Search Results (78)

This paper reviews the fundamental principles and techniques of nickel electrodeposition, with a particular focus on metallizing polymeric substrates. It outlines the electrochemical mechanisms involved in depositing nickel from an acidic Watts bath, detailing the roles of key electrolyte components—i.e., nickel sulfate, nickel chloride, and boric acid—and the influence of process parameters, such as current density, temperature, and pH, on deposit quality (density and surface condition) and mechanical properties. In addressing the unique challenges posed by non-conductive polymers, this review compares emerging methods like silver conductive paint, highlighting differences in deposition time, surface resistivity, and environmental impact. Additionally, this paper examines how process parameters affect the as-deposited microstructure, adhesion, and overall mechanical properties (such as hardness, ductility, and tensile strength), while identifying critical issues such as low deposition density and substrate degradation. These insights provide a structured background for optimizing electroplating processes for applications in electronics, automotive, aerospace, and biomedical sectors, and suggest future research directions to enhance deposition uniformity, sustainability, and process control. Full article

Investigations of the synthesis of multicomponent coatings and their subsequent application to metal substrates to increase the wear resistance of materials is relevant for industry. Nickel compounds obtained from oxidized magnesia-iron nickel ores with a desorption rate of more than 94% were used to create Ni-MoO₃-WO₃ electroplating. Such composite samples formed from an aqueous alcohol solution reduced the content of sodium and ammonium chlorides. The annealing and dehydration of samples at a temperature of 725 °C in an air atmosphere made it possible to achieve the highest level of crystallinity. In this case, an isomorphic substitution of W atoms by Mo occurs, which is confirmed by electron paramagnetic resonance (EPR) spectroscopy studies. The invariance of the shape of the EPR spectrum with a sequential increase in microwave radiation power revealed the stability of the bonds between the particles. The surface morphology of Ni-MoO₃-WO₃ films deposited on an Al substrate is smooth and has low roughness. In this case, an increased degree of wear resistance has been achieved. Thus, a recipe for the formation of an electroplating with stable bonds between the components and increased wear resistance was obtained. Full article

The novel pyridine oxime-based complexing agents 2-pyridinecarboxaldehyde oxime, 2-acetylpyridine ketoxime and 2-pyridine amidoxime were synthesized for alkaline Zn-Ni alloy electrodeposition, outperforming conventional citrate/TEPA systems in corrosion resistance and microstructural control. The N,O-bidentate chelation mechanism governs metal ion reduction kinetics via diffusion-limited pathways, enabling γ-phase Ni₅Zn₂₁ intermetallic formation and nanocrystalline refinement. Electrochemical and microstructural analyses demonstrate suppressed random nucleation and hydrogen evolution side reactions, leading to enhanced charge transfer resistance and reduced corrosion current density. Notably, 2-pyridine amidoxime achieves ultrasmooth surfaces through defect-free nanocluster growth, while 2-pyridinecarboxaldehyde oxime maximizes γ-phase crystallinity. The synergy between grain boundary density and surface integrity establishes a dual protection mechanism combining barrier layer formation and active dissolution suppression. This work advances microstructure engineering via coordination chemistry, offering a breakthrough over traditional zincate electroplating for high-performance anti-corrosion coatings. Full article

Iron and iron-nickel alloy electrodeposits synthesized from sulfate-based electroplating baths were applied to a mild carbon steel substrate. Coated specimens were immersed in an oxygen-saturated, weak ammonium hydroxide solution (pH 9.5–10.0), and their corrosion performance was evaluated using electrochemical techniques. Galvanic and general corrosion behaviors were analyzed to assess the sacrificial protection provided by Fe and Fe-Ni coatings relative to uncoated steel. The influence of anode-to-cathode (A/C) surface area ratios (1:1, 10:1, and 100:1) on the occurrence of plating-induced surface cracks was also examined. Surface morphology and elemental composition of the deposits were characterized. Results of the study indicated that increasing the Ni²⁺/Fe²⁺ molar ratio of the electroplating bath from 0 to 0.167 led to (1) reduced surface porosity and cracking, (2) decreased galvanic corrosion rates between the electrodeposit and substrate, and (3) a progressive increase in the temperature dependence of the general corrosion rate between 20 °C and 60 °C. The development of Fe and Fe-Ni alloy electrodeposits as protective coatings is of particular interest in water-tube power boiler applications, where production of corrosion products must be controlled. Further research is needed to develop coatings that perform predictably under elevated pressures and temperatures typical of operating boiler environments. Full article

This paper presents a non-enzymatic sensor for glucose detection in an environment where glucose and insulin coexist. The sensor is based on a three-electrode chip fabricated by etching the copper foil of a printed circuit board. The working electrode is coated with a graphene oxide-polyvinyl alcohol composite film, followed by the electroplating of a nickel–cobalt layer and an additional surface treatment using O₂ plasma. The experimental results indicate that within a glucose concentration of 2 mM to 10 mM and an insulin concentration of 0.1 mM to 1 mM, the measured current exhibits a linear relationship with the concentration of glucose or insulin, regardless of whether cyclic voltammetry or linear sweep voltammetry is used. However, the detection limit for insulin is 0.01 mM, ensuring that glucose detection remains unaffected by insulin interference. In this sensor, nickel–cobalt serves as a catalyst for glucose and insulin detection, while the graphene oxide-polyvinyl alcohol composite enhances sensing performance. Full article

In order to solve the problem of poor weld quality caused by brittle metal compounds in the welding of dissimilar metals between aluminum and steel, a pre-welding treatment method of prefabricated copper–nickel binary coating between aluminum and steel has been proposed. Laser lap welding tests and weld performance tests were conducted using 6061 aluminum alloy and DP590 duplex steel with a thickness of 0.5 mm as base materials, with steel on top and aluminum on bottom. The research results indicate that the prefabricated copper–nickel binary coating can effectively suppress the formation of brittle phase compounds of Fe and Al; the increase of copper and nickel elements is beneficial for the formation of tough compounds such as (Fe, Cu, Ni)₃Al, (Fe, Cu, Ni)Al₃, and CuAl₅ in the weld zone; when the thickness of the copper coating is 155 μm and the thickness of the nickel coating is 110 μm, the mechanical properties of the aluminum steel lap welding seam are the best, and the maximum shear force that can be withstood is 208.09 N, which is 56% higher than uncoated sample. Full article

The electrical contact and tribological performance of contacts are critical for the reliable transmission of electric power and signals. In this study, a nickel layer was applied as an underlayer at the interface, and the effects of its thickness and plating process on the electrical and tribological properties were systematically investigated. Results showed that the coefficient of friction (COF) was reduced due to the nickel layer. The wear loss significantly decreased as the nickel layer thickness increased from 0.5 μm to 2 μm. This is primarily due to the nickel layer reducing adhesive wear. Additionally, the electrical contact resistance (ECR) increased as the top coating was worn out, owing to a reduction in the effective conductive area. Furthermore, ECR, COF, and wear rate were further reduced when the nickel layer was deposited using electroless plating compared with electroplating. In conclusion, the wear resistance of electrical contacts can be improved by a thicker nickel layer or electroless plating. This study provides a theoretical basis for understanding the role of the nickel layer in improving sliding electrical contact and wear behaviors. Full article

The application of deep eutectic solvents (DESs) as an innovative class of environmentally friendly liquid media represents a significant advancement in materials science, especially for the development and enhancement of structural materials. Among the promising applications, DESs are particularly attractive for the electrodeposition of corrosion-resistant coatings. It is established that corrosion-resistant and protective coatings, including those based on metals, alloys, and composite materials, can be synthesized using both traditional aqueous electrolytes and non-aqueous systems, such as organic solvents and ionic liquids. The integration of DESs in electroplating introduces a unique capacity for precise control over microstructure, chemical composition, and morphology, thereby improving the electrochemical corrosion resistance and protective performance of coatings. This review focuses on the electrodeposition of corrosion-resistant and protective coatings from DES-based electrolytes, emphasizing their environmental, technological, and economic benefits relative to traditional aqueous and organic solvent systems. Detailed descriptions are provided for the electrodeposition processes of coatings based on zinc, nickel, and chromium from DES-based baths. The corrosion–electrochemical behavior and protective characteristics of the resulting coatings are thoroughly analyzed, highlighting the potential and future directions for developing anti-corrosion and protective coatings using DES-assisted electroplating techniques. Full article

In this study, pre-treated low-carbon steel substrates were electroplated with Zinc–Nickel (ZN) alloy composite coatings enhanced by the incorporation of nano-silicon dioxide (SiO₂) particles in an alkaline solution. ZN deposits with varying concentrations of nano-SiO₂—specifically, 1, 2, 3, 5, and 10 wt%—were achieved by adjusting the ratio between the nano-SiO₂ and ZN alloy electroplating solutions. The influence of the nano-SiO₂ content on both the quality of the coating and its corrosion behavior was investigated in detail. Scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), and an atomic force microscope (AFM) were utilized to assess the surface, cross-section structure, elemental composition, and thickness of the coatings. Notably, the addition of nano-SiO₂ improved the microstructure of the coating, leading to a reduction in grain size as well as enhancements in uniformity and density while revealing that co-deposition reached an optimal concentration at 3 wt% nano-SiO₂. The corrosion behavior of coated specimens was evaluated through electrochemical impedance spectroscopy (EIS) and polarization techniques within a 3.5 wt% NaCl solution serving as a corrosive medium. Specifically, for typical prepared coatings, the corrosion current density decreased from 1.410 × 10⁻⁴ A·cm⁻² to 5.762 × 10⁻⁶ A·cm⁻², which is a remarkable reduction by one to two orders of magnitude relative to the SiO₂-free coatings mentioned previously. These findings provide a straightforward approach for selecting 3 wt% nano-SiO₂ as an effective additive in ZN composite coatings. Full article

This study investigated the performance optimization of nickel-cobalt (Ni-Co)-coated absorber panels in solar flat plate collectors (SFPCs) using response surface methodology for sustainable operation and optimized performance. Ni-Co coatings, applied through an electroplating process, represent a novel approach by offering superior thermal conductivity, durability, and environmental benefits compared to conventional black chrome coatings, addressing critical concerns related to ecological impact and long-term reliability. Experiments were conducted to evaluate the thermal efficiency of Ni-Co-coated panels with and without reflectors under varying flow rates, collector angles, and reflector angles. The thermal efficiency was calculated based on the inlet and outlet water temperatures, solar radiation intensity, and panel area. The results showed that the SFPC achieved average efficiencies of 50.9% without reflectors and 59.0% with reflectors, demonstrating the effectiveness of the coatings in enhancing solar energy absorption and heat transfer. A validated quadratic regression model (R² = 0.9941) predicted efficiency based on the process variables, revealing significant individual and interaction effects. Optimization using the Box–Behnken design identified the optimal parameter settings for maximum efficiency: a flow rate of 1.32 L/min, collector angle of 46.91°, and reflector angle of 42.34°, yielding a predicted efficiency of 79.2%. These findings highlight the potential of Ni-Co coatings and reflectors for enhancing SFPC performance and provide valuable insights into the sustainable operation of solar thermal systems. Furthermore, the introduction of Ni-Co coatings offers a sustainable alternative to black chrome, reducing environmental risks while enhancing efficiency, thereby contributing to the advancement of renewable energy technologies. Full article

In this study, sodium polyacrylate (PAAS) and ultrafiltration membranes were used to extract and separate Cu²⁺ and Ni²⁺ ions from electroplating wastewater. The effects of pH, the P/M ratio (mass ratio of sodium polyacrylate to metal ions), tartaric acid, and sodium citrate on the complexation of Cu²⁺ and Ni²⁺ by sodium polyacrylate were investigated. The retention of Cu²⁺ and Ni²⁺ by PAAS in single metal solutions with a P/M ratio = 4 and pH = 5 differed by 45.36%. When the complexation system of PAAS with a single metal contained tartaric acid and sodium citrate, the retention of PAAS for Cu²⁺ and Ni²⁺ increased to 80.36% and 58.84%. PAAS retention for Ni²⁺ decreased, but retention for Cu²⁺ remained the same. All the results indicated that there was competition between tartaric acid, sodium citrate, and PAAS for the adsorption of Cu²⁺ and Ni²⁺. Some of the Ni²⁺ complexed with PAAS were detached from PAAS complexed by tartaric acid and sodium citrate and permeated through the membrane pores, while the Cu²⁺ complexed with PAAS was not complexed by tartaric acid and sodium citrate and could not permeate through the membrane pores. Therefore, this study helps to provide a theoretical basis for the separation of Cu²⁺ and Ni²⁺ in electroplating wastewater. Full article

Pulsed current has proven to be a promising alternative to direct current in electrochemical deposition, offering numerous advantages regarding deposit quality and properties. Concerning the electrodeposition of metal alloys, the role of pulsed current techniques may vary depending on the specific metals involved. We studied an innovative tin–ruthenium electroplating bath used as an anti-corrosive layer for decorative applications. The bath represents a more environmentally and economically viable alternative to nickel and palladium formulations. The samples obtained using both direct and pulsed currents were analyzed using various techniques to observe any differences in thickness, color, composition, and morphology of the deposits depending on the pulsed current waveform used for deposition. Full article

The spinning cup, a crucial component of textile equipment, relies heavily on 2A12 aluminum alloy as its primary raw material. Commonly, electroplating and chemical nickel–phosphorus (Ni-P) plating are employed to improve the surface characteristics of the object. Nevertheless, due to the growing expectations for the performance of aluminum alloys, the hardness and wear resistance of Ni-P coatings are no longer sufficient to fulfill industry standards. This study primarily focuses on the synthesis of Ni-B-PTFE nanocomposite chemical plating and its effectiveness when applied to the surface of 2A12 aluminum alloy. We examine the impact of the composition of the plating solution, process parameters, and various other factors on the pace at which the coating is deposited, the hardness of the surface, and other indicators of the coating. The research findings indicate that the composite co-deposited coating achieves its optimal surface morphology when the following conditions are met: a nickel chloride concentration of 30 g/L, an ethylenediamine concentration of 70 mL, a sodium borohydride concentration of 0.6 g/L, a sodium hydroxide concentration of 90 g/L, a lead nitrate concentration of 30 mL, a pH value of 12, a temperature of 90 °C, and a PTFE concentration of 10 mL/L. The coating exhibits consistency, density, a smooth surface, and an absence of noticeable pores or fissures. The composite co-deposited coating exhibits a surface hardness of 1109 HV_0.1, which significantly surpasses the substrate’s hardness of 232.38 HV_0.1. The Ni-B-PTFE composite coating exhibits an average friction coefficient of around 0.12. It has a scratch width of 855.18 μm and a wear mass of 0.05 mg. This coating demonstrates superior wear resistance when compared to Ni-B coatings. The Ni-B-PTFE composite coating specimen exhibits a self-corrosion potential of −6.195 V and a corrosion current density of 7.81 × 10⁻⁷ A/cm², which is the lowest recorded. This enhances its corrosion resistance compared to Ni-B coatings. Full article

Composite coatings have been successfully fabricated at the laboratory scale in many research centers around the world; however, it is still a major challenge to transfer the positive results of the work to the industrial scale. This paper presents the technology for the production of Ni-B and Ni-B/B composite coatings on a pilot experimental semi-technical line by chemical reduction. A process scheme for the fabrication of Ni-B layers and composite coatings with a nickel–boron matrix and a dispersive phase in the form of boron nanoparticles was developed. All stages of the fabrication process were described in detail. The dispersion phase of the boron particles was characterized, and the performance properties of the Ni-B and Ni-B/B composite coatings produced on a pilot electroplating line were studied. The structure and morphology of the Ni-B/B composite coatings were characterized for comparison with nickel–boron coatings. Their mechanical and tribological properties and adhesion to the substrate were studied. The influence of the dispersion phase of boron particles on the structure and functional properties of the composite coatings was evaluated. In order to improve the performance of the fabricated coatings, a heating process at 400 °C was carried out, and the performance of Ni-B and composite Ni-B/B coatings was studied after the heat treatment operation. Full article

Due to the lower cost compared to screen-printed silver contacts, the Ni/Cu/Ag contacts formed by plating have been continuously studied as a potential metallization technology for solar cells. To address the adhesion issue of backside grid lines in electroplated n-Tunnel Oxide Passivating Contacts (n-TOPCon) solar cells and reduce ohmic contact, we propose a novel approach of adding a Ni/Si alloy seed layer between the Ni and Si layers. The metal nickel layer is deposited on the backside of the solar cells using electron beam evaporation, and excess nickel is removed by H₂SO₄:H₂O₂ etchant under annealing conditions of 300–425 °C to form a seed layer. The adhesion strength increased by more than 0.5 N mm⁻¹ and the contact resistance dropped by 0.5 mΩ cm² in comparison to the traditional direct plating Ni/Cu/Ag method. This is because the resulting Ni/Si alloy has outstanding electrical conductivity, and the produced Ni/Si alloy has higher adhesion over direct contact between the nickel–silicon interface, as well as enhanced surface roughness. The results showed that at an annealing temperature of 375 °C, the main compound formed was NiSi, with a contact resistance of 1 mΩ cm⁻² and a maximum gate line adhesion of 2.7 N mm⁻¹. This method proposes a new technical solution for cost reduction and efficiency improvement of n-TOPCon solar cells. Full article