An ultrafine-grained low-activation multicomponent alloy with exceptional thermal stability and ultrahigh-temperature mechanical properties

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外文摘要：We developed a novel low-activation,ultrafine-grained W-Cr-V multicomponent alloy(MCA)with excel-lent thermal stability and desirable high-temperature strength.The as-sintered W70Cr15V15(at.％)alloy was mainly composed of a body-centered cubic(BCC)solid solution matrix with an average grain size of～0.45 μm,minor hexagonal close-packed(HCP)phase,and ultrafine oxides at grain boundary(GB)regions.The average grain size of the MCA was＜2 μm after heating at 1500 ℃ for 1 h,showing a high thermal stability of the microstructure.Accordingly,the estimated grain growth exponent n(～7)and the corresponding activation energy(～433 kJ mol-1)of the MCA indicate that diffusion during the grain growth in the present W-Cr-V alloy is dominated by the GB diffusion.Such high thermal stability can be mainly attributed to the significant pinning effects from the in-situ formed oxides at GBs.Besides,the nonequilibrium segregation of Cr and V at GBs also contributes to the thermal stability of the alloy at temperatures of 1200 ℃ and below.Furthermore,the average high-temperature compressive strength of the alloy was over 1376 MPa at 1100 ℃,mainly due to the prominent solid solution and GB strengthening which were still effective at the high temperature.The results indicate that the present low-activation W-Cr-V alloy system with exceptional thermal stability and high-temperature mechanical properties could be a promising candidate for structural materials in future fusion reactors.

外文关键词：

Ultrafine-grainLow-activationRefractory multicomponent alloyThermal stabilityUltrahigh-temperature strengthIn-situ second phases

作者：

Xinkai Wang、Kefu Gan、Bin Liu、Qiankun Yang、Yong Zhang、Dingshun Yan、Zhiming Li

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作者单位：

State Key Laboratory for Powder Metallurgy,Central South University,Changsha 410083,China

School of Materials Science and Engineering,Central South University,Changsha 410083,China

基金：

National Natural Science Foundation of ChinaNational Natural Science Foundation of ChinaNational Natural Science Foundation of ChinaNational Natural Science Foundation of ChinaNatural Science Foundation of Hunan province in ChinaNatural Science Foundation of Hunan province in ChinaNatural Science Foundation of Hunan province in ChinaFundamental Research Funds for the Central Universities of Central South University

项目编号：

519712485220115452101166520201050132023RC10132021JJ100562021JJ407362020zzts072

出版年：

2024

DOI：

10.1016/j.jmst.2024.03.002

材料科学技术(英文版)

中国金属学会中国材料研究学会中国科学院金属研究所

材料科学技术(英文版)

CSTPCD

影响因子：0.657

ISSN：1005-0302

年,卷(期)：2024.197(30)