CrMnFeVCu系高熵合金的微观组织和性能  

Microstructure and Mechanical Properties of CrMnFeVCu High Entropy Alloys

作　　者：宋若康 张琳 Song Ruokang;Zhang Lin(Beijing System Design Institute of Electro Mechanic Engineering,Beijing 100854,China;Bgrimm MTC Technology Co.,Ltd,Beijing 102628,China)

机构地区：[1]北京机电工程总体设计部,北京100854 [2]北矿检测技术有限公司,北京102628

出　　处：《稀有金属材料与工程》2021年第10期3707-3713,共7页Rare Metal Materials and Engineering

基　　金：国家高技术研究发展计划(“863”计划)(2012AA03A513)。

摘　　要：在CrMnFeV四元合金的基础上添加奥氏体形成元素Cu元素,同时降低Mn元素含量,并采用电弧熔炼+铜模吸铸工艺制备了CrMnFeVCu系高熵合金,并系统研究了合金的成分设计和元素配比对高熵合金组织和性能的影响机理。结果表明,CrMnFeV四元合金由bcc固溶体和极少量B2颗粒组成,CrMn_(x)FeVCu_(0.2x)(x=0.3,0.5,0.7,1.0)合金由bcc结构的树枝晶相和fcc结构的枝晶间相组成,且随着Cu含量的增加,fcc枝晶间相的体积分数和尺寸逐渐增大,相形态从颗粒状逐渐转变为长条状和块状。压缩试验表明,CrMn_(0.3)FeVCu_(0.06)合金的屈服强度最高(1273 MPa),且塑性优异(εf=50.7%)。进一步增加Cu含量,合金的力学性能逐渐降低。这主要归因于CrMn_(x)FeVCu_(0.2x)合金中主要的强化机制是位错强化和第二相强化,而fcc相尺寸的增大会降低第二相强化的效果。A series of Cr-Mn-Fe-V-Cu high-entropy alloys were designed by adding Cu and decreasing Mn in CrMnFeV alloy,and prepared using arc melting and suction casting.The effects of composition on microstructure and mechanical properties of CrMnFeVCu HEAs were systematically investigated.It is found that the CrMnFeV HEA is consisted of bee and minor B2 phases,whereas the CrMn_(x)FeVCu_(0.2x)HEAs are consisted of bee and fee phases.With increase of Cu content,the volume fraction and grain size of fee phase increase,and the morphology of the fee phase transforms from granular particles to long strips and blocks.The compression test shows that the CrMn_(0.3)FeVCu_(0.06)alloy exhibits the highest compressive yield strength(1273 MPa)and excellent ductility(εf=50.7%).However,further increase of Cu content can reduce the mechanical properties of the HEA.The dislocation and precipitate strengthening are responsible for the high strength of the CrMn_(x)FeVCu_(0.2x)HEAs.With increase of Cu,therefore,the long strip and block shaped fee phase would degrade the precipitate strengthening effect.

关 键 词：高熵合金 树枝晶 固溶体 强化机制 

分 类 号：TG139[一般工业技术—材料科学与工程] TG113[金属学及工艺—合金]