Process of electroless Ni-P-nano-SiC plating

The electroless Ni-P-nano-SiC plating was carried out on iron using nickel sulfate as main salt and sodium hypophosphite as reducing agent.The effects of mass concentration of nickel sulfate,bath temperature and pH on deposition rate were studied.The optimal process conditions are as follows:nickel sulfate 24-26 g/L,sodium hypophosphite 20-35 g/L,citric acid 10-20 g/L,sodium acetate 10-15 g/L,sodium succinate 2-4 g/L,nano-SiC 0.6 g/L,pH 4.1-4.8 and bath temperature 80-85 °C.The results showed that the Ni-P-nano-SiC composite coating is amorphous and has a much higher corrosion resistance than a Ni-P alloy coating.