Ti1.0Cr1.5V1.7合金的氢同位素效应

采用电弧熔炼的方法, 制备了Ti_1.0Cr_1.5V_1.7合金。通过SEM、EDS和XRD对合金的形貌、组成及其氢化物的结构进行表征。结果表明, 合金组成不均匀, 存在网状的析出相。吸氢过程中的相转变只与吸氢量有关, 而与氢同位素种类无关。分离因子(α_H-D)测试表明, 压力对α_H-D的影响不大, 但氘丰度的增加会导致α_H-D的降低。温度对α_H-D的影响较复杂。α_H-D在213 K时有极大值2.29。当温度高于213 K时, α_H-D的实验值与谐振模型的计算值符合得很好, 且lnα_H-D与1/T之间存在线性关系; 当温度低于213 K时, 实验值与计算值之间存在较大差异。Ti_1.0Cr_1.5V_1.7合金氢化物的DSC分析结果表明, α_H-D在低温时的突变与相转变之间并无直接的联系。

Hydrogen Isotope Effects in Ti1.0Cr1.5V1.7 Alloy

Ti_1.0Cr_1.5V_1.7 alloy was prepared by arc melting and then its morphology and constitution were analyzed by SEM and EDS. The observations showed that the alloy was unhomogeneous with some network-shaped precipitates. The structures of the hydrides of Ti_1.0Cr_1.5V_1.7 were determined by XRD. The structures of the hydrides depended only on the hydrogen content, not on the kind of hydrogen isotopes. The dependences of separation factor (α_H-D) on pressure, deuterium concentration and temperature were investigated systematically. Not significantly influenced by pressure, α_H-D decreased with the increase of deuterium concentration. However, the dependence of α_H-D on temperature was complicated. In 213-373 K, α_H-D increased with the decrease of temperature, which agreed with the harmonic oscillator model (HOM). In 77-213 K, the experimental α_H-D was different from the calculated value of HOM. According to the results of DSC measurement for the hydrides of Ti_1.0Cr_1.5V_1.7 alloy, the disagreement between the experiments and the HOM in 77-213 K was not induced by phase transitions. Moreover, the maximum α_H-D reached 2.29 at 213 K.