Cr含量及热处理对NbMoZrAl基高熵合金微观组织与力学性能的影响  

Effects of Cr Addition and Heat Treatment on Microstructure and Mechanical Properties of NbMoZrAl Based High Entropy Alloys

作　　者：王涛 时洁 潘虎成 商洪宇 滕常青 张伟 杨吉军[3] 吴璐[2] WANG Tao;SHI Jie;PAN Hu-cheng;SHANG Hong-yu;TENG Chang-qing;ZHANG Wei;YANG Jijun;WU Lu(Key Laboratory for Anisotropy and Texture of Materials(Ministry of Education),College of Materials Science and Engineering,Northeastern University,Shenyang 110819,Liaoning,China;The First Sub-Institute,Nuclear Power Institute of China,Chengdu 610041,Sichuan,China;Key Laboratory of Radiation Physics and Technology,Ministry of Education,Sichuan University,Chengdu 610064,Sichuan,China)

机构地区：[1]东北大学,材料科学与工程学院,材料各向异性与织构教育部重点实验室,辽宁沈阳110819 [2]中国核动力研究设计院第一研究所,四川成都610041 [3]四川大学辐射物理与技术教育部重点实验室,四川成都610064

出　　处：《铸造》2024年第9期1210-1217,共8页Foundry

基　　金：国家自然科学基金(U2067218,U2167213,U2241235);四川省科技厅项目(21MZGC0400,2022JDJQ0021);中国核工业集团有限公司青年英才菁英项目(CNNC-2021-31);反应堆燃料与材料国家重点实验室项目(6142A06190510);中央高校基本业务费项目(N2202020)。

摘　　要：采用真空电弧熔炼的方法制备了高熵合金(Nb_(70)Mo_(10)Zr_(10)Al_(10))_(100-x)Cr_(x)(x=5,10,15 at.%),通过X射线衍射仪(XRD)、扫描电镜(SEM)、能谱仪(EDS)和电子万能试验机等研究了Cr含量和高温热处理对该合金微观组织和力学性能的影响。结果表明,随着Cr元素的添加,合金中析出了Cr_(2)(Nb,Zr)型第二相,随着Cr元素含量的增加,第二相的体积分数增加且枝晶细化;经过1200℃、24 h的高温热处理后,更多的Cr元素扩散析出到枝晶间形成Laves相,并与Al-Zr相交错分布。NbMoZrAl-Cr合金压缩屈服强度逐渐从0Cr合金的945 MPa提升到5Cr合金的1153 MPa、10Cr合金的1212 MPa以及15Cr合金的1305 MPa,第二相强化及细晶强化是屈服强度提升的主要原因。相关结果将为新型难熔高熵合金的设计提供一定的参考和依据。In this work,the high entropy alloys(Nb_(70)Mo_(10)Zr_(10)Al_(10))_(100-x)Cr_(x)(x=0,5,10,15,at.%)were prepared by vacuum arc melting.The effects of Cr content and high temperature heat treatment on the microstructure and mechanical properties of the alloys were studied by means of X-ray diffraction(XRD),scanning electron microscopy(SEM),energy dispersive spectroscopy(EDS)and universal testing machine.The results show that with the addition of Cr element,the Cr_(2)(Nb,Zr)type second phase is precipitated in the alloy,and with the increase of Cr element content,the volume fraction of the second phase increases and the dendrites are refined.After high temperature heat treatment at 1200℃,more Cr elements diffuse and precipitate into the interdendritic region to form Laves phase,which is interlaced with Al-Zr phase.Therefore,with the increase of Cr content,the compressive yield strength of NbMoZrAl-Cr alloy gradually increases from 945 MPa of 0Cr alloy to 1153 MPa of 5Cr alloy,1212 MPa of 10Cr alloy and 1305 MPa of 15Cr alloy.The main mechanism of strength improvement is second phase strengthening and fine grain strengthening.The relevant results would provide reference and basis for the design of new refractory high-entropy alloys.

关 键 词：难熔高熵合金 高温热处理 力学性能 热稳定性 第二相 

分 类 号：TG249.3[金属学及工艺—铸造]