Effect of heat treatment on hydrogen storage properties and thermal stability of V68Ti20Cr12 alloy
Effect of heat treatment on hydrogen storage properties and thermal stability of V68Ti20Cr12 alloy
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热处理对V68Ti20Cr12合金储氢性能及热稳定性的影响
DOI：
10.1016/j.pnsc.2017.08.012
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发表时间：
2017-10-01
影响因子：
4.7
通讯作者：
Zhou, Huaiying
中科院分区：
文献类型：
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作者：
Rong, Maohua;Wang, Feng;Zhou, Huaiying
研究了热处理对电弧熔炼V68Ti20Cr12合金晶体结构、显微组织、储氢性能和热稳定性的影响。结果发现，铸态和退火 (973 K/72 h) V68Ti20Cr12 合金均由单一体心立方 (bcc) 相组成。热处理后，由于成分均匀、结构完善，铸态合金的吸放氢动力学特性得到很大改善。根据Johnson-Mehl-Avrami (JMA)方程进一步研究了铸态和退火合金的吸/脱氢过程机制。铸态和退火合金的吸氢过程受一维扩散过程控制，而铸态和退火合金的氢解吸过程则受几何收缩模型控制。压力-成分-温度（PCT）测量表明，退火合金的平台压力变得相对平坦。此外，使用基辛格方法计算了铸态和退火合金的脱氢活化能，表明热处理是改善合金吸/放氢动力学的非常有益的方法。
Effect of heat treatment on the crystal structure, microstructure, hydrogen storage properties and thermal stability of V68Ti20Cr12 alloy prepared by arc-melting was studied in this work. It was found that both the as-cast and annealed (973 K/72 h) V68Ti20Cr12 alloys consisted of a single body-centered cubic (bcc) phase. After heat treatment, the hydrogen absorption/desorption kinetic characteristics of the as-cast alloy was improved greatly due to the homogeneous composition and perfect structure. The mechanism of hydrogen absorption/desorption process in the as-cast and annealed alloys was further investigated according to the Johnson-Mehl-Avrami (JMA) equation. The hydrogen absorption process of the as-cast and annealed alloys would be controlled by the one-dimensional diffusion process, while the hydrogen desorption process in the as-cast and annealed alloys was dominated by the geometrical contraction model. The pressure-composition-temperature (PCT) measurements show that the plateau pressure of the annealed alloy becomes comparatively flat. Furthermore, the activation energies of the dehydrogenation in the as-cast and annealed alloys were calculated using the Kissinger method, indicating that heat treatment is a very beneficial way to improve hydrogen absorption/desorption kinetics of the alloy.