Softening Behavior of Ti6Al4V Alloy during Hot Deformation

Abstract

The effect of strain rate and strain on the hot compression behaviour of Ti6Al4V has been analysed to understand the microstructural evolution and restoration behaviour. Cylindrical samples with partially equiaxed grains were deformed in the α+β region at different thermo-mechanical conditions. EBSD has been used to study the microstructural behaviour and the restoration mechanisms. The microstructural evolution showed a complex restoration behaviour, where both fragmentation and nucleation of new grains have been observed. The volume fraction of the equiaxed grains increased with an increase in the strain, but oppositely decreased with the strain rate. At the same time the average grain size of the equiaxed grains decreased with an increase in both the strain and strain rate. The measured activation energy for deformation revealed a good agreement with reported values in the literature.

An Analysis of the Forgeability of Ti-10V-2Fe-3Al β Titanium alloy using a combined Estrin Mecking and Avrami Material Constitutive Model

“…A comparison of J-C model and modified Zerilli-Armstrong model developed for Ti-6Cr-5Mo-5V-4Al, β titanium alloy provided an accurate prediction of deformation behaviour over high strain rate ranges, although, it failed to predict the work hardening behaviour of the alloy [12]. Among the various reported constitutive models for α+β titanium alloys, a combined Estrin-Mecking and Avrami (EM+Avrami) model is reported to be capable of predicting the flow behaviour in Ti-6Al-4V alloy considering the work hardening and flow softening [13]. Therefore, a constitutive model that can predict the deformation behaviour in Ti-10V-2Fe-3Al alloy, considering the mechanisms related to deformation and microstructural evolution, is needed for the increasing industrial demands.…”