Microstructure and Mechanical Properties of In-situ Synthesized Al2O3/TiAl Composites

Al2O3 particle-reinforced TiAI composites are successfully reaction-synthesized from the powder mixture of Ti, A1, TiO2, and Nb2O5, using the hot pressing reaction synthesis technique. The microstmcture and mechanical properties of the as-sintered products are investigated. It is found that in the as-sintered products consisting of γ-TiA1, α2-Ti3Al, Al2O3, and NbAl3 phases, the f'me Al2O3 particles tend to disperse on the grain boundaries. With the Nb2O5 content increasing, the grains are remarkably refined and the Al2O3 particles are dispersing more uniformly in the TiAI matrix, forming a partial lamellar structure containing γ and lamellar phases. The hardness of the in-situ composites increases gradually, and the bending strength and the fi-acture toughness of the as-sintered products reach the maxi-

作 者： Ai Taotao   作者單位： Department of Materials Science and Engineering, Shaanxi University of Technology, Hanzhong 723003, China  刊 名： 中國航空學(xué)報(bào)（英文版）  ISTIC 英文刊名： CHINESE JOURNAL OF AERONAUTICS  年，卷(期)： 2008 21(6)  分類號(hào)： V2  關(guān)鍵詞： TiAI   composites   microstructure   mechanical properties   hot pressing