Enhanced mechanical performance of grain boundary precipitation-hardened high-entropy alloys via a phase transformation at grain boundaries  

作　　者：Y.L.Qi L.Zhao X.Sun H.X.Zong X.D.Ding F.Jiang H.L.Zhang Y.K.Wu L.He F.Liu S.B.Jin G.Sha J.Sun 

机构地区：[1]State Key Laboratory for Mechanical Behavior of Materials,Xi’an Jiaotong University,Xi’an,710049,China [2]Analytical&Testing Center,Northwestern Polytechnical University,Xi’an,710072,China [3]School of Materials Science and Engineering,Nanjing University of Science and Technology,Nanjing,210094,China

出　　处：《Journal of Materials Science & Technology》2021年第27期271-284,共14页材料科学技术（英文版）

基　　金：supported financially by the National Natural Science Foundation of China(No.51871178)。

摘　　要：Grain-boundary(GB)precipitation has a significant adverse effect on plasticity of alloys,which easily leads to catastrophic intergranular failure in safety-critical applications under high external loading.Herein,we report a novel strategy that uses the local stress concentration induced by GB precipitates as a driving force to trigger phase transformation of preset non-equiatomic high-entropy solid-solution phase at GBs.This in situ deformation-induced phase transformation at GBs introduces a well-known effect:transformation-induced plasticity(TRIP),which enables an exceptional elongation to fracture(above 38%)at a high strength(above 1.5 GPa)in a GB precipitation-hardened high-entropy alloy(HEA).The present strategy in terms of"local stress concentration-induced phase transformations at GBs"may provide a fundamental approach by taking advantage of(rather than avoiding)the GB precipitation to gain a superior combination of high strength and high ductility in HEAs.

关 键 词：Non-equiatomic Grain-boundary precipitation High-entropy alloys DUCTILITY Transformation-induced plasticity 

分 类 号：TG139[一般工业技术—材料科学与工程]