Effects of Temperature and Initial Hydrogen Pressure on the Hydriding Properties of Zr9Ni11 Alloy

摘要:

通过定容变压法研究了不同温度(25~150 ℃)与初始压力(10~160 kPa)对Zr9Ni11合金吸氢性能的影响。氢化实验结果表明，随着温度的升高，Zr9Ni11合金平衡压力明显升高，但吸氢量随之降低。当温度低于75 ℃时，Zr9Ni11合金初始吸氢速率随温度升高而增大，而当温度高于75 ℃时，初始吸氢速率随温度升高而降低。初始氢气压力对合金动力学性能影响显著，初始氢气压力低于50 kPa时，合金吸氢速率随初始压力增长而急剧增加，并且在初始氢气压力较低时，仍能快速吸氢。合金吸氢量与平衡压力也随初始氢气压力增加而增大。XRD与TEM分析表明，合金在吸氢前主要为Zr9Ni11相，吸放氢循环后，变为混晶，同时存在非晶态。SEM分析显示，合金在氢化过程中表面粗糙化并出现大量裂痕。研究表明，Zr9Ni11合金可以作为除氚的备选材料

Abstract:

The hydriding properties of Zr9Ni11 alloy at different temperatures (25~150 °C) and various initial hydrogen pressures (10~160 kPa) were investigated. The results show that with the increase of temperature, the equilibrium pressure of the Zr9Ni11 alloy increases significantly, but its hydrogen absorption quantity decreases dramatically. When the temperature is less than 75 °C, the hydriding reaction rate of Zr9Ni11 alloy increases with increasing of temperature; while the temperature is higher than 75 °C, the hydriding reaction rate of the alloy decreases with increasing of temperature. The initial hydrogen pressure has a great influence on the kinetic properties of the alloy. When the initial pressure is lower than 50 kPa, the hydriding reaction rate of the alloy increases obviously with the increase of the initial hydrogen pressure, and even in the case of relatively low pressure, the alloy can still absorb hydrogen dramatically. The hydrogen absorption quantity and the equilibrium pressure of the alloy increase with the increase of the initial hydrogen pressure. The samples of the alloy before and after hydrogenation were analyzed by XRD, SEM(EDS) and TEM(SAED). After several hydriding-dehydriding cycles, the surface of the alloy which is homogeneous and smooth before hydrogenation becomes rough and crannied, and the ratio of Zr and Ni on the surface is varied. It is also found the amorphous states might be increased and mischcrystal formed through hydriding-dehydriding cycles. Zr9Ni11 alloy might be a promising candidate for extracting tritium according to our investigation.