Synthesis of Al2O3/Ti3Al composites by in-situ displacement reactions

The employment of aluminothermic reactions of displacement as an alternative for the production of The employment of aluminothermic reactions of displacement as an alternative for the production of Al2O3/Ti3Al composite composite materials has been investigated. Compacted samples from an intensely ground mixture of powders of TiO2 + Al2O3 + Al were sintered at 1500 degrees C during 1 hour by hot pressing in an argon atmosphere. The TiO2 is used as predecessor to generate in-situ Al2O3 via its reduction by means of metallic Al. Al reacts also in a simultaneous way with the reduced titanium to form an intermetallic alloy of the type TixAly, The Al2O3 employed in the precursor materials is used as a way for the dissipation of the heat build-up during the aluminothermic reduction of the TiO2. The results of the characterizations indicate that Al2O3-based composite materials were obtained with reinforcement particles of TixAly The microstructure of these materials is dense, fine and homogeneous. The preliminary characterization of the microstructure and its composition features subsequent to the cycle of in-situ processing are presented here.