Showing papers on "Electroless nickel plating published in 2022"

The Microstructure and Tribological Behavior of Ultrasonic Electroless Ni-P Plating on TC4 Titanium Alloy with Heat-Treatment

Abstract: Abstract The ultrasonic electroless Ni-P plating is fabricated on the TC4 titanium alloy pretreated by zinc double immersion and alkaline pre-plating, and then is carried out heat-treatment at different temperature. The effects of heat-treatment on the microstructure and phase structure of the ultrasonic electroless Ni-P plating and their tribological behavior are investigated by SEM/EDS, XRD, a Vikers indenter, and a pin-on-disk wear testing machine. It is observed that the morphology of the ultrasonic electroless Ni-P plating has the typical cauliflower-like nodular structure and the average size of nodular is approximately 7 μm. EDS studies suggest that the phosphorous content of the plating is as high as 11 at%. The ultrasonic electroless Ni-P plating exhibits obvious amorphous structure characteristics by XRD analyzers. After heat-treatment at 400 °C, the structure of the ultrasonic electroless Ni-P plating changes from amorphous to crystalline state, and the interface of the nodular structure becomes clear and the nodular size is refined. It is because the dispersed Ni3P second-phase particles are uniformly and continuously distributed in the nickel solid solution. Compared with the TC4 substrate, the microhardness and the wear resistance of the ultrasonic electroless Ni-P plating are greatly improved, especially for the heat-treatment at 500 °C. The wear mechanism of the TC4 substrate is severe adhesion and abrasion wear, with slight oxidation wear, while the ultrasonic electroless Ni-P plating shows plastic deformation and microabrasion wear. After heat-treatment, the wear mechanism of the ultrasonic electroless Ni-P plating is slight abrasion wear.

Recovery of nickel from electroless nickel plating wastewater based on the synergy of electrocatalytic oxidation and electrodeposition technology

Abstract: Nickel exists primarily as a stable complex in electroless nickel plating wastewater, and the Ni recovery from it cannot be achieved solely through electrodeposition. As the electrocatalytic oxidation has excellent oxidation potential to break down the complex, an efficient and stable electrochemical system using the synergy of electrocatalytic oxidation and electrochemical deposition technology was developed for the recovery of nickel from electroless nickel plating wastewater. In the present study, the effects of initial pH, current density, and initial nickel ion concentration on the treatment performance of the electrochemical system was investigated. The highest Ni recovery (94.84%) and total organic carbon removal (63.94%) were achieved at a current density of 83.3 mA/cm2, initial pH of 3.0, and initial Ni concentration of 0.01 M. At the same time, the recovered nickel product was confirmed by scanning electron microscopy, energy dispersive X‐ray, X‐ray powder diffraction, and X‐ray photoelectron spectroscopy. Furthermore, the electrochemical system displayed good stability and economic benefits, thereby suggesting its excellent application potential for the treatment of electroless nickel plating wastewater.

Electroless Deposition of 4 μm High Ni/Au Bumps for 8 μm Pitch Interconnection

Abstract: We propose that electroless plating is a superb approach to preparing metallic bumps with an ultrafine pitch for the integration of a micro light-emitting diode (micro-LED). Electroless plating does not suffer from lift-off-related issues, which are ubiquitous in thermal evaporation. Besides, it can result in much more uniform bumps than electroplating because the bump height is not affected by the current distribution. This study reports ultrafine pitch Ni/Au bumps fabricated by electroless nickel immersion gold (ENIG) plating. Furthermore, cheap metals iron and nickel are selected to catalyze the electroless nickel process. The results indicate that uniform and consistent Ni/Au bumps can be obtained through the iron sheet and nickel layer method. Besides, no voids and impurities are found inside the bumps, which is beneficial for the following interconnection process. Moreover, the change in Ni bump height values with the electroless plating time is also provided.

Supercritical-CO2 electroless nickel plating enhanced anti-corrosion properties of micro-arc oxidized AZ31 magnesium alloy

Abstract: Magnesium alloys which perform low density, high strength-to-weight ratio and excellent mechanical properties have received extensive attention especially in the weight-constrained components in aerospace and automotive industries. Nevertheless, magnesium alloys generally exhibit poor corrosion and wear resistance, which seriously limit their lifespan and developments. Regarding the aforementioned issues, we selected an AZ31 magnesium alloy as the controlled specimen, on which a designed multilayer structure was fabricated to be the surface protective coating. The multilayer coating consisted of an oxide layer prepared by micro-arc oxidation (MAO), a sputtered Ag intermedium layer and a Ni-based anti-corrosion coating deposited by supercritical CO 2 assisted electroless deposition (SC-EL-Ni). The Ag/MAO interlayer performed an excellent compatibility between the Ni coating and Mg substrate, leading to a good coating adhesion. Moreover, the as-prepared amorphous SC-EL-Ni layer exhibited a dense and uniform surface, which can effectively prevent the intergranular corrosion and galvanic corrosion. Therefore, the obtained SC-EL-Ni/Ag/MAO sample presented a much better corrosion resistance compared with the Mg alloy and the porous MAO-treated sample. • Surface properties of SC-EL-Ni/Ag/MAO coating have been systematically analyzed. • Sputtered Ag layer performed excellent compatibility between Ni and MAO coating. • Amorphous Ni film with dense and uniform surface was obtained. • SC-EL-Ni exhibited outstanding anti-corrosion property.

Electroless plating of ni-mo-p alloy

Abstract: Electroless plating of Ni-Mo-P alloy coatings is described from a solution containing sodium pyrophosphate and ammonium chloride as ligands. Application of these ligands allowed using relatively large sodium molybdate concentrations in the solution (8…16 mM), while the high electroless plating rate (up to 20 μm/h) was preserved and semibright coatings were obtained. Depending on the sodium molybdate concentration in the solution, Ni-Mo-P alloys contained 3.5…7.4 at.% of molybdenum in the metallic state. Phosphorus was included into the alloy in the form of nickel phosphide NiP. According to the XRD data. the Ni-Mo-P coatings had a nanocrystalline structure with the coherent scattering region size of 25…34 nm.

Magnetorheological Finishing of Chemically Treated Electroless Nickel Plating

Abstract: Electroless nickel plating with a nanofinished surface is used in space mirrors, automobile parts, aircraft components, optical instruments, and electronic equipment. Finishing of these components using conventional finishing techniques is limited due to size, shape, material, and process constraints. This work reports the nanofinishing of electroless nickel-plated surfaces using a magnetorheological finishing process where the surfaces are pre-treated with chemicals. The chemicals used in this work are hydrogen peroxide (H2O2) and hydrofluoric acid (HF). The effect of exposure time and concentration on the microhardness and roughness is studied to understand the surface chemistry after chemical treatment. The hydrogen peroxide forms a passivated layer, and it helps in easy material removal. Hydrofluoric acid improves surface quality and also helps in the removal of contaminants. The finished surface is characterized to understand the effect of chemical treatment on the finishing rate and surface topography. Normal and tangential forces are mainly affected by the hardness and surface condition after the chemical treatment. The best combination of parameters (chemical treatment with 1% HF for 30 min) was obtained and finishing was carried out to obtain a nanofinished surface with its areal surface roughness (Sa) reduced to 10 nm.

Research on Optimization of Process Parameters of Electroless Nickel Plating Based on Orthogonal Test

Abstract: As a widely used surface strengthening technology, electroless plating can be applied to various materials such as metals and non-metals, but its process parameters are numerous and difficult to optimize. For this reason, this study designed a three-factor and four-level orthogonal experimental scheme with the main salt/reducing agent molar ratio, lactic acid and PH value as the factors, and the plating speed and microhardness as the evaluation indicators. The range analysis was carried out on the experimental results, the best process parameters were selected, and the influence rules and reasons of the three factors on the evaluation indexes were discussed.

Effect of Etching and Electroless Plating Time on Contact Angle of Acrylonitrile Butadiene Styrene for 3D-Printed Substrates

Abstract: Acrylonitrile Butane Styrene (ABS) is a type of polymer that can be metallized with metal through the electroless plating process so as to produce a strong and economical layer bond compared to metal. In this study, ABS plastic will be coated with nickel and the contact angle of ABS after the coating process will be examined. The first step is the etching process for 55 and 75 minutes using chromic acid to improve the adhesiveness and uniformity of the coating metal later. After the etching process is complete, then the surface roughness test is carried out using Mitutoyo SJ 201 Surface Roughness. Furthermore, the activation process with stannous chloride as a catalyst is carried out to accelerate the deposition of metal particles on the substrate surface so that during the electroless plating process the polymer turns into a conductor. Then the electroless plating process with time variations of 15, 25, 35, 45, 55 minutes using nickel sulfate, ammonium chloride, sodium hypophosphite, and sodium hydroxide to deposit nickel metal on the ABS surface. The results of the coating are then analyzed for surface topography using AFM and SEM, as well as investigating the contact angle of the droplets that are dropped on the coated ABS surface. It can be said that the etching variation of 55 minutes electroless nickel plating 75 minutes is the most hydrophobic because it has the largest contact angle and the smoothest surface topography compared to other variations.

Study of electroless nickel plating on rapid prototyping model using acrylonitrile butadiene styrene

Abstract: Electroless plating on Acrylonitrile Butadiene Styrene (ABS) is a metallization process that involves a reduction and oxidation reaction between the nickel source and the substrate material. The purpose of this research is to determine the ability of nickel deposition in the nickel electroless plating process with a specific etching time variation. This nickel electroless procedure begins with a chromic acid etching process that can last anywhere from 15 to 55 minutes and is useful for increasing roughness and creating submicroscopic cavities. After the etching process is finished, the surface roughness test is performed with a Mitutoyo SJ-210. Additionally, the activation step is carried out for 5 minutes in order for the polymer to become a conductor, allowing the plating process to proceed. The electroless plating process was then carried out for 55 and 75 minutes, with the goal of depositing nickel metal on the ABS surface. The coating results were analyzed using Fourier Transform Infrared (FTIR) spectroscopy IRSpirit/ATR-S serial No. A224158/Shimadzu to determine the functional groups formed both before and after the coating process, X-Ray Diffraction (XRD) to determine the character of the crystal structure, and phase analysis of a solid material using PANalytical type E'xpert Pro, To determine the surface morphology, the Zeiss EVO MA 10 was used to perform scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) at 1000x magnification. The test findings demonstrate that, based on a range of investigations, etching variations of 15,25,35,45, and 55 minutes etching time 55 minutes are the best nickel deposited substrates, as evidenced by EDS data, where this treatment has the largest weight fraction of nickel. As a result, the longer the etching period, the rougher the surface becomes, affecting the capacity of nickel deposition to increase. Furthermore, it can be demonstrated in this investigation that the nickel deposited is in an amorphous form.