Mechanical behavior of the HfNbZrTi high entropy alloy after ion irradiation based on micro-pillar compression tests

•Micropillar compression test has application on HfNbZrTi high entropy alloy, and show the irradiation strengthening mechanism, which is less pronounced in the low dose regime.•The examined HEA alloy exhibits superior radiation resistance on yield strength compared to conventional nuclear structural materials. High entropy alloys (HEAs) have exhibited excellent irradiation resistance regarding structure stability. However, limited knowledge has been available on the tendency of mechanical properties of HEAs with body-centered cubic structures after ion irradiation. In this study, the evolution of mechanical properties of the HfNbZrTi irradiated with 3 MeV C ions is studied based on micropillar compression tests. The yield strength increases almost linearly from 974 to 2068 MPa with increasing irradiation doses up to 0.98 dpa. The correlation between the mechanical and microstructural changes agrees well with the prediction of Δδy=αMGb(ND)12, indicating a similar strengthening mechanism with conventional alloys. Nonetheless, the irradiation strengthening effect in this alloy is less pronounced in the low dose regime, and the saturation is postponed, compared with the stainless steel and the 3d metal high entropy alloys with face-centered cubic structures, exhibiting promising irradiation resistance regarding mechanical properties.