Electroless Nickel Plating Process Research Articles

Investigating the Potential of Electroless Nickel Plating for Fabricating Ultra-Porous Metal-Based Lattice Structures Using PolyHIPE Templates.

The use of polymerized high internal phase emulsions (polyHIPEs) as templates for electroless nickel plating is a promising method for producing ultra-porous metallic lattice structures with consistent wall thickness. These structures have desirable properties such as low density, high specific strength, resilience, and absorbency, making them suitable for various applications including battery electrodes, catalyst supports, and acoustic or vibration damping. This study aimed to optimize and investigate the electroless nickel plating process on polyHIPEs. Initially, a surfactant (Hypermer)-stabilized water-in-oil emulsion based on 2-ethylhexyl-acrylate and isobornyl-acrylate was used as a 3D printing resin to create polyHIPE structures. Then, the electroless nickel plating process was optimized using polyHIPE discs. The study also examined the effects of air, argon, and reducing atmospheres during the heating process to remove the polyHIPE template using metallized 3D-printed polyHIPE lattice structures. The findings indicated that different atmospheres led to the formation of distinct compounds. While nickel-coated polyHIPEs were fully oxidized in an air atmosphere, nickel phosphide (Ni3P) structures occurred in argon and reducing atmospheres along Ni metal. Moreover, in argon and reducing atmospheres, the porous structure of the polyHIPEs was retained as the internal structure was completely carbonized. Overall, the study demonstrated that intricate polyHIPE structures can be used as templates to create ultra-porous metal-based lattices for a wide range of applications.

A new environmentally friendly non-destructive activation process of electroless nickel plating on alumina ceramics

A new non-destructive activation process before electroless nickel plating (ENP) was proposed, which reduced the use of strong corrosive drugs and noble metals， and was environmentally friendly without damaging the surface of alumina ceramics. The process successfully attached nickel nanoparticles firmly to the alumina ceramic surface and used the nickel nanoparticles as a catalytic center of ENP for electroless plating. The important parameters of the non-destructive activation process were optimized by orthogonal experiments. A scanning electron microscope (SEM), an X-ray photoelectron spectroscopy (XPS), an energy dispersive spectrometer (EDS) and thermal shock tests were used to characterize and analyzed the surface morphology, microstructure, composition and binding force of the coating, and measured the plating rate and conductivity to analyze the coating quality. The rate of ENP reduced with the decrease of ion concentration. When the plating time was 30 ，60 and 90 min, the average plating rate was 10.93, 10.85 and 8.76 µm/h, respectively. The difference in the square resistance of the coating of different samples was small, indicating that the coating thickness was basically the same. When the coating was applied for 90 min, the coating thickness was about 14.3 µm and the resistivity was about 107.2 × 10−6 Ω·cm, conforming to the international standard of nickel plating with phosphorus. Therefore, the process has advantages of simple operation and low cost, and it is a non-destructive and environmentally friendly activation process for substrates.

Hierarchically Flexible Polyamide Composite Films for Thermal Management and Electromagnetic Shielding

With the integration and high power of electronic devices, as well as the rapid development of 5G and new energy, the application of materials with good flexibility, mechanical properties, and multifunctional properties is increasing. In this study, we prepared polyamide composite films with high thermal conductivity (TC) (33.27 W/(m·K)), excellent electromagnetic interference shielding effectiveness (EMI SE) (63.0 dB), and good mechanical properties (tensile strength 44.5 MPa, toughness 13.8 MJ/m3) by using hierarchical design and recombination strategy. The top layer of the composite film is a graphene/graphene oxide film (GNP/GO) as the TC and EMI shielding layer. The base layer of the composite film is a commercially available polyamide mesh to improve mechanical properties. The dense Ni layer was deposited on the polyamide fabric by the electroless nickel plating process, which improved the shielding performance against electromagnetic interference. The water-borne polyurethane (WPU) cladding is further coated on the nickel-plated polyamide fabric to protect the cladding and bond the top and base layers simultaneously. In addition, the practical application of the film in thermal management and electromagnetic shielding fields is also proved through the application experiments.

Failure analysis on the pin fin heat sink for the power module of new energy vehicles

For new energy vehicles, the power module in the inverter plays a key role in electricity conversion. Considering that a large amount of heat generated by the power module during operation can cause thermal damage, a kind of special pin fin heat sinks with nickel-phosphorus coating is designed for achieving a better heat dissipation effect. Nevertheless, during the corrosion resistance test before assembly, many defects suspected to be caused by corrosion were found on the surface of pin fin heat sinks, which did not meet the design requirements and made the pin fin heat sinks fail in the test. In order to find out the root cause of the failure, the copper substrate qualities, hydrogen content of the coating, coolant compositions, macroscopic and microscopic morphologies, and the electroless nickel-plating process were systematically characterized and analyzed. Through comprehensive failure analysis, the corrosion factor inferred initially was excluded, and the explosive release of the local hydrogen aggregating in the nickel-phosphorus coating was finally determined as the root cause. Based on the conclusions, the corresponding countermeasures were proposed to avoid the reoccurrence of similar defects in the future manufacturing process. The obtained achievements would be helpful to improve the plating quality of pin fin heat sinks and enhance the reliability of the new energy vehicles.

Metallization on Sapphire and Low-Temperature Joining with Metal Substrates.

To meet the packaging requirements of sapphire in special electronic components, there is an urgent need for a joining process that can realize a good connection between sapphire and dissimilar metals at a low temperature. In this work, the surface of a sapphire substrate was successfully catalytically activated and metallized by an electroless nickel plating process. Moreover, the solderability and interconnection of metallized sapphire with Sn-based solders were evaluated and investigated at 250 °C, and the wetting angle of the Sn-based solders on sapphire on sapphire without and with metallization was 125° and 51°, respectively. The interfacial microscopic morphology and element distribution in the Cu/Sn-Ag solder/sapphire solder joints were analyzed. It was found that the middle solder layer has diffused during the reflow process, inferring good adhesion between sapphire and Cu substrate with the aid of the Ni-P deposition. Thus, a sapphire welding method with a simple process suitable for practical applications is demonstrated.

A New Environmentally Friendly Non-Destructive Activation Process of Electroless Nickel Plating on Alumina Ceramics

A New Environmentally Friendly Non-Destructive Activation Process of Electroless Nickel Plating on Alumina Ceramics

Multiscale analysis of enclosed nickel metal layer constructed via a palladium-triggered autocatalytic reaction on aramid fiber surfaces

Conductive aramid fibers have been attracting great interest owing to their lightweight, flexibility and metal-specific properties. Revealing the actual growth process of electroless nickel plating on the surface of aramid fibers is conducive to better control the quality of the prepared metal layer. Herein, we have fabricated different samples using the sensitization-activation two-step method and electroless nickel plating. Chemical element and valence analysis confirmed that the Pd, Ni and P uniformly attached to the surface of aramid fibers have zero valence. The chemical phase analysis and microstructure characterization demonstrated that the NiP alloy layer was amorphous as a whole, whereas Pd and Ni were the crystals with the characteristics of face-centered cubic crystals, and both of them could play a catalytic role in the redox reaction of electroless nickel plating. Furthermore, the possible mechanism of NiP growth on the surface of aramid fibers was proposed, which included the principle of closed assembly of the metal layer and three stages of ‘initial growth, high-speed growth and leveling’.

Deposition of High-Density Carbon Nanotube-Containing Nickel-Based Composite Films by Low-Pressure Cold Spray

Carbon nanotubes (CNTs) have a large specific surface area and, thus, are expected to have applications as electrodes, e.g., in fuel cells. A CNT-containing composite metal film with high electrode performance could be realized by implementing a large number of CNTs on the film. However, a composite film with a high density of CNTs has not yet been obtained. In the thermal spray field, including cold spray, metal–CNT composite films with more than 20 wt% of carbon nanotubes has not yet been deposited. In this study, high-density CNT-containing metal-based composite films were deposited onto an aluminum substrate by low-pressure cold spray from electroless nickel-plated CNT particles. The electroless nickel plating process caused slight structural damage to the CNTs, whereas the cold spray process did not cause any significant structural damage to the CNTs. Two phases were observed in the films: a CNT-rich layer and a nickel-rich layer. However, the CNTs maintained sufficient adhesive strength to remain attached to the bottom nickel phase. Composite films with at least 65 wt% CNT were produced with our method.

Process of environmentally-friendly direct electroless nickel plating on AZ91D magnesium alloy surface

Process of environmentally-friendly direct electroless nickel plating on AZ91D magnesium alloy surface

Physicochemical Model of Selection of Complex Compounds for Electroless Metal Plating

A physicochemical model of the choice of a ligand for the electroless deposition of metal–phosphorus alloys is proposed based on determining the conditions for electrochemical reactions that cause the formation of the alloy and minimizing possible side reactions that impede the quality of the deposition process. Based on the physicochemical model, the optimal range of values of the stability constants and pH was determined for electroless nickel plating. It is shown that, for the pH range 7–9, which corresponds to the maximum deposition rates, stability constants take values from 5 to 10; carrying out the process in more alkaline solutions requires the use of more stable complexes. The predictive ability of the model is confirmed by experimental studies of the process of electroless nickel plating from solutions of various ligand compositions.

Fabrication of a laminated felt-like electromagnetic shielding material based on nickel-coated cellulose fibers via self-foaming effect in electroless plating process

Sustainable low-cost cellulose-based electronics has exhibited brighter prospects. In this study, a laminated felt-like electromagnetic shielding material was prepared by using cellulose paper as the matrix through the self-foaming effect in electroless nickel plating process in which an efficient palladium-free activation was conducted that alkaline sodium borohydride (NaBH4) reduced nickel ions into nickel cluster to initiate the plating process. NaOH concentration in NaBH4 solution, pH of the plating bath and the plating time affected the thickness, metal deposition and surface resistance of the electromagnetic shielding material. By understanding the morphology, inner structure, chemical component and thermal stability, the pH in the plating solution is a key for the preparation. When the pH was 8.51, the electromagnetic shielding effective reached 65 dB in the frequency ranges of 9 kHz to 1.5 GHz, which could shield more than 99.99% electromagnetic radiation. This work offers a novel and feasible path to develop functional cellulose-based materials.

Enhanced thermoelectric properties of Bi2S3 polycrystals through an electroless nickel plating process.

Bi2S3 is an eco-friendly alternative compound for thermoelectric devices. However, the low electrical conductivity of the pristine Bi2S3 hinders the improvement of its ZT value, which further restricts its application in the field of thermoelectricity. In this work, we report the first attempt to optimize the thermoelectric properties of Bi2S3 by electroless nickel plating. A nickel plated Bi2S3 powder sample was synthesized by electroless nickel plating on the precursor Bi2S3 powder prepared by mechanical alloying. Then, the powder was sintered to a bulk material by spark plasma sintering. The relationships between the composition, microstructure and thermoelectric properties of the bulk samples were investigated. The XRD results showed a AgBi3S5 second phase which was formed by the reaction of Ag residues with the Bi2S3 substrate during the sintering process. The nickel element and AgBi3S5 second phase introduced in the nickel plating process directly affect the electronic conductivity and Seebeck coefficient of the nickel plating sample, resulting in the relatively high power factor of 244 μW m−1 K−2 at 628 K. What's more, the thermal conductivity of the sample was also reduced moderately, obtaining a low value of 0.40 μW m−1 K−1 at 628 K. Therefore, a maximum ZT value of 0.38 was obtained at 628 K for the nickel plated sample, which is three times higher than that (0.12 at 628 K) of pristine Bi2S3 materials.

KMnO4‐system etching process and electroless nickel plating on ABS

Etching treatment for acrylonitrile butadiene styrene (ABS) resin and electroless nickel plating process have been studied. The ABS first was etched in a chromium‐free potassium permanganate etching system with different etching times. Scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FT‐IR), and hydrophilicity test showed that the ABS is of moderate and homogeneous hole size after being etched at a temperature of 65 °C with 6 g L−1 potassium permanganate for 20 min. Then electroless nickel process was performed by immersing the ABS into in a Ni plating bath at 45 °C for 20 min at a pH of 8.5–9.5. The coating was even, dense, and reveals good corrosion resistance. In addition, the nickel plating adhesion strength reached 2.73 MPa. Therefore, the excellent performance of the KMnO4‐H2SO4‐H3PO4‐H2O etching system may replace the traditional chromic anhydride‐sulfuric acid etching system as an environmentally friendly process.

Influence of temperature on the surface property of ABS resin in KMnO4 etching solution

The KMnO4‐H3PO4‐H2SO4 system was used to roughen and hydrophilically modify on the surface of ABS resin at different etching temperatures, and then, electroless nickel plating process was carried out. The surface of ABS resin after etching was characterized by XPS and SEM. It is found that the surface etching effect of ABS resin is relatively good when the etching temperature is 65°C. The resin surface generates ─OH and ─COOH hydrophilic groups, the roughness of resin surface is increased significantly, and the surface hydrophilic contact angle is 40.51°. After electroless nickel plating on the ABS etching surface, the bonding force of the coating can reach 2.73 MPa. Electrochemical polarization curves and electrochemical impedance spectra also show that the corrosion resistance of coating after 65°C etching postprocessing is improved.

Preparation of nickel coating on ZTA particles by electroless plating

With the aim to effectively improve the interface between ZrO2 toughened Al2O3 (ZTA) particles and metal matrix, nickel was deposited on the surface of ZTA particles by electroless plating method. Formation mechanism of nickel coating and effects of the solution pH, loading capacity of ZTA particles and temperature on the nickel deposition were investigated. Microstructures, thickness and element distributions of nickel coating were analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The results showed that the nickel was successfully deposited on the surface of ZTA particles by electroless plating without noticeable defects. The process of electroless nickel plating could be explained by combination of atomic hydrogen and electrochemistry theories. The interfacial nucleation of nickel is easier to form than spontaneous nucleation in the solution. Deposited Nickel has priority on the surface of ZTA particles comparing to that in solution. The optimal conditions to coat nickel on the surface of ZTA particles are: solution pH 4.7–4.8, loading capacity 15–20 g/L, and electroless plating temperature 85 °C. The ZTA particle reinforced iron matrix composites prepared by powder metallurgy could have better interfacial bonding between ZTA particle and iron matrix because of the nickel coating on the surface of ZTA particle. Nickel diffuses into the iron matrix during the sintering preparation of composite materials. The interface between ZTA particle and iron matrix presents the evidence of non-chemical bonding.

Pengaruh Konsentrasi dan Waktu Aktivasi Katalis Palladium pada Electroless Plating Nickel Permukaan Plastik ABS

ABS plastic is widely used for automotive components and interior design because of its lightweight, easily shaped, strong, but low hardness, no friction-resistant, and heat resistant. Electro less plating is a method of metallization before electro plating to improve the quality and appearance. To get a good bond between plastic and metal is necessary to the activation of the palladium which is influence by concentration, temperature and activation time. The research aims to determine the influence of the palladium solution concentration and activation time of the electroless nickel plating process on surface roughness, layer thickness, hardness and wear resistance of ABS plastic. The concentration of palladium was prepared at 3%, 5% and 7% in HCl solution (37%). The activation time was carried out during 4 to 12 minutes. The research shows that those parameters increase wear resistance of the surface. In addition the activation time parameter is also found to increase layer thickness and roughness value of the specimens. Yet, those parameters are not found to affect significantly on its hardness value.

The corrosion behavior and mechanical properties of CrN/Ni[sbnd]P multilayer coated mild steel as bipolar plates for proton exchange membrane fuel cells

This research mainly studies on the interfacial conductivity and corrosion resistance of mild steel (MS)/electroless plating nickel (EN)/CrN composite coating. The MS/EN/CrN composite coating is deposited on a mild steel substrate using a combination of electroless nickel plating process and closed field unbalanced magnetron sputter ion plating system. The simulative working environment of proton exchange membrane fuel cell (PEMFC) is implemented to test the electrical and corrosion properties of uncoated mild steel and coated samples. Results show that the performance of the MS/EN/CrN coated samples was greatly improved. The SEM results indicate that the surface of MS/EN/CrN is dense and smooth. CrN (111) and Ni (111) are observed in the MS/EN/CrN coating by XRD. The potentiodynamic polarization and EIS tests show that the incorporation of electroless nickel deposits into the CrN coating can provide better corrosion resistance. Potentiostatic polarization tests reveal that MS/EN/CrN coating has the lowest current density both in anodic and cathodic environment. The Interfacial contact resistance (ICR) results show that the ICR of MS/EN/CrN coated sample reduces to 3.3 mΩ cm2 at a compaction force of 140 N/cm2. Moreover, after potentiostatic polarization, the ICR values of the MS/EN/CrN coating are still less than DOE's 2020 target. In addition, compared with other samples, the hardness and adhesion property of the MS/EN/CrN multilayer coating were greatly improved, which is beneficial for resisting the shock and wear during the assembly process of fuel cell stacks.

1-16 褐炭を用いた無電解ニッケルめっき廃液からのNi回収((6)石炭灰,金属,Session 1 石炭・重質油等,研究発表(口頭発表))

1-16 褐炭を用いた無電解ニッケルめっき廃液からのNi回収((6)石炭灰,金属,Session 1 石炭・重質油等,研究発表(口頭発表))

Process and performance of electroless nickel plating on AZ91D magnesium alloy

PurposeThe purpose of the investigation was to research the best process of electroless nickel (EN) plating on AZ91D magnesium alloy and the performance of EN plating coating.Design/methodology/approachThrough single factor test and orthogonal test, EN plating on AZ91D magnesium alloy was researched. The plating rate and porosity were analyzed. The coating appearance of EN plating coating and magnesium alloy substrate was evaluated. The electrochemical properties of EN plating coating and substrate were researched using electrochemical workstation, and their compositions and structure were examined using X-ray diffraction and scanning electron microscopy.FindingsThe results made by combination of experimental and orthogonal test showed that the best formula of EN plating was 8.8 g·L−1 nickel ion, 25 g·L−1 lactic acid, 28 g·L−1 reducing agent, 1.8 ml·L−1 corrosion inhibitor, 1 mg·L−1 stabilizer, temperature at 85°C and pH value at 5.5. The plating was uniform, dense and with no cracks. The electrochemical tests showed that the corrosion resistance of EN plating was better than that of magnesium alloy substrate.Originality/valueThe results indicated that the corrosion resistance of magnesium alloy improved markedly after EN plating at the best formula and the plating covered magnesium alloy completely.

Effect of laser surface texturing depth on the adhesion of electroless plated nickel coating on alumina

Chemical pretreatment is often used in electroless plating process to enhance the bonding of metallic coating to ceramic substrates. In order to alter the chemical pretreatment which is not suitable for local processing and not environmentally friendly for operating personnel, laser surface texturing (LST) was applied in electroless nickel plating on alumina in this paper.The electroless nickel plating was carried out on alumina surfaces that were either chemically coarsened or laser textured with different pit depths. The morphology of textured alumina surfaces was characterized by optical microscope and 3D laser confocal microscope, while its surface roughness was measured by a TA620 roughness tester. The adhesive performance of nickel coatings was evaluated by indentation and scratch tests.The results showed that laser surface texturing can improve the adhesive performance of electroless plated nickel coating on the alumina samples. The critical load of the properly laser surface textured samples is more than 2 times of that of the chemically coarsened samples. For the process of electroless nickel plating, laser surface texturing can replace traditionally chemically coarsening pretreatment, which can reduce the contact opportunity with strong acid for operating personnel.