Transformation toughening of Al_2O_3/ZrO_2 laminated ceramics with residual compressive stress  

作　　者：Bei Chen Chuan Cheng Lan Xiong Li-Ao Wang 

机构地区：[1]Key Lab of High Voltage Engineering and Electrical New Technology, Chongqing University, Chongqing 400044, China [2]Institute of Resource and Environment Science, Chongqing University, Chongqing 400044, China

出　　处：《Journal of University of Science and Technology Beijing》2007年第5期449-453,共5页北京科技大学学报（英文版）

基　　金：This work was financially supported by the National Natural Science Foundation of China (No.59995440).

摘　　要：With the help of scanning electronic microscopy and X-ray diffraction, the relationships of microstructure characteristics, phase assemblage, and fracture micrograph of Al2O3/ZrO2 laminated ceramics were studied. Compared with monolithic Al2O3/ZrO2 ceramics, the existence of surface compressive stresses greatly restrained the growth of ZrO2 and Al2O3 grains at high sinter temperature, fined the grain size, and increased the content of metastable t-ZrO2, which made the fracture transformation energy quantity 70% higher than that of the monolithic ceramics. The trans-granular and inter-granular fracture features were observed in the surface and center layers, which further verified that transformation toughening is the main mechanism, whereas, micro-crack toughening is helpful for enhancing fracture toughness.With the help of scanning electronic microscopy and X-ray diffraction, the relationships of microstructure characteristics, phase assemblage, and fracture micrograph of Al2O3/ZrO2 laminated ceramics were studied. Compared with monolithic Al2O3/ZrO2 ceramics, the existence of surface compressive stresses greatly restrained the growth of ZrO2 and Al2O3 grains at high sinter temperature, fined the grain size, and increased the content of metastable t-ZrO2, which made the fracture transformation energy quantity 70% higher than that of the monolithic ceramics. The trans-granular and inter-granular fracture features were observed in the surface and center layers, which further verified that transformation toughening is the main mechanism, whereas, micro-crack toughening is helpful for enhancing fracture toughness.

关 键 词：laminated ceramics transformation toughening fracture micrograph grain size surface compressive stress 

分 类 号：TQ174[化学工程—陶瓷工业]