Novel as-cast AlCrFe2Ni2Ti0.5 high-entropy alloy with excellent mechanical properties

摘要

We designed a novel Co-free AlCrFe2Ni2Ti0.5 high-entropy alloy(HEA)that features an excellent combination of strength and ductility in this study.The as-cast AlCrFe2Ni2Ti0.5 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 AlCrFe2Ni2Ti0.5 HEA both high strength and plasticity.At room temperature,the as-cast AlCrFe2Ni2Ti0.5 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.