Effect of SiC size on Ni-P-SiC coatings prepared by magnetic stirring-electroless plating method

Ni-P-SiC coatings were prepared by magnetic stirring-electroless plating method on 45 steel.The effect of SiC size on surface morphology,microhardness and binding force was investigated.The results show that the flatness and density of Ni-P-SiC coatings increase with SiC particle size decreasing.When the particle size of SiC is 0.2 μm,tiny SiC particles are uniformly distributed on the surface of coatings,the coatings are smooth and dense,and the average microhardness is 853.4HV.When the SiC particle size is 1 μm and 2 μm,the microhardness change is bigger at different location of Ni-P-SiC coating,and the maximum is 25.8HV and 40.5HV,respectively.During the friction and wear test process,the wear rate of Ni-P-SiC coating with SiC size of 0.2 μm increases slowly.While the coatings with SiC size of 2 μm and 1 μm,the wear rate increases very sharply.