HfZrTiTaAl 系高熵合金动态变形、损伤及破坏行为

High-entropy alloys are applied in extreme environments, such as high-speed collision and explosive impact,due to their excellent comprehensive mechanical properties. To study the deformation, damage,and failure behaviors of high-entropy alloys under dynamic loading,HfZrTiTaAl-based refractory high-entropy alloys are designed and prepared. Quasi static compression experiment and split Hopkinson bar (SHPB) experiment are conducted on the high-entropy alloys, and the Johnson-Cook constitutive model parameters containing damage are obtained through numerical simulation. The damage evolution process and failure of material under dynamic loading are simulated. The results indicate that the refractory high-entropy alloy exhibits good plasticity under quasi-static compression conditions. Within the strain rate range of 0. 001 s^-1 -3 500 s^-1,the HfZrTiTaAl-based high-entropy alloy exhibits a strain rate effect,with a yield strength increasing from 1 140 MPa to 1 568 MPa. Numerical simulation shows that the damage of specimen is mainly concentrated on the cross-section at 45° angle to the loading direction under high strain rate loading,and the damage degree of the elements in the middle of the specimen is greater than that of the elements on both sides of the specimen. As the loading strain rate increases,the percentage of elements with a damage degree greater than 0. 8 in the total specimen elements gradually increases.