Correlation between the milling time and hydrogen storage properties of ZrCrFe ternary alloy

Laves phases with AB(2) compositions are common type of topologically close packed structure. Furthermore, lave phases are capable of dissolving considerable amounts of ternary alloying additions. ZrCr(2) crystallized in the hexagonal C14 type of structure is one of interesting candidate among them, but it is not used as storage compound due to its excessive stability, at 323 K the equilibrium pressure is only 1.2 kPa. However the substitution of chromium by other elements can modify the crystal structure, the hydriding capacity and dissociation pressure of hydrogen. In this work Fe has been chosen as a substitute material for Cr and ZrCrFe ternary alloy is prepared using arc furnace. The mechanical alloying process has been introduced to produce nanocrystalline material. This paper presents comprehensive study on structural aspects of ball milled ZrCrFe alloy. On comparison of the XRD data, the broadening was found in the peak width with the increase of milling time which is clear indication of refinement of crystallite size. This refinement could also be confirmed from the SEM analysis also. PCT measurements were performed for a temperature range 303 K-373 K. (C) 2009 Professor T. Nejat Veziroglu. Published by Elsevier Ltd. All rights reserved.