ジルコニアセラミックスの低温下における強度特性

抄録

The influence of temperature on the strength and fracture toughness of ZrO₂-3mol% Y₂O₃ (YZ-3), ZrO₂-6mol% Y₂O₃ (YZ-6), ZrO₂-12mol% CeO₂(CZ-12) and ZrO₂-14mol% CeO₂ (CZ-14) ceramics was studied from R. T. down to 77K. The strength was estimated by the three-point-bending method and the fracture toughness was evaluated by the size of initial defects observed on the fracture surface. The bending strength of YZ-3 and YZ-6 increased with decreasing temperature, whereas that of CZ-12 and CZ-14 decreased with decreasing temperature. CZ-12 had a tetragonal to monoclinic transformation temperature from R. T. down to 77K. Other ceramics had no transformation temperature. The temperature dependence of strength for YZ-3 and YZ-6 agreed with that of fracture toughness.