Effect of Healing Temperature on Crack-Healing of Al2O3 Toughened by SiC Particles
Al2O3 Toughened by SiC particles was hot-press sintered. Cracks of ~300μm in diameter were introduced in the surfaces of specimens, which then healed at 1000°C, 1200°C, 1300°C, 1400°C, and individually for 2h, 4h, 6h and 8h. Effect of healing temperature on bending strength, healing mechanism were systematically investigated, the results show that the best bending strength recovered at room temperature was 583.61MPa obtained at 1300°C for 4h, which was the same value as perfect specimens. The recovery of bending strength contributes to three kinds of mechanisms. When specimens were healed individually at 1000°C, 1200°C, 1300°C for 2h, adsorption mechanism and proliferation mechanism were as the dominant healing mechanisms; when healed at 1400°C for 2h, oxidation reaction mechanism was the important healing mechanism. Also, the length of surface cracks is shorter as healing temperature increasing.
Yafang Han, Tianmin Wang and Shaoxiong Zhou
C. Y. Shi et al., "Effect of Healing Temperature on Crack-Healing of Al2O3 Toughened by SiC Particles ", Materials Science Forum, Vol. 650, pp. 109-114, 2010