共晶高熵合金C_(x)CoCr_(3)Fe_(5)Ni强度-韧性协同效应  

Synergistic strengthening and toughening of eutectic C_(x)CoCr_(3)Fe_(5)Ni high entropy alloy

作　　者：黄思睿 张继峰 朱和国[1] Si-rui HUANG;Ji-feng ZHANG;He-guo ZHU(College of Materials Science and Engineering,Nanjing University of Science and Technology,Nanjing 210094,China)

机构地区：[1]南京理工大学材料科学与工程学院,南京210094

出　　处：《Transactions of Nonferrous Metals Society of China》2024年第4期1204-1213,共10页中国有色金属学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.51571118)。

摘　　要：通过真空感应熔炼制备C_(x)CoCr_(3)Fe_(5)Ni(x=0,0.1,0.2和0.3,摩尔分数)高熵合金(HEAs),研究碳含量对微观结构和力学性能的影响。随着碳含量的增加,合金相结构由FCC+BCC双相结构转变为M_(23)C_(6)碳化物和FCC相的共晶结构。与CoCr_(3)Fe_(5)Ni基体合金(屈服强度307.5 MPa、极限抗拉强度646.5MPa以及伸长率55.4%)相比,C_(0.2)CoCr_(3)Fe_(5)Ni共晶HEA的屈服强度(378.9MPa)、极限抗拉强度(837.1MPa)和伸长率(56.1%)均显著提高。该合金力学性能的提高主要归因于碳合金化所引起的间隙固溶强化和特殊的共晶结构带来的第二相强化。C_(x)CoCr_(3)Fe_(5)Ni(x=0,0.1,0.2 and 0.3,at.%)high entropy alloys(HEAs)were prepared via vacuum induction melting.The effects of carbon content on the microstructures and mechanical properties of the HEAs were intensively investigated.With the increase of the carbon content,the phase structure transforms from a dual-phase(FCC+BCC)to a eutectic mixture(FCC phase+M_(23)C_(6) carbide).Compared to CoCr_(3)Fe_(5)Ni base alloy,the C_(0.2)CoCr_(3)Fe_(5)Ni eutectic HEA exhibits a significantly improved yield strength(from 307.5 to 378.9 MPa),ultimate tensile strength(from 646.5 to 837.1 MPa),and ductility(from 55.4% to 56.1%).It is shown that these comprehensive enhancements of strength and ductility result from the effect of interstitial solid solution strengthening by carbon alloying and second phase strengthening via the eutectic structure.

关 键 词：高熵合金 M_(23)C_(6)碳化物 共晶组织 力学性能 强化机制 

分 类 号：TG139[一般工业技术—材料科学与工程]