Effect of Fracture Mode on Wear Resistance of Alumina-based Ceramics

Wear resistance of alumina, alumina/silicon carbide composite and alumina/mullite composite was determined by abrasive wear tests. Microstructure of the samples was observed by transmission electron microscope (TEM). Morphologies of the worn and fracture surfaces were analyzed by scanning electron microscope (SEM). The influence of fracture mode and wear surface pullout on wear resistance was studied. The results are listed as follows, the main wear mechanisms of alumina and alumina/silicon carbide are fracture wear and plastic wear respectively, and as alumina/mullite composite is concerned, fracture wear and plastic wear mechanism exerted combined effect. Compared with that of alumina, wear resistance of alumina/silicon carbide compsosite and alumina/mullite composite is improved by 2-4 times. The primary source for the improvement is the reduction of area fraction of pullout induced by fracture mode transition.