The Effects of the Third Element(Cr, Mo, Mn) on the Mechanical Properties of the Combustion Synthesized TiAl with Co/Al Sintering Additive

In this paper, the effects of the third element (Cr, Mo, and Mn) on the mechanical properties of TiAl intermetallic compound made by combustion synthesis were considered. The powders of Ti, Al, Co, and the third element (Cr, Mo, and Mn) were mixed. The green compact was made from the mixed powder, and was reacted in an electric vacuum furnace. The density, the microstructure, the hardness, and the compressive strength of the obtained synthesized products were investigated. The density of the synthesized products became more than 90% by Co/Al sintering additive. The grain size of them was 20 μm. The components of the synthesized products were TiAl and Ti3Al. As addition quantity of the third element increased, the hardness of them rose and the strength of them fell. The ductility of the synthesized product that added Cr 5% especially is excellent. Further the fracture surfaces of them were discussed.