Effect of Y2O3 and Dy2O3 on Microstructure and Mechanical Behaviors of Aluminum Nitride Ceramics

The effects of two types of additives, Y2O3 and Dy2O3, on the sintering and mechanical behaviors of AIN 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 AIN ceramics. The strength of AIN ceramics with Y2O3 and Dy2O3 are 326 and 320 MPa, respectively, which are 97.6% and 93.9% higher than the un-doped AIN ceramics. The fracture behavior on the fracture surfaces of rare earth oxide AIN ceramics was found to be a mixed mode of transgranular fracture and intergranular fracture. As a result, it is concluded that the improvement of bending strength of AIN ceramics with Y2O3 and Dy2O3 addition are mainly achieved by strengthening the grain boundary.