Tribological Study of the Electro Plating Nickel Composite coatings that for used on Frictional components of Vehicle

• Main Authors: Ho, Hung-Po, 何宏博
• Other Authors: 侯光煦
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/08015824663561786744

碩士 === 國防大學中正理工學院 === 兵器系統工程研究所 === 96 === In this study, we attempt to evaluate the tribological ability of the Ni-based composite coatings for surface modified technique that applied on the frictional components of vehicles. To discuss the tribological behavior of modified components that influence by the processing parameters of electroplating composite. These coatings were prepared with same ceramic particle concentration and same peak current densities range with 2.5~10 A/dm2 conditions that using direct current (DC) plating or pulse current (PC) plating methods to produce the DC Ni-Al2O3 and PC Ni-P-Al2O3 composite coatings. Experimental results revealed that the PC Ni-P-Al2O3 coatings have a higher hardness ranged 589~733 Hv, and highest Al2O3 content with 9.648 vol.%. The dry frictional experiments show the heat-treated Ni-P-Al2O3 coatings with high phosphorous content that possess dual strengthen effect include the Ni3P precipitated strengthening and Al2O3 particle dispersion hardening. The optimum Ni-P-Al2O3 coating has lowest wear weight loss 0.3 mg that with highest wear resistance. Lubrication friction tests show that the coatings exhibit the lower friction coefficient and lower wear loss as it’s with smaller surface roughness variation. In view the wear mechanisms of Ni-P-Al2O3 coatings, the greater wear losses were affected by the plowing, plastic deformation and adhesive wear. The squeezed out nanometer Al2O3 particles that existed in the interface of rubbed surface would be formed a rolling frictional movement to enhance the reduce that the frictional coefficients and the wear loss. The coatings with dense grain structure and low roughen surface morphology would also exhibited the higher wear resistance.