Hydrogen storage in TiZrNbFeNi high entropy alloys, designed by thermodynamic calculations
Hydrogen storage in TiZrNbFeNi high entropy alloys, designed by thermodynamic calculations
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DOI：
10.1016/j.ijhydene.2020.09.047
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发表时间：
2020-10
影响因子：
7.2
通讯作者：
R. Floriano;G. Zepon;K. Edalati;Gabriella Fontana;Abbas Mohammadi;Zhongliang Ma;Haiwen Li;R. Contieri
中科院分区：
文献类型：
--
作者：
R. Floriano;G. Zepon;K. Edalati;Gabriella Fontana;Abbas Mohammadi;Zhongliang Ma;Haiwen Li;R. Contieri
研究了新型等原子TiZrNbFeNi和非等原子Ti20Zr20Nb5Fe40Ni15高熵合金的储氢性能。这些合金是使用CALPHAD方法借助于热力学计算设计的，这是由于它们倾向于形成单一的C14 Laves相，这是室温储氢所需的相。通过电弧熔炼合成的合金显示出具有（Zr，Ti）1（Fe，Ni，Nb，Ti）2组成的C14 Laves相和少量立方相（<1.4wt%）的主要存在，与热力学预测良好一致。储氢性能，在室温下没有任何活化程序，检查显示，达到最大的储氢容量的等原子合金相比，非等原子合金（1.64重量%对1.38重量%），在第一个周期，然而，非等原子合金提出了上级的可逆性1.14重量%的氢。从氢化物形成元素和非氢化物形成元素的化学涨落、C14 Laves相的单位晶胞体积和价电子分布等方面讨论了两种合金在可逆性和容量方面的差异。
The hydrogen storage properties of the novel equiatomic TiZrNbFeNi and non-equiatomic Ti20Zr20Nb5Fe40Ni15high entropy alloys (HEAs) were studied. These alloys were designed with the aid of thermodynamic calculations using the CALPHAD method due to their tendency to form single C14 Laves phase, a phase desirable for room-temperature hydrogen storage. The alloys, which were synthesized by arc melting, showed a dominant presence of C14 Laves phases with the (Zr, Ti)1(Fe, Ni, Nb, Ti)2constitution and small amounts of cubic phases (<1.4 wt%), in good agreement with the thermodynamic predictions. Hydrogen storage properties, examined at room temperature without any activation procedure, revealed that a maximum hydrogen storage capacity was reached for the equiatomic alloy in comparison to the non-equiatomic alloy (1.64 wt% vs 1.38 wt%) in the first cycle; however, the non-equiatomic alloy presented superior reversibility of 1.14 wt% of hydrogen. Such differences on reversibility and capacity among the two alloys were discussed based on the chemical fluctuations of hydride-forming and non-hydride-forming elements, the volume per unit cell of the C14 Laves phases and the distribution of valence electrons.