电镀钯对锆合金吸氢性能的影响

Effect of Palladium Electroplating on Hydrogen Absorption Properties of Zirconium Alloy

锆具有良好的吸氢性能,被认为是储氘领域的候选材料。但由于其吸氢温度较高且吸氢动力学较慢,目前尚不能进行广泛应用。采用电镀钯的方法对锆进行表面改性,以提高其吸氢性能。结果表明:在经过镀钯且退火处理后的锆合金,在室温下可以实现吸氢,并且有适当的孕育期;与此同时,随着温度的升高,镀钯且退火处理后的锆合金孕育期缩短,吸氢速率变快。通过对微观结构进行分析,发现在氢化后,钯层与锆基板之间形成了过渡区,过渡区中存在PdH_(1.33)和H_(0.62)Zr_(0.38)。由此可见,过渡区中的氢化物对改善锆的吸氢性能起着重要作用。通过对动力学机制进行研究,确定在室温下,镀钯且退火处理后的锆合金吸氢过程符合一维扩散机制;而在250℃时,符合二维扩散机制。

Zirconium is an excellent hydrogen absorption material and has been regarded as a candidate material in the deuterium storage field.However,due to its higher hydrogen absorption temperature and slower hydrogen absorption kinetics,it cannot be applied at present.Palladium electroplating was used as a surface modification to improve the property.The results show that after the palladium electroplating and annealing,the zirconium alloy can absorb hydrogen at room temperature with an appropriate incubation period.With the increase in temperature,the hydrogen absorption rate becomes faster with a shorter incubation period.A transition zone forms between the palladium layer and zirconium substrate,and PdH_(1.33) and H_(0.62)Zr_(0.38) are found in the transition zone after hydrogenation.These hydride phases in the transition zone play an important role in improving the hydrogen absorption property of zirconium.For the kinetics mechanism,it is determined to be 1-D diffusion at room temperature and 2-D diffusion at 250℃.