Dense ZrB2–MoSi2 composite coating fabricated by low pressure plasma spray (LPPS)

Low pressure plasma spray was applied to fabricate ZrB2–MoSi2 composite coatings. Their microstructure and oxidation behavior were characterized and compared with those of the ZrB2–SiC coatings. The ZrB2–MoSi2 coating displayed compact and lamellar microstructure with porosity lower than 5%, where MoSi2 phase was uniformly distributed in the ZrB2 matrix. ZrB2–30 vol% MoSi2 coating exihibited much better oxidation-resistance at high temperature compared to the ZrB2–30 vol% SiC coating. It is thought that the fine distribution of sufficient MoSi2 in the matrix and dense microstructure of the ZrB2–MoSi2 coating contributed to its excellent high temperature oxidation-resistance.