CATHODIC PROCESS AND WEAR RESISTANCE OF ELECTRODEPOSITED RE-Ni-W-P-SiC COMPOSITE COATING

摘要

Cathodic deposition current density of the composite coatings increases when SiC particles and rare earth (RE) were added in the bath, which is profitable for Ni-W-P alloy to deposit in the cathod, forming Ni-W-P-SiC and RE-Ni-W-P-SiC composite coatings. On the contrary, the addition of PTFE in the bath decreases cathodic deposition current density of the coatings. The current density increases a little when the amount of RE is 7-9g/l; however, the current density increases greatly when the amount of RE is increased to 11-13g/l. But if the amount of RE is raised further, the current density decreases. Hardness and wear resistance of RE-Ni- W-P-SiC composite coating have been studied, and the results show that the hardness and wear resistance of RE-Ni- W-P-SiC composite coating increase with increasing heat treatment temperature, which reach peak values at 400 deg C; while the hardness and wear resistance of the coating decrease with the rise of heat treated temperature continuously.