钛锆基单相贮氚高熵合金薄膜的制备及固氦性能研究

Due to tritium decay, it produces helium isotope in metals. In addition to their insolubility in metals, the produced helium atoms have a tendency of accumulating, precipitating, and forming helium-vacancy complexes, even helium bubbles. With the increase of helium content, the helium bubbles are easily growing up at the grain boundaries, phase boundaries, and dislocations, resulting in swelling and then reducing the mechanical properties of materials. Based on the unique distortion crystal structure and the atomic stress distribution of high entropy alloy, TiZr-based single-phase high entropy alloys for tritium storage will be designed and prepared in this work, as well as the relevant single-phase high entropy alloy films prepared by physical vapor deposition (PVD) method, in which helium ions with low energy are injected in situ. By thermal treatment, structural analysis, semi-in-situ microscopic observation, and the early analysis of post-tritium aging, we will study the phase structure and thermostability of the high entropy alloy films, the microscopic information and the evolution behavior of helium bubbles in high entropy alloy, and evaluate the practical significance of this simulating test method. Through revealing the helium retention performance and mechanism in high entropy alloy, it may provide new basis and guidance to the designing of tritium storage materials with both high tritium storage capacity and excellent helium retention performance in the future.

由氚衰变而产生于金属中的氦，不溶于材料基体，积累的氦将聚集、沉淀，形成氦-空位复合物，乃至形成氦泡。随氦含量增加，氦泡易于在晶界、相界及位错处聚集长大，导致材料宏观性能下降。基于高熵合金独特的畸变晶体结构和原子应力分布，本项目拟设计和制备钛锆基单相贮氚用高熵合金，采用物理气相沉积（PVD）方法制备单相高熵合金薄膜，并原位产生含He材料，采用热处理、结构分析、半原位微观观测、充氚后时效早期分析等，研究高熵合金薄膜的相结构和热稳定性，高熵合金中的氦泡显微信息和氦泡演变行为，并评估该模拟实验方法的实用意义。通过揭示高熵合金的固氦性能及其固氦机制，为设计兼具高贮氚容量和高固氦性能的新型贮氚材料提供依据和指导。

由氚衰变而产生于金属中的氦，不溶于材料基体，积累的氦将聚集、沉淀，形成氦-空位复合物，乃至形成氦泡。随氦含量增加，氦泡易于在晶界、相界及位错处聚集长大，导致材料宏观性能下降。基于高熵合金独特的畸变晶体结构和原子应力分布，本项目通过合金设计，成功获得了TiZrHfScMo、TiZrHfVNb、TiZrHfMoNb等多种单相bcc结构的高熵合金，并进行了分析表征；完成了单相高熵合金膜材的制备与表征。完成了含氦单相高熵合金薄膜的制备、热处理及表征；验证了高熵合金薄膜的吸氘性能及吸氘后结构稳定性，为探索其贮氚可行性奠定基础；获得了含氦高熵合金薄膜中氦泡的显微信息，并与纯Ti及TiY二元合金的固氦能力作比较。通过本项目的研究，成功掌握了具有高贮氚量、高固氦性能的单相高熵合金及对应膜材的设计技术和制备技术，初步获得了贮氚用高熵合金的固氦性能及其固氦机制，为设计兼具高贮氚容量和高固氦性能的新型贮氚材料提供了依据和指导。