Study on the Evolution of Damage Degradation at Different Temperatures and Strain Rates for Ti-6Al-4V Alloy

Abstract

It is a significant issue to deeply understand the nature relationships between damage degradation and deforming parameters, and then identify the changes of initial ductile fracture time with processing parameters and further adjusting the forming processes for obtaining the fracture-free components. For Ti-6Al-4V alloy, the strain-stress data in the temperature range of 1023-1323 K and strain rate range of 0.01-10 s -1 were obtained by compression tests. The finite element model with stress-strain data was constructed to simulate the ductile damage cumulating processes under different conditions and obtained the maximum damage values. Subsequently, the ductile fracture criterion (DFC) of Ti-6Al-4V alloy was established and the effects of temperature and strain rate on DFC were discussed. The results show that the variation range of DFC under different deformation conditions is 0.07-0.15. Subsequently, the deformation conditions with higher fracture risk were identified as 1200∼1275 K & 1∼10 s -1 and verified with the experiment observations.