Hot workability of as-cast Ti-45Al-5.4V-3.6Nb-0.3Y alloy

In this paper, the hot workability of as-cast Ti-45Al-5.4V-3.6Nb-0.3Y (at.%) alloy under hot deformation conditions in the strain rate ranging from 0.005 s^-1 to 1 s^-1 and the temperature ranging from 1100 C to 1200 C was investigated by implementing a series of hot compressive test, analyzing the true stress and true strain data, and observing the microstructure changes. A hot processing map for as-cast Ti-45Al-5.4V-3.6Nb-0.3Y (at.%) was developed, based on the dynamic materials model (DMM) and experimental data. It showed that there were four different domains, for Ti-45Al-5.4V-3.6Nb-0.3Y alloy, according to the efficiency of power dissipation η, and a much safer hot working window was disclosed, which was that the deformation temperature was higher than 1150 C, and the deformation rate was lower than 0.01 s ^-1. Also different deformation mechanisms for different domains were illustrated from the aspect of microstructure changes during the process of deformation, and a sound as-forged Ti-45Al-5.4V-3.6Nb-0.3Y alloy was successfully manufactured conducted by the developed hot processing map.