Preparation of Al_2O_3-YAG Composite by the Heterogeneous Precipitation Method
WANG Hong-Zhi; GAO Lian; LI Wei-Qun(State Key Lab of High Performance Ceramics and Superfine Microstructure, Shanghai Institute ofCeramics, Chinese Academy of Sciences, Shanghai 200050, China)
Zeta potential of YAG powder was measured, and well-dispersed YAG aqueous sus-pension could be obtained through regulating pH value. Al_2O_3-YAG composite powder containinguniformly distributed YAG was prepared by using the heterogeneous precipitation method. Sintered bodies were gotten by hot-pressing, and addition of YAG influenced little on sintering temperature. Bending strength and fracture toughness of Al_2O_3-5vol%YAG composite were 485MPaand 4.2MPa·m~1/2 respectively. Both were higher than those of monolithic Al_2O_3 ceramics, andthe reliability of values was also better than that of Al_2O_3 ceramics. Through TEM observa-tion, it could be seen that YAG particles were uniformly distributed throughout materials. Itindicated that Al_2O_3-YAG composite with good YAG dispersion could be obtained by using theheterogeneous precipitation method.