Nickel Plating Layer Research Articles

Research on hydrogen distribution of electroless nickel plating on aluminum-based silicon carbide composites

Abstract Aluminum-based silicon carbide composite materials have the characteristics of high thermal conductivity, low thermal expansion, and good dimensional stability. Therefore, the composites are widely used in space microwave component shell products. In order to meet the functional requirements of conductivity, welding, and heat dissipation when applied to antenna microwave components, aluminum-based silicon carbide composite materials need to be chemically plated with nickel, which introduces hydrogen, thus requiring research on hydrogen release and control. Here, SEM, XRD, and other methods are used to characterize the microstructure of aluminum-based silicon carbide substrate and nickel plating layer. There are certain pore structures in both the substrate and plating layer, providing a place for hydrogen storage. The experimental method of hydrogen microprinting has been used to characterize the distribution of hydrogen. The results showed that the hydrogen distribution pattern in aluminum-based silicon carbide nickel plating is as follows: after nickel plating on aluminum-based silicon carbide, hydrogen is distributed in the nickel plating layer and the shallow substrate under the coating; with the extension of time, hydrogen spontaneously diffuses to the deep substrate; hydrogen is mainly distributed in the Al matrix and less on SiC particles.

The Effect of the Rare Earth Element Cerium on the Electrocrystallization and Microstructure of Nickel Electrodeposits in Industrial Electrolytes

To meet the industrial production needs for high-quality and precisely controllable structured high-end nickel foils, rare Earth compounds are added as additives in complex industrial electrolytes to improve the quality of the nickel deposition layer. This study investigates the effects of adding rare Earth compounds to the existing industrial production electrolytes (which already contain various organic and inorganic additives in a mixed acid solution) on the surface microstructure, cerium content, grain size, and crystal orientation of the nickel deposition layer. Using direct current electrodeposition, different concentrations of rare Earth compounds were added to the industrial electrolyte, and the cerium content, grain size, and crystal orientation were characterized. The results show that adding 0.8 g·l−1 CeCl3 accelerates the nucleation rate and shortens the nucleation relaxation time. The addition of rare Earth elements promotes multi-directional preferential growth, resulting in uniform and fine grain size, improved grain structure of the deposition layer, and reduced surface roughness of the nickel plating layer. Therefore, rare Earth elements can be used to regulate the structure, microstructure, and grain refinement of the nickel deposition layer without affecting its composition.

Effects of hydrogen permeation on the mechanical characteristics of electroless nickel-plated free-cutting steel for application to the hydrogen valves of hydrogen fuel cell electric vehicles

Electroless nickel plating is a suitable technology for the hydrogen industry because electroless nickel can be mass-produced at a low cost. Investigating in a complex environment where hydrogen permeation and friction/wear work simultaneously is necessary to apply it to hydrogen valves for hydrogen fuel cell vehicles. In this research, the effects of hydrogen permeation on the mechanical characteristics of electroless nickel-plated free-cutting steel (SUM 24L) were investigated. Due to the inherent characteristics of electroless nickel plating, the damage (cracks and delamination of grain) and micro-particles by hydrogen permeation were clearly observed at the grain boundaries and triple junctions. In particular, the cracks grew from grain boundary toward the intergranualr. This is because the grain boundaries and triple junctions are hydrogen permeation pathways and increasing area of the hydrogen partial pressure. As a result, its surface roughness increased by a maximum of two times, and its hardness and adhesion strength decreased by hydrogen permeation. In particular, hydrogen permeation increased the friction coefficient of the electroless nickel-plated layer, and the damage caused by adhesive wear was significantly greater, increasing the wear depth by up to 5.7 times. This is believed to be due to the decreasing in wear resistance of the electroless nickel plating layer damaged by hydrogen permeation. Nevertheless, the Vickers hardness and the friction coefficient of the electroless nickel plating layer were improved by about 3 and 5.6 times, respectively, compared with those of the free-cutting steel. In particular, the electroless nickel-plated specimens with hydrogen embrittlement exhibited significantly better mechanical characteristics and wear resistance than the free-cutting steel.

Electrochemical properties of electroless Ni plated super duplex stainless in 3.5% NaCl solution

Si wafers used in semiconductors require precise machining; therefore, they are processed using an STS304 saw wire, which is made of an austenitic stainless steel with excellent strength and corrosion resistance. However, the recently developed super duplex stainless steel (SDSS) exhibits superior performance compared to STS304 and is suitable for use as a saw wire. SDSS is a stainless steel composed of austenite and ferrite, with the ratio varying depending on the temperature during heat-treatment. Ferrite has better wear resistance than austenite; therefore, Ni plating was applied to ferritized SDSSs to improve the saw wire performance, and the electrochemical properties were analyzed. The nickel layer increased with time, forming a non-uniform coating until 180 s, followed by uniform plating. This was confirmed by the changes in the surface roughness and surface images. With the formation of a uniform nickel-plating layer, the distinction between austenite and ferrite became visible, resulting in decreased surface roughness. When the time exceeded 240 s, the difference in roughness increased owing to the difference between in the reactivities of austenite and ferrite. This difference in the surface roughness influenced the electrochemical behavior. The uneven nickel-plating layer exhibited a potential change of over 200 mV during the initial open-circuit potential (OCP) stage (prior to 800 s). In a potentiodynamic polarization test, plating for more than 300 s resulted in a reduced corrosion resistance owing to overplating. Increasing the thickness of the Ni layer altered the electrochemical behavior from SDSS to nickel. By analyzing the surface conditions and electrochemical properties, a uniform nickel-plating layer, exhibiting the characteristics of SDSS, was observed at 240 s. Therefore, the optimal duration for electrolytic nickel plating of ferritized SDSS was 240 s

Promoting the corrosion resistance of carbon steel via facile catalytic deposition of novel hierarchical carbon film layer in an ethanol combustion flame

In this work, a novel flame treatment method to improve the corrosion resistance of carbon steel was developed. With the method, a highly protective carbon film layer could be directly grown in situ on the surface of the nickel plating layer on the steel substrate and the whole deposition process costed only 10 min. Different from other carbon counterparts in literature, such as graphene deposited on Ni substrate with CVD, the as-fabricated carbon layer displayed a smooth surface but with a unique staggered interface with the Ni underlayer, which was reported for the first time. The influence of the flame treatment on the anti-corrosion performance of the coatings was comprehensively studied. Diverse corrosion protective efficiency could be achieved by simply adjusting the flame treating time. It was found that the optimized flame time was 10 min and the resulted sample showed a minimum corrosive current density of 13.27 μA/cm2, which was reduced by ~20 times as compared to that of bare Ni-plated carbon steel, leading into a remarkable protective efficiency of 97.26% in 0.1 M HCl. In contrast, such a great promotion could not be realized at all for the bare carbon steel subjected to the same flame treatment, which was due to the contrasting catalytic activity of Ni and carbon steel for the flame deposition of carbon, as analysis indicated that only Fe3O4 rather than carbon film was produced in the case of bare carbon steels. Moreover, the highest bonding level (5B) was achieved for the carbon film to the substrate, which could be related to the unique carbon/Ni staggered interface in situ formed during the flame deposition process. The facile deposition of the anti-corrosive carbon topcoat and its strong bonding to the metal substrate will find its promising practical application in various industries.

Preparation and Thermal Properties of BN and LPSO Hybrid Reinforced Magnesium Matrix Composite

Hexagonal boron nitride (h-BN) is a ceramic material with high thermal conductivity (TC) and low coefficient of thermal expansion (CTE), which can improve multiple thermal properties of metal-matrix composites as a reinforcing particle, but its wettability with metal melt is very poor. In order to enhance the wettability between the h-BN and magnesium alloy melt, the electroless plating was used to coat a thin layer of pure nickel on h-BN particles, which was proved to be effective and efficient in this study. The results showed that by adding Y element to magnesium alloy melt to consume Ni element melted from the nickel-plating layer, the long period stacking ordered (LPSO) structure composed of Mg-Ni-Y was successfully formed, and the magnesium matrix composite reinforced by hybrid h-BN and LPSO structure was obtained. After ultrasonic treatment (UT), the TC of the magnesium composite containing 3 vol% h-BN and 14.16 vol% LPSO is 99.92 W/(m·K), which is a 8.3% enhancement compare to the composite without UT. The average CTE (293-373 K) of the composite is 18.36×10-6 K-1, which is reduced by 29.4% compared with pure magnesium.

Adhesion strength enhancement of nickel-plated carbon fiber using edge selectively oxidized graphene

In this study, electroless nickel-plated carbon fiber (CF) was prepared with edge-selectively oxidized graphene (EOG) to reinforce the interface between nickel and CF for use in a composite for electromagnetic interference (EMI) shielding. The EOG layer was formed by generating ionic interaction through a modified layer-by-layer assembly between negatively charged EOG and positively charged polyethyleneimine (PEI). EOG-coated CFs with rough surfaces improved the specific surface area and adhesion strength with the nickel-plating layer. To evaluate the adhesion strength, the interfacial shear strength (IFSS) was investigated using microdroplet testing. After EOG coating, the interfacial bonding strength was enhanced by about 65%. The composite nickel-plated carbon fabric with EOG coating showed EMI shielding of around 58 dB, which is significant for future EMI shielding applications.

Effect of hydrophobicity on the corrosion resistance of microarc oxidation/self-assembly/nickel composite coatings on magnesium alloys

A microarc oxidation (MAO) film was prepared on the surface of magnesium alloy by using microarc oxidation technology. Three kinds of self-assembled films with different hydrophobicities were prepared on the surface of the MAO film by self-assembly (SAM) technology using different self-assembled molecules. The static contact angle tests determined that the contact angles of the self-assembled films were 33.71°, 93.99°, and 140.46°. After that, three layer composite coatings were successfully prepared by electroless nickel (EN) technology. SEM, EDS, XRD and XPS were used to characterize the surface morphology and composition of the samples. The Mott Schottky (M-S) curves characterize the semiconductor properties of the samples. The electrochemical test evaluates the corrosion resistance of the samples. The results show that the characteristic peaks of Ni were detected on the surfaces of the three three-layer composite coatings, and the electroless nickel plating layer was successfully prepared on the surface of MAO/SAM layers with different hydrophobicity. The better the hydrophilicity of the self-assembled layer is, the fewer morphological defects of the composite coatings there are, and the thicker the electroless nickel layer is. The composite coatings prepared by the most hydrophobic self-assembled layer only exhibited N-type semiconductor characteristics, while the other two exhibited PN dual-semiconductor characteristics. The MAO/SAM/EN three-layer composite coatings provide better protection for the Mg alloy substrate, but as the hydrophobicity of the self-assembled layer increases, the corrosion resistance of the composite coating decreases. The deposition reaction mechanism proves that the hydrophilic film is more conducive to electroless nickel plating. Molecular dynamics simulations show that the Ebinding of the three molecules gradually decreases. Both theories agree with the experimental results.

Interface evolution and mechanical properties of nickel coated graphene nanoflakes/pure titanium matrix composites

The uncontrollable interface reaction has always been a difficult issue in fabricating graphene reinforced titanium matrix composites during high temperature processing. To overcome the graphene nanoflakes (GNFs) agglomeration and relieve the severe C–Ti interface reaction, electroless plating method was applied to synthesize high-quality nickel coated graphene nanoflakes (Ni-GNFs) as reinforcements in Ti matrix. In the present work, the Ni-GNFs/Ti composites were fabricated by spark plasma sintering (SPS) and subsequent heat treatment (HT). The investigations of microstructure revealed that nickel-plating layer played an important role in controlling the degree of interface reaction, and the intrinsic nanostructure of GNFs was maintained after HT at 1123 K for 15min. Feather-shaped NiTi2 precipitation was generated when the nickel layer diffused into Ti matrix. A special crystallographic orientation relation of NiTi2 (1¯33)//Ti (100) and NiTi2 (51¯1¯)//Ti (1¯11) was found between NiTi2 and Ti matrix, which accounted for the improvement of load transfer capability. The compressive tests showed that the yield strength reached to 873 MPa when the composites containing only 0.05 wt% GNFs, which was an increase of 30.1% compared to the pure titanium. This work provides a new strategy for the interface microstructure design of bulk nano-carbon/titanium composites.

Deposition mechanism of electroless nickel plating of composite coatings on magnesium alloy

To investigate the deposition mechanism of the outermost electroless nickel plating layer in a three-layer composite coatings on the magnesium alloy surface, the electroless nickel plating layers with six different plating times (3, 5, 10, 30, 60, and 90 min) were selected as research targets. The transformations in microcosmic morphology, element composition and material structure of the samples electrolessly plated at six different plating times were characterized by SEM、EDS and XRD. The changes in corrosion resistance of samples with different electroless plating times were measured by polarization curve. It was concluded that the nickel-phosphorus deposition process on the activation composite coatings was a “cell-like three-dimensional” growth judging from the microscopic morphology of coating surface obtained by SEM. The elemental changes obtained from the EDS were consistent with the growth of nickel cells obtained SEM. The XRD results showed that the diffraction peaks of nickel were not detected on the surface at an electroless plating time of 3 min. Nickel peaks appeared after 5 min of electroless plating, and the nickel peak width broadened and the intensity increased as the electroless plating time increased. The corrosion resistance is greatly improved when the electroless plating is performed for 60 min due to the complete nickel coating without defects as shown in the SEM. It can be concluded that the deposition mechanism of electroless plating on the double-layer active surface is an initial ecological reduction [H] autocatalytic reduction deposition process according to the micromorphology and structure of the samples electrolessly plated at six different plating times.

Crack generation in electroless nickel plating layers on copper-metallized silicon nitride substrates during thermal cycling

The reliability of metallized ceramic substrates at high temperatures has been one of the main issues for high-power semiconductor modules. Cracks generated in the nickel plating layers, which prevent oxidation of the metal conductor layers, reduce the reliability. Thus, we evaluated the cracks generated in electroless nickel plating layers on copper-metallized silicon-nitride substrates subjected to thermal cycles of three different temperature ranges in air. The different temperature ranges for the thermal cycles were −40 to 150 $${}^{\circ }\text{C}$$ , −40 to 200 $${}^{\circ }\text{C}$$ , and −40 to 250 $${}^{\circ }\text{C}$$ . The results indicated that the cracks were generated in the Ni layers after 500 thermal cycles in the temperature range of −40 to 250 $${}^{\circ }\text{C}$$ . These cracks penetrated the Ni layer completely and extended into the Cu layers to a depth of several micrometers. Copper oxide formed under the cracks, part of which ascended through the cracks and deposited on the surface of the Ni layers due to the volume expansion during oxidation. On the other hand, no cracks were observed on the surface of the Ni layers even after 1000 thermal cycles when the upper limit of temperature was 200 $${}^{\circ }\text{C}$$ or lower. The thermal cycles with the upper limit of temperature at 250 $${}^{\circ }\text{C}$$ or higher strongly affected the formation of cracks in the Ni plating layers.

Study on Growth Mode and Properties of Electroless Nickel Plating on Aluminum Alloy

In this paper, Ni-P alloy coating was prepared by electroless nickel plating with alkaline plating-acid plating double solution system on aluminum alloy 6061 sheet. This paper mainly studies the changes of coating morphology after pretreatment in different alkaline plating baths and the properties of the electroless nickel plating after different time plating in the acidic chemical plating bath, analyze the experimental results, use scanning electron microscopy (SEM) to observe the surface morphology of the samples, and use EDS determine the coating composition, then obtained the growth pattern of the electroless nickel plating layer on aluminum alloy, test the properties of the coating, and the surface roughness, adhesion, microhardness and porosity of the coating were measured.

Failure Analysis of a Nickel-Plated Electronic Connector Due to Salt-Induced Corrosion (ENGE 2014)

When electronic connectors in mobile devices are miniaturized, the thickness of plating decreases. However, this thin plating is expected to decrease the life of the connector due to problems with corrosion. In this study, salt spray aging tests were performed on miniaturized nickel-plated stainless steel electronic connectors to observe failure mechanisms in realistic environments. The tests were performed three times using a 5% NaCl solution in an atmosphere of 45 °C; each test included several cycles where one cycle was one 24-h period consisting of 8 h of salt spray and 16 h without salt spray. The nickel-plating layers were periodically observed by electron probe X-ray micro-analyzer, wavelength dispersive spectroscopy, and field-emission scanning electron microscopy to analyze and identify the corrosion mechanism. We found that the primary failure mode of the nickel plating is blistering and delamination. The corrosion mechanism is typically a chain reaction of several corrosion mechanisms: pitting corrosion --> stress corrosion cracking --> hydrogen-induced cracking --> blistering and delamination. Finally, we discuss countermeasures to prevent corrosion of the nickel layer based on the corrosion mechanisms identified in this study.

Effects of Internal Stress of Electroless Nickel Plating on Solder Joining Strength

Nickel/gold electroless plating is commonly used for surface finish of printed circuit boards due to its environmental stability and good solder wettability. However, since deposition of electroless gold plating is a substitution reaction, local corrosion of nickel surface sometimes occurs and it deteriorates joining reliability of solders or wire bonding. In this study, we focused on internal stress of nickel-plating layer. Gold electroless plating was performed on several deferent internal stress level of nickel plating layers, and local corrosion behavior and shear strengths of solder balls were investigated. As a result, it became clear that tensile strength of nickel layer increases occurrence of local corrosion and accordingly it results in deteriorate of solder joining strength.

The study of electroless nickel plating directly on magnesium alloy

Magnesium alloy was disposed by three kinds of acid pickling formula and activation formula and the effect of the three kinds of acid activation formula on magnesium alloy was studied by contrast experiment. The experimental results indicated that after disposed by acid pickling formula of HNO3 25ml/L, H3PO4 25ml/L, room temperature and activation formula of NH4H2PO4 80–100g/L, NH4F 30–50g/L, room temperature, magnesium alloy could realize electroless nickel plating directly. The properties of the nickel plating layer and activation layer were researched by electrochemical polarization curves, X-ray diffraction and scanning electronic microscope and its energy spectrometer. The results showed that the structure of Ni–P coating was amorphous, the Ni–P coating was very meticulous and uniform, the activation coating was mainly MgF2 and Mg2P2O7, and comparing with magnesium substrate, the corrosion potential of magnesium alloys increased by about 1.1V and the corrosion current density declined obviously. Tested by thermal shock test and file test, the adhesion of magnesium alloy and Ni–P coating was good.

Silica Sol-Gel Film on Bright Nickel Plating of Steel A3 Substrate

At present, ceramic coatings have attracted more and more attention for its good resistance, good chemical stability, and high temperature resistant, hydrophobic and other properties. SiO2 sol was prepared by chelated silicon powders to prepare SiO2 sol-gel film on the nickel plating layer. Pre-plating ordinary bright nickel-plating layer and composite bright nickel plating layer on the iron surface in advance, research some properties such as abrasion resistance, porosity, and NaCl solution soak test of SiO2 sol-gel films by changing the times of immersing SiO2 sol and baking temperature after immersing. The results show that: The time of emerging rust points for sol-gel coating on composite bright nickel-plated is much longer than that on ordinary bright nickel-plated in salt water soak test. The porosity of sol-gel coatings on composite bright nickel-plated is lower than that on ordinary bright nickel-plated. When the drying temperature is at 400°C or 500°C, the porosity rate is zero for the composite bright nickel without coatings or coated with any times of sol. It can improve wear resistance of the composite bright coating when immersing SiO2 sol at 500°C for 3 to 5 times. Porosity of SiO2 sol-gel coatings on the ordinary bright nickel layer is zero when baking at 500°C, immersing 3 times or more than 3 times. The best drying temperature is at 500°C, the best immersing times is 4 times to obtain better corrosion resistance for the bright nickel deposits. The color of the better appearance for a film is rainbow, its drying temperature of 500°C, immersing 4 times.

The interfacial structure of plated copper alloy resistance spot welded joint

Plated copper alloys are widely used in electron industry. The plating lay caused the farther decreasing of the welding property of copper alloys, whose intrinsic weldability was poor. In this paper, the bronze and brass specimens with nickel–tin double plating layer were joined by resistance spot welding method. The microstructure and peel strength of the joints were investigated. The experiment results show that a sandwich-like structure was obtained in the faying surface after welding, and the nickel plating layer thickness had severe effect on the reliability of the joints.

A new generic surface micromachining module for MEMS hermetic packaging at temperatures below 200 °C

This paper presents the different processing steps of a new generic surface micromachining module for MEMS hermetic packaging at temperatures around 180 °C based on nickel plating and photoresist sacrificial layers. The advantages of thin film caps are the reduced thickness and area consumption and the promise of being a low-cost batch process. Moreover, sealing happens by a reflow technique, giving the freedom of choosing the pressure and atmosphere inside the cavity. Sacrificial etch holes are situated above the device allowing shorter release times compared to the state-of-the-art. With the so-called over-plating process, small etch holes can be created in the membrane without the need of expensive lithography tools. The etch holes in the membrane have been shown to be sufficiently small to block the sealing material to pass through, but still large enough to enable an efficient release.

Synergistic Fluoropolymer Coating on Magnesium Alloys

The synergistic fluoropolymer self-lubrication coatings on magnesium alloys were studied. Magnesium alloy was firstly treated by electroless nickel plating. Then micropores of electroless nickel plating layer was enlarged. Then the fluoropolymer particles were infused into micropores, precise vacuum heat treatment ensured thorough infusion with fluoropolymer, finally the synergistic coating was formed. The hardness of the coating reached 600HV, the dynamic coefficient of friction of the coating was less than 0.15, and the low coefficient of friction could be kept during a long duration wear to realize the permanent dry lubrication. The corrosion resistance was also excellent to endure 5% neutral salt spray test for 500 hours. Also the structure and composition of the coating were observed and studied.

Cavitation erosion behavior of electroless nickel-plating on AISI 1045 steel

Electroless nickel-plating is widely used in anti-corrosion engineering with a bonus of the capability of precipitation hardening due to Ni 3P formation after a 1 h heat treatment at 400 °C. But its application in cavitation erosion protection has been rarely discussed in the literature. In this study, electroless nickel-plating is produced on AISI 1045 steel with and without post-heat treatment and cavitation erosion test is evaluated. The test was carried out both in distilled water and 3.5 wt.% NaCl solution, respectively. The results showed that the specimen having an electroless nickel film, without post-heat treatment, underwent an easy flaking-off during both cavitation erosion tests, whereby the cumulative mass loss of the specimens was much higher than the mass loss of the blank steel substrate or the electroless nickel-plating with post-heat treatment (PHT) due to weak adhesion strength of film. Specimens, which had undergone post-heat treatment showed a dramatic reduction in cumulative mass loss in both distilled water and 3.5% NaCl solution. The damage developed on the surface of the specimen suggests that the progress of material removal via fatigue was caused by the brittle nature of the PHT nickel-plating layer. From an electrochemical point of view, the PHT specimen resembled the as-plated specimen in 3.5 wt.% NaCl solution, indicating that the cavitation resistance of the PHT specimen originated from enhanced mechanical strength due to precipitation hardening. However, when the plated nickel film is eroded, a galvanic corrosion will start between the plated film and the steel substrate damaging the steel substrate, especially in cavitation erosion systems.