, with thicker deposits at lower flow speeds and narrower electrode gaps, suggesting gas bubble effects. Applying a perpendicular magnetic field generally increased current density and thickness, except at the highest flow rate and widest gap. Design of Experiments analysis revealed the magnetic field homogeneously improved surface roughness uniformity compared to other variables. Lower current densities yielded smoother surfaces. Magnetic field exposure enhanced wettability, indicating increased surface energy that can be attributed to ion alignment during deposition. These findings demonstrate magnetic fields can manipulate the wetting behavior of electroplated surfaces, with potential applications in immersion cooling of microelectronics. Additionally, controlling wettability through magnetic field-assisted electroplating offers opportunities to tailor surface properties for specific applications.
... The PVD process is a widespread and well-known coating technique. Having low maintenance and cost-effectiveness, it is well-established [43]. PVD deposition can help to achieve durability and toughness in machining, increasing hardness in extreme environments, chemical reaction stability, abrasion resistance, and stiffness [44]. ...
Thin conducting films are distinct from bulk materials and have become prevalent over the past decades as they possess unique physical, electrical, optical, and mechanical characteristics. Comprehending these essential properties for developing novel materials with tailored features for various applications is very important. Research on these conductive thin films provides us insights into the fundamental principles, behavior at different dimensions, interface phenomena, etc. This study comprehensively analyzes the intricacies of numerous commonly used thin conducting films, covering from the fundamentals to their advanced preparation methods. Moreover, the article discusses the impact of different parameters on those thin conducting films’ electronic and optical properties. Finally, the recent future trends along with challenges are also highlighted to address the direction the field is heading towards. It is imperative to review the study to gain insight into the future development and advancing materials science, thus extending innovation and addressing vital challenges in diverse technological domains.
... The specimen surfaces were then smoothed with fine sandpaper to facilitate the electroplating process (Child, 1993). Next, the electrolyte solution was prepared according to the M. Iksanudin, Rahmad D. Widodo, Deni F. Fitriyana, Ayub B. Anggoro/ The Effect of electrolyte concentration and temperature at electroplating with copper on the plate thickness and corrosion rate of plated gray cast iron book "Electroplating: Basic Principles, Processes and Practice" (Kanani, 2004), where the standard concentration range for copper is 150-250 g/L copper (II) sulfate (CuSO4) and 30-75 g/L sulfuric acid (H2SO4) in 1 liter of distilled water. The solutions used were solution 1 (195 g/L copper sulfate, 45 g/L sulfuric acid), solution 2 (205 g/L copper sulfate, 50 g/L sulfuric acid), and solution 3 (215 g/L copper sulfate, 55 g/L sulfuric acid), each dissolved in 1 liter of distilled water and stirred until the copper sulfate was completely dissolved. ...
This study aims to determine the effect of variations in electrolyte solution concentration and copper electroplating temperature on gray cast iron to achieve the desired copper layer thickness and reduce the corrosion rate of gray cast iron impeller pumps. A total of 30 test specimens made from gray cast iron were used, with dimensions conforming to the ASTM G31-72 standard for corrosion rate testing. The specimens were coated with copper electroplating using three different solutions: solution 1 (195 g/L copper sulfate, 45 g/L sulfuric acid), solution 2 (205 g/L copper sulfate, 50 g/L sulfuric acid), and solution 3 (215 g/L copper sulfate, 55 g/L sulfuric acid). Each solution was used with dipping temperatures of 30 – 34 °C, 40 – 44 °C, and 50 – 54 °C. After being coated with copper, the layer thickness was measured using a digital coating thickness gauge (F&NF type). The corrosion rate was then tested using the weight loss method, following the ASTM G31-72 standard, by immersing the specimens in seawater for 240 hours. The test results showed that the highest average thickness was achieved with solution 3 and a plating temperature of 50 – 54 °C, measuring 27.46 μm. The lowest average thickness was with solution 1 and a plating temperature of 30 – 34 °C, measuring 26.23 μm. The lowest corrosion rate was observed with solution 3 and a plating temperature of 50 – 54 °C, at 0.0041 mmpy, whereas the highest corrosion rate was found with solution 1 and a plating temperature of 30 – 34 °C, at 0.0079 mmpy. For comparison, the average corrosion rate of uncoated specimens was 2.2947 mmpy.
... Electrodeposition is the most trusted method for material synthesis, through the electro-crystallisation of metal atoms by reducing metal ions due to impressed potential/current [1]. Electrodeposition of Ni-Fe alloys has attracted considerable attention due to their fascinating characteristic nature and a broad range of unique properties, such as high corrosion resistance, low thermal expansion [2][3][4], etc. ...
... We utilized direct-current electrodeposition in boric acid (H 3 BO 3 )/Zn-based solutions to fabricate Zn metal electrodes with distinctive crystal morphology on a copper (Cu) foil. This was achieved through the incorporation of H 3 BO 3 additive and vigorous stirring, creating an ideal environment to eliminate harmful side reactions [31][32][33][34][35] . As a result, under the prerequisite of mitigating side reactions, the crystallographic orientation and texture of the electrodeposited Zn metals were exclusively dependent on the anions present in the deposited electrolytes. ...
The optimization of crystalline orientation of a Zn metal substrate to expose more Zn(0002) planes has been recognized as an effective strategy in pursuit of highly reversible Zn metal anodes. However, the lattice mismatch between substrate and overgrowth crystals has hampered the epitaxial sustainability of Zn metal. Herein, we discover that the presence of crystal grains deviating from [0001] orientation within a Zn(0002) metal anode leads to the failure of epitaxial mechanism. The electrodeposited [0001]-uniaxial oriented Zn metal anodes with a single (0002) texture fundamentally eliminate the lattice mismatch and achieve ultra-sustainable homoepitaxial growth. Using high-angle angular dark-filed scanning transmission electron microscopy, we elucidate the homoepitaxial growth of the deposited Zn following the “~ABABAB~” arrangement on the Zn(0002) metal from an atomic-level perspective. Such consistently epitaxial behavior of Zn metal retards dendrite formation and enables improved cycling, even in Zn||NH4V4O10 pouch cells, with a high capacity of 220 mAh g⁻¹ for over 450 cycles. The insights gained from this work on the [0001]-oriented Zn metal anode and its persistently homoepitaxial mechanism pave the way for other metal electrodes with high reversibility.
... Numerous industries, including biotechnology, electronics, aerospace, automotive, etc., use these alloy coating films [21][22][23][24][25] . Many techniques, including spraying [26] , laser ablation [27] , magnetron sputtering [28] , powder metallurgy [29] , and electrodeposition techniques [30][31][32] , have been used to create Ni-Ti alloy films. Among these methods, electroplating is particularly significant since it may be used to create a variety of coatings at room temperature, at a cheap cost, and with a high deposition rate. ...
Acidic sulphate bath having ZnSO4, TiSO4 and sulphamic acid, was optimized for the deposition of bright Zn-Ti coating on mild steel. The effect of current density, on deposit characters, such as corrosion rate, thickness, and hardness were discussed. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods were used to evaluate the corrosion properties of the deposit. The composition of deposits was determined by energy dispersive X-ray (EDX) analysis. Scanning electron microscopy (SEM) was used to examine the surface topography of the deposited layer. Atomic force microscopy (AFM) was used to determine the surface roughness. A new and low-priced sulphate bath, for bright Zn-Ti coatings on mild steel has been proposed, and the results indicate better corrosion resistance properties, and these coatings can be used for biomedical tools like Tuning fork, etc, applications.
... Dry cells are easy to carry because its lightweight and Nickel cadmium cells are rechargeable [6]. Electrochemical cell technology is applied to separate pure metals from metallic compounds, to separate other chemical compounds like water and to electroplate metals [7]. Electroplating is the technique of coating an object with a layer of metal by utilizing electrodeposition [8]. ...
Electrical energy is used to drive a non-spontaneous redox reaction in an electrolytic cell battery, which is composed of an electrochemical cell. The process of breaking down chemical compounds through electrolysis is frequently utilized, and it is derived from the Greek word lysis, which means to disintegrate. The electrolytic cell is composed of an electrolyte, two electrodes (one cathode and one anode), and three other components. Water or other solvents are typically used to make an electrolyte, which is a solution that contains dissolved ions. The purpose of this study is to test, analyze, and construct an electrolytic cell battery using various electrolytic solutions, salt-water concentrations, and the integration of fuel cells and electrodes. The research is designed to be experimental and relies on descriptive analysis to assess it. The design focused on the finding the optimal combination of electrode limited to zinc, copper, and aluminum (soda can), different electrolyte, type of connection of the fuel cells and the different concentration of saline solution used in order to provide optimum energy output. According to the data gathered and analyzed, the Zinc-Copper electrode produces an average voltage of 0.705 V per cell. Saltwater electrolyte produces the most effective results based on its cost effectiveness. When saline solution is 30% concentrated, the optimal voltage output is achieved, and fuel cells perform their best when connected in series. Using this parameter, twenty fuel cells are constructed that can produce 14.10 V without any load. The voltage was 7.57 V and the current was 1.1 A when connected to a DC lighting load that has a 12V power supply.
... Using a Micro-pH Meter (Systronics-362), the bath pH was adjusted to 4.0 using either H 2 SO 4 or NH 4 OH (depending on the necessity). The usual Hull cell approach was used to optimise bath composition and plating factors, as previously discussed [20,21]. The bath conditions and plating variables of optimal bath arrived after the Hull-cell experiment are reported in Table 1. ...
... Because of the dissolution of the Cu anode, the Cu 2+ concentration boundary layer with high Cu 2+ concentration formed near the anode surface 21,22) . The boundary condition and the dissolved Cu 2+ concentration in a uniform liquid solution near the anode surface when imposing a current from time t=0 are described by the following equations 23) : ...
The mass transfer in the concentration boundary layer is often the rate-determining step for solid-liquid chemical reactions. Decreasing the concentration boundary layer thickness is essential to intensify the solid-liquid chemical reaction. Because convection contributes to decreasing the concentration boundary layer thickness, traditional methods excite a macro-scale flow in the bulk region. Since the concentration boundary layer exists in the velocity boundary layer near the solid-liquid interface, the traditional methods have limitation in enhancing the mass transfer. Based on this reason, the direct flow excitation near the solid-liquid interface by imposing an electromagnetic force was proposed. The aim of this research is to evaluate the effect of the time-varying electromagnetic force and its frequency on the mass transfer near the solid-liquid interface by evaluating the effective diffusion coefficient. The effective diffusion coefficient was evaluated under the imposition of a static electromagnetic force or a time-varying electromagnetic force with a frequency of 2 Hz or 6 Hz. The results found that by imposing the time-varying electromagnetic force, the mass transfer was enhanced compared to that under the imposition of the static electromagnetic force. The mass transfer was further enhanced by decreasing the time-varying electromagnetic force frequency.
... The electrodes are immersed in the electrolyte with the anode connected to the positive leg of the power supply and the cathode to the negative leg. As the current is increased from zero, a point is reached where metal plating begins to occur on the cathode (Fotovvati et al., 2019;Kanani, 2004;Ojo & Dharmadasa, 2018). A desired metal's cations are reduced in solution by the electroplating method, which uses an electrical signal from an external power source to create a metallic coating (Chen et al., 2013). ...
Metals are the best engineering materials owing to their superior conductivity, mechanical properties, and formability. However, they can be highly affected by environmental elements like oxygen, chlorine, etc. This reaction of metals with the environmental elements will indeed alter their electrical, chemical, and mechanical properties. To protect against corrosion, various protection methods such as electroplating have been established. The presence of anodic or cathodic films on the substrate surface protects steel from corrosion damage at ambient atmospheric temperature. This work focuses on the effect of temperature on the oxidative (corrosion) rate of non-plated, nickel-plated, and chrome-plated ASTM A283GC mild steel samples. A temperature range of 200–800 °C and a total heating time of 120 min were considered in this experiment. A temperature-regulated muffle furnace with a maximum heating capacity of 1000 °C has been used. Weight changes were determined every 30 minutes of heating using a digital weight balance with a precision of 0.001 g. The obtained experimental results of non-plated, nickel-plated, and chrome-plated mild steel samples were analyzed and compared with each other. The effect of oxidation on the surface hardness has also been studied with the help of a Vickers hardness testing machine. Changes in the physical nature of the samples caused by oxidation were also observed and pictured using a camera.
... 55 Today, metal plating is commonly used to form closed films on sur-faces for protection and to give them novel properties. 56,57 Sadly, Li deposition or plating on anodes of LIBs can lead to fast degradation, corrosion, and several safety-related issues and is therefore not recommended. A detailed understanding of the underlying mechanism is essential to prevent Li deposition or plating. ...
Lithium-ion batteries (LIBs) remain at the forefront of energy research due to their capability to deliver high-energy-density. Understanding their degradation mechanism has been essential due to their rapid engagement in modern electric vehicles (EVs), where battery failure may incur huge losses to human life and properties. The literature on this intimidating issue is rapidly growing and often more complex. This review strives to succinctly present current knowledge contributing to a more comprehensible understanding of the degradation mechanism. First, this review explains the fundamentals of LIB and various degradation mechanisms. Then, the degradation mechanism of novel Li-rich cathodes, advanced characterization techniques for identifying it, and various theoretical models are presented and discussed. We emphasize that the degradation process is not only fastened to the charge-discharge cycles; synthesis-induced stress also plays a vital role in catalyzing the degradation. Finally, we propose further studies on the advanced battery materials that can potentially replace the layered cathodes.
... Consequentemente, o uso da liga metálica de Zamac na indústria tem sido bastante elevado e peças deste material podem ser vistas facilmente no dia a dia. Entre as aplicações da liga de Zamac, podem-se citar o setor calçadista, com a obtenção de fivelas e enfeites, o setor moveleiro, com a obtenção de puxadores, no setor automobilístico, com a obtenção de radiadores e carburadores, entre outras várias aplicações [5][6][7][8][9][10]. ...
Studies have shown that Zamac containing coatings obtained by electroplating, used as sanitary metal, has low resistance to corrosion, which was attributed to the formation of porosity in the alloy due to the pressure injection process. In this case, the electrodeposited coatings do not satisfactorily cover the surface porosity of the Zamac injected under pressure. Research has shown that zamac anodizing has minimized or closed these porosities. This work aims to verify the behavior of electrodeposited layers in zamac samples with and without anodization. For this, Zamac samples were anodized in 0.3 M oxalic acid electrolyte, with process parameters of 100 V, 10 mA/cm², for 300 s, in a source of potential × current (300 V, 500 mA) and subsequently electrodeposited in alkaline copper, acid copper, nickel and chromium baths. The samples were evaluated by SEM (Scanning Electron Microscopy) by top analyses, cross section and by Energy Dispersive Spectroscopy - EDS. The results showed that the anodizing process allows for better leveling of the alkaline copper and acid copper coating electrodeposited in Zamac, impacting final coatings (up to chrome electrodeposition) with greater thickness when compared to those obtained in the industrial process.
Keywords
Zamak; Anodizing; Porosity; Electrodeposition
... Sobre o metal (ânodo) cresce uma camada de óxido que pode ser do tipo barreira ou do tipo porosa [6][7][8]. A camada de óxido obtida possui espessura maior que a formada naturalmente ao ar e apresenta as seguintes características: grande aderência, pouca elasticidade, grande resistência ao desgaste mecânico e à corrosão [5,[9][10][11][12][13]. ...
Studies have already shown that zamac anodizing is an alternative to minimize the corrosive effects of the alloy. Other studies, in aluminum, demonstrated that when anodized and sealed by the hot process, it promotes an increase in its resistance to corrosion. However, there are no reports in the literature about heat sealing in anodized zamac. The objective of this work is to identify the effect of sealing, in terms of corrosion resistance, on anodized zamac. For this purpose, industrially sanded and polished pieces of zamac 5 were anodized in 0.3 M oxalic acid electrolyte at different times (5, 30 and 60 minutes), and subsequently sealed in distilled H2O at 90ºC for one hour. The parts were analyzed using morphological techniques and corrosion tests. The results showed that with increasing anodization time, the bigger crystallites dissolve, originating smaller crystallites until the formation of a smooth layer. In addition, the sealing process promoted hydration of the anodized zamac products. However, with increasing anodizing time, the oxide layer became more compact, due to smaller crystallites, with a decrease in thickness, due to the smooth layer. This resulted in the best anti-corrosive performance of the 5-minute anodized and sealed sample.
Keywords
Zamak; Anodizing; Hot sealing
Copper coatings are recognized for their outstanding corrosion resistance, wear resistance, and mechanical properties in diverse industrial applications. However conventional electrodeposition techniques often encounter challenges such as nonuniform growth and rough surface formation. This chapter reviews strategies to overcome these limitations by integrating external forces and additives into the electrodeposition process. The study explores the effects of different parameters on the coatings' microstructure, surface morphology, and microhardness. The impact of additives like leveling, grain refining, and brightening agents is examined. Additionally, electrochemical measurements evaluate the additives' effect on corrosion resistance. By optimizing deposition parameters and incorporating additives, significant improvements in copper coatings can be achieved. This review provides insights into the mechanisms of electrodeposition and offers strategies for enhancing the performance and durability of these coatings, promising wider industrial applications.
This paper explores the benefit of induced magnetic field ( B) in the co-deposition of (Ni–Co) alloy coatings for better corrosion protection. The phenomenon of magnetohydrodynamic (MHD) convection has been used as the tool to deposit (Ni–Co) alloy coatings of high corrosion protection from an electrolytic bath having low [Co ⁺² ] ions. Experimental studies demonstrated that under optimal conditions of magnetic field intensity ( B), magneto-electrodeposited (MED) coatings, developed under parallel (||) and perpendicular (⊥) magnetic field, are respectively about 3 times and 11 times more corrosion resistant than conventionally electrodeposited (ED) alloy coatings, developed from the same bath. The properties of MED (Ni–Co) alloy coatings were found to be changed with the direction of the applied B. The reasons responsible for improved corrosion performance of MED (Ni–Co) alloy were explained through FESEM, EDX and XRD analyses. Attempt has been made to understand changed properties of MED alloy coatings in the light of magnetic field controlled diffusion of Co ⁺² ions and increase in its limiting current density ( i L ). The improved corrosion resistance of MED (Ni–Co) alloy coatings, compared to ED (Ni–Co) alloy coatings were attributed to its increased Co content, affected due to forced convection of magnetoelectrolysis, and experimental results are discussed.
Nickel coatings have demonstrated significant benefits in protecting copper from oxidation and fouling, thereby enhancing the longevity of copper-based components. This study employed an electroplating apparatus featuring a Watts bath and copper electrode to investigate the impact of flowing electrolyte, both with and without an applied magnetic field, on the interfacial characteristics of nickel-coated copper surfaces. The findings reveal the relationship between current density and deposition thickness. The application of a perpendicular magnetic field and increase in current density generally increased coating thickness to 0.2 ?m from 0.05 ?m, with the most pronounced effects at moderate flow rates and narrower gaps; however, at the highest flow rate and widest gap, deposition thickness diminished due to the divergence of magnetic field lines. Design of Experiments analysis revealed the magnetic field homogeneously improved surface roughness uniformity compared to other variables. Lower current densities produced smoother surfaces, while magnetically-assisted electroplating yielded consistent roughness values even at higher current densities. Exposure to the magnetic field improved wettability, evidenced by decreased contact angles. This enhancement is attributed to the alignment of nickel particles during deposition, facilitating a transition from the Cassie-Baxter to the Wenzel wetting state. Notably, thicker deposits were observed at lower flow rates and narrower electrode gaps, suggesting significant influence of gas bubble dynamics on the deposition process. These findings provide insights into the complex interplay between electrochemical reactions, hydrodynamics, and magnetic fields in nickel electrodeposition, with implications for optimizing coating.
With the rapid growth of online transactions, there has been a significant increase in fraud involving pharmaceuticals, textiles, and food, among others. This work proposes the use of non-cloneable authentication tags for product brand protection, in which both the type of substrate used and its geometry are combined, resulting in a unique spectral response. These tags are manufactured in two phases, a first one that forms of a laser-induced graphene (LIG) layer, and a second one, based on an electroplating process, which produces traces with variable sheet resistance depending on the manufacturing parameters. This technology can be carried out using a common laser (e.g. CO
2
laser) to directly convert various precursors into graphene materials (e.g. polyimide). A prototype scanner for characterizing the electromagnetic signature of the tags is presented. Preliminary results obtained with simple resonators and complex images show the feasibility of this technology.
This paper presents a novel approach for the sensitive detection of Cu(II) ions in acidic industrial samples, used in the manufacture of printed circuits. The study outlines the synthesis and...
The blister formation mechanism in electrogalvanized steel was studied by analyzing the blister’s internal structure. Electrochemical hydrogen charging was employed to absorb hydrogen into the steel plate and to induce blister formation. Analysis of the blister interior revealed that the initial formation of blisters occurred at the cracks located at the interface between the zinc layer and the steel substrate. These cracks originated from the steel substrate’s intergranular fracture or carbon contaminants’ adsorption on the steel surface. Grain boundary precipitates in hot-rolled plates form the intergranular crack after cold-rolling. A hydrogen anion was found inside the blister formed at the pre-existing intergranular crack. However, methylidyne (CH−) and methylene anion (CH2−) dissociated from methane, as well as hydrogen anions were detected inside the blister formed at the carbon-contaminated steel surface. Methane gas is generated by the combination of absorbed hydrogen with carbon inside the crack. This research clarifies the detailed formation mechanism of blisters in electrogalvanized steel.
Surface treatment technologies are pivotal across diverse industrial sectors such as mechanical engineering, electrical engineering, and the automotive industry. Continuous advancements in manufacturing processes are geared towards bolstering efficiency and attaining superior product quality. This study aimed to empirically compare practical outcomes with theoretical insights. Employing galvanic zinc plating under constant voltage with varying plating durations unveiled a correlation between coating thickness and electrolyte composition alongside plating duration. The graphical representation delineated the optimal electrolyte composition conducive to maximal coating thickness. Notably, an evident decrease in leveling ability was noted with prolonged plating durations. The experiment corroborated the notion that theoretical formulas for coating thickness estimation possess limited accuracy, often resulting in measured values surpassing theoretical predictions. These findings underscore the imperative for refined theoretical models to comprehensively grasp galvanic surface treatment processes.
In this article, copper electroplating in presence of some forms of benzoic acid derivatives was studied. the impact of operational variables, together with organic additives concentrations and temperature on the limiting current were investigated by the potentio-dynamic polarization technique. The adsorption of all inhibitors on copper cathode was found to comply Temkin, Flory-Huggin and kinetic adsorption isotherm. The calculated free energy of adsorption (ΔGads) of inhibitor on copper surface indicated that the adsorption reactions were spontaneous (ΔGads <0). The thermodynamic activation parameters (Ea, ΔH*, ΔS* and ΔG*) were also calculated. it had been found that energy of activation values for copper electroplating in inhibited solutions were higher than that for uninhibited solution. The high substance adequacy was discussed in terms of strong adsorption of inhibitor molecules on the copper surface. Also, during this study, biological activities of some synthesized compounds were investigated.
The present study reports the electrochemical deposition and characterization of Co-P alloy coatings from an electrolytic bath having sodium hypophosphate and cobalt chloride as salts, potassium sodium tartrate (PST) as complexing agent, NH4Cl as conducting salt and glycine as the brightener. Bath composition and operating variables were optimized by conventional Hull cell method for bright and uniform coating. Co-P alloy coatings were developed at varied current densities (1.0 A dm-2 to 4.0 A dm-2), keeping pH = 8.5. The corrosion behaviors of Co-P alloy coatings were evaluated by electrochemical AC and DC methods in 3.5% NaCl solution. Scanning electron microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS) and X-ray diffraction (XRD) techniques were used to study the surface morphology, chemical composition and phase structure of the coatings, respectively. The electrodeposited alloy coatings are characterized by the presence of cracks on its surface. The compositional data revealed that Wt. % of P in the deposit has increased with deposition current density and XRD study demonstrated that solid solution of Co and P were formed in the entire range of current density studied. The observed facts stand to the reason that the bath follows induced type of codeposition in the rage of experimented current density. Corrosion study validated that Co-P alloy coating deposited at 1.0 A dm-2 is the most corrosion resistant compared to all other current densities. The highest corrosion stability of Co-P alloy corresponding to 1.0 A dm-2 is attributed to high Wt. % of Co and inhibition effect of corrosion product formed on the surface, demonstrated by cyclic polarization study. Increase of corrosion rate towards high current density were analyzed in the light of composition, surface morphology and phase structure of alloy coatings and results are discussed.
Key words: Co-P alloy coatings, corrosion study, cyclic polarization, SEM and XRD study.
Quantum chemical parameters~(QCPs) of four additives were calculated by using DFT, and MD simulations were performed. By comparing binding energies of four additives (benzalacetone~(BA), sodium benzoate~(SB), polyoxyethylene nonylphenylether~(NP) and dispersant NNO), with Zn~(001) surface, BA has the smallest binding energy, which is due to the smallest hardness parameter, and NNO has the largest binding energy, which is due to the largest dipole moment despite its small hardness parameter. In order to enhance the adsorption of BA onto Zn~(001) surface, NP was selected to be combined with BA, because BA has the lowest energy level of LUMO, which is more capable of accepting electrons from Zn~(001) surface than others, and NP has the highest energy level of HOMO, which is more capable of donating electrons to Zn~(001) surface than others. By calculating the binding energies of the complex of BA and NP, it has larger binding energy than individual BA, SB, and NP, but smaller than NNO.
ContextElectroplated zinc layers have shown excellent corrosion resistance, especially those are stable in the atmosphere after the passivation, and therefore zinc electroplating is widely used in various fields such has mechanical, vehicle, construction, and ironware industries.Benzalacetone (BA) was reported as brighteners for zinc deposition, while polyoxyethylene nonylphenylether (NP) was used as levelers or carriers for zinc electroplating. Sodium benzoate (SB) and dispersant NNO cooperatively act as auxiliary additives.Quantum chemical parameters (QCPs) of four additives were calculated by using DFT, and MD simulations were performed. By comparing binding energies of four additives (benzalacetone (BA), sodium benzoate (SB), polyoxyethylene nonylphenylether (NP) and dispersant NNO), with Zn (001) surface, BA has the lowest binding energy, which is due to the lowest hardness parameter, and NNO has the highest binding energy, which is due to the highest dipole moment despite its small hardness parameter.Methods
For DFT calculation, NWChem was employed, which uses the Gaussian basis set. The B3LYP functional was used for exchange-correlation interaction between electrons, and the 6-311G+ (d,p) basis sets were used for all the atoms. Solvation effect was considered by using COSMO (COnductor-like Screening MOdel), in which the dielectric constant of solvent was set to 78.54 of water. For dispersion correction, DFT-D method of Tkatchenko and Scheffler (TS) was used.MD simulations were performed by using GULP (General Utility Lattice Program) code with Dreiding forcefield and atomic Hirshfeld charges from DFT calculations. MD simulations were performed on the conditions of NVT ensemble with a step of 1 fs and simulation time of 500 ps at 298 K and 323 K. To consider solvation effect, 1,000 water molecules were inserted into the box.
This paper reports the production of Ni–Zn multilayer alloy coating to improve the anticorrosive behavior of the mild steel material. The deposition technique follows the square wave current pulse technique. Initially, the effect of current densities on the anticorrosive behavior of the Ni–Zn was investigated. Later, the current densities were optimized in different combinations to get a multilayer of Ni–Zn with different degrees of layering. The Ni–Zn multilayer coatings were developed on the surface of mild steel with different numbers of layers by square pulsing current density of 1 Adm ⁻² and 3 Adm ⁻² . The deposited Ni–Zn alloy coating was studied for its electrochemical behavior toward corrosion. Results revealed that the anticorrosive behavior of the multilayer Ni–Zn alloy coating was found to be many folds higher than that of monolayer Ni–Zn alloy coating. The comparison study of corrosion data revealed that (Ni–Zn) 1/3/300 multilayer coatings are less prone to undergo corrosion among all developed monolayer and multilayer coatings. The corrosion rate of (Ni–Zn) 1/3/300 was found to be less and in the range of 0.37 mm year ⁻¹ among all developed coatings.
In recent years, specific current waveforms for the deposition of metallic coatings have proven a suitable means of producing specific technological coating properties. In this connection, the author describes studies carried out with the aim of extending the knowledge gained chiefly from working with noble metals and their alloys by clarifying the effect of pulse plating on the deposition and coating properties of common metals, especially nickel and zinc.
Scanning Probe Microscopy (SPM) encompasses a range of probe techniques such as Atomic Force Microscopy (AFM) which have many potential applications in the fields of metal finishing and surface engineering. The power of the technique lies in its ability to image deposition and corrosion processes at extremely high resolution, even down to the atomic scale when required. At the University of Portsmouth, we have used AFM in areas such as the early growth of copper electrodeposits in the presence of organic additives, topographical studies ofzincale immersion layers, electroless nickel coatings and ceramic electrode materials. We have also used the technique for quantitative surface metrication studies and surface roughness characterisation of femoral heads (90%Ti, 6%A1, 4%V) ofhlpprostheses. This paper provides a concise review of these techniques and their application In surface finishing. Future developments of the technique In the areas of metal finishing and corrosion are also considered.
The filamentary growths of single crystals on material surfaces are termed whiskers. They are seen to nucleate and grow on certain electronic materials either from vapour and liquid phases or by a process induced by residual stresses in electroplated surfaces. Whisker growth does not depend on the existence of an electric field and surfaces prone to their growth may nucleate and form whiskers as a result of exposure to a space environment. This paper includes a detailed examination of tin whiskers which were found to have 1 to 4 micron diameters and lengths exceeding 2 mm. Some were found to carry currents between 22 and 32 mA before burning out. Conductive whiskers can cause extensive short circuit damage to spacecraft electronics particularly as miniature devices progressively employ closer spacings between conductors. Several modes of whisker growth on spacecraft electronic materials (molybdenum, tungsten, Kovar, tin) have been observed and are described. Tin, cadmium and zinc surfaces can support stress-induced whisker growth and it is recommended that these metal finishes are excluded from spacecraft design and possibly replaced by a tin-lead alloy.
Methods of analyzing surfaces, thin films and interfaces in the thickness range from 0 to 100 nm are discussed and illustrated by practical examples. Auger electron, photoelectron and secondary mass spectroscopies are shown to be the most promising techniques for materials science and technology.
A number of techniques are now available for the characterisation of solid surfaces. In particular, techniques such as Auger electron spectroscopy (AES), X-ray photoelectron spectroscopy (XPS or ESCA) and secondary ion mass spectrometry (SIMS) have become available which combine spatial resolution (of varying utility) with an ability to determine the composition of the outermost atomic layers (with varying precision and sensitivity). The remarkable depth resolution of these methods may also be exploited when used with surface sectioning techniques such as sputter-etching to provide composition-depth profiles. This paper is aimed at introducing the principles and analytical procedures of these techniques and at illustrating their potential areas of application in the materials finishing industry.
Ammoniacal palladium electrolytes which are characterized by a particularly low absorption of light in the wave length ranges of lasers, and which are only insignificantly affected by the pH value and the metal concentration, were investigated. The influence of the thermal conductivity of the basis metal, the thickness of the substrate and the pH value on the laser radiation were studied. It is also shown that the laser radiation affects the deposition of a Pd-Ag alloy favorably.
In the discussion concerning polymer-metal adhesion, the fact that electrochemical reactions take place near the phase interface between the polymer and the metallising bath prior to and during the deposition of the metal is only rarely taken into account. Using the theory of electrical double layers, it is possible to describe the conditions at a metal-electrolyte interface. Similar theoretical pointers are also applicable to interfaces between polymer and metal and between polymer and electrolyte. From the observation that the reduction of the metal ion to metal occurs only in the vicinity of the polymer-electrolyte phase interface, i. e. in a specific area of the metallising bath, it follows that this area differs electrochemically from the surrounding area. The article draws on a number of examples to discuss parameters affecting the properties of the interfaces and hence the adhesion between polymer and metal.
The paper is concerned with the mechanism of adhesion of coatings produced by electroless plating. Taking synthetic polymers as an example, some morphological aspects of the interaction between an electrolessly applied coating and the polymer surface, as well as the influence of the surface energy characterisation of the surface, are described. With regard to the latter, it is shown that - by boundary angle phenomena measurement - the adhesion is better the nearer the surface tension characteristics of the two compments are. The alignment of the surface tensions is one of the functions of the pretreatment of the electrolytic or electroless application of metals.
Modern electronics includes a broad range of machines such as various size computers with main memory, storage devices, input and output devices, telecommunication equipment, various purpose instruments and more or less sophisticated consumer electronic devices. Electrochemical processes are used today in almost every category of devices, machines and appliances: in the fabrication of conductors, contacts and connections, for mechanical wear-resistance, corrosion protection and decorative purposes. Often the electrochemical approach is the only one which can satisfy the need, gives the desired property or is cost competitive. Examples are given of some applications of electrochemical technology in electronics, of some interesting modifications of the elecrochemical processes to meet the needs of electronic devices and device fabrication. The future of electrochemistry and electrodeposition in electronics is discussed in view of problems experienced and in view of the advantages and the potential electrochemical technology offers by comparison to other technologies.
Pulse plating has been employed as a technique since the 1950s but in the last 10 years, it has been recognized as being useful in certain specific applications; in particular, instances of throwing power where activation polarization and solution conductivity may be the controlling factors. This is especially true for through-holes in printed circuit boards (PCB). The research has been concerned with the use of acid copper electrolyte for PCB production and the development of pulse programs to optimize through hole plating rates. It involved the study of cathode polarization behavior and used the Wagner number to rationalize the data obtained.
A new PC program package for measuring the thickness of layers according to the X-ray fluorescence method opens a wider range of applications. Changes over the prior state of software are rather qualitative, providing an improvement of measuring accuracy and more specifically a wider range of applications.
Initial results are reported concerning a method with the aid of which the effect of temperature in laser-aided electrolysis can be investigated. Hard-gold baths of Au-Co, Au-Ni and Au-Fe type were tested. It was found that in the temperature range prevailing during laser-aided electrolysis ( greater than equivalent to 100 degree C) the incorporation of impurity elements decreases greatly. This also affects, among other things, the hardness and structure of the coatings.
The mechanism of laser activation and metalization in the deposition of contact structures on nonmetallic substrates from chemically reductive baths is investigated. Laser metallizing is defined as the production of a metallic layer structure on the substrate, while laser activation is the production of a nucleus structure on the chemically reductively applied coating. In both cases the degree of absorption of the substrate for laser radiation in a specific bath determines the deposition, i.e, the rate of advance or the working table in a corresponding direction. Also in the case of noncatalytically active substances it is of value to know whether laser metallization is possible.
Scanning tunneling microscopy (STM) is a powerful tool for atomic resolution imaging of the topography of electronically conductive samples. Highly dispersed Pd is a preferred catalyst for electroless formaldehyde-driven Cu deposition on glass fiber reinforced epoxy printed circuit boards. Using surface oxidized highly oriented pyrolytic graphite (HOPG) as a model substrate, it was possible to obtain STM images of Pd clusters (typical size 1-5 nm). An electrochemical mechanism with separation of anode reaction (oxidation of formaldehyde on Pd) and cathode reaction (deposition of Cu on graphite) is proposed for electroless Cu plating.
Chemists, physicists, biologists and electrical engineers are growing increasingly excited by the microscopic properties of molecular materials. Since the late 1970's many workers have striven to produce materials which hold the important electronic and optical properties of semi-conductors and metals. The ultimate aim of molecular electronics is believed to be the development of molecular scale devices. Molecules may perform active roles in processing, transmitting and storage of information. If the capabilities of biological membranes are represented as the ultimate goal information storage in the order of 10 6 Tbit cm 2 1 can be expected. Dreaming aside molecular conducting systems are already with us and have uses as varied as reprographics and printing, wire and cable and energy storage systems. The printed circuit board industry too has taken its first steps towards embracing electrical conducting organic materials, in an attempt to solve the production cost and environmental difficulties which go hand in hand with conventional electroless copper chemistry. In this article, the basic aspects of the physics of such organic systems are discussed leading on to their specific application to the hole walls of manufactured printed circuit boards.
Investigations of the initial stages of electrolytic copper deposition. The structure of electrodeposited metal coatings is largely determined by the initial phase of the deposition process. In this connection, nucleation and growth are of fundamental importance. Among other things, these depend on the chemical nature and structural quality of the substrate. With the aid of in-situ scanning tunneling microscopy, interrelationships of this type can be investigated at atomic dimensions.
Increasingly stringent environmental regulations have brought about a process of reorientation and a new approach in industry. The integration of economical and ecological process engineering concepts is an essential prerequisite for successful operation of a future-oriented electroplating industry. This article looks at the tasks facing plant operators, companies and research institutes, and the possibilities and perspectives open to them.
Starting from the principles of solid-state diffusion, it is demonstrated that no homogeneous, exactly bounded alloy layer can be obtained by diffusion alloying following electroplating. On the contrary, there always occurs a more or less noticeable concentration gradient in the single-phase or multiphase alloy layers. Using nickel-cadmium diffusion layers as an example, the sequence of diffusion alloy layer formation is discussed. It is shown that undesirable alloy formation can occur particularly in the case of low-melting electrodeposited metal coatings, but this can be largely prevented by intermediate diffusion barrier layers, consisting mostly of nickel or palladium.
In thickness measurements of surface layers by optical microscopy, the minimum measurable layer thickness determined by the resolving power of the microscope can be reduced by one order of magnitude if an appropriate sectioning method is used. This is illustrated by several examples including a Au layer on GaAs and a SiO//2 layer on Si.
It is shown that layer thickness measurement by means of X-ray fluorescence constitutes the most modern state of the art in this field. It is possible to measure layer thicknesses even on very small parts with high accuracy. The smallest surface that can be measured amounts to 0. 1 mm. A distinct advantage is that elements with almost the same orders of magnitude can be measured. A further advantage is that the layer thickness and composition can be determined simultaneously.
It is shown that the use of laser-assisted electrolysis is of interest wherever a selective metal deposition at high deposition rates is required. The most important applications in the near future are likely to be selective coating of contact materials in electronics and, above all, the development of a maskless, etch-free printed circuit board production. Owing to the high deposition rate, large-area electroless coating with the aid of a grating technique might be of interest for certain systems.
The principal theoretical and practical aspects of chemical copper plating which are crucial for the development of efficient plating baths are examined. The effects of stabilizers, complexing agents, and surfactants are discussed. Problems involved in practical application of the additive technique for the manufacture of printed circuits are dealt with.
Apart from measuring individual layers, the characterization of two-fold and alloyed layers has become a routine job for a long time, when it comes to layer thickness measuring with X-ray fluorescence. The aim is now to analyze three-fold and ternary alloys layers. A prerequisite for this is, however a powerful data processing system.
Enhancement of Efficiency by "In Situ"-Regeneration of Process Solutions. From the environmental and economic point of view, there is no reasonable alternative to minimal-wastage process engineering. At the same time, it is necessary to establish a cost-effective relationship between the internal material circuit and the external recovery operation by optimizing the system to achieve the highest possible level of recovery. An economical method of recycling in support of the internal material circuit is represented by the "in situ"-regeneration of pickling solutions.
The use of X-ray fluorescence for continuous thickness measurement of electrodeposited coatings has significant advantages over other methods. An extremely small measuring area can be used. Thickness is determined with high precision despite a relatively short measurement time. Simultaneous measurement of final and intermediate coatings is possible. For instance, gold over nickel over copper can be measured quite accurately. The gold thickness can be determined with a precision of plus or minus 1 to 2 percent and the nickel from 5 to 10 percent, provided the gold thickness does not exceed 80 mu in. Both the thickness and composition of binary alloy coatings (e. g. , tin-lead) can be measured simultaneously.
The author explains the role of X-ray fluorescence in obtaining coating thickness measurements on extremely small test areas. It is shown that X-ray fluorescence for coating thickness measurement can be used for a multitude of coating/substrate combinations using a single instrument. Test areas down to 0. 1 mm can be measured, unaffected by changes in substrate composition of intermediate coating of varying thickness. Dedicated mathematical methods used in combination with detection circuits allow simultaneous measurement of top and intermediate thicknesses.
This paper deals with obtaining cobalt films by means of the programme-controlled pulsed current electrolysis method. A method of depositing multitayered cobalt films composed of alternating layers ofh.c.p. andf.c.c. phases is suggested. An X-ray analysis of the cobalt films phase compositions has been carried out.
In this paper methods of electrodeposition of metallic multilayers by a program-controlled pulsed current are presented. A method of depositing microlayered coatings composed of ultrathin alternating microlayers of one and the same metal each having different structure, texture and phase composition is suggested. Results of the analysis of some physical, physico-mechanical and physical-chemical properties of microlayers are given.
Formation and characteristics. In practice, the growth of whiskers is an undesirable characteristic of electrodeposited coatings. The formation of whiskers on parts made of bronze, copper, brass and steel, coated with tin, cadmium or zinc, which are used in electrical and electronic engineering applications, is of particular importance. The article describes various influencing factors and the characteristics of zinc whiskers.
So far, electrically self-conductive polymers, such as polypyrrol, have been used exclusively for the through connection of printedcircuit boards. Within the framework of producing semiconductor/conductive polymer compound materials with sensoric properties, polypyrrol was precipitated electrochemically and photo-electrochemically on germanium and titanium oxide. The electronical and chemical properties of the compound materials obtained were investigated by spectroscopical methods.
Composite multi-layer systems constitute a new generation of materials. The production of these sandwich-type metal materials and the broad spectrum of their characteristics are presented here.
Gold and palladium-nickel were deposited on semiconductors and polyimide in conventional plating solutions using laser irradiation instead of electrical current. Gold thickness varied from a few hundred angstroms to several micrometers and depended on the energy intensity of the laser. The gold deposits exhibited Schottky barrier contact behavior on n-type silicon and gallium arsenide. A deposition mechanism involving photochemical reduction of metal ions is postulated.
Morphology of the surface, structure, texture and characteristics. Steel coatings are in demand to improve the wear resistance of components and moving parts. The latest research into controlled steel electroplating provides information about the relationship between process parameters and structure, morphology, and texture.
Laser-enhanced palladium electroless plating was found to be possible in the presence of a small quantity of Tl+ or Pb2+. The thermal conductivity of the substrate is an important factor. In order to induce electroless plating, a localized increase in temperature at the metal-solution interface by laser irradiation is necessary. Although the laser-enhanced palladium plating did not occur on copper and brass, which are good heat-conductive materials, it became possible with 5 μm of poorly heat-conductive nickel plating on these metals. The effects of the velocity of flow of the plating solution and the laser power, on the shape of the palladium deposit were evaluated. Line drawing was attempted, and the best results were obtained at 7-7.5 μm/s of laser sweep rate, with which the line width was about 20 μm.
Vor gerade erst zehn Jahren begannen Gerd Binnig und Heinrich Rohrer am IBM-Forschungslabor in Zürich, eine neue, hochauflösende Methode zur spektroskopischen Untersuchung dünner Oxidfilme zu entwickeln. Das Ergebnis ihrer unkonventionellen Vorgehensweise war das Raster-Tunnelmikroskop (RTM) [1]. Es sollte sehr bald die ursprünglichen Erwartungen hinsichtlich seines lateralen Auflösungsvermögens in topographischen und energieselektiven Abbildungstechniken und vor allem hinsichtlich der Breite seiner Anwendungsmöglichkeiten weit übertreffen. Heute, nach drei internationalen Konferenzen seit 1986 und weit über eintausend Publikationen zum Thema Tunnelmikroskopie (vgl. [2]) zeigt sich, daß die Methode nicht nur eine sehr nützliche Erweiterung des „Geräte-Zoos” der Oberflächenphysiker darstellt, sondern im Begriff ist, auch in Chemie und Biologie neue Einsichten in atomare und molekulare Mechanismen zu vermitteln. Im kreativen und kooperativen Klima, das in der Gemeinde der Tunnelmikroskopiker herrscht, entstand inzwischen eine Reihe interessanter technischer Erweiterungen, und in den drei letzten Jahren entwickelten sich aus dem RTM sogar neue eigenständige Mikroskopieverfahren, wie die Kraftmikroskopie, die Thermoskopie und die optische und akustische Nahfeldmikroskopie. Über einige jüngere Ergebnisse und Weiterentwicklungen der Tunnelmikroskopie wird in diesem Artikel berichtet.
Mit der Rastertunnelmikroskopie begann 1981 die Entwicklung einer großen Familie unterschiedlicher Nahfeld-Rastersondenmethoden, für die das englische Akronym SXM geprägt wurde. „S” steht hierbei für Scanning, „M” für Microscopy, und „X” steht alternativ für Tunneling, Force, Near field Optical, Near field Acustical, Ion Conduction, Thermal, etc. Oft werden die SXM-Methoden einseitig mit der Abbildung atomarer Landschaften assoziiert, die meist nur für die Grundlagenforschung von Interesse sind. Weitaus weniger bekannt sind die Möglichkeiten der SXM-Methoden in der anwendungsorientierten Forschung und Entwicklung, wo es auf die atomare bzw. molekulare Skala meist gar nicht ankommt. Welche Fragestellungen lassen sich denn nun erstmals mit diesen Techniken lösen oder zumindest effizienter lösen als mit konventionellen Methoden der (industriellen) Oberflächenanalytik?
Auger electron spectroscopy is the most general and popular of the current surface analysis methods. What do we mean by surface analysis? Typically we mean the chemical analysis of the outermost atom layers at a free surface and, sometimes, in addition, the analysis of the atom layers below the surface to a depth of 1 μm or so. The free surface is simply the surface that we see and is concerned, here, mainly with solid metals. Internal surfaces or interfaces may also be studied if they can be converted to free surfaces for the analysis. We shall discuss this later in Sect. 8.5.1.
Photoelectron spectroscopy with characteristic x-rays was developed into a useful analytical technique by Kai Siegbahn and collaborators at Uppsala in the late sixties. The most important applications depend on the ability to measure small shifts in core-electron binding energies, which are related to the valence state and chemical bonding of the atom. In metals the core-electron binding energy is a function of the cohesive energy of the solid. Changes in the cohesive energy at the surface of a bulk metal, or in a small metal cluster, find expression in the core-electron binding energy. More detailed analysis or core-electron photoemission spectra from metals reveals the contributions of the collective excitations which accompany the ejection of an energetic electron. These include the screening response of the conduction electrons, which modifies the shape of primary line, and the excitation of plasmons and interband transitions, which manifest themselves as satellites of this line. The technique can also be used to obtain the valence band density of states of metals and alloys, and is particularly well adapted to the elemental analysis of thin (20 A) surface layers.
High-Tc superconductors and conducting polymers can be used to form composite structures that exhibit interesting properties (the Figure shows polypyrrole grown on YBa2Cu3O7-δ). The polymers can be used to control the electrical properties of the thin film superconductor structure.
Abstract
High-Tc superconductors and conducting polymers can be used to form composite structures that exhibit interesting properties (the Figure shows polypyrrole grown on YBa2Cu3O7-δ). The polymers can be used to control the electrical properties of the thin film superconductor structure.
The mechanism responsible for the very high plating rates at electrodes illuminated by a laser beam was investigated. Absorption of the laser energy by the electrode results in a localized increase in temperature at the metal‐solution interface. This leads to: (i) a shift in the rest potential, (ii) an increase in the charge transfer rate, and (iii) strong microstirring of the solution due to thermal gradients and, at high laser power densities, to strong local boiling. Verification of the first two effects was achieved by measuring the enhancement in plating rates as a function of overpotential, laser power, and substrate thickness and by comparing these results with measurements using solutions at various bulk temperatures. Observation of the cathode through a video monitor, as well as detection of bubble formation using a miniature microphone, verified that a correlation exists between the ejection of bubbles from the cathode and sharp increases in the current. Application of laser‐enhanced electroplating for maskless generation of patterns is also briefly discussed.
The paper describes two well-known mechanisms for degradation of electronic circuitry. Intended as a tutorial for individuals working in electronic packaging who have limited background in materials and little experience with these mechanisms, the paper describes the two latent shorting phenomena. Major papers and conferences dealing with the phenomena are cited. Examples of copper migration to form electroplated shorts in both thick film hybrid multilayer and printed circuit multilayer boards are discussed, and common features to both systems are outlined. Related mechanisms that may occur with the simple electrochemical (metal plating) mechanisms to produce a broad array of electrical isolation breakdowns are also described. The closing of this part of the paper is a brief review of the Sarnoff-developed RCA/GE multilayer copper materials system.
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New techniques of laser assisted microstructuring of polybithiophene (PBT) and silver in different microbarriers on n-type silicon are presented. The deposition process was investigated in order to produce custom tailored structures. The process is influenced by primary (diameter of the laser beam), and secondary effects of which hole diffusion is shown to be dominant. To suppress secondary effects and to localize the electrochemical reaction spot, different kinds of barriers were prepared by anisotropic etching or micromachining. Both positive and negative structures with high aspect ratios and a minimum width of 2 μm were obtained. During the deposition process an influence of the substrate structure was observed eg close to a mechanically induced pit no deposition is observed, whereas anisotropically etched pit does not effect the deposition. The electrochemical characterization methods of single polymer lines in the micrometer range applying cyclic voltammetry, SECM and conductivity measurements prove a change of conductivity within the applied potential range. It was shown that the polymer microstructures can be used as organic switches, which are stable for more than 103 redox cycles without overoxidation.
