Abstract: MoB/CoCr cermet coatings were deposited by low pressure plasma spraying (LPPS).The microstructure and phase component of coatings were characterized by XRD, SEM and EDAX, the coatings were also studied on bond strength and thermal shock resistance performance. The results show that phase component of powder and coating had little change, chamber pressure influenced the melting of powder dramatically during LPPS, and the ratio of fully-melted zone/partly-melted zone increased as chamber pressure increasing. The coatings are dense and have excellent combination with substrate. The main constituents of coatings remain invariant and the coatings have excellent performance of bond strength and thermal shock resistance. And the MoB/CoCr coating has much higer durability in the molten Al-12.07wt;Si after 1080 h immersion test.

Key words: MoB/CoCr cermet coatings were deposited by low pressure plasma spraying (LPPS).The microstructure and phase component of coatings were characterized by XRD, SEM and EDAX, the coatings were also studied on bond strength and thermal shock resistance performance. The results show that phase component of powder and coating had little change, chamber pressure influenced the melting of powder dramatically during LPPS, and the ratio of fully-melted zone/partly-melted zone increased as chamber pressure increasing. The coatings are dense and have excellent combination with substrate. The main constituents of coatings remain invariant and the coatings have excellent performance of bond strength and thermal shock resistance. And the MoB/CoCr coating has much higer durability in the molten Al-12.07wt;Si after 1080 h immersion test.