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

摘要

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