A comprehensive mean-field approach to simulate the microstructure during the hot forming of Ti-17

Abstract

Thermomechanical processing of titanium alloys involves several hot forming steps to shape the workpiece and achieve a final microstructure that meets the desired mechanical properties. While mean-field models are commonly used to design the process and understand the influence of the processing route on the final microstructure, they cannot provide detailed spatial information on the local microstructure and stress evolution during the deformation of a workpiece. To address this limitation, we propose a comprehensive approach in which the mean-field model is validated in a region of a cylindrical workpiece at a constant strain rate and temperature during deformation. The validated model is integrated as a material model into a finite element-based software to analyse the effect of the thermomechanical history on the local microstructural and mechanical responses of the α and β phases. The model robustly predicts the role of the α-phase in the microstructural evolution of the β-phase, the α-dynamic globularisation kinetics in regions with different thermomechanical histories, and the influence of strain rate jumps on β-microstructural and mechanical responses. This comprehensive approach provides valuable insights into the intricate interplay between processing parameters, microstructure, and thermomechanical response in titanium alloys.