Effect of the strain on processing maps of titanium alloys in isothermal compression

Effect of the strain on the grain size, the efficiency of power dissipation and the instability parameter are investigated in the isothermal compression of Ti–6Al–4V alloy. And, the processing maps in the isothermal compression of Ti–6Al–4V alloy, Ti–5.6Al–4.8Sn–2.0Zr alloy and Ti–10V–4.5Fe–1.5Al alloy are constructed at a series of strains. Those results show that the grain size of primary α phase of Ti–6Al–4V alloy varies significantly with strain. The effect of strain on the efficiency of power dissipation is significant at strain rates of 0.001 s−1 and 10.0 s−1. However, the efficiency of power dissipation varies significantly with strain at a strain rate of 0.1 s−1 in the α + β two-phase region, but that does slightly in the β single-phase region. And, the instability parameter of Ti–6Al–4V alloy varies significantly with strain at each strain rate and deformation temperature. Effect of the strain on the unstable regions in the processing maps of isothermally compressed Ti–6Al–4V alloy, Ti–5.6Al–4.8Sn–2.0Zr alloy and Ti–10V–4.5Fe–1.5Al alloy are obtained. Compared with the processing maps of different types titanium alloys, it can be found that the effect of strain on the processing map of Ti–10V–4.5Fe–1.5Al alloy (a kind of β type titanium alloy) is most significant, that of Ti–6Al–4V alloy (a kind of α + β type titanium alloy) is secondary and that of Ti–5.6Al–4.8Sn–2.0Zr alloy (a kind of near α type titanium alloy) is less.