LEI Huicong1，XIE Zhipeng 2，AN Di2
(1. School of Materials Science and Engineering, Jingdezhen Ceramic University, Jingdezhen 333403, Jiangxi, China; 2. State Key Laboratory of New Ceramics and Fine Technology, School of Materials, Tsinghua University, Beijing 100084, China)
Abstract: ATZ ceramics(20 wt.% Al2O3＋80 wt.% 3Y-ZrO2) have excellent room temperature mechanical strength, high temperature mechanical properties and strong hydrothermal aging resistance.ATZ ceramics with high strength and hardness were prepared by using spark plasma sintering. The densification process and strengthening and toughening mechanism were deeply studied. The ATZ ceramics have few defects due to the action of the pressure and electricity. The optimized sample, with sintering temperature of 1450℃ and grain size of 298 nm,exhibited bending strength and Vickers hardness of as high as 1767MPa and 14.5GPa, respectively. Both high-density semi-coherent grain boundary and coherent grain boundary were observed, according to the transmission electron microscopy(TEM) images. The special grain boundary structure and fine grain are responsible for the high strengthand high hardness of the ATZ ceramics.
Key words: ATZ Ceramics;spark plasma sintering; ultrahigh strength