Abstract:The hot deformation behavior of a Ta-particle reinforced TiAl composite was studied. Ti-48Al-2Cr-2Nb- 0.2W(at.%)/20vol.%Ta metal matrix composite was fabricated by spark plasma sintering. The deformation behavior was investigated by hot compression tests at the temperature ranging from 1050 to 1200 °C and the strain rate ranging from 1×10^-3 to 1 s^-1. The constitutive equation containing true strain variables was established. The values of activation energy Q under different strain degrees are between 240 and 280 kJ/mol, which are lower than that of pure TiAl. Based on dynamic material modeling, the processing maps at various strain degrees were established, and the optimized parameters for hot working are 1050-1100 °C and 0.005-0.01 s^-1. The microstructural evolution during deformation was characterized, which indicated that the dynamic recrystallization plays an important role in this process.

Key words: TiAl-based composite; flow behavior; processing map; dynamics recrystallization