Al2O3/ZrO2层状复合陶瓷的显微结构特征与强韧化的关系

利用自带能谱的扫描电镜(SEM)和透射电镜(TEM)仪,对Al2O3/ZrO2层状复合陶瓷的显微结构特征及断口形貌进行深入分析研究.研究结果表明:表面压应力的作用细化了晶粒,提高了可相变四方相的含量,增加了相变增韧的效果;沿界面两端表现出2种不同的断裂机制:界面以外靠近表面部分,其断裂主要是穿晶断裂;在基体层的断裂则表现为沿晶和穿晶混合型断裂方式.该断裂行为与ZrO2层状陶瓷的相变增韧机制密切相关.

Study on Relation of Microstructure Characteristic and Strengthened Toughness of Al2O3/ZrO2 Laminated Ceramics

With the help of scan electronic microscopy and transmission electronic microscopy, the relationship between microstructure characteristic and fracture micrograph of Al_2O_3/ZrO_2 laminated ceramics is studied. Research results show that the action of surface compression stress leads to grain refining,and allows increased content of transformable tetragonal t-ZrO_2,and effect of strengthened toughness of phase transition; Both ends of boundary indicate 2 different mechanisms of fracture:transcrystalline rupture appears in the section close to surface outside the boundary; and the fracture at the matrix layer is shown as the mixing mode of fracture along and through the grain boundaries. This fracture behavior is closely related to the mechanism of phase transition increased toughness of ZrO_2 laminated ceramics.