吸氢处理增强Fe基非晶合金磁热效应的作用机理研究

Magnetic refrigeration due to its great merits such as environmental friendliness and relatively high efficiency, has been regarded as a potential alternative to replace the conventional gas-compression/expansion refrigeration. The study of magnetic refrigerant materials with high performance is the core question for their application. Fe-based amorphous materials due to their attractive properties such as excellent soft magnetic properties, large refrigerant capacity, zero loss, outstanding mechanical properties and low costs, have attracted a special interest in the field of magnetic refrigeration. But the relatively low peak entropy change compared with other materials is their bottleneck which limited their application. Based on ours previous research, penetration of hydrogen atoms into Fe-based amorphous alloys can dramatically increase its magnetic entropy change, but the underlying mechanism is still unclear very well. Therefore, this work plans to continue the investigation and clarify the mechanisms acting in the process of hydrogen enhancing magnetocaloric effect on Fe-based amorphous alloys. Firstly, by adjusting the penetration conditions, achieve absorption of hydrogen into the alloys quantitatively. Then discuss the influence of hydrogen absorption on the microstructure and magnetic structure of the alloys, analyze the mechanism of hydrogen improving the magnetocaloric effect of Fe-based amorphous alloys, and understand the physical essence of magnetic entropy increase theory. Finally, by optimizing the composition of Fe-based amorphous alloys and its hydrogen absorption, acquire an alloy with large room-temperatuer magnetic entropy change and wide working temperature span, speed up the application of Fe-based amorphous alloys in magnetic refrigeration in practice.

磁制冷技术因其低损耗、低噪音、无环境污染等优点，有望发展成为下一代新型制冷技术。研发室温环境具有磁制冷效能、高性价比磁制冷材料是实现该技术工业化应用的关键物质基础。Fe基非晶合金成本低廉、损耗近似为零、居里温度可调，具有磁制冷工业化应用的潜在优势。但目前该类合金磁熵变值仍然偏低，制约着其走向实用。项目申请人在前期研究中发现，吸氢处理可显著提高Fe基非晶合金磁熵变值，但其相关作用机理尚不清楚。为此本项目开展Fe基非晶合金定量吸氢控制技术及氢对合金磁热效应的影响机制研究。首先通过调控工艺条件，精密控制Fe基非晶合金定量吸氢；然后研究氢对非晶合金精细结构和磁结构的影响规律，分析氢渗入对Fe基非晶合金磁热效应的作用机理，弄清氢增强Fe基非晶合金磁热性能的物理本质，最后通过母合金成份优化和吸氢工艺条件优化，研制出具有室温宽温域、高磁熵变Fe基非晶磁制冷合金，为其工业化应用奠定理论研究基础。

Fe基非晶合金成本低廉、损耗近似为零、居里温度可调，是一种优良的新型磁制冷材料。但目前该类合金磁熵变值仍然偏低，制约着其走向实用。本项目主要开展Fe基非晶合金定量吸氢控制技术及氢对合金磁热效应的影响机制研究。研究了Fe90−xZr10Bx（x：0 ~ 9）合金和Fe93−xZr7Bx（x：3 ~ 13）非晶合金的磁热效应；对Fe 基非晶合金进行吸氢处理，确立了氢中合金中分布；研究了吸氢处理对Fe90Zr10合金和Fe90Sc10非晶合金的磁结构和磁热效应的影响规律及其机理。通过项目的研究，掌握了Fe基非晶合金的吸氢技术；获得了研究氢对非晶合金精细结构和磁结构的影响规律，弄清了氢渗入对Fe基非晶合金磁热效应的作用机理，研制出了具有室温宽温域、高磁熵变Fe基非晶磁制冷合金，为其工业化应用奠定理论研究基础。