Corrosion behavior of low pressure plasma sprayed MoB/CoCr coatings exposed to molten Al-12.07wt.Si alloy

摘要

MoB/CoCr, a novel material for thermal spraying, is used to resist erosion by molten Al-12.07wt.%Si alloy due to its high durability. MoB/CoCr cermet coatings were deposited by low pressure plasma spraying (LPPS), and the durability of the MoB/CoCr coating has been investigated using a molten-metal immersion tester. The microstructure of coating was characterized by XRD, SEM and EDAX. The results show that the coatings with layer structure are mainly composed of ternary borides of Co2MoB2 and CoMoB, and the coatings have excellent performance of bond strength and thermal shock resistance. After 1080 h immersion test in the molten Al-12.07wt%Si, the results show that the mainly chemical composition and crystal structure were little changed, and MoB/CoCr coatings have shown excellent durability in the Al-12.07wt%Si alloy without dissolution.