Electron backscatter diffraction analysis of strain distribution in adiabatic shear band and its nearby area in Ti-3Al-5Mo-4.5V alloy

摘要

Adiabatic shear bands (ASBs) were produced in the hat shaped specimen of Ti-3AI-5Mo-4.5V alloy by split Hopkinson pressure bar technique. Strain distribution in the ASB and its nearby area was investigated by electron backscatter diffraction technology. Image quality, confidential index and Fit value treated as strain sensitive parameters are applied to evaluate the strain field in the present study. The results show that the region including the ASB and its nearby area can be divided into three parts according to the strain gradient. The first part is the area of the ASB, which has the largest strain in the whole region; the second part is the area within ~2 μm on both sides of the ASB, where the strain is second only to the ASB area; and the last part is far from the ASB area, and the strain there is the smallest. In addition, further analysis reveals that the initiation and propagation of the microcrack could occur more likely in the ASB area than in the other areas.