Modelling of active transformation of microstructure of two-phase Ti alloys during hot working

Being very strong and of limited ductility, Ti alloys require special techniques to manufacture the parts with complex shapes. Many of these technologies are based on superplastic and near-to-superplastic deforming. In these processes the transformation of the microstructure of the material can be very significant and can lead to changes in the mechanical properties of the material during deformation. Because of this an appropriate description of the correlation between mechanical loading, changes in microstructure and mechanical behavior of material is required. A phenomenological scalar model with an internal variable based on a statistical description of microstructure is proposed and used for simulation of the high temperature deformation of Ti-6Al-4V alloy. The problems of obtaining the parameters of the model and sensitivity of the model to the accuracy of this process are discussed