Accelerated precipitation of the B2 particles and its effect on Al0.3CoCrFeNi high-entropy alloy by electric current assisted annealing

Abstract

Precipitation of the B2 particles in Al0.3CoCrFeNi high-entropy alloy requires a considerably long time of the thermal exposure. Electric current has proved its capacity to accelerate atomic diffusion. We carried out electric current assisted annealing and proposed a finite precipitation growth model considering gradually reduced growth rate in this study. The proposed model reveals that current boosts precipitation growth by lowering its diffusion activation energy QD leading to the reduction of the required annealing time into 90 min. Owing to the combined contribution of the precipitation strengthening and twinning, the ultimate tensile strength increases from 781.3 to 870.2 MPa after annealing. The precipitated B2 particles also increase Vickers hardness of the sintered sample from 196.6 ± 4.7 to 227.2 ± 4.9 HV. As a consequence, its wear resistance enhances as the volumetric loss vs decreases from 2.392 × 10−1 to 1.897 × 10−1 mm3.