Dynamic Deformation and Ballistic Properties of Ti-6Al-4V Alloy 2. Dynamic Torsional Properties and Ballistic Performance

摘要

The effects of microstructural morphology on dynamic deformation and fracture behavior and ballistic performance of a Ti-6Al-4V alloy were investigated in this study. Ballistic impact tests were conducted on equiaxed and bimodal microstructures, which were processed by different heat treatments, and then the test data were analyzed in relation to microstructures, tensile properties, and dynamic torsional test data. In the impacted region of the equiaxed microstructure, a number of adiabatic shear bands and cracks were observed to be formed along plastic flow lines, and delamination occurred because of cracking along the plastic flow lines or shear bands. In the case of the bimodal microstructure, shear bands were found in limited area near the impacted region without occurring delamination, and their number was fewer than that of the equiaxed microstructure. Thus, ballistic performance of the bimodal microstructure was better than that of the equiaxed microstructure. The ballistic performance of the two microstructures was also discussed by comparing the possibility of adiabatic shear band formation obtained from dynamic torsional test data.