Arrhenius-Type Constitutive Equation Model of Superplastic Deformation Behaviour of Different Titanium Based Alloys

Abstract

Modelling and predicting the flow behaviour of metallic materials subjected to superplastic deformation is mandatory for providing useful information about the metal forming process. This information helps the designers to reduce the manufacturing time and costs by choosing appropriate deformation conditions based on the models results. The study developed a constitutive model to predict the flow behaviour of various Ti-based alloys (Ti-2.5Al-1.8Mn, Ti-6Al-4V and Ti-4Al-1V-3Mo) at elevated temperatures. The constant strain rate tests within the superplastic temperature and the strain rate ranges for each alloy were performed. The experimental tensile tests results were used to develop the hyperbolic sine Arrhenius-type constitutive models for each alloy. The performance of the developed model for each alloy was evaluated regarding the correlation coefficient (R), the mean absolute relative error (AARE) and the root mean square error (RMSE). The results revealed that the predicted flow stresses have a good agreement with the experimental flow stresses for the studied alloys.