Numerical prediction of Biphasic Titanium Alloys Microstructure in Hot Forging Operations.

Abstract

Modern transportation industries shall comply with two demanding requirements: reducing operational consumption together with production costs coming from materials and labour. Current trend of engineering is oriented to meet both requirements increasing the rate of polymer matrix composites which implies association with structures made of titanium alloys. Hot forming can be used to reduce the production costs of titanium components: forging in closed dies of billets or semi finished form, in the temperature range where the Beta phase of titanium is stable, grants an adequate plasticity of the Ti-6Al-4V alloy, the most commercially used, allowing production of complex shapes with limited amount of edge trim removal and machining rework after forging. Unfortunately, as far as Ti6Al4V titanium alloy is regarded, several material peculiarities have to be properly taken into account. In the paper, a numerical model is presented for hot forging of Ti-6Al-4V titanium alloy. Once set up, the model was tested through comparison with experimental data found in literature. A good agreement between the numerically calculated and the experimentally measured data was observed, indicating that the model can be utilized as a design tool in complex hot forging processes of titanium alloys.