Abstract：WC/Al
2O3 composite cermet coating was sprayed on AZ91D magnesium alloy by supersonic plasma
spraying technology.The surface structure, coating thickness and the bonding strength between coating and matrix
were tested by X-ray diffraction (XRD) , scanning electron microscope (SEM ), thickness gauge, viscometer and
other equipments.And the friction and wear properties of the coating were measured by the coating wear tester.
The results show that the bonding strength is about 35 MPa when the coating thickness is controlled at 0.8~
1.0 mm.The principal crystalline phases of the coating are WC and Al2O3 phases and the spraying effect of com‐
posite cermet coating is good.The photo of SEM shows that the coating has stable layer structure and lower po‐
rosity. The coating could obtain excellent wear resistance(rate of wear is 13.9×10-3 mm3/(N·m) when the coating
temperature is 400 ℃. The coating friction factor is stable at 0.272, the wear amount is 0.003 5 g, and the wear
mechanism is abrasive wear when the test load of the friction and wear test is 5 N and the time is 2 h.
2022, Vol. 32 
