Damage behaviors in microstructures and mechanical properties of pure tungsten induced by repetitive thermal loads
Damage behaviors in microstructures and mechanical properties of pure tungsten induced by repetitive thermal loads
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重复热载荷引起的纯钨微观结构和力学性能的损伤行为
DOI：
10.1016/j.jnucmat.2021.153433
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发表时间：
2022
影响因子：
3.1
通讯作者：
Wu X.
中科院分区：
文献类型：
--
作者：
Wang H.;Xie Z.M.;Zhang L.C.;Han L.;Liu R.;Fang Q.F.;Wang X.P.;Liu C.S.;Wu X.
利用EBMP-30电子束装置研究了ITER级钨在重复热载荷作用下的损伤行为。在反复热载荷作用下，对试样进行了金相观察、背散射电子扫描电镜、背散射电子衍射、原子力显微镜分析和拉伸试验。结果表明，当吸收功率密度（APD）小于10 MW/m2时，对涂层的微观结构、表面形貌和力学性能影响不大。而在30 MW/m2热负荷下，由于再结晶完全发生，材料表面出现严重的损伤，包括沿沿着晶界的突出结构和晶粒随形状演变而明显粗化。此外，在暴露于30 MW/m2的APD和50次热负荷后，拉伸性能急剧恶化，导致极限拉伸强度仅为328 MPa，甚至在300 °C下的总伸长率为零。分析了热载荷、组织演变与力学性能退化之间的关系。
Damage behaviors of ITER grade tungsten (W) induced by repetitive thermal loads have been investigated using an electron beam device EBMP-30. The metallographic observation, backscattered electron scanning electron microscopy, electron backscattered diffraction, atomic force microscopy analysis and tensile tests were carried out after the repetitive heat loads. Results indicate that there are negligible effects on the microstructures, surface morphologies and mechanical properties with the absorbed power densities (APD) lower than 10 MW/m2. While serious damages including the severe surface roughness with protruding structures along grain boundaries, and significant grains coarsening with the evolution of the grain shape occur undesirably due to the full recrystallization during the repetitive 30 MW/m2heat loads. Furthermore, after exposed to an APD of 30 MW/m2with 50 heat loads, the tensile properties deteriorate dramatically, resulting in a limited ultimate tensile strength of only 328 MPa and even a zero total elongation at 300 °C. The relationships between the thermal loads, microstructures evolution and degradation of mechanical properties have been analyzed.