ムライト/SiCウイスカー複合セラミックスの応力下でのき裂治癒挙動,強度および破壊じん性値

概要

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Mullite/SiC whisker composite ceramic was sintered. The three point bending specimen was made from the composite ceramic. A semi-elliptical surface crack up to 400μm in diameter (aspect ratio N≒0.9) was introduced on the specimen. The basic crack-healing behavior was studied systematically as a function of crack-healing temperature, and the bending strength of the crack-healed sample was also tested systematically. Followings are main conclusions obtained; (1) The mullite reinforced by SiC whiskers exhibited a large crack-healing ability. (2) The fracture toughness (K_<IC>) of the mullite composite was increased about 60% by the SiC whisker reinforcement. (3) The crack-healed mullite exhibited lower bending strength (σ_B) than that of the crack-healed base material by 150〜200MPa. (4) The mullite was able to heal a crack even under constant or cyclic stresses. The critical stress intensity factor (K_<HS^C>) for the healing was found to be 2.1MPa・m^<1/2>.
社団法人日本材料学会の論文
2005-02-15