Electroless Ni Plating Research Articles

Nanoindentation and microstructure of interfacial layer in Ni-NiTi coated zirconia toughened alumina particles reinforced high chromium cast iron matrix composites

The Ni-NiTi coated zirconia toughened alumina particles (ZTAp@Ni-NiTi) are prepared by electroless Ni plating and NiTi electroplating in succession. And the ZTAp@Ni-NiTi reinforced high chromium cast iron matrix composites (ZTAp@Ni-NiTi/HCCI) with tight interfacial bonding are produced by nonpressure casting infiltration. X-Ray Diffraction results show that an interface layer, containing new phases of Ti2O3, TiO, Ni3Ti, NiTi2, NiTi and FeCrNi, is formed between the HCCI matrix and ZTA particles. The hardness and Young’s modulus of the interfacial layer in ZTAp@Ni-NiTi/HCCI are 5.691 GPa and 224.707 GPa, respectively. Compared to ZTA particles reinforced high chromium cast iron matrix composites, a high modulus of the interface layer can effectively ease the unevenness of plastic deformation in ZTA reinforcement and HCCI matrix, exhibiting an excellent comprehensive nanomechanical property.

Manufacturing and Performance of Carbon Short Fiber Reinforced Composite Using Various Aluminum Matrix

A new fabrication process without preform manufacturing has been developed for carbon short fiber (CSF) reinforced various aluminum matrix composites. And their mechanical and thermal properties were evaluated. Electroless Ni plating was conducted on the CSF for improving wettability between the carbon fiber (CF) and aluminum. It was confirmed that pores in Ni plated CSF/Al and Al alloy matrix composites prepared by applied pressure, 0.8 MPa, had some imperfect infiltration regions between the CF/CF and CF/matrix in all composites. However, pores size in the region between the CF/CF and CF/matrix to use the A336 matrix was about 1 µm. This size is smaller than that of other aluminum-based composites. Vickers hardness of Ni plated CSF/A1070, A356 alloy, and A336 alloy composites were higher as compared to matrix. However, the A1070 pure aluminum matrix composite had the highest hardness improvement. The Ultimate tensile strength of the A1070 and A356 aluminum matrix composite was increased due to carbon fiber compared to only aluminum, but the Ultimate tensile strength of the A336 aluminum matrix composite was rather lowered due to the highest content of Si precipitate and large size of Al3Ni compounds. The Thermal Conductivity of Ni plated CSF/A1070 composite has the highest value (167.1 W·m−1·K−1) as compared to composites.

Novel in-situ electroflotation driven by hydrogen evolution reaction (HER) with polypyrrole (PPy)-Ni-modified fabric membrane for efficient oil/water separation

Efficient separation of oil/water emulsion is still a worldwide challenge. Herein, a new conception/strategy of in-situ electroflotation driven by hydrogen evolution reaction (HER) combining with a polypyrrole (PPy)-Ni-modified fabric membrane was proposed for efficient oil/water separation. To realize this new conception, nickel-decorated polyester fabric membrane was successfully fabricated via facile electroless Ni plating process on the polypyrrole (PPy)-modified surface. The Ni-decorated fabric membrane processed superhydrophilicity, underwater superoleophobicity and excellent electrical conductivity (electrical resistance of ~14.1 Ω), which could serve as cathode for HER. The fabric membrane itself couldn't separate oil/water emulsion, but achieved extremely high permeation (above 12526.5 L m−2 h−1) and oil rejection (above 98.6%) for separating stratified oil/water mixtures under gravity force. By applying an extra electric field on the conductive fabric membrane, an in-situ electroflotation process driven by HER can be produced. Under the optimized electroflotation conditions (20.0 V cm−1 electric field intensity, 20 g L−1 electrolyte concentration and 30 min electroflotation time) in this study, this new process could efficiently separate oil/water emulsion with high permeation flux (840.6 L m−2 h−1) and oil rejection (98.5%). The present work provided a new conception of in-situ electroflotation-membrane separation process for treatment of oily wastewater, showing strong application significance.

An Experimental Study on Electroless Nickel Plating on Alumina Ceramic

In this paper a low temperature metallization i.e. standardization of electroless Ni plating on alumina ceramic is summarized. It includes three main steps (i) pre-treatment, (ii) activation and (iii) Ni plating. Pre-treatment includes degreasing with non-silicate soap solution followed by ultrasonic cleaning in acetone and etching the alumina surface to generate roughness for making it suitable for adhesion. Etching has been obtained by immersion in 10% NaOH at 50℃ for 10 minutes and 50% HF for 15 minutes at room temperature. Activation of the surface is the most important step before electroless plating on alumina ceramic. Activation has been achieved with Ginplate 442 (commercial chemical) by immersing the alumina specimen for 5 minutes at room temperature. Activated alumina samples have been used for electroless Ni plating in Ginplate 418 bath at 88°C.Uniform, densely compact coating has been achieved as revealed by SEM image. XRD plot confirms the presence of metallic nickel together with phases of Ni2P, NiP, Ni3P confirming the nickel phosphite based plating. Subsequently, tube to tube joining of these metallized alumina ceramic tubes has been conducted through vacuum brazing process with copper silver eutectic alloy (28Cu-72Ag) whose cross section showed good joint with excellent wettability of Cu-Ag with Ni plating.

Synthesis of core-shell Ti@Ni-P spherical powder by Ni electroless plating

Ni-P plated Ti powders with core-shell structure were prepared by Ni electroless plating. The micromorphology and growth mechanism of core-shell Ti@Ni-P powders were analyzed by field emission scanning electron microscopy (FESEM) with an energy dispersive spectrometer (EDS). The results show the overall uniformity of Ni-P coated Ti powders is improved by two pretreatments, namely NaOH preprocessing and alkaline electroless preplating, compared with a single alkaline electroless pretreatment. The surface morphology of the Ni-P plated powders is a typical spaced spherical nodular structure. Meanwhile, the growth mechanism of the Ni-P coated Ti powder is illuminated in detail.

Enhancement of fiber–matrix adhesion in carbon fiber reinforced Al-matrix composites with an optimized electroless plating process

Coating is the most common method to offer better wettability between carbon fibers (CFs) and metal matrix of the composites. An optimal electroless Ni plating process was studied in this paper to improve the interfacial adhesion of CF reinforced Al-matrix composites. By using Pd-colloid activation, the typical island-like agglomeration on the coating surface was significantly eliminated, providing a Rq reduction of 56.5%. Applying strong-oxidizing mixed acid (SMA) etching provided larger adhesion force (140.53 nN) and interfacial shear strength (IFSS) (35.1 MPa) than that of the original process (53.72 nN and 31.1 MPa), which can be attributed to rougher surface and larger numbers of carboxyl functional groups on CF surface. By combining these processes, the adhesion force further increased to 207.99 nN with improved IFSS to 40.9 MPa, and Rq was reduced by 72.1%. The ultimate tensile strength (UTS) of the composites increased to 140 MPa, which is 35.9% higher than that with CFs by original method.

Development of W-band waveguide based on plastic additive manufacturing with Ni electroless plating

Development of W-band waveguide based on plastic additive manufacturing with Ni electroless plating

Friction and Wear of Ni-P Electroless Plating By Adding for WO3 Particles

Electroless Ni (nickel) plating is known as an industrially unique wet plating. In particular, nickel plating is widely used for precision mechanical parts, pipes, bearings, cylinders, etc. due to its corrosion resistance, excellent hardness, and uniform plating properties. However, depending on the use environment, due to the low thermal stability, the grain growth and recrystallization of the plating layer reduce the corrosion prevention properties. For the purpose of improving thermal stability, elements such as W (Tungsten) and Mo (Molybdenum) can be added to improve mechanical properties. The composite plating containing W shows excellent heat resistance, and hardness and abrasion resistance can be improved. In addition, there is a trend to study composite plating of PTFE (Polytetrafluoroethylene) and MoS2 (Molybdenum disulfide) to improve lubricity and non-adhesion. In this study, Ni-P-PTFE-WO3 was plated using WO3 (Tungsten trioxide) powder to improve thermal stability, abrasion resistance, and lubricity. The experiment was plated at 90 ° C for 1 hour in the plating solution, and the heat treatment process was performed at 300 ° C for 1 hour. We analyzed the change in crystallinity before and after heat treatment using XRD (X-ray Diffraction), and observed the plating thickness and surface using SEM (Scanning Electron Microscope). By using wear test, the change of abrasion resistance and lubricity with and without WO3 plating will be compared.

Interfacial microstructure evolution of solder joints by doping Cu nanoparticles into Ni(P) electroless plating

To enhance the effects of electroless Ni–P plating on inhibiting atom diffusion in Sn-58Bi joint systems, adding nano-sized metals into coating was regarded as an efficient method. Therefore, Cu nanoparticles were chosen as the additive in current study, and the interfacial microstructure evolution of solder joints by doping Cu nanoparticles into Ni(P) electroless plating were investigated. Experimental results revealed that growth rates of IMCs at the joint interface remarkably decreased with increasing content of Cu nanoparticles. In the Ni(P)–0.8 g/L Cu based joint, transformation from (Ni,Cu)3Sn4 to (Cu,Ni)6Sn5 occurred since more Cu atoms supplied by the coating participated in the interfacial reaction between solder and coating. Meantime, sizes of IMC grains at each isothermal aging stage decreased with increasing content of Cu nanoparticles, which could be attributed to introduction of potent nuclei. The IMC growth was mainly volume diffusion-controlled and followed parabolic laws. Diffusion coefficients were analyzed to be 1.18 × 10–2 μm2/h, 2.89 × 10–4 μm2/h and 2.56 × 10–4 μm2/h in Ni(P), Ni(P)–0.4 g/L Cu and Ni(P)–0.8 g/L Cu-based joint systems, respectively, suggesting that diffusion coefficient gradually decreased with increasing content of Cu nanoparticles.

A facile process combined with defect-induced electroless plating and selective laser sintering forming to fabricate catalytically active free-standing material

The most common method for preparation of catalytically active free-standing hybrid material (CAFH) is that supporting material is formed and subsequent catalytic agent deposited on its surface. But it remains challenging to agilely prepare CAFH with different shape and size. We employ a facile process combined with defect-induced electroless nickel plating and selective laser sintering (SLS) forming to fabricate CAFH. Results manifested CH3COOH-etched treatment resulted in the formation of defect (amorphous structure, amide group and hole) on the Nylon 12 (PA12) surface, which would induce electroless Ni plating. The mechanism of the electroless plating is the destruction of the structure of [C6H5O73−-Ni] ligand around defect; subsequently, the reduction of the REDOX barrier. The following laser sintering of the plated PA12 powder could fabricate CAFH with an irregular network. There are two stages during the SLS process: balling of particle and formation of sintered neck. The combination of the structural stability, high surface area and recyclability gives a CAFH with demonstrated catalytic property. CAFH is agile to prepare, easy for quick-to-assemble material and realizable in CAFH shape design. The new technology possesses vast exploration and application value.

Performance and preparation of the electroless Ni wood-based composites

A wood-based composite exhibiting excellent electromagnetic shielding performance was prepared by electroless Ni plating. The properties of the material were characterized by a series of tests. The results showed that the growth route of Ni particles was first arranged along the inherent grain of the wood to form a banded metal layer. With extension of the duration of electroless plating, the growth of Ni particles gradually extended around and filled the pores between wood fibers, and finally formed flake-shape structure. The metal coatings formed a strip along the inherent grain of the wood surface and then changed into a sheet until it covered the entire wood surface. The coatings resistance was from 12 Ω to 0.5 Ω with the increase in duration of electroless plating. When the duration was 20 min, the composite coating resistance was 0.5 Ω. Here, the contact angle of composite coatings was 98.3° when the plating time was 15 min. When the wood surface was modified via two depositions of Ni, the average electromagnetic shielding value of the composites was over 80 dB in the frequency ranging from 0.3 kHz to 3.0 GHz.

Ni-coated graphene nanoplatelets and their application as reinforcements for WC-Co cemented carbides

In the current research, Ni-coated graphene nanoplatelets (Ni-GNPs) were fabricated by electroless Ni plating process. The Co-cemented tungsten carbides (WC-Co) samples doped with Ni-GNPs were obtained by vacuum hot pressing sintering. The effect of various content of Ni-GNPs on the mechanical and frictional properties of as-sintered WC-Co samples was investigated. Vickers hardness of WC-Co samples decreased from 1896 MPa to 1743 MPa with the content of Ni-GNPs varied from 0.0 wt% to 0.4 wt%. The fracture toughness reached to the highest value of 10.85 MPa · m1/2 with 0.05 wt% Ni-GNPs. The friction coefficient dropped from 0.43 of the sample with 0.0 wt% Ni-GNPs to 0.21 of the sample with 0.4 wt% Ni-GNPs. The results revealed that the Ni-GNPs have considerable effect on improving the combination properties of WC-Co cemented carbides. Within the mentioned content range, the optimal content of the Ni-GNPs in WC-Co sample was 0.05 wt%.

XPS, ToF SIMS and wettability analyses on Ni surfaces after Ar-H2 RF plasma treatment: An efficient and optimized plasma treatment approach

Electroless Ni plating is widely used for its properties such as wear resistance, uniform coating and excellent brazing and solderability. In electronic and mechatronic applications, the chemical composition of the Ni layer and its surface quality still remains elusive and improvisation of Ni layer surface quality is vital. This research work investigates the surface properties of Ni films subjected to Ar-H2 RF plasma treatment. Plasma treatment parameters are defined by utilizing D-Optimal design of experiments. A precise mapping of the evolution of Ni surface global chemical composition is obtained using an XPS. Principal component analysis on XPS mapping coupled with 3D ToF-SIMS chemical cartography enables precise identification of the different oxidation states of nickel and their distribution in the plasma-treated nickel samples. The nickel surface wettability is then determined using the classical sessile drop technique. The findings of the study enable to define the plasma optimal power and accomplish the best compromise between the positive effects of the surface decontamination and the negative effects of the surface recontamination. The optimized plasma treatment succeeds to modify the surface nature of the nickel from hydrophobic to strongly hydrophilic. It demonstrates that the Ar-H2 plasma treatment is a very efficient process to increase the Ni surface wettability and thereby to improve the electronic and mechatronic assembly processes.

Catalytic characteristics of Ni(B)-coated YSZ powder by neutral electroless plating

In this study, an eco-friendly, electroless, and neutral (pH 7.0) process of nickel plating at low temperature (40 °C) was used to develop an anode catalyst for a solid oxide fuel cell (SOFC). Electroless Ni(B) plating on yttria-stabilized zirconia (YSZ) particles resulted in the formation of a Ni(B)/YSZ core–shell. We examined the crystallinity and uniformity of the Ni(B) layer on the plated core–shell powder and found that it had an amorphous-like structure. In addition, we evaluated the rate of carbon deposition and characteristics of the SOFC anode catalyst: the carbon deposition rate was 19.42%, H2 selectivity was nearly 88% at 800 °C, and methane conversion was maintained at 100% at temperatures above 850 °C. It was ascertained that in the high-temperature region, which is the main operating temperature of SOFCs, the amorphous-like microstructure of the Ni(B) layer on the Ni(B)–YSZ core–shell powder played an important role in enhancing these properties.

Fabrication of highly conducting nickel-coated graphite composite particles with low Ni content for excellent electromagnetic properties

Nickel-coated flaky graphite particles (FGP@NiCPs) have been widely employed as key fillers of electromagnetic functional composites. However, the existing such fillers suffer from disadvantages of uncompacted shells, unsatisfactory conductivity or high nickel content, making it hard to meet high requirements for electronic connection and electromagnetic compatibility. Herein, we have demonstrated an efficient approach to achieving sufficiently heterogeneous nucleation coupled with electroless Ni plating to fabricate highly conducting FGP@NiCPs with low Ni content for excellent electromagnetic properties of polymer-matrix composites. Preparation of the typical FGP@NiCPs consists of rinsing flaky graphite particles (FGPs), adsorbing nickel ions, in-situ reduction into nickel nuclei and electroless Ni plating. On the one side, the hydrophilicity of FGPs can be improved by soxhlet extraction. This is one of important factors to adsorb more nickel ions on FGPs because they can be uniformly dispersed or fully exposed to NiSO 4 solution. On the other side, the rinsed FGPs are immersed into a high concentration ([NiSO 4 ]) solution, which facilitates to further adsorb enough nickel ions through electrostatic attraction. Subsequently, these nickel ions adsorbed on FGPs are in-situ reduced into a lot of nickel nuclei, indicating that increasing hydrophilicity and immersing into a high [NiSO 4 ] for FGPs synergistically favor heterogeneous nucleation burst. Finally, low content nickel densely-coated FGPs composite particles are successfully synthesized by controllable electroless Ni plating. As-obtained FGP@NiCPs exhibit dense shells, low Ni content and excellent electrical conductivity compared to the commercial FGP@NiCPs (CFGP@NiCPs). Furthermore, shielding effectiveness of composites containing the typical FGP@NiCPs is between 28.0 and 35.2 dB with frequency of electromagnetic wave ranging from 30 to 1500 MHz, and stronger than that of composites containing CFGP@NiCPs, owing to the relatively high electrical conductivity. Consequently, this work holds a promising potential for electromagnetic functional polymer-matrix composites. Increasing hydrophilicity and immersion into a high concentration of NiSO 4 solution for FGPs synergistically favor nucleation burst, which is advantageous to fabricate low content Ni densely-coated FGPs composite particles for excellent electromagnetic properties of their polymer-matrix composites. • Hydrophilicity of flaky graphite particles (FGPs) can be improved by soxhlet extraction. • Increasing hydrophilicity and immersion into a high concentration of NiSO 4 solution for flaky graphite particles (FGPs) favor nucleation burst. • Sufficient heterogeneous nucleation facilitates to fabricate low content Ni densely-coated FGPs with high conductivity. • As-obtained composite particles promise important applications in electronic connection and electromagnetic compatibility.

Hollow ni-p amorphous alloy nanospheres: An efficient catalyst for sugars hydrogenation to polyols

In this paper, hollow Ni − P nanospheres (NSs) are prepared through Ni electroless plating on the Au-activated silica NSs externally covered by aminopropyl moieties, followed by removing the silica template with sodium hydroxide. With various characterizations, the resulting hollow Ni − P NSs are identified to be amorphous alloy. During liquid-phase hydrogenation of sugars to sugar alcohols, the hollow Ni − P amorphous alloy NSs delivered much superior catalytic performances to the commercial Raney Ni catalyst, showing a good potential in practical applications. Of particular interest is the unique hollow chamber structure of the hollow Ni − P amorphous alloy NSs, which allows for improving catalytic activity and durability relative to those associated with the dense Ni − P amorphous alloy NSs. This work demonstrated that such hollow Ni materials with nanoporous chamber structure displayed advantages such as easy experimental handling and high accessibility for the reactants in liquid-phase reaction, more Ni active sites, as well as the existence of more electron-enriched inner surface, which is essential to provide highly efficient catalysts for some reactions.

Activation of wood surface by Pd pulsed laser deposition for Ni electroless plating

PurposeDifferent types of wood (ash, oak and beech) have been activated by new activation method. The aim of this work is to study the effect of different types of wood on the physical and chemical properties of Ni/Pd coatings.Design/methodology/approachThe wood was activated by ablation of the Pd target using pulsed laser deposition (PLD) technique. Different diagnostic techniques such as X-ray photoelectron spectroscopy (XPS), attenuated total reflection (ATR) spectroscopy and energy dispersed X-ray spectroscopy (EDS), in parallel with scanning electron microscopy (SEM) were used to achieve this goal.FindingsThe XPS technique confirmed that the highest concentration of Pd was found in the Pd/beech sample, which is associated to the texture of the beech wood substrate surface. EDS results confirmed the absence of any contamination related to electroless plating method. It is concluded that the wood morphology and its surface roughness play a conclusive role to obtain different quantity of metal by PLD and electroless plating methods.Originality/valueAlthough several works have been performed to study the influence of substrates on the coated metals and away of the traditional methods in activating non-catalytic surface, in this paper, PLD method is used to obtain a good quantity of Pd distributed on the entire surface and inside the porous of the wood. This study could be considered as a step investigation for understanding the role of the wood substrate morphology on the physical and chemical properties of films. To our knowledge, there are no works of combining a coated Ni/Pd by electroless plating and PLD methods on wood.

Robust bonding and thermal-stable Ag–Au joint on ENEPIG substrate by micron-scale sinter Ag joining in low temperature pressure-less

Robust bonding and thermal-stable sinter Ag joining on an Au finished substrate was first time achieved for use in SiC power modules. Five kinds of Ag paste, including different solvents and Ag fillers, and four kinds of Au plating processes (ENIG, ENIGEG, ENEPIG and ENEPIGEG) were used to optimize the initial shear strength of Ag–Au joints. Here, EN means electroless Ni plating, EP means electroless pure palladium plating, IG means immersion gold plating process and EG is the process of electroless gold plating. Micro-scaled Ag flake paste showed the best die shear strength at 33.9 MPa by in-suit formation of Ag nanoparticles, accomplished with a sintering temperature of 250 °C without pressure in air. With the use of Electron backscatter diffraction (EBSD) analysis, the ENEPIG plating process exhibited an Au surface with greater Au (111) grain orientation and larger grain size, which both of that benefits bonding with Ag paste. The thermal-stable sinter Ag joining on ENEPIG was evaluated by aging at 250 °C up to 1000 h. The shear strength had slightly increased to 36.5 MPa after 1000 h. The mechanism of robust bonding and thermal-stable during high temperature aging were systematically analyzed via Scanning Electron Microscope (SEM), Energy dispersive X-ray spectroscopy (EDS), Transmission Electron Microscope (TEM) and X-ray diffraction (XRD), which was attributed to the large Au grains size, the favorable surface condition of the ENEPIG, and the Pd barrier layer which prohibited Ni diffusion into the Au layer during sintering and aging.

Ni@nylon mesh/PP composites with a novel tree-ring structure for enhancing electromagnetic shielding

Two different composites one with a novel tree-ring structure and the other with a multi-layer structure were fabricated based on polypropylene (PP) film and Ni@nylon mesh by using the hot compressive molding. The Ni@nylon mesh prepared by electroless Ni plating generated continuously conductive networks for the composites to possess excellent electromagnetic shielding effectiveness (SE) along with the improvements of thermal conductivities. The maximum SE value of the composites with tree-ring structure achieved 50.6 dB, which was greater than that (25.8 dB) of the conventional multi-layer composites. There was not much difference in thermal conductivity (0.53–0.55 W/m·K) for both two composites with 3.07 vol% Ni, while they were still about 1.2 times higher than that of composites without Ni inclusion. Moreover, the compressive strength (48.8 MPa) of composite with tree-ring structure was higher than that (45.7 MPa) of multi-layer composite at the same Ni content (3.07 vol%).

Inkjet printing assisted electroless Ni plating to fabricate nickel coated polypropylene membrane with improved performance

While electroless nickel plating is considered as a promising candidate for fabrication of metallized polymer composite membranes with high performance, it suffers from problems of complex and high-cost pretreatment procedure, hindering its large-scale implementations. It is hypothesized that, inkjet printing integrated with electroless plating (ELP) can serve as a facile and economical membrane fabrication method to overcome above problems. The new method proposed in this study was processed by inkjet printing silver ions and pyrrole inks as catalytic layer followed by electroless Ni deposition on polypropylene (PP) membrane surface. Successful modification was verified by characterizing the surface morphology and elemental compositions of the membranes. In comparison to the pristine PP membrane, the PPy-Ag/Ni modified membrane demonstrated lower surface resistance (2.3 Ω), better hydrophilicity (44.9°) and higher pure water flux (1135.1 L m−2 h−1). When applying an external electric field (10.0 V cm−1), the average flux of the PPy-Ag/Ni membrane for yeast filtration increased from 107.8 to 137.7 L m−2 h−1, which was about 2.0 times higher than that of the pristine PP membrane. Meanwhile, the PPy-Ag/Ni membrane possessed a maximum flux recover rate when applied with an external electrical field. This work provided a facile and efficient approach for fabrication of composite conductive membranes.