Influences of Feedstocks and Laser Remelting on Erosion Resistance of Al2O3-13wt.%TiO2 Coatings Prepared by Plasma Spraying

Abstract

Conventional and nanostructured ceramic coatings were prepared with conventional and nanostructured aggregate Al2O3-13wt.%TiO2 ceramic powders through plasma spraying and plasma spraying-laser remelting combined technique. Influences of feedstocks and laser remelting on erosion resistance of the prepared coatings were discussed, and the erosion failure mechanisms of four types of coatings were discussed. Results demonstrate that compared with coatings prepared by plasma spraying, the coating prepared by laser remelting has better erosion resistance. Given the equal conditions, nanostructured coating shows stronger erosion resistance than conventional coating. Conventional ceramic coating shows typical brittle erosion characteristics and nanostructured ceramic coating also shows brittle erosion characteristics, accompanied with certain degree of plastic erosion characteristics. Erosive wearing of plasma coating is mainly lamellar peeling, accompanied with certain degree of brittle ceramic particle crushing. Coating prepared by laser remelting present crack initiation and propagation on near surface, finally leading to crystal crushing and peeling of remelting layers.