材料科学
热稳定性
合金
热的
冶金
复合材料
热力学
化学工程
物理
工程类
作者
X.L. Wang,Kefu Gan,Bin Liu,Qiankun Yang,Yong Zhang,Dingshun Yan,Zhiming Li
标识
DOI:10.1016/j.jmst.2024.03.002
摘要
We developed a novel low-activation, ultrafine-grained W-Cr-V multicomponent alloy (MCA) with excellent 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 less than 2 μm after heating at 1500°C 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°C and below. Furthermore, the average high-temperature compressive strength of the alloy was over 1376 MPa at 1100°C, 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.
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