A novel immiscible high entropy alloy strengthened via L1_(2)-nanoprecipitate  

通过L1_(2)结构的纳米相强化新型不混溶高熵合金

作　　者：WANG Zheng-qin FAN Ming-yu ZHANG Yang LI Jun-peng LIU Li-yuan HAN Ji-hong LI Xing-hao ZHANG Zhong-wu 王政钦;范明雨;张洋;李俊澎;刘力源;韩基鸿;李星豪;张中武(Key Laboratory of Superlight Materials and Surface Technology,Ministry of Education,College of Materials Science and Chemical Engineering,Harbin Engineering University,Harbin 150001,China)

机构地区：[1]Key Laboratory of Superlight Materials and Surface Technology,Ministry of Education,College of Materials Science and Chemical Engineering,Harbin Engineering University,Harbin 150001,China

出　　处：《Journal of Central South University》2024年第6期1808-1822,共15页中南大学学报（英文版）

基　　金：Projects(52001083,52171111,U2141207)supported by the National Natural Science Foundation of China;Project(LH2020E060)supported by the Natural Science Foundation of Heilongjiang,China。

摘　　要：The low-cost Fe-Cu,Fe-Ni,and Cu-based high-entropy alloys exhibit a widespread utilization prospect.However,these potential applications have been limited by their low strength.In this study,a novel Fe_(31)Cu_(31)Ni_(28)Al_(4)Ti_(3)Co_(3) immiscible high-entropy alloy(HEA)was developed.After vacuum arc melting and copper mold suction casting,this HEA exhibits a unique phase separation microstructure,which consists of striped Cu-rich regions and Fe-rich region.Further magnification of the striped Cu-rich region reveals that it is composed of a Cu-rich dot-like phase and a Fe-rich region.The aging alloy is further strengthened by a L1_(2)-Ni_(3)(AlTi)nanoprecipitates,achieving excellent yield strength(1185 MPa)and uniform ductility(~8.8%).The differential distribution of the L1_(2) nanoprecipitate in the striped Cu-rich region and the external Fe-rich region increased the strength difference between these two regions,which increased the strain gradient and thus improved hetero-deformation induced(HDI)hardening.This work provides a new route to improve the HDI hardening of Fe-Cu alloys.低成本的Fe-Cu,Fe-Ni和Cu基的高熵合金展现出了广泛的应用前景。然而,它们的低强度限制了其潜在的应用。在这项研究中,开发了一种新型的Fe_(31)Cu_(31)Ni_(28)Al_(4)Ti_(3)Co_(3)不混溶高熵合金。经过真空电弧熔炼和铜模吸铸后,该高熵合金展示出独特的相分离微观结构,由条纹状的富Cu区域和富Fe区域组成。进一步放大条纹状富Cu区域后发现,它由富Cu的点状相和富Fe区域组成。经过时效处理的合金通过L1_(2)-Ni_(3)(AlTi)纳米析出物进一步强化,实现了优异的屈服强度(1185 MPa)和均匀伸长率(约8.8%)。L1_(2)纳米析出相在条纹状富Cu区域和外部富Fe区域的差异分布增加了这两个区域之间的强度差异,从而增加了应变梯度,进而提高了异质变形诱导硬化的效果。这项工作为提高Fe-Cu合金的异质结构硬化效果提供了新的途径。

关 键 词：heterogeneous microstructure precipitation strengthening high-entropy alloy phase separation mechanical property 

分 类 号：TG139[一般工业技术—材料科学与工程]