Microstructure and mechanical properties of beta TiAl alloys elaborated by spark plasma sintering

The microstructure evolution and room temperature mechanical property of beta containing Ti-44Al-3Nb-1Mo-1V-0.2Y alloy consolidated by spark plasma sintering was studied. Pre-alloyed powders were sintered for 2 min in the range 900-1250 °C under 100 MPa. It was found that duplex and lamellar microstructures were obtained depending on the SPS temperature. The duplex microstructure formed at 1150 °C and 1175 °C, and the lamellar structure was achieved above 1200 °C. However, coarsening of lamellar colonies occurred with further increasing of the sintering temperature. The specimen with fine lamellar colonies exhibited a relatively high compressive strength, whereas the one with duplex microstructure showed a superior final strain.