Transformation toughening of Al₂O₃/ZrO₂ laminated ceramics with residual compressive stress

Bei Chen1,2), Chuan Cheng2), Lan Xiong1), and Li-Ao Wang2) 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

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 tem- perature, 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：