Investigation of the Workability and Response of Ti-6Al-4V Titanium alloys at Lower Elevated Temperature and Higher Strain Rate

摘要

Titanium and its alloys have a wide range of applications in various industries such as aerospace, medical, automotive and even commercial products. However, formability of titanium alloys has always been an issue. This study presents the results of an investigation on the workability and response of Ti-6Al-4V deformed at different strain rates and lower elevated temperatures with different initial microstructures. Compression tests of cylindrical specimens were performed at various temperatures (300 deg C, 400 deg C, 450 deg C, 500 deg C) and at different strain rates (0.001 s~(-1), 0.02 s~(-1) and 0.1 s~(-1)). The effects of strain rate, temperature and initial microstructure on the workability of the Ti alloy were investigated. Based on these experimental results, workability maps for the respective initial microstructures were developed. Results showed that temperature played an important role in the formability of Ti-6Al-4V titanium alloys unlike strain rate. In addition, feasibility study on Multi-Directional Forging (MDF) was performed and positive results were obtained. It was demonstrated that Ti-6Al-4V titanium alloys can undergo severe plastic deformation at lower elevated temperature (400 - 500 deg C) and at a higher strain rate of 0.1 s~(-1).