Speaker
Abstract
Yttrium hydride (YHx) exhibits excellent neutron moderating capability and thermal stability, giving it broad application prospects in high-temperature reactors. However, the inherent brittleness of metal hydrides, along with cracking induced by hydrogen-induced phase transformation during the hydrogen absorption process, poses challenges to the fabrication of crack-free yttrium hydride. Microalloying is an effective approach to mitigate hydrogen-induced cracking. In this study, first-principles calculations were employed to systematically investigate hydrogen diffusion behavior, hydrogen-induced phase transformation, and pressure–composition–temperature (PCT) curves in yttrium‑based alloys. The results show that microalloying increases the diffusion coefficient of hydrogen in the yttrium-based alloy, while low-concentration doping does not hinder the phase transformation of YHx along the {0001}HCP/{111}FCC path. Moreover, this study accurately describes the PCT curves of yttrium and yttrium‑based alloys using a purely computational approach.
摘要
氢化钇（YHx）因其优异的中子慢化能力和热稳定性，在高温反应堆中具有广阔的应用前景。然而，金属氢化物固有的脆性，以及金属吸氢过程中因氢致相变引发的开裂，使得无裂纹氢化钇的制备面临挑战。微合金化是缓解氢致开裂的有效手段。本研究采用第一性原理计算方法，系统研究了钇基合金中的氢扩散行为、氢致相变及压力-组分-温度（PCT）曲线。结果表明，微合金化提高了氢在钇基合金中的扩散系数，而低浓度掺杂不会阻碍YHx沿{0001}HCP/{111}FCC路径发生的相结构转变；同时，本研究基于纯计算方法准确描述了钇及钇基合金的PCT曲线。
| 关键词 | 氢化钇；第一性原理计算；扩散；相变；PCT |
|---|---|
| Keywords | Yttrium hydride; first-principles calculations; diffusion; phase transformation; PCT |
