ジルコニア粒子分散アルミナセラミックスの微細構造と強度特性の相関性

概要

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Effects of 3 mol% Y_2O_3-doped tetragonal zirconia polycrystalline addition upon the mechanical properties and microstructure of Al_2O_3 were investigated. Al_2O_3 specimens containing 5wt.%, 15wt.%, and 30wt.% of 3mol% Y_2O_3-doped Z_rO_2 were prepared by the sureless sintering method at 1 550℃, 1 600℃, and 1 650℃. Then, the bending strength and fracture toughness (K_c) were evaluated, and the microstructure of these composites were examined. Addition of Z_rO_2 to Al_2O_3 greatly improved the bending strength, fracture toughness and hardness. It was found that, the bending strength and fracture toughness were maximum when the content of Z_rO_2 was 30wt.%. Specimens sintered at 1 650℃ indicated inferior mechanical properties due to grain growth. Through X-ray diffraction pattern analysis, examination of the phase transformation of Z_rO_2 from tetragonal structure (t-Z_rO_2) to monoclinic structure (m-Z_rO_2) was conducted. In the case of the composite specimen containing 3Owt.% Z_rO_2, the most marked phase transformation was recognized. Substantial grain bridging was observed in the crack growth behavior of composite containing 3Owt.% Z_rO_2 and sintered at 1 550℃.
一般社団法人日本機械学会の論文
1996-04-25