Durability of Low Pressure Plasma Sprayed MoB/CoCr Coating in Molten Al-12.07wt%Si Alloy

MoB/CoCr, a novel material for thermal spraying, with high durability is used to resist erosion by molten Al-12.07wt%Si alloy. The durability of the MoB/CoCr coating prepared by low pressure plasma spraying (LPPS) has been investigated using a molten-metal immersion tester. The test revealed that the MoB/CoCr coating has much higher durability without dissolution in the molten Al-12.07wt%Si alloy. Little change of crystal structure, mainly composed of ternary borides of Co₂MoB₂ and CoMoB, is observed after the immersion test, suggesting that the ternary borides have much higher durability.