Study on microstructure evolution and deformation mechanism of Ti-6554 based on power dissipation efficiency at supertransus temperatures

Abstract

The microstructure evolution and deformation mechanism of a Ti-6Cr-5Mo-5 V-4Al (Ti-6554) alloy during high temperature compression is investigated based on the power dissipation efficiency (η). It is found that raising the temperature and decreasing the strain rate can promote the DRX process. Two types of DRX are found: discontinuous dynamic recrystallization (DDRX) and continuous dynamic recrystallization (CDRX). Furthermore, combined with the change of η in the whole strain range and the peak η under different conditions, this study links η with the corresponding deformation mechanism of Ti-6554 alloy. It can be summarized as follows: the corresponding efficiency value of the DDRX process needs to exceed 0.45; the occurrence of CDRX requires that the η value is higher than 0.3. Dynamic recovery (DRV) becomes dominant when the η value is less than 0.3. Some typical instability phenomena appear when the η value is less than 0.2. This study can provide an effective means to determine the deformation mechanism of the Ti-6554 alloy.