Crack‐Healing Behavior of Al ₂ O ₃ Toughened by SiC Whiskers

Abstract

Al 2 O 3 reinforced by SiC whiskers (Al 2 O 3 /SiC‐W) was hot‐pressed to investigate the crack‐healing behavior. Semielliptical surface cracks of 100 μm in surface length were introduced using a Vickers indenter. The specimens containing precracks were crack‐healed at temperatures between 1000° and 1300°C for 1 h in air, and their strengths were measured by three‐point bending tests at room temperature and elevated temperatures between 400° and 1300°C. The results show that Al 2 O 3 /SiC‐W possesses considerable crack‐healing ability. The surface cracks with length of 2 c = 100 μm could be healed by crack‐healing at 1200° or 1300°C for 1 h in air. Fracture toughness of the material was also determined. As expected, the SiC whiskers made their Al 2 O 3 tougher.