Abstract:
We designed a novel Co-free AlCrFe
2Ni
2Ti
0.5 high-entropy alloy (HEA) that features an excellent combination of strength and ductility in this study. The as-cast AlCrFe
2Ni
2Ti
0.5 alloy showed equiaxed grains undergoing spinodal decomposition, which consisted of ultrafine-grained laminated body-centered cubic (bcc) phases and an ordered body-centered cubic (b2) phase, and some precipitates embedded in the b2 matrix. The bcc and b2 phases also feature a coherent interface. This unique structure impedes mobile dislocations and hinders the formation of cracks, thereby giving the AlCrFe
2Ni
2Ti
0.5 HEA both high strength and plasticity. At room temperature, the as-cast AlCrFe
2Ni
2Ti
0.5 alloy exhibited a compressive yield strength of 1714 MPa, an ultimate strength of 3307 MPa, and an elongation of 43%. These mechanical properties are superior to those of most reported HEAs.