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

Abstract

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 0.005s−1 to 1s−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 0.01s−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.