Sliding wear of self-mated Al2O3-SiC whiskerreinforced composites at 23?1200�C

Microstructural changes occurring during sliding wear of self-mated AlO-SiC whiskerreinforced composites were studied using optical, scanning electron microscopy and transmission electron microscopy. Pin-on-disc specimens were slid in air at 2.7 m s sliding velocity under a 26.5 N load for 1 h. Wear tests were conducted at 23, 600, 800 and 1200°C. Mild wear with a wear factor of 2.4 x 10−1.5 x 10 mm N m was experienced at all test temperatures. The composite showed evidence of wear by fatigue mechanisms at 800°C and below. Tribochemical reaction (SiC oxidation and reaction of SiO and AlO) leads to intergranular failure at 1200°C. Distinct microstructural differences existing at each test temperature are reported.