Wear Resistance of Plasma-Sprayed Al_2O_3-TiO_2 Nanocoatings

摘要

Wear resistance of Al_2O_3-8wt.%TiO_2 coatings plasma-sprayed using nanopowders was investigated. Four types of nanostructured Al_2O_3-8wt.%TiO_2 powders were plasma-sprayed on a low-carbon steel substrate by using different critical plasma spray parameters (CPSP). The coatings consisted of completely melted and partially melted regions. The hardness of the coatings increased with increasing CPSP, while the wear resistance was the highest for the coating sprayed with the lowest CPSP. The main wear mechanism was a delamination mode in the coating sprayed with the high CPSP, but was changed to an abrasive mode in the coating sprayed with the low CPSP. According to this change in the wear mechanism, the wear resistance was the best in the coating sprayed with lowest CPSP, while its hardness was lowest.