Dynamic Mechanical Properties and Modified Material Constitutive Model for Hot Forged Ti₂AlNb over Wide Ranges of...

In this paper, the stress-strain curves of Ti₂AlNb are established based on uniaxial impact tests over wide ranges of temperature and strain rate. The Ti₂AlNb exhibited the work hardening effect but did not show an obvious yield stage during a quasi-static compression test. In the SHPB test, an obvious temperature softening effect was found, the strain rate strengthening effect was detected when the strain rate was 4000-8000 s^-1, and the strain rate softening effect was detected in the range of 8000-12,000 s^-1. A function describing the effect of strain rate on the strain rate strengthening parameters under various temperatures was proposed to modify the basic J-C constitutive model. The relative errors between the experimental measured value and predicted values in various experimental conditions with a modified J-C model were less than 5.0%. The results verified that the modified J-C model could accurately describe the dynamic mechanical properties of Ti₂AlNb at high temperatures and strain rates. The research could help to illustrate the cutting mechanism and finite element simulation of Ti₂AlNb alloy.