Plating Solution Research Articles

Control system and process optimization for electroless nickel plating

A novel method based on mid-frequency vibration is proposed to eliminate coating defects such as bubbles during electroless nickel plating. An automated control system for the plating, enabling precise and stable measurements and adjustments of critical parameters such as plating solution temperature, pH, and nickel ion concentration, is also established, which significantly improves process efficiency and coating quality. Experimental results indicate that the system is capable of realizing stable operation over extended periods. A nonporous nickel–phosphorus coating with a thickness greater than 200 μm is successfully obtained, with high phosphorus content, robust adhesion, and superior machinability.

Study on the Corrosion Resistance of Electrodeposited NiW/TiO2 Composite Coating and Its Application in Methylene Blue Degradation in Simulated Wastewater

NiW/TiO2 composite coatings were electrodeposited on the surface of Q235B steel to investigate the effect of different TiO2 particle concentrations on the deposition rate, thickness, chemical composition, and surface morphology of the composite coatings. The corrosion resistance of the NiW/TiO2 composite coatings and their photocatalytic degradation of methylene blue in simulated wastewater were examined and verified. The NiW/TiO2 composite coating electrodeposited from a plating solution with 15g/L TiO2 particle exhibited the fastest deposition rate (402mg/h) and the largest thickness (23.92 μm). All electrodeposited NiW/TiO2 composite coatings comprised C, Ti, Ni and W, with granular surface morphology. Increasing the TiO2 particle concentration in the plating solution enhanced the mass transfer rate of Ni ions, thereby increasing the Ni and Ti contents in the composite coating. However, at an excessive TiO2 particle concentration of 20g/L, the viscosity increased and the transfer rate of particles and nickel ions decreased, resulting in a decrease in the Ni and Ti contents in the composite coating. Among all NiW/TiO2 composite coatings, the NiW/TiO2 composite coating electrodeposited from a plating bath containing 15g/L TiO2 particle demonstrated optimal corrosion resistance with the most positive corrosion potential (-0.533V) and the lowest corrosion current density (8.6×10-6 A/cm2). The electrodeposited NiW/TiO2 composite coatings effectively degraded the methylene blue in the simulated wastewater, achieving an optimal degradation efficiency of 60.7%.

Self-healing efficiency of ceria-doped Zn-Co coatings: Insights into particle-free versus biphasic plating baths

Achieving the superior properties of nanocomposite materials involves addressing several challenges, particularly the agglomeration of nanoparticles in the plating bath. This study focuses on the electrodeposition and characterization of Zn-Co-CeO2 composite coatings using a particle-free plating bath, which is an effective strategy to mitigate agglo¬meration. For comparison, the composite coatings were also deposited from a traditional biphasic plating solution. The coatings were deposited galvanostatically, at various current densities. Scanning electron microscopy revealed that using a particles free plating solution in conjunction with lower current densities enhanced the compactness and the overall quality of the coatings. Lower current densities favoured the codeposition of particles, as indicated by energy-dispersive X-ray spectroscopy results. Notably, the coatings produced from the particle-free bath exhibited significantly improved corrosion resistance and durability in chloride-rich environments, attributed to their self-healing properties, as shown by electrochemical impedance spectroscopy.

Preparation mechanism and characterization of PET/Cu composite foils

PET/Cu composite foils are expected to have widespread applications due to their lightweight, good bendability and excellent electrical conductivity. However, efficiently and stably preparing copper cladding layers on the surface of PET film with good bonding to the substrate remains a challenge. In this study, by optimizing the process route and adopting a synergistic method involving electroless plating and electroplating, PET/Cu composite foils with excellent conductivity and robust bonding can be successfully prepared. The experimental results indicate that the optimal performance of PET/Cu composite foils is achieved when the PET substrate is roughened with KMnO4/H+ solution, activated with salt-based colloidal palladium, subsequently treated with a weak alkaline electroless nickel plating solution for 5 min, and plated copper at a current density of 0.4 A·dm−2. The adhesion strength of the PET/Cu composite foils meets the ASTM 5B standard and the electrical conductivity reaches up to 4.17 × 107 S/m. The method proposed in this study offers an efficient and concise approach for preparing high-quality PET/Cu composite foils that hold great potential for diverse applications in flexible copper clad laminates.

PTFE layer formation during brush electroplating of nickel

Brush electrodeposition of Ni/PTFE composite coatings was explored using a nickel high speed solution and polytetrafluoroethylene (PTFE) particles 6–9 μm in diameter. A novel bilayer-like, partially intercalated structure was produced, consisting of a rough nickel sublayer covered by an outer, compact, smooth PTFE layer. The study of the coating growth revealed that the PTFE particles bind together on the nickel coating valleys and grow until all the surface is covered by a polymer layer without the need of a baking stage. The resulting coating presents a hydrophobic surface with a low coefficient of friction (0.10) and higher corrosion resistance to salt spray testing than the nodular nickel coating. The coatings were produced using an aqueous nickel plating solution, where the hydrophobic PTFE particles were suspended using different substances: cetrimonium bromide (CTAB) cationic surfactant, isopropyl alcohol premixed with the particles, and ethanol premixed with the particles. High concentrations of the suspending products were detrimental for the deposition process, but optimal values of 0.1 g/l, 3 ml/l and 3 ml/l respectively were found. All compounds successfully suspended the PTFE particles and both alcohols produced the Ni/PTFE coating described before, but the CTAB failed to co-deposit the polymer.

Optimization of Electroless Plating Solution Parameter for Coating PETG Electrode with Copper using Design of Experiment (DOE)

In the study, an attempt was made to electrolessly plate copper onto PETG plastics that aren't conductors. Three manipulating factors, i.e. volume of copper sulphate and sulphuric acid (A), volume of sulphuric acid (B), and mass of copper sulphate (C), were selected and carried out using Taguchi method with three levels to examine their interactions and effects on the responses, including plating thickness, and electrical resistance. The Design Expert 13 software creates a total of nine runs with a single centre point. Three days were spent submerging every electroplated sample part in a different bath solution concentration. The resistance of the metalized PETG component was measured in the meantime using a digital multi-meter. The Cu-deposited PETG was analysed and measured using scanning electron microscopy (SEM). The ideal situation was identified as having 10 possibilities for achieving the goal, based on interaction effects. According to the results of the experiment, run number 3 provides the ideal solution parameter for copper deposition metallization. For the lowest electrical resistance of 0.64 ohm and the highest plating thickness value of 211.49 m, these runs yield the best ideal results. Because each factor reacts to a response individually, the Analysis of Variance (ANOVA) demonstrates that there are little interactions between the factors and responses. The lowest electrical resistance and highest plating thickness values are obtained with the best chemical composition parameter choices.

Electrolyte Solution Stirring Effect on Deposition Rate, Crystallographic Orientation, and Electrochemical Behaviour of Ni Film

Abstract Stirring the electrolyte meanwhile electrodeposition process is running may influence the properties of the forming films. In this work, the electrodeposition of copper (Cu) over aluminium (Al) alloy was performed. Subsequently, the electrodeposition of nickel (Ni) onto the formed Cu layer was conducted. In order to enhance the films properties, some various stirring speeds then are implied on the plating solution of the Ni electrodeposition process. The synthesized of Ni films were analysed by means of both X-ray diffraction (XRD) and a potentiostat equipment. The sample made shows different physical properties before and after electrodeposition based on sample weighed to examine the deposition rate. XRD patterns confirmed that all samples have a face-centered cubic (fcc) crystal structures with a space group of Fm-3m. Stirring speed play an important role of an inverse relationship with deposition rate, crystallite size, lattice strain, and corrosion rate. The sample that was made using the highest stirring speed yield a better corrosion resistance at around 0.239 mmpy due to less lattice strain.

Preparation and tribological performance of Ni-SiC composite coating on 304 stainless steel through brush plating

The low hardness of 304 stainless steels makes them susceptible to wear, which increasing the probability of workpiece failure during actual use. In this study, a Ni-SiC composite coating was successfully prepared on 304 stainless steel using brush plating equipment, effectively enhancing the material's surface wear resistance. By characterizing the microstructure and properties of the composite plating layer, we determined the optimal process parameters for brushing Ni-SiC wear-resistant plating and revealed the wear mechanism of this protective layer. When the parameters for preparing the composite plating coating were adjusted to a voltage of 10 V, a relative motion rate of 8 m/min, a plating solution temperature of 50 °C and a SiC concentration of 15 g/L, the resulting wear-resistant plating coating exhibited an impressive microhardness value of 457 HV0.1 and a friction coefficient of 0.46. It was observed that the fatigue wear mechanism dominated in Ni-SiC composite coatings with a solution SiC concentration below 5 g/L, while oxidative and abrasive wear mechanisms were dominant in Ni-SiC composite coatings with solution SiC concentrations exceeding 10 g/L.

Gluconate solutions for nickel electrodeposition and nickel electroless plating

Nickel electroplating has found a wide range of industrial applications as a technique for creating protective and decorative coatings of metallic and non-metallic surfaces, protecting materials against corrosion at elevated temperatures in both alkaline environments and organic acid solutions, forming a sublayer for obtaining coatings of other metals on steel, enhancing the hardness and wear resistance of surfaces, as well as for improving solderability. Such coatings can be obtained from weakly acidic aqueous and weakly alkaline complex electrolytes. In this review, we analyze the available literature on complexation of nickel(+2) with D-gluconate ion CH2OH(CHOH)4COO‾, along with that on compositions and some technological characteristics of complex D-gluconate solutions for nickel electrodeposition and electroless plating. Thus, a corrosion-resistant smooth light-colored nickel coating, tightly adhered to a copper substrate, was obtained from an electrolyte with a pH level of 8, containing 53 g/dm3 of NiSO4 •6H2O, 44 g/dm3 of D-C6H11O7Na, 25 g/dm3 of H3BO3, 53 g/dm3 of (NH4)2SO4, and 0.5–3 g/dm3 of CO(NH2)2, at a temperature of 25 °C, a cathodic current density of 2.5 A/dm2 with a current efficiency of 96.4%. An electroless Ni-P(3–18 wt%) alloy coating on copper was obtained from a solution with a pH level of 9, containing 5–30 g/dm3 of NiSO4 •6H2O, 10–60 g/dm3 of D-C6H11O7Na, 5–40 g/dm3 of NaH2PO2 •H2O, 3 g/dm3 of HOOCCH2CH2COOH, 0.5 g/dm3 of CH3(CH2)11OSO3Na, 0.002 g/dm3 of Pb(CH3COO)2•3H2O, at a temperature of 90 °C and a deposition rate of up to 0.75 μm/min. The review also discusses methods for preparing D-gluconate electrolytes for nickel plating using sodium D-gluconate, D-glucono-1,5-lactone, and nickel D-gluconate. One advantage of D-gluconate nickel plating solutions consists in the absence of toxicity and low cost of D-gluconates.

Fabrication of Three-Dimensional Dendritic Ag Nanostructures: A SERS Substrate for Non-Invasive Detection.

This paper discusses the fabrication of three-dimensional dendritic Ag nanostructures, showcasing pronounced Localized Surface Plasmon Resonance (LSPR) effects. These nanostructures, employed in surface-enhanced Raman scattering (SERS), function as sensors for lactic acid in artificial sweat. The dendritic structures of the silver nanoparticles (AgNPs) create an effective SERS substrate, with additional hotspots at branch junctures enhancing LSPR. We achieve differential LSPR effects by varying the distribution and spacing of branches and the overall morphology. Adjustments to electrodeposition parameters, such as current and plating solution protective agents on an anodized aluminum oxide (AAO) base, allow for precise control over LSPR intensities. By pre-depositing AgNPs, the electron transmission paths during electrodeposition are modified, which leads to optimized dendritic morphology and enhanced LSPR effects. Parameter optimization produces elongated rods with main and secondary branches, covered with uniformly sized, densely packed, non-overlapping spherical AgNPs. This configuration enhances the LSPR effect by generating additional hotspots beyond the branch tips. Fine-tuning the electrodeposition parameters improved the AgNPs' morphology, achieving uniform particle distribution and optimal spacing. Compared to non-SERS substrates, our structure amplified the Raman signal for lactic acid detection by five orders of magnitude. This method can effectively tailor SERS substrates for specific analytes and laser-based detection.

A New Process for Efficient Non-Destructive Metal-Activated Composite Plating of Ni-P-Al2O3 on Titanium Base and Its Performance Research

A new high efficient and non-destructive mental activation process of electroless composite plating was proposed. The process utilized electromagnetic induction equipment to heat the titanium alloy substrate and used its energy to complete the activation process, which could successfully attach the nickel nanoparticles firmly to the surface of the titanium alloy; at the same time, the process pre-activated Al2O3 nanoparticles and added the activated nanoparticles to the plating solution. In the process of plating, the activated titanium substrate was used as the catalytic center of electroless nickel plating (ENP) for electroless composite plating. The new activation process avoided complicated traditional processes such as acid etching and zinc dipping. Such traditional processes require huge doses of chemicals, including various strong acids, so improper waste liquid treatment will cause harm to the environment. The important parameters of the process were optimized by orthogonal experiments. A scanning electron microscope (SEM), an X-ray photoelectron spectroscopy (XPS), an energy dispersive spectrometer (EDS), thermal shock experiments and friction and wear experiments were used to characterize and analyze the surface morphology, composition, binding force and friction coefficient of the coating, and analyze the coating quality by measuring the plating rate and the thickness of the coating. The results showed that the rate of electroless composite plating increased with the increase in Al2O3 nanoparticle concentration. When the concentration of Al2O3 nanoparticles reached 1.5 g/L, the ENP rate decreased with the increase in Al2O3 nanoparticle concentration. The adhesion of the sample was evaluated by the scratch test, which showed that the binding grade of the sample was 0, and the Vickers hardness was 688.5 HV. Results showed that the coating produced by this new process has excellent performance. Therefore, the process is an environmentally friendly and fast activation composite plating process.

Study on process optimization of electroless Ni-P plating on binderless WC

Abstract In the field of Precision Glass Molding (PGM), binderless tungsten carbide (WC) is a pivotal material for molds, despite its high processing costs and complexities. Nickel-phosphorus (Ni-P) alloys also exhibit superior performance at elevated temperatures. The innovation of Ni-P/WC composite molds addresses the issue of the poor machinability of WC. This research delves into the influence of the activating solution’s concentration on the surface activation energy of WC, the quality of plating, and the deposition rate during the electroless Ni-P plating process. Additionally, the study scrutinizes how the pH level of the plating solution impacts the quality of Ni-P, the rate of deposition, and the phosphorus content. These investigations have led to the realization of an efficient and high-quality Ni-P plating process for WC.

Improved wear and corrosion protection of Ni–P alloy coating by an electrodeposited Ni–Co–P alloy coating

To improve the comprehensive protection performances of steel C1045 surface, the Ni–Co–P alloy coatings with varying CoSO4·7 H2O concentration (0, 10, 20, 30, 40, 50, 60 and 70 g·L–1) were successfully prepared by an electrodeposition technique on a steel C1045 surface. The effect of the addition of CoSO4·7 H2O in the plating solution on the surface microstructure, elemental composition, crystallite size, microhardness, wear and corrosion resistance of the Ni–Co–P alloy coatings were analyzed by using a scanning electron microscope, an energy dispersive spectroscopy, an X-ray diffraction, a microhardness tester, a friction wear tester and an electrochemical workstation, respectively. The results indicated that the Ni–Co–P alloy coating exhibited a flatter morphology, compact microstructure and more excellent properties compared with Ni–P alloy coating, and the addition and variation of CoSO4·7 H2O in the plating solution had significant effects on the surface microstructure and comprehensive protection performances Ni–Co–P alloy coating. Notably, when the mass concentration of CoSO4·7 H2O in the plating solution was 50 g·L–1, the Ni–Co–P alloy coating had the highest content of Co element (22.67 wt·%), smallest crystallite size (20.41 nm) and highest microhardness (716.2 HV0.1). Furthermore, its wear resistance and corrosion resistance were considerably improved compared to that of the Ni–P alloy coating. The minimum average dynamic friction coefficient, wear scar width and depth of Ni–Co–P alloy coating at 50 g·L–1 were 0.47±0.02, 450.9 µm and 14.1 µm, respectively. The corrosion current density (Icorr) of Ni–Co–P alloy coating was the smallest (0.68 µA·cm–2), the corrosion rate (Rcorr) was slowest (8.25 µm·year–1), and the polarization resistance (Rp) of the Ni–Co–P alloy coating was highest (29.83 kΩ·cm2). The corrosion resistance of Ni–Co–P alloy coating was best.

Electroless Plating of Nanoporous Substrates for Thin Film-Solid Oxide Fuel Cells

Thin-film solid oxide fuel cells (TF-SOFCs) are an attractive renewable energy source due to their high efficiency, increased power output and ability to be efficiently stacked for power generation at a small or large-scale. [N. Q. Minh, J Am Ceram Soc. 1993; 76(3):563-588.] Nanoporous Al2O3, also known as anodized aluminum oxide (AAO) is an appropriate substrate for TF-SOFCs due to its high temperature stability, chemically inert nature, and porosity that allows gas flow to the anode. The aligned, nano-sized pores allow for both conformal sputtering on the surface and efficient fuel delivery to the anode, making it particularly suited for thin film deposition. Electroless nickel plating is used to achieve a fully conductive, nanoporous substrate which catalyzes the hydrogen oxidation reaction and improves current collection efficiency in TF-SOFCs. A minimum plating temperature of 60°C is needed to grow nanoscale Ni deposits into a conductive film without compromising the porosity of the surface. Effective stirring methods are used to deliver the plating solution throughout the high-aspect ratio pores of the AAO substrate and create thru-plane conductivity. To achieve conformal plating, the number of pre-treatment steps was optimized to prevent overplating and create a homogenous Ni deposit. Finally, with the creation of a conformally coated, conductive porous substrate, we can improve the efficiency and power output of TF-SOFC performance with commercially relevant active areas (larger than 1 cm2).

Multi-Physics Simulation and Optimization of Jet Electrodeposition for Ni–Diamond Composite Coatings

This work investigated the influence of current density, plating solution flow rate, and nozzle outlet-to-cathode distance on the properties of Ni–diamond composite coatings. A multi-physics field simulation was employed to analyze the interplay between current density, plating solution flow rate, and nozzle outlet-to-cathode distance on the flow field and electric field distribution. Additionally, particle tracing simulations were incorporated into the model to evaluate the incorporation efficiency of diamond particles during composite electrodeposition. It was found that when the inlet flow rate of the electrolyte was 5 L/min, the distance between the nozzle outlet and the cathode was 3 mm, and the current density was 60 A/dm2, the composite electrodeposited coating had a higher particle content and better uniformity. The simulation results were validated through experimental preparation and performance testing. This combined approach provides valuable insights for optimizing the jet electrodeposition process for Ni–diamond composite coatings with superior properties.

Effect of Heat Treatment on Chemical Plating of Ni-Cr-P on 65Mn Alloy Steel

The chemical plating of Ni-Cr-P significantly affects the improvement of the structure and characteristics of the metal surface. This study aimed to investigate the impact of various plating solution components and process parameters on the deposition rate and surface hardness of Ni-Cr-P coatings on 65Mn alloy steel. Additionally, the study examined the changes in coating properties resulting from different heat treatment temperatures. The specimens coated with Ni-Cr-P underwent heat treatment at temperatures of 180°C, 200°C, 220°C, and 240°C, respectively. The testing results indicate that the plating layer achieves its highest level of performance when subjected to a heat treatment temperature of 200°C. The heat-treated coating exhibits superior wear and corrosion resistance compared to the 65Mn steel substrate. Additionally, the coefficient of friction decreases from 0.5 to 0.4. The self-corrosion potential shifts positively from -569 mV to -389 mV, and the corrosion current decreases from 61.4 μA to 14.48 μA. Furthermore, the impedance improves from 234 Ω·cm2 to 3512 Ω·cm2.

Electroless Copper Plating on a Cotton Surface: Effect of Metal Ion Ligand Stability Constant on Reduction Deposition.

Electroless plating facilitates the metallization of nonconductive substrate surfaces, and of note, the precise control of the bath stability constant influences the deposition process of metal particles. In this paper, trisodium citrate, potassium sodium tartrate, nitrogen triacetic acid, thiourea, and ethylenediamine tetraacetic acid disodium were selected as coordination agents, and the effect of the metal ion ligand stability constant on the reduction deposition was studied. Coordination bonds can be established between the Cu2+ and O/N/S particles in the ligand because paired electrons in O/N/S hybrid orbitals tend to occupy empty Cu2+ hybrid orbitals and establish coordination bonds. More importantly, the copper-potassium sodium tartrate ligand exhibits the lowest stability constant and lowest reduction barrier. As an exception, a consecutive Cu-plated coating with an excellent crystallinity property was deposited on the cotton surface when potassium sodium tartrate was used as the coordination agent in the plating solution. The deposition amounts are 55.2% and 74.1% after 1 and 4 h of electroless copper plating, respectively. The surface resistivity of Cu-plated cotton is 0.38 Ω/cm2, and additionally, the surface resistivity ratio before and after 1000 cycles fluctuated between 0.9 and 1.1, indicating that the Cu-plated cotton exhibits outstanding flexibility. In this paper, the deposition rate can be optimized by adjusting the copper particle ligand stability constant in the plating solution, aiming to achieve optimal results.

Hydrogen generation from catalytic hydrolysis of ammonia borane with Co-Cu-B/g-C3N4/NF catalyst

In this study, different double-supported Co-Cu-B/g-C3N4/Ni foam (NF=Ni foam) catalysts were synthesized by chemical deposition method in a certain pH value range (pH value between 10.5 and 12.0). Their catalytic performances of hydrolyzing ammonia borane (NH3BH3) hydrolysis were investigated to produce hydrogen at 298 K. Because of the adding of g-C3N4 in the plating solution, the obtained sample had certain photocatalytic activity when the visible light was introduced the hydrolysis experiment. The results displayed that the as-prepared Co-Cu-B/g-C3N4/NF catalyst at pH = 10.5 exhibited an improved catalytic effect for NH3BH3 hydrolysis under visible light irradiation. The corresponding hydrogen generation rate reached 8893 mol·min−1·g−1, and the activation energy was 41.8 kJ·mol−1. The catalytic performance of Co-Cu-B/g-C3N4/NF catalysts prepared by this method is better than that of as-obtained mono-metal Co-B/g-C3N4/NF catalyst. More importantly, its activity has exceeded many single-carrier cobalt-based catalysts reported so far, and even some single-support precious metal catalysts for NH3BH3 hydrolysis. It indicated that the strategy of double carriers and introduction of light contributed to the improvement in catalytic activity for the non-noble metal-based catalysts during NH3BH3 hydrolysis.

A novel electroless nickel plating process for fabrication of optical fiber corrosion sensors

In this work, a novel silanization pre-treatment method has been successfully proposed to solve the problems of discontinuity and poor adhesion strength of electroless nickel plating using in the ultrasensitive optical fiber corrosion sensors. The chemically etched and hydroxylated optical fiber is simply treated with a mixed solution containing the hydrolyzed γ-APS with bifunctional group and PdCl2 before dipping into nickel plating solution. ATR-FTIR, AFM, SEM and theoretical calculations are applied to demonstrate the feasibility of the method and reaction mechanism. Results show that the –NH2 in γ-APS preferentially interacts with the Pd2+, while the Si-OH at the other end forms a covalent bond with the Si-OH on the optical fiber surface, forming a needle-like silane intercalation film by oriented adsorption. With this simple silanization pre-treatment method, a uniform and continuous electroless nickel plating can be successfully prepared. Our DFT calculations are good consistent with the experimental measurements.

Effect of bath temperature on electroplating of nickel on a copper substrate

ABSTRACT Nickel electroplating is known to be industrially effective for enhancing various substrate properties. In the present work, nickel coatings were developed on copper substrates by electroplating using standard nickel plating solution at various electrolyte bath temperatures ranging from 40 ± 2°C to 60 ± 2°C in steps of 10°C. Energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and field emission scanning electron microscopy (FESEM) were used to study the composition, phase structure and morphology of the coatings. The coatings were also analysed for hardness and porosity, and process current efficiency was measured. The electrolyte bath temperature has a profound effect on the nature of the developed nickel coatings, and is observed to have an impact on the surface morphology, crystallographic direction, and hardness, as well as deposition current efficiency.