Preparation and characterization of plasma-sprayed Al/Al2O3 composite coating

Al/Al2O3 composite coating was prepared by plasma spraying and characterized by XRD and SEM. Some thermal-mechanical properties of the composite coating including thermal diffusivity, microhardness, fracture toughness and sliding wear rate were measured. The results showed that the Al/Al2O3 composite coating, compared with Al2O3 coating, exhibits denser structure and developed splat interface. The coexistence of Al metal phase and Al2O3 ceramic phase effectively increased the fracture toughness and thermal diffusivity of composite coating, in spite of the slight decrease in microhardness. Furthermore, the wear resistance of Al/Al2O3 composite coating is superior to that of Al2O3 coating.