Tribological Properties and Thermal Shock Resistance of Plasma Sprayed NiAl-MoO₃ Composite Coatings at High Temperature

NiAl coating and NiAl-MoO₃ composite coating were prepared on the surface of S31008 matrix by atmospheric plasma spraying（APS） technology. The results show that the prepared composite coatings have a compact structure. The bonding strength and microhardness of the composite coating with the addition of solid lubricant are lower than that of NiAl coating, which reduces from 66.4 MPa and 248.6 HV0.3 to 35.9 MPa and 232.8 HV0.3, respectively. At 800 ℃,the friction coefficient and wear rate decrease to 0.16 and 6.55×10^-5mm³/（N·m）, respectively. After 50 cycles of heating-water cooling, the larger area of peeling does not occur in the composite coating.