Superplastic properties in a Ti5Al3Mo1.5 V titan alloy processed by multidirectional forging process

Abstract

In this study, ultrafine grains in microstructures of Ti5Al3Mo1.5 V titan alloy was achieved by the multidirectional forging (MDF) process. The essence of the MDF is pressing steps combined with rotations of the workpiece in all directions within a forging cycle. The MDF process was performed for one to three cycles at temperatures from 850 °C to 950 °C. The achieved average grain size in the microstructure is about 1 µm at 900 °C after the third cycle. Subsequently, the superplastic properties after the MDF process were studied. Tensile tests that evaluate the superplastic deformation ability of alloy are performed at high temperatures from 800 °C to 900 °C and the strain rates in the range 10-3 s−1 –9.10-3 s−1. The result obtained the maximum relative elongation of 1120%, showing an exceptional enhancement of superplasticity of the studied alloy.