OPTIMIZATION OF CHROMIUM PLATING PROCESS OF Al-Si ALLOY

The technology of chromium plating on Al-Si alloy was studied.The optimized formulation for the chromium plating was 80 g/L CrO3,0.7 g/L H2SO4,3 g/L Cr3+and 3g/L CeO2.Compared with the appearance,thickness,hardness and adhesion of the chromium coating,the optimized parameters for the process were recommended to be 40 ℃,current density of 30 A/dm2,and electroplating time of 120 min.A smooth,chromium electrodeposit with high hardness and wearability was obtained.Concentration of chrome acid and environment pollution were decreased.