Effect of Silicon Carbide Particle Size on Wear Resistance of Electroless Nickel-Phosphorous-Silicon Carbide Composite Coatings of Magnesium Alloy Substrate

Ni-P-SiC composite coatings were prepared on Mg alloy substrate via electroless plating while SiC particulates with different sizes(nanoscale,sub-micron and micron) were separately introduced as reinforcing phases into the electroless plating bath.The effect of SiC size on the morphology,composition,hardness and wear resistance of as-obtained Ni-P SiC composite coatings was investigated with a scanning electron microscope,an energy dispersive spectrometer,a hardness meter,and a friction and wear tester.It was found that Ni-P-SiC composite coating reinforced with sub-micron SiC particles contained uniform and fine surface crystal clusters,and showed the highest hardness and the best wear resistance(with a friction coefficient of 0.33).