Papers by Keyword: Electroless Composite Plating

Abstract: A new processing concept has been developed to produce Ni-P-PTFE electroless composite coating. This method combines magnetic field and electroless composite plating techniques to prepare high-quality Ni-P-PTFE electroless composite coating. The influence of magnetic on composite plating process and coatings performance by changing some factors such as the plating time, magnetic field strength, magnetic field direction. The results indicate that the external magnetic field improved deposition rate and the PTFE particles content of composite coatings, meanwhile, some performances of composite coating like thickness, corrosion resistance, were effected by external magnetic field strength. Therefore, the method combines magnetic field and electroless completing techniques had a wide application prospect in the aspect of improving the properties of electroless composite coating.

Abstract: In order to obtain more excellent performance of composite coating, a layer of Ni-P alloy was plated firstly, then Ni-P-PTFE composite coatings was plated. If plating time ratio of electroless plating Ni-P alloy and Ni-P-PTFE composite plating was properlly controlled, performance of pure Ni-P-PTFE composite coating could be improved. The study have shown that the total plating time is 2 hours, and the plating time ratio is 1:1, and good bonding strength with the substrate, right hardness, low friction coefficient, good corrosion resistance of Ni-P /Ni-P-PTFE composite coatings have been obtained.

Abstract: Ni-P diamond particles (20μm) composite coating on friction shims were prepared by electroless plating. Morphology and phase composition of the composite coating were measured by SEM with EDS and XRD. The friction coefficient of the coating was test with scratch test. The results showed that diamond particles distribution was uniform and not stacked by two steps for 10 min. The diamond particles were half embedded in the Ni-P substrate. The element of the coating was Ni,P,C and the phase composition was Ni and diamond. Adhesion of the composite coating was higher than that of the Ni-P coating. Friction coefficients of the Ni-P coating and Ni-P composite coating were 0.47 and 0.18. Half –naked diamond particles played a pinning role and prevented from wear of the coating to get the big friction coefficient and good wear resistance. This Ni-P composite coating on friction shims would improve friction shims technology and realize the production of localization of friction shims.

Abstract: In this study, Ni-Fe₃O₄ composite particles are deposited on polyester fabric modified with 3-aminopropyltrimethoxysilane (APTMS) by electroless plating. Surface morphology, chemical composition and crystal structure of the Ni-Fe₃O₄ deposits were investigated by scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and X-ray diffraction (XRD), respectively. The magnetic properties of the Ni-Fe₃O₄ composite plated polyester fabric are also evaluated. Relatively dense plating was obtained under the given plating conditions. As the Ni-Fe₃O₄ weight on the treated fabric is 34.28g/m2, the saturation magnetization of the sample was 2.88emu/g.

Abstract: In order to obtain the composite coatings of abrasion resistance and anti-corrosion, experiments of Ni-P-Al2O3-SiO2 chemical composite plating were carried out by electroless composite plating technology, and then the added amount of composite particles influenced coatings performance were investigated. After experiments, the metallographic structure, the micro-hardness, bonding strength, thickness and anti-corrosion of composite coatings were characterized by using a XJZ-6A type metalloscope and a HVS1000 type micro-hardometer, respectively. The results show that the composite coatings have bright surface appearance and the properties of bath are stable. Besides having a higher hardness, a higher thickness and a lower porosity, composite coatings combine well with the matrix and the abrasion resistance is better when the amount of Al2O3-SiO2 composite particles were added correctly. These composite particles should be treated by ultrasonic vibration firstly.

Abstract: The orthogonal test method has been used to study the effects of the concentration of SiC, the speed of mixing, the temperature and the surfactants on depositing rate, and obtained the optimized technological scheme and fine Ni-P-SiC composite coating. The results showed that using citric acid-acetic acid as complexing agents can obtain high speed of depositing and homogeneous coating with SiC well-distributed. Among the technological parameters, the effects of temperature on depositing rate is biggest, and the surfactants is next. Give consideration to depositing rate and stability of the liquid, the temperature should be controlled at 82±2°C, the concentration of SiC particles and surfactants should be controlled in 4g/L and 60mg/L.

Abstract: The orthogonal test method has been used to study the effects of the concentration of SiC, the speed of mixing, the temperature and the surfactants on micro-hardness, and obtained the optimized technological scheme and fine Ni-P-SiC composite coating. The results showed that using citric acid-acetic acid as complexing agents can obtain high speed of depositing and homogeneous coating with SiC well-distributed. Among the technological parameters, the effects of the concentration of SiC particles on micro-hardness is biggest, and the surfactants is next. Give consideration to depositing rate and stability of the liquid, the temperature should be controlled at 82±2°C, the concentration of SiC particles and surfactants should be controlled in 4g/L and 60mg/L.

Abstract: The orthogonal test method has been used to study the effects of the concentration of SiC, the speed of mixing, the temperature and the surfactants on depositing rate and micro-hardness, and obtained the optimized technological scheme and fine Ni-P-SiC composite coating. The results showed that using citric acid-acetic acid as complexing agents can obtain high speed of depositing and homogeneous coating with SiC well-distributed. Among the technological parameters, the effects of temperature on depositing rate is biggest, and the surfactants is next; the effects of the concentration of SiC particles on micro-hardness is biggest, and the surfactants is next. Give consideration to depositing rate and stability of the liquid, the temperature should be controlled at 82±2°C, the concentration of SiC particles and surfactants should be controlled in 4g/L and 60mg/L.

Abstract: Experiments of Ni-P-SiC chemical composite plating were carried out, and then the crafts and performances of Ni-P-SiC chemical composite plating were investigated. Based on the previous researches of the chemical composite plating, different amount of SiC particles and different conditions of technologies were selected. After experiments, the distribution surface particles, the metallographic structure and hardness of composite coatings were characterized by using a XJZ-6A type metalloscope and a HVS1000 type micro-hardometer, respectively. The results show that the composite coatings have bright surface appearance. Besides having a higher hardness, composite coatings combine well with the matrix and the deposition rate is quick. In the factors which influenced the properties of the composite coatings, the amount of SiC particles and plating time are analyzed.

Abstract: An Investigation on the Ni-P-SiCp Electroless Composite Plating of AZ91D magnesium alloy was investigated.The morphology and phase structrue of the electroless composite plating were investigated by means of SEM and XRD.The effect of concentration of the second phase particle in electroless plating solution on wear resistance of the Ni-P-SiCp composite coating were studied.The properties of the coatings before and after heat treatment were compared.The result shows that the obtained coatings were flat and compact.X-ray diffractometry indicated that the coatings were amorphous,but crystallization would happen in the process of heat treatment.From the lost weight of the coatings it can be seen that the wear resistance of composite coatings was better than that of Ni-P coatings .