Heterostructured eutectic high-entropy alloys(EHEAs)have attracted significant attention owing to their novel properties,such as balanced combinations of strength and fracture toughness.However,the toughening/strength...Heterostructured eutectic high-entropy alloys(EHEAs)have attracted significant attention owing to their novel properties,such as balanced combinations of strength and fracture toughness.However,the toughening/strengthening mechanisms of these EHEAs have not been thoroughly investigated.In this study,we developed a series of dual-phase Al_((18–2x))Co_(30)Cr_((11+x))Fe_((11+x))Ni_(3)0(x=-1,0,1)eutectic and neareutectic HEAs containing face-centered cubic(FCC)and body-centered cubic(BCC)phases.Despite the high amount of BCC,which is referred to as the brittle phase,newly developed EHEAs exhibited superior fracture toughness.Interestingly,we discovered that a fully eutectic HEA exhibited further improvements in both yield stress and fracture toughness,outperforming our off-eutectic and other previously reported HEAs.By combining experiments and theoretical models,we demonstrated that the synergistic increase in both strength and toughness in our fully eutectic HEA was derived from the high hetero-deformationinduced(HDI)strengthening/toughening associated with a high misorientation angle at the grain/phase boundaries.展开更多
基金supported by the National Research Foundation of Korea(No.NRF-2021R1A6A3A0108674211)the Fundamental Research Program of the Korean Institute of Materials Science(No.PNK8730)by Research Grant Council(RGC),Hong Kong Government,through General Research Fund(Nos.CityU11213118,CityU11200719 and CityU11209317).
文摘Heterostructured eutectic high-entropy alloys(EHEAs)have attracted significant attention owing to their novel properties,such as balanced combinations of strength and fracture toughness.However,the toughening/strengthening mechanisms of these EHEAs have not been thoroughly investigated.In this study,we developed a series of dual-phase Al_((18–2x))Co_(30)Cr_((11+x))Fe_((11+x))Ni_(3)0(x=-1,0,1)eutectic and neareutectic HEAs containing face-centered cubic(FCC)and body-centered cubic(BCC)phases.Despite the high amount of BCC,which is referred to as the brittle phase,newly developed EHEAs exhibited superior fracture toughness.Interestingly,we discovered that a fully eutectic HEA exhibited further improvements in both yield stress and fracture toughness,outperforming our off-eutectic and other previously reported HEAs.By combining experiments and theoretical models,we demonstrated that the synergistic increase in both strength and toughness in our fully eutectic HEA was derived from the high hetero-deformationinduced(HDI)strengthening/toughening associated with a high misorientation angle at the grain/phase boundaries.
