Microstructure and Properties of Brush Electroplated Nano-SiC-Al2O3/Ni Composite Coating
This paper investigated the effect of nano-SiC particle on microstructure and properties of brush electroplated nano-Al2O3/Ni composite coating. Three kinds of coatings, such as pure nickel coating, nano-Al2O3/Ni composite coating and nano-SiC-Al2O3/Ni composite coating, were fabricated on 1045 steel substrate. Before deposited, Zeta potential of nano-particles in the solution was examined. The results show Zeta potential of the nanoparticles in the nano-Al2O3/Ni electrolyte is negative, but that of the nanoparticles in nano-SiC-Al2O3/Ni electrolyte is positive when the pH value of electrolyte is about 7.5. Energy dispersive spectroscopy (EDS) results show Al element content in the nano-Al2O3/Ni coating is 5.65%, while the content of Al and Si elements in nano-SiC-Al2O3/Ni coating is 5.63% and 4.86% respectively. It confirms that nano-SiC particle co-deposited in the composite coating while nano-Al2O3 particle content keeps constant. The microhardness of nano-SiC-Al2O3/Ni coating exhibits the highest, while the pure nickel coating is the lowest. And surface morphology of nano-SiC-Al2O3/Ni coating is the most smooth and compact among the three coatings. The wear test results reveal that wear resistance of nano-SiC-Al2O3/Ni coating is 1.7 times of that of nano-Al2O3/Ni coating, and 2.3 times of that of pure nickel coating. The above results show the nano-SiC particle services a strengthening effect on the combination performance of nano-SiC-Al2O3/Ni coating.
M.K. Lei, X.P. Zhu, K.W. Xu and B.S. Xu
H. Yang, S. Y. Dong, B. S. Xu, "Microstructure and Properties of Brush Electroplated Nano-SiC-Al2O3/Ni Composite Coating", Key Engineering Materials, Vols. 373-374, pp. 285-288, 2008