Nanocrystalline Metal Hydrides Obtained by Severe Plastic Deformations

Abstract

It has recently been shown that Severe Plastic Deformation (SPD) techniques could be used to obtain nanostructured metal hydrides with enhanced hydrogen sorption properties. In this paper we review the different SPD techniques used on metal hydrides and present some specific cases of the effect of cold rolling on the hydrogen storage properties and crystal structure of various types of metal hydrides such as magnesium-based alloys and body centered cubic (BCC) alloys. Results show that generally cold rolling is as effective as ball milling to enhance hydrogen sorption kinetics. However, for some alloys such as TiV 0.9 Mn 1.1 alloy ball milling and cold rolling have detrimental effect on hydrogen capacity. The exact mechanism responsible for the change in hydrogenation properties may not be the same for ball milling and cold rolling. Nevertheless, particle size reduction and texture seems to play a leading role in the hydrogen sorption enhancement of cold rolled metal hydrides.

Effect of cold rolling on the hydrogen absorption and desorption kinetics of Zircaloy-4

“…Further rolling passes resulted in a higher decrease of hydrogen capacity. This decay in hydrogen capacity for cold rolled samples may be associated to a distortion of interstitial sites due to excessive micro-strains accumulated ( Table 2) and/or excessive surface oxidation [8,9,13]. Szpunar et al [14] observed that deformation in Zircaloy play an important role on the hydride nucleation and orientation.…”

Electrochemical behavior of Ti–V–Cr alloys in alkaline solution

“…BCC alloys with body-centered cubic lattice (BCC lattice), for example in the Ti-V-Cr system, occupy a special place among the most promising materials for hydrogen storage [1][2][3]. They can absorb up to 3.8 wt.% of hydrogen in the favorable temperature range of hydrogen output, which is a key factor for their application in practice [4][5][6]. Recently, Ti-V-Cr alloys were also used as catalysts for magnesium alloys [5,7].…”

“…They can absorb up to 3.8 wt.% of hydrogen in the favorable temperature range of hydrogen output, which is a key factor for their application in practice [4][5][6]. Recently, Ti-V-Cr alloys were also used as catalysts for magnesium alloys [5,7]. However, up till now these materials have mainly been saturated from the gas phase [8][9][10].…”

Hydrogen storage of nanocrystalline Mg–Ni alloy processed by equal-channel angular pressing and cold rolling

“…The beneficial H-sorption kinetics of cold rolled Mg-based alloys was systematically reviewed by Huot [22]. By comparing the kinetics of MgH 2 doped with transition metal oxides as catalysts, it was found that cold rolled samples possess relatively slower dehydrogenation kinetics compared to the milled counterparts, since atomic mixing is more difficult by CR than by HEBM [23].…”