ジルコニア-アルミナウイスカー系複合セラミックスの機械的性質

概要

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Zirconia (3 mol% Y_2O_3) composite ceramics reinforced with 10, 20 and 40 vol% α-alumina whiskers were prepared by hot-pressing at 1500℃ under 30 MPa for 30 min, and the mechanical properties were measured. The α-alumina whiskers were fabricated by thermal decomposition of aluminum borate (9Al_2O_3・2B_2O_3) whiskers at 1500℃ for 72 h in air. Almost full dense composites (>99%) were obtained by 1500℃ hot-pressing. Improvement of room temperature bending strength was observed because of the whiskers. In fracture tests at 1200℃, monolithic zirconia showed plastic deformation and bent, while the composite had a strength of around 300 MPa. Elastic modulus and hardness increased linearly with increasing whisker content. As the whisker content increased, fracture toughness also increased due to crack deflection by whiskers and pull-out of whiskers, and showed a maximum value (around 5.4 MPa・m^<1/2>) at the whisker content of 40 vol%, which was 1.4 times as large as that of monolithic zirconia.
社団法人日本セラミックス協会の論文
1992-04-01