Archive | 2021
Numerical and Experimental Study on Microstructure Evolution of Ti-6Al-4V Alloy Shaft Perform in Cross-Wedge Rolling Process
Abstract
\n To seek a fundamental understanding for further improving the Ti-6Al-4V alloy utilization of Cross-Wedge Rolling (CWR) and the comprehensive mechanical properties of shaft parts, the effect of the CWR processing parameters on the microstructure evolution of Ti-6Al-4V alloy shaft preform is studied in this paper. An Arrhenius-type microstructure structure evolution model was employed and implemented into the finite element software DEFORM-3D. The average grain size and dynamic re-crystallization volume fraction distribution in the α+β two-phase region and the β single phase region under different rolling temperature, roller rotating speed and area reduction were analyzed, respectively. It is finding that the area reduction, rolling temperature and roller rotating speed significantly affect the microstructure evolution of Ti-6Al-4V alloy. Meanwhile, the corresponding CWR and Metallographic experiments were conducted to verify the reliability of the FE simulation results. Results showed that the agreement of the process parameters effect on dynamic recrystallization in the α+β two-phase region between simulation and experimental is reasonably good. The difference in average grain size in the β phase region between simulation and experimental is ranged from 5.77% to 18.56%. In addition, the evenly distributed microstructure can be found as the area reduction of 50%, rolling temperature of 950℃ and the speed of 5 r⋅min−1 were employed. After rolling under optimized processing conditions, the tensile strength of Ti-6Al-4V alloy shaft preform increased by 18.57% and the plasticity enhanced significantly due to smaller grain size and bi-model microstructure obtained.