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

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 degrees C to 950 degrees C. The achieved average grain size in the microstructure is about 1 mu m at 900 degrees 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 degrees C to 900 degrees 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.