A study on the hot workability of a cast Ti–Al intermetallic compound

The hot deformation behavior of a cast Ti–45Al–2Cr–4Nb–0.4B (numbers indicate at.%) intermetallic compound under hot-working conditions in the temperature range of 1100–1300 °C and strain rate range of 0.01–5 s−1 has been studied by performing a series of hot compression tests. The dynamic materials model (DMM) has been employed for developing the processing maps, which show variation of the efficiency of power dissipation with temperature and strain rate. Also the Kumar's model has been used for developing the instability map, which shows variation of the instability for plastic deformation with temperature and strain rate. The efficiency of power dissipation increased with decreasing strain rate and increasing temperature. High efficiency of power dissipation over 40% was obtained at a finite strain level of 0.2 under the conditions of strain rate lower than 0.1 s−1 and temperature higher than 1200 °C. Plastic instability was expected in the regime of strain rate higher than 0.1 s−1 and temperature lower than 1200 °C.