Properties and structure of RE-Ni-W-P-SiC composite coating prepared by impulse electrodeposition

The properties and structure of electrodeposited RE （CeO2）-Ni-W-P-SiC composite coating were investigated. The results show that the hardness and electrodepositing speed of composite coatings obtained at an impulse current are higher than those at a direct current. The hardness and wear resistance of the coating are obviously increased by adding RE and SiC. The hardness of the coating increases with the increase of treatment temperature and current density, and reaches the optimum value at 400 ℃ and at 10 A/dm^2, respectively. The optimum operation parameters of electrodeposition of the composite coating are as follows： pH value is 4.5, bath temperature is 65 ℃, and current density is 10 A/dm^2.