Research on Hydrogen-Storage Amorphous and Nano-structured Alloys

本研究的目的是寻找具有非晶和纳米晶结构的新型储氢合金，并研究其储氢性能。此外，还研究了加氢对金属多层膜结构变化或稳定性的影响。对含过渡金属和/或稀土的二元和三元合金进行了研究。5-30 at的Nd-Fe、Nd-Fe- b和Nd-Co-B系合金。对Nd进行了详细的研究，揭示了非晶合金的储氢能力与原子结构之间的关系。此外，Zr-Ni-V和Zr-Ni-Nballoys的非晶合金在25-35 aat。%Zr和5-25 at。对%V和Nb进行了研究。我们成功制备了几种具有良好储氢能力和结构稳定性的非晶态合金，但它们在373K以下的吸氢和解吸动力学与传统金属间化合物相比不够快，值得进一步研究。主要研究了Mg-Ni、Ng-Ni-La和Mg-Ni- nd纳米晶合金的吸氢性能。通过在刚好高于结晶温度的温度下退火熔纺非晶合金，获得了晶粒尺寸为50-100 nm的纳米晶结构。这些纳米晶合金比相应的粗晶铸态合金具有更快的吸氢动力学和更好的PCT特性。随着进一步的改进，它们将被用作实用的储氢材料，工作温度为473- 573k。在研究Pd/Ti、Ni/Ti和Fe/Ti等金属多层膜的吸氢过程中，我们发现在723K左右的加氢温度下，多层膜的结构是热稳定的。在不加氢的情况下，它们应经过层间混合以形成均匀平衡的金属间相。这种稳定性归因于Ti层向TiH_2的转变，并且可能适用于多层技术。少

The objective of this research is to find novel hydrogen-storage alloys with amorphous as well as nanocrystalline structures, and to investigate their hydrogen storage properties. In addition, effects of hydrogenation on the structural change or stability of metallic multilayrs have also been studied.1. Hydrogen absorption in amorphous alloys Binary and ternary alloys containing transition metals and/or rare earths have been investigated. Alloys of Nd-Fe, Nd-Fe-B and Nd-Co-B systems with 5-30 at.%Nd have been studied in detail, and relationships between the hydrogen-storage ability and atomistic structures of the amorphous alloys have been revealed. Furthermore, amorphous alloys of Zr-Ni-V and Zr-Ni-Nballoys with 25-35 aat.%Zr and 5-25 at.%V and Nb have been studied. We succeeded in producing several amorphous alloys with good hydrogen-storage ability and structural stability, but their hydrogen absorbing and desorbing kinetics below 373K were not fast enough in comparison with those o … More f conventional intermetallic compounds and deserve further investigation.2. Hydrogen absorption in nanocrystalline alloys Alloys of Mg-Ni, Ng-Ni-La and Mg-Ni-Nd systems have been mainly studied. Nanocrystalline structures of these alloys with grain sizes of 50-100 nm have been obtained by annealing melt-spun amorphous alloys at temperatures just above the respective crystallization temperatures. These nanocrystalline alloys exhibit faster hydrogen absorbing kinetics and better PCT characteristics than the corresponding as-cast alloys with coarse grains. With further improvements, they will be used as practical hydrogen storage materials operative at 473-573K.3. Structure stabilization of metallic multilayrs by hydrogenation In the course of study of hydrogen absorption in metallic multilayrs such as Pd/Ti, Ni/Ti and Fe/Ti, we found that the multilayr structures are thermally stabilized by hydrogenation up to about 723K.Without hydrogenation, they should undergo interlayr mixing to form homogeneous equilibrium intermetallic phases. This stabilization is attributed to the transformation of Ti layrs into TiH_2, and may be applicable to multilayr technologies. Less