Nickel Alloy Plating Research Articles

Study on the mechanism of additives affecting corrosion resistance in zinc alloy plating

In the plating process, the addition of additives can improve the quality of the plated layer. Suitable additives can make the plated layer more resistant to corrosion while obtaining a flat and bright plated layer. In this paper, the effects of four types of additives on the corrosion resistance of electroplated zinc–nickel alloy plating were investigated, and the process conditions such as current density and plating time were determined by Hull tank experiments and small tank experiments. The effects of the content of various additives and different additives on the corrosion resistance of the plating layer were investigated, and the optimal additives were the compound combination of BH-A and BH-B at 6 mL/L each. Under the same plating process conditions, the effect of adding suitable additives and not adding additives on the corrosion resistance of the plated layer was investigated. The findings revealed that, in comparison to the plating solution sans additives, the integration of appropriate additives not only enhanced the deposited layer’s corrosion resistance but also led to a decrease in grain size, increased uniformity, density, and achieved a higher degree of flatness. The results indicate that, in contrast to the plating solution without additives, the inclusion of suitable additives not only enhances the corrosion resistance of the resulting plated layer but also generates a smaller grain size, uniformity, density, and higher flatness in the deposited layer.

Interface Characterization of Ni/Al Bimetallic Explosively Welded Plate Manufactured with Application of Exceptionally High Detonation Speed

The investigation is dedicated to the detailed microstructure characterization of explosively welded clads, in which, exceptionally and for cognitive purposes, a very high detonation speed of about 2800 m/s was used to manufacture bimetallic aluminum-nickel plates. The study involves detailed microstructural characteristics of the bonded zone at micro and nano level, especially focused on the expanded melted regions consisted mostly of Al3Ni, Al3Ni2 and AlNi phases. In situ heating experiment in transmission electron microscope allowed observing microstructure transformation revealing that additionally present metastable Al9Ni2 phase was transformed to Al3Ni and Al3Ni2. Microhardness measurements across the welded zone showed the increase of the microhardness of nickel alloy plate from 153 up to 170 HV when approaching to the Ni201/A1050 interface, while the value for aluminum plate was of 45 HV. Within the melted zones the microhardness was found to be 135 HV and it enormously increased to 850 HV after annealing of the sample at 500 °C. This change was due to the transformation of the interface region from the waves with the melted zones into the continuous layers of two intermetallic phases: Al3Ni and Al3Ni2. The second phase grew at the expense of the Al3Ni.

Copper–Nickel Alloy Plating to Improve the Contact Resistivity of Metal Grid on Silicon Heterojunction Solar Cells

As a dominant metallization technique of crystalline silicon solar cells, screen printing with silver paste has been generally used in photovoltaic industries. In case of the silicon heterojunction solar cells (SHJ) structure, a metal contact with silver paste has lower electrical conductivity than pure silver due to the other compositions of the paste. For the reason, copper plating is attractive substitute for the silver paste since the plated-copper contacts have high conductivity and easily reduce line width which is beneficial to light absorption. In this experiment, we studied copper–nickel (Cu–Ni) alloy plating to form a seed layer of the copper plating on an indium tin oxide (ITO) layer which is used for the transparent conductive oxide of the SHJ solar cells. As a requirement of suitable seed layer, contact resistivity (ρc) between the seed and the ITO is important to obtain high fill factor by decreasing series resistance of solar cells. Contact resistivity values of the samples with varied nickel contents in the Cu–Ni films were extracted by using transfer length method. Also, the composition ratio of the alloy layer was analyzed by energy dispersive spectrometer. Moreover, X-ray diffraction was used to compare lattice parameter and crystallite size of the film.

Cyclic stress measurement method under high temperature using nickel alloy plating

Cyclic stress measurement method under high temperature using nickel alloy plating

Separation and Recovery of Copper (II), Nickel (II) from Simulated Plating Wastewater by Solvent Extraction Using Lix984

The process of solvent extraction was applied to separate and recover Cu2+ and Ni2+ from plating wastewater from copper and nickel alloy plating process, because there are abundant Cu2+ and Ni2+. And the influence parameters have been investigated. Lix984 was chosen as the extractant due to it has good performance to extract metals from the water. The results showed the separation of Cu2+ and Ni2+ from sulphate medium can be realized by adjusting pH value with the help of Lix984, And more, the optimal pH values for extracting Cu2+and Ni2+ are 4 and 10, respectively. The maximal extraction efficiency for Cu2+ and Ni2+ can reach above to 90.6% and 93.5% by single-stage extraction. The recovered Cu2+ and Ni2+ were stripped in 170g/L and 200g/L H2SO4 medium, respectively. And the stripping of Cu2+ and Ni2+ are >99.2% and >99.4%, respectively. It can be successfully applied to the field of plating wastewater, decreasing the environment pollution from Cu2+ and Ni2+ and providing a kind of new copper and nickel resource.

Cadmium- and chromate-free coating schemes for corrosion protection of 15CDV6 steel

Electrodeposits of cadmium- and chromate-based inorganic inhibitor pigments in paint formulations are extensively used in the aerospace industry to provide long-term corrosion protection for high-strength steel hardware. Due to environmental concerns and worker safety issues, there is a pressing need to identify and adopt alternative ecofriendly coatings with equivalent performance. In this work, an ecofriendly cadmium- and chromatefree coating scheme comprised of zinc nickel alloy plating, trivalent chromium- based passivation, followed by a primer based on polyaniline phosphate, is studied for its anticorrosive properties. Long-term performance evaluation studies of this eco-friendly coating scheme were carried out on 15CDV6 steel, an ultra-high- strength steel used in the aerospace industry. For comparative purposes, two extensively used cadmium- and chromate-based schemes complying to aerospace and military specifications comprised of cadmium plating, hexavalent chromium-based passivation followed by two different chromate-based primers were studied on 15CDV6 steel substrate. Electrochemical impedance spectroscopic studies and salt fog exposure tests were carried out to evaluate the anticorrosive properties of the coat- ing schemes. Cadmium- and chromate-free scheme exhibited excellent performance in the long-term corrosion evaluation studies. The results obtained in accelerated tests show the possibility of replacement of cadmium- and chromate-based schemes for corrosion protection of steels with an eco-friendly option.

Fabrication of high hardness Ni mold with electroless nickel–boron thin layer

The nickel electroforming method using a high-concentration nickel sulfamate bath is commonly used to fabricate micro metal molds in the LIGA process; however, this method does not produce micro metal molds of sufficient hardness. One means of improving the hardness of micro metal molds made using the nickel electroforming method is to include additives in the nickel plating solution. Another method is nickel alloy plating or a similar technique. In this research, we used a nickel–boron (Ni–B) electroless alloy plating method to obtain a hard nickel plated film having hardness of 832 Hv. It was also ascertained that Ni–B electroless alloy plated film retains its high hardness even during heat treatment in conditions of 250°C for 1 h. To deal with the high stresses developed in high-hardness plated films, we proposed double-layer nickel electroforming. This method is covered and used on conventional nickel electroforming layer by high hardness micro mold. High hardness micro metal mold using double-layer was fabricated by nickel electroforming and Ni–B electroless alloy plating method.

Evaluation of Some Mechanical Properties of Reinforced Acrylic Resin Denture Base Material(An In Vitro Study)

Aims: To evaluate the effect of thickness of acrylic denture base resin on the transverse strength, also to evaluate the effect of metal and fiber reinforcements on the fracture resistance of denture base resin by four mechanical tests: Transverse strength; Charpy impact strength; Tensile strength and Rockwell Indentation Hardness. Materials and methods : Heat–cured resin, and three types of reinforcing metals were used which were: The cobalt–chromium alloy mesh, stainless steel wire and nickel alloy plate. Three forms of glass fiber also were used: Random, woven, and aligned unidirectional. The effect of these reinforcing materials on the mechanical properties of heat–cured resin had been evaluated by measuring the transverse strength by the Instron testing machine, tensile strength by the Textile tensile strength Tester, the impact strength by the Charpy type impact Tester and finally the hardness by the Rockwell hardness tester. Three hundred samples were prepared in this study. Results: Revealed a statistically significant effect of thickness on the transverse strength of heat–cured resin. Results also showed that all forms of fiber and metal reinforcements had a significant effect on the transverse strength, tensile strength , impact strength and hardness of denture base resin. Conclusions: The thickness significantly increased the transverse strength of denture base resin. All forms of metal and glass fiber reinforcement significantly improved the transverse strength, impact strength and tensile strength of denture base resin. All forms of metal and fiber reinforcement acted to reduce the hardness of denture base resin

RESEARCH ACTIVITIES ON ROCKET-RAMJET COMBINED-CYCLE ENGINE IN JAXA

Recent activities on the scramjet and rocket-ramjet combined-cycle engine of Japan Aerospace Exploration Agency (JAXA) are herein presented. The scramjet engines and combined-cycle engines have been studied in the world and JAXA has also studied such the engines experimentally, numerically and conceptually. Based on the studies, 2 to 3 m long, hydrogen-fueled engine models were designed and tested at the Ramjet Engine Test Facility (RJTF) and the High Enthalpy Shock Tunnel (HIEST). A scramjet engine model was tested in Mach 10 to 14 flight condition at HIEST. A 3 m long scramjet engine model was designed to reduce a dissociation energy loss in a high temperature condition. Drag reduction by a tangential injection and two ways of a transverse fuel injection were examined. Combustor model tests at three operating modes of the combined-cycle engine were conducted, demonstrating the combustor operation and producing data for the engine design at each mode. Aerodynamic engine model tests were conducted in a transonic wind tunnel, demonstrating the engine operation in the ejector-jet mode. A 3 m long combined-cycle engine model has been tested in the ejector-jet mode and the ramjet mode since March 2007. Carbon composite material was examined for application to the engines. Production of the cooling channel on a nickel alloy plate succeeded by the electro-chemical etching.

Formation of Carbon Fibres in High-Voltage Low-Current Electrical Discharges

A novel method to synthesize carbon fibres using low-current electrical-discharge plasma in hydrocarbon vapours is presented in the paper. The low-current arc discharge of positive polarity was generated between a stainless steel needle, and a nickel alloy plate, over a voltage range from 2 kV to 30 kV. The discharge was stabilised by a high series resistance (1 – 12.5 M'). The experiments were carried out in an argon atmosphere at normal temperature and atmospheric pressure. The arc discharge of current in the range of 1 to 4 milliamps was found to be a potentially effective method for the production of carbon fibres. The diameter of the fibres varied from about 20 to 120 μm with a growth rate of about 0.5 mm/s.

Hydrogen permeation inhibition by zinc–nickel alloy plating on steel XC68

The inhibition of hydrogen permeation and barrier effect by zinc–nickel plating was investigated using the Devanathan–Stachurski permeation technique. The hydrogen permeation and hydrogen diffusion for the zinc–nickel (12–15%) plating on steel XC68 is compared with zinc and nickel. Hydrogen permeation and hydrogen diffusion were followed as functions of time at current density applied (cathodic side) and potential permanent (anodic side). The hydrogen permeation inhibition for zinc–nickel is intermediate to that of nickel and zinc. This inhibition was due to nickel-rich layer effects at the Zn–Ni alloy/substrate interface, is shown by GDOES. Zinc–nickel plating inhibited the hydrogen diffusion greater as compared to zinc. This diffusion resistance was due to the barrier effect caused by the nickel which is present at the interface and transformed the hydrogen atomic to Ni 2H compound, as shown by GIXRD.

めっき膜に生じるクラック検出のための電気化学インピーダンス解析法

Cracks are often formed in nickel-alloy plating by high tensile stress. Therefore, an accurate crack detection method is required. The method for detecting cracks in Ni-W plating film with electrochemical impedance spectroscopy (EIS) was studied in the present paper. The impedance of Ni-W plating film without cracks in 1M sulfuric acid solution shows two capacitive loops. The impedance of Ni-W plating film with cracks in 1M sulfuric acid solution shows also two capacitive loops. The capacitive loops of impedance of Ni-W plating film without crack were smaller than those of Ni-W plating film with cracks. Curve-fitting was performed for the impedance spectra by assuming equivalent circuits, and the calculated impedance spectra were in agreement with the experimental results. In those results, the charge transfer resistance and double-layer capacitance varied with the area of cracks in Ni-W plating film. It can be concluded that impedance analysis can detect cracks in Ni-W plating film.

Copper based nickel alloy plating on sintered iron-neodymium-boron magnets: K. Fritz et al (Max-Planck Inst, Stuttgart, Germany), Z für Metallkunde, Vol 83, No 11, 1992, 791–793

Copper based nickel alloy plating on sintered iron-neodymium-boron magnets: K. Fritz et al (Max-Planck Inst, Stuttgart, Germany), Z für Metallkunde, Vol 83, No 11, 1992, 791–793

電子部品への無電解ニッケル合金めっきの応用

電子部品への無電解ニッケル合金めっきの応用