Effects of Processing Technology on Property and Microstructure of Rare Earth Containing Ceramic Composite

摘要

Effects of processing technology on the properties such as relative density, flexural strength, fracture toughness, hardness, etc. and the microstructure of rare earth yttrium containing Al_2O_3/(W,Ti)C ceramic composite were experimentally investigated. It suggests that different processing parameters can undoubtedly result in different micro-structures and different mechanical properties of the material. Under the experimental conditions, the suitable hot pressing temperature is 1720 ～ 1780℃, the time duration is 10 ～ 30 min and the hot pressing pressure is 30 ～ 35 MPa. The corresponding relative density can even be higher than 98%. With SEM and TEM observation, each phases in the ceramic material is found to be in fine grains and distribute homogeneously. Typical fracture feature of the material is the mixture of both intergranular and introgranular fracture. Additionally, the existence of rare earth yttrium containing nanometer or sub-micron meter sized ceramic grains, dislocations and spontaneous microcracks can also contribute to the further improvement of the mechanical properties of the ceramic composite.