Abstract:The multi principal element alloy forms a simple phase structure due to high entropy effect, resulting in excellent properties, such as, high strength, high wear resistance, corrosion resistance, thermal stability, and excellent radiation resistance. However, the prediction of mechanical properties of high entropy alloy induced by irradiation is still lack, which seriously limits the evaluation of its long-term service performance. Based on the crystal plasticity theory and experiment, the cavity-shape dependent hardening behavior, dislocation-ring induced hardening behavior and oxide dispersion enhanced mechanical properties in high entropy alloy are studied. The results show that the spatial interaction of polyhedral voids and dislocations in FCC metal is considered, and the yield stress of irradiated FCC metal is accurately predicted; lattice distortion has an important contribution to the yield strength; oxide dispersion plays a strong role in pinning the dislocation movement, thus affecting the strength and directly determining the radiation resistance. As a new type of structural material with comprehensive excellent mechanical properties, high entropy alloy is expected to be widely used in advanced nuclear power systems, such as nuclear fuel cladding tubes of nuclear reactors.