Effect of Y2O3 and Sm2O3 on sintering and mechanical behaviors of alumina ceramics

The effects of Y2O3 and Sm2O3 doping on the sintering temperature, microstructure and mechanical behaviors of Al2O3 ceramics were investigated. The experimental results show that the sintering temperature can be decreased and the mechanical behavior can be improved by adding rare earth in alumina ceramics. The relative density of rare-earth-doped alumina ceramics reaches 98.8% after sintering at 1600 degreesC for 2 h, and its bending strength and fracture toughness reach 439 MPa and 5.28 MPa (.) m(1/2), respectively. Introduction of Y2O3, and Sm2O3 in Al2O3 can restrain the Growth of grains, refine the size of grains, and thus form a fine-grained structure. The fracture characteristic is the mixed modes of intergranular and transgranular fracture.