报告题目：Phase composition and crystal structure of High-Entropy Alloys for hydrogen storage

报告时间：2025-09-08，周一上午10:30

报告地点：大学城B5副楼三楼会议室

主办单位：材料科学与工程学院

报告人简介：

Jacques Huot 教授的研究领域是金属-氢相互作用的理解和表征，特别是金属氢化物。 Huot 教授还对合成具有适合工业条件的储氢特性的新型低成本金属氢化物感兴趣。他正在研究纳米材料和经过严重塑性变形的材料的储氢特性。他研究的另一个方面是氢扩散以及氢对金属涂层化学和物理特性的影响。他的目标是从根本上了解成分或晶体结构的变化对储氢性能的影响。Huot教授在材料表征领域，特别是中子和同步辐射的使用方面拥有扎实的专业知识。Huot教授目前担任Journal of Alloys and Compounds期刊编辑、MH2024金属-氢国际学会会议执委委员。

报告摘要：

Hydrogen is likely to play a key role in the development of renewable energies. For a widespread use of hydrogen as an energy vector, there should be safe and low-cost ways to store it. Presently, high pressure and liquid are the two main ways to store hydrogen. However, both have limitations in terms of pressure and temperature of operation. Storing hydrogen in metal hydrides could be a good way to overcome these limitations. In this lecture, after a brief introduction on the general features of metal hydrides, we will present our recent works on high entropy alloys for hydrogen storage. Recently, high entropy alloys (HEA) have been investigated for hydrogen storage applications. Many studies have been reported, but a complete understanding of the hydrogenation behaviour of these alloys is still lacking. In this talk we will present recent results obtained in our laboratory on the hydrogen storage characteristics of HEA. The well-known body centred cubic (BCC) HEA for hydrogen storage TiVZrHfNb will be discussed. We substituted a large atom (Nb) by a smaller atom (Fe) in compositions TiVZrHfNb1-xFex where x = 0, 0.2, 0.4, 0.6, 0.8 and 1. We found that replacing Nb by Fe has for effect of inducing a Laves phase. The proportion of Laves phases increases with increasing x. The conditions for the appearance of a single phase HEA and C14 have been checked. We also found from neutron diffraction that, in the Laves phase, elements occupy specific atomic positions. A fast first hydrogenation is only possible for alloys with large content of Laves phase. The synergetic effect in a two-phase system was further investigated for the alloy Ti16Zr4V35Cr15Ni10Mn20. We found that the synergy between the Laves phase and the BCC phase is essential for a fast and complete hydrogenation.