The hot deformation behavior and processing map of Ti-47.5Al-Cr-V alloy

The high temperature flow behavior of as-extruded Ti-47.5A1-Cr-V alloy has been investigated at the temperature between 1100 degrees C and 1250 degrees C and the strain rate range from 0.001 s(-1) to I s(-1) by hot compression tests. The results showed that the flow stress of this alloy had a positive dependence on strain rate and a negative dependence on deformation temperature. The activation energy Qwas calculated to be 409 ki/mol and the constitutive model of this material was established. By combining the power dissipation map with instability map, the processing map was.established to optimize the deformation parameters. The optimum deformation parameter was at 1150 degrees C-1200 degrees C and 0.001 s(-1)-0.03 s(-1) this alloy. The microstructure of specimens deformed at different conditions was analyzed and connected with the processing map. The material underwent instability deformation at the strain rate of 1 s(-1), which was predicted by the instability map. The surface fracture was observed to be the identification of the instability. (C) 2015 Elsevier Ltd. All rights reserved.