Hydrogenation properties and structural change of HfxZr7−xNi10 (x=0–7)
Hydrogenation properties and structural change of HfxZr7−xNi10 (x=0–7)
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HfxZr7−xNi10 (x=0–7) 的加氢性能及结构变化
DOI：
10.1016/j.jallcom.2005.02.080
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
T. Oishi
中科院分区：
文献类型：
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作者：
H. Takeshita;N. Fujiwara;N. Takeichi;Hiroshi Senoh;T. Oishi
Hf 7 Ni 10具有与Zr 7 Ni 10相同的晶体结构，它表现出几种不寻常的氢化性能，如通过不可逆相变进行可逆氢化和氢化后脱氢引起的结构变化，其氢化性能一直是未知的。研究了HfxZr 7− xNi 10合金在Zr 7 Ni 10（x= 0）~ Hf 7 Ni 10（x= 7）组成范围内的相关系和氢化性能。所有样品均通过电弧熔炼然后在真空中热处理获得。用X射线衍射和显微分析相结合的方法鉴定了组成物相，用差示扫描量热法和Sieverts法考察了加氢性能。在Zr 7 Ni 10合金中，Hf的加入并没有使合金的结构发生由Cmca型向tetraxAl 4/mmm型和Pbca型的转变，而且在所有成分范围内，Zr 7 Ni 10合金中的Zr都被Hf取代。目标相的晶格常数随Hf含量的增加而减小。用差示扫描量热法（DSC）对Hf取代合金进行了研究，结果表明Hf取代合金在氢化过程中表现出与Zr 7 Ni 10相同的相变，即只在脱氢过程中出现中间氢化物相，而在氢化过程中不出现中间氢化物相。相变温度随Hf含量的增加而降低。
Hf 7 Ni 10 has the same crystal structure as Zr 7 Ni 10, which shows several unusual hydrogenation properties such as reversible hydrogenation by irreversible phase transformation and structural change caused by hydrogenation followed by dehydrogenation, and its hydrogenation properties have been unknown. The phase relation and hydrogenation properties of Hf x Zr 7− x Ni 10 alloys were investigated in the compositional range from Zr 7 Ni 10 (x= 0) to Hf 7 Ni 10 (x= 7). All the samples were obtained by arc melting followed by heat treatment in vacuum. The constituent phase was identified by the combination of X-ray diffraction and microscopic analysis and hydrogenation properties were examined by differential scanning calorimetry and Sieverts’ method. No structural change from orthorhombic Cmca type to another one such as tetragonal I 4/mmm type and orthorhombic Pbca type was observed for the addition of Hf and Hf was substituted for Zr in Zr 7 Ni 10 in all the compositional range we examined. The lattice constant of the aimed phase decreased with an increase in Hf content. The measurements using differential scanning calorimetry indicated that the Hf-substituted alloys showed the same phase transformation as Zr 7 Ni 10 in hydrogenation, that is the unusual phase transformation that an intermediate hydride phase appears only in dehydrogenation but not in hydrogenation. The transformation temperature decreased with an increase in Hf content.