Effect of Palladium Electroplating on Hydrogen Absorption Properties of Zirconium Alloy

Abstract:

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_0.62Zr_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 °C.

Key words:zirconium;palladium electroplating;hydrogen absorption temperatures;hydrogen absorption kinetics