热冲击作用下钨钒合金的表面开裂及熔化行为

本文研究了机械合金化+热压（HP）烧结制备的钨钒（W-V）合金在热冲击作用下的表面损伤行为。以合金中钒的质量分数作为变量，探究钒质量分数的变化（1%~10%）对钨钒合金抗热冲击性能的影响。利用光学显微镜、扫描电镜、能谱仪、纳米压痕仪等多种测试方式，分析表征了HP烧结钨钒合金的组织结构特征及其经过热冲击测试后的表面开裂及熔化行为特征。结果表明:在1 800℃、20 MPa的压力条件下保温2 h可以制备出致密度高、合金化程度高的钨钒合金，且随着钒质量分数的增加，合金样品的致密度有所提高；合金样品中钨基体硬度大于富钒相，在高能电子束模拟的国际热核聚变实验堆（ITER）边界局域模（ELMs）热冲击作用下，钨基体对裂纹扩展的阻碍作用明显强于富钒相；随着钒质量分数的升高，合金的开裂阈值和熔化阈值均降低，本文对相关机理进行了讨论。 

Surface cracking and melting behavior of tungsten-vanadium alloys under thermal shock

Surface cracking and melting behavior of tungsten-vanadium (W-V) alloys prepared by mechanical alloying + hot pressing (HP) sintering under thermal shock has been investigated in this paper. Mass fraction of V in the alloy is taken as a variable to explore the effect of mass fraction of V (1%-10%) on thermal shock resistance of W-V alloys. A variety of test methods such as optical microscope, scanning electron microscope, energy disperse spectrometer, and nano indentation are used to analyze the structure characteristics of W-V alloys produced by HP sintering, and the characteristics of surface cracking and melting behavior of W-V alloys under thermal shock. Results show that under the conditions of 1 800℃ and 20 MPa，and with heat preservation for 2 h, W-V alloys with high density and high alloying degree can be produced. Moreover, with the increase of vanadium content, the density of W-V alloys increases. In the alloys, the hardness of tungsten matrix is bigger than vanadium rich phase, and therefore, tungsten matrix's ability of preventing the crack growth is obviously greater than vanadium rich phase, when exposed to thermal shock in international thermonuclear experimental reactor (ITER) edge localized modes (ELMs) which are simulated by high energy electron beam; with the increase of vanadium content, the cracking threshold and melting threshold both decrease. The underlying mechanism is discussed detailed in this paper.