The wear behaviour of Al2O3-SiC ceramic nanocomposites

The sliding wear behavior of alumina-SiC nanocomposites with additions up to 15vol%SiC was compared with the alumina monolith. Two alumina monoliths were compared, one with a coarser grain size than the composites, and one with a similar grain size to the composites. For a similar grain size, SiC addition to alumina resulted in a substantial reduction in sliding wear rate. The monolithic alumina suffered a transition from 'mild wear' to catastrophic intergranular wear after a sliding distance determined by the grain size. The composites did not exhibit any transition behavior, but exhibited surface transgranular fracture and pitting throughout the test. Further, the wear rate of the monolithic alumina in the 'mild wear' regime was lower than that of the composite materials.