A study on tensile flow and strain hardening behaviour of β-Titanium at elevated temperatures

In this paper, the tensile flow and work hardening behaviour of Beta titanium alloy was examined over a wide temperature range of 28 to 500°C. The work hardening of the material was modelled using different empirical relations such as Swift, Voce and Ludwigsen and the prediction accuracy of these models were compared with different statistical parameters. The hardening rate of the material was analysed with K-M analysis. The fracture behaviour of the tensile samples was studied using SEM results. The yield strength and ultimate tensile strength of the material was found to be decreased from room temperature to 200°C followed by a gradual increase with increase in temperature. Uniformly distributed serrations were observed in the entire plastic region of the flow curve in the temperature range of 200– 400°C. This serrated behaviour could be due to the manifestation of dynamic strain aging in this temperature range. The Voce hardening model was identified as a best hardening model to describe the material hardening. SEM results revealed the ductile mode of fracture at all temperature with large number of dimples in fractographs.