High Temperature Forming of Ti-6Al-4V Alloy Considering Microstructural Evolution

A study has been made to investigate the high temperature deformation behavior of Ti-6Al-4V alloy and to predict the final microstructure under given forming conditions. Equiaxed and Widmanstatten microstructures of Ti-6Al-4V alloys were prepared as initial microstructures. By performing the compression tests at high temperatures (700 similar to 1100degreesC) and a wide range of strain rates (10(4) similar to 10(2)/s), various parameters such as strain rate sensitivity (m).and activation energy (Q) were calculated and used to establish constitutive equations. When the specimens were deformed up to epsilon(c) approximate to 0.6, equiaxed microstructure did not show any significant changes in microstructure, while Widmanstatten microstructure revealed considerable flow softening, which was attributed to the globularization of a platelet at the temperature range of 800similar to970degreesC and at the strain rate range of 10(-4)similar to10(-2)/s. To predict the final microstructure after forming, finite element analysis was performed considering the microstructural evolution during the deformation. The grain size and the volume fraction of second phase of deformed body were predicted and compared with the experimental results.