Hydrogen retention and affecting factors in rolled tungsten: Thermal desorption spectra and molecular dynamics simulations
Hydrogen retention and affecting factors in rolled tungsten: Thermal desorption spectra and molecular dynamics simulations
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DOI：
10.1016/j.ijhydene.2023.03.151
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发表时间：
2023-08-24
影响因子：
7.2
通讯作者：
Wu，Yucheng
中科院分区：
文献类型：
--
作者：
Chen，Hongyu;Wang，Lin;Wu，Yucheng
钨在核聚变反应堆中的氢同位素滞留问题沿着是研究的热点之一。本文对不同轧制表面的钨样品进行了机械抛光、D2+辐照和热脱附处理。为了更好地理解实验观察结果，本研究还进行了分子动力学（MD）模拟，并研究了温度，晶粒数，晶界密度和晶体取向对氢保留的影响。结果表明，在RD/TD、RD/ND和TD/ND三个表面上，轧制钨的晶粒数和晶界密度依次增加。RD/ND表面表现出最好的抗氢辐射性，而TD/ND表面不令人满意。MD模拟进一步表明，随着钨晶粒密度的增加，氢的滞留更加明显，氢原子更容易在晶界富集。随着温度的升高，氢原子在单晶/多晶钨中的保留率显著降低。氢原子的平均注入深度在沿着<111>和<112>晶向最深，这表明氢的保留依赖于晶体取向。模拟结果与实验数据吻合较好，表明晶界对氢的保持起着重要作用。
Hydrogen isotope retention of tungsten in nuclear fusion reactors is one of the hot research issues all along. In this paper, tungsten samples in different rolled surfaces were polished by mechanical processing, subsequently subjected to D2+irradiation and thermal desorption. To better understand the experimental observations, this study also performed molecular dynamics (MD) simulation and investigated the effects of temperature, grain number, grain boundary density, and crystal orientation on hydrogen retention. It is found that the grain number and grain boundary density of rolled tungsten increase successively in RD/TD, RD/ND, and TD/ND surfaces. The RD/ND surface exhibits the best hydrogen radiation resistance, whereas the TD/ND surface is unsatisfactory. MD simulations further indicate that hydrogen retention is more obvious with the increase of grain density in tungsten, and hydrogen atoms are more easily enriched at the grain boundaries. With the increase in temperature, the retention of hydrogen atoms in monocrystalline/polycrystalline tungsten decreases significantly. The average implantation depth of H atoms is deepest along the <111> and <112> crystalline directions, which reveals that hydrogen retention is dependent on the crystal orientations. The good agreement between the experimental data and simulation results reveals that grain boundaries play an important role in hydrogen retention.