Microstructure and mechanical properties of partially stabilized zirconia.

研究了弧熔氧化锆合金的显微组织和力学性能。得到的结果如下：1。随着氧化钇和氧化铈等立方稳定氧化物的加入，合金的微观结构发生了显著变化。<ZrO_2> - <Y_2O_3>合金的无扩散c-t相变具有二级相变的性质，具有独特的显微组织变化特征。在<ZrO_2> - <Y_2O_3>合金中，钇含量约为3mol %.4，形成人字形结构。在等温时效过程中，<ZrO_2> - <Y_2O_3>合金在立方方两相区形成了调制组织。这一结构可能与spinodal分解引起的亚稳相分离有关。部分稳定氧化锆的成分和组织控制对提高其断裂韧性尤为重要。确定了<ZrO_2> - <Y_2O_3>和<ZrO_2> - <CeO_2>合金的最佳断裂韧性成分。

Microstructure and mechanical properties of arc-melted zirconia alloys were examined. The results obtained are as follows;1. Microstructure markedly changes with the amount of cubic stabilizing oxides such as yttria and celia.2. The diffusionless c-t transition in <ZrO_2> - <Y_2O_3> alloys has a nature of second order phase transition, which is characterized by an unique microstructural change.3. The herring-bone structure is developed in <ZrO_2> - <Y_2O_3> alloys with yttria content around 3 mol%.4. The modulated structure is formed during isothermal aging in the cubictetragonal two phase region in <ZrO_2> - <Y_2O_3> alloys. The structure seems to be related to the metastable phase separation induced by spinodal decomposition.5. The composition and microstructural control is particularly important to improve the fracture toughness of partially stabilized zirconia. The optimum composition for attaining the highest fracture toughness was determined in <ZrO_2> - <Y_2O_3> and <ZrO_2> - <CeO_2> alloys.