Abstract: The microstructure and mechanical properties were studied for ZrO2-Y2O3 alloys with 2mol% Y2O3 prepared by cold-isostatic pressing (CIP) and pressureless sintering. The results show that Viker’s hardness of the alloys decrease with the appearance of monoclinic phase (m-ZrO2) and increase its content. Comparing with pure tetragonal phase (TZP), the dual-phase (t+m) structure with microcracks possesses a much bigher fracture toughness because there is only transformation-toughening effect in the former, but a multiple mechanism of transformation-toughening, microcrack-toughening, and residual stress (strain)-toughening operates in the later.

Key words: 残余应力, 陶瓷, 显微裂纹, 相变