Effect of solution heat treatment on the stress-induced martensite transformation in two new titanium alloys

Ti-10V-2Cr-3Al and Ti-10V-1Fe-3Al alloys are newly designed two phase titanium alloy for stress-induced martensite (SIM) transformation on the basis of Ti-10V-2Fe-3Al alloy. The effect of solution heat treatment on the SIM transformation in these two alloys was studied through microstructural observation and mechanical property test. The results show that, after β, α + β and β + (α + β) solution treatments, most of the samples contain a highly metastable β microstructure. Under compression loading, the β phase transform to a martensite. The stress at which β to α″ transformation is triggered is very stable to the solution time. The pre-existing thermal martensite has an obstructive effect on SIM transformation. In β + (α + β) solution conditions, tuning the volume fraction of the α phase leads to a sufficiently stable β phase so that no martensite is formed under deformation and only slip is activated. Moreover, the effect of solution temperature on triggering stress is more intense compared with that of solution time.