抄録
Al_2O_3 and mullite composite ceramics rein-forced by SiC whisker were sintered. Three point bending specimen was made from the composite ceramics. A semi-elliptical surface crack up to 450μm in diameter (aspect ratio ≒ 0.9) was introduced on the specimen. Basic crack-healing behavior of the cracked-sample was studied systematically as a function of crack-healing temperature, and also bending strength of crack-healed sample was tested systematically. Followings are main conclusion obtained; (1) Alumina and mullite rein-forced by SiC whisker exhibited large crack-healing ability. (2) The fracture toughness K_<IC>s of the composite alumina and mullite were increased by the SiC whisker reinforcement by about 100% and 60%, respectively. (3) The crack-healed alumina exhibited same level bending strength (σ_B) to the base material and very high σ_B up to 1473K. (4) The crack-healed mullite exhibited lower bending strength (σ_B) than that of crack-healed base material by 150 ∿ 200MPa.
