Multiple hydriding dehydriding of Zr1.02Ni0.98 alloy

The hydriding kinetics and hydrogen absorption capacity of Zr1.02Ni0.98 all oy powder were investigated in a temperature range of 150-250 degrees C. An isothermal volumetric method within a pressure range of 0-1 bar was used. As expected, the temperature increase causes both an increase of the hydrid ing rate and a shift in the equilibrium of the Zr1.02Ni0.98 + x/2H(2)<->Zr1 .02Ni0.98Hx reaction towards the left. Performing multiple hydriding/dehydr iding cycles, an increase in hydriding rate accompanied by a decrease in ma ximal hydriding capacity was observed after each subsequent hydriding cycle s of the same sample. Using X-ray diffractometry, this was shown to be a co nsequence of an irreversible destruction of the alloy. (C) 1999 Internation al Association for Hydrogen Energy. Published by Elsevier Science Ltd. All rights reserved.