Pulverization mechanism of hydrogen storage alloys on microscale packing structure

Recent Developments in the Application of Surface Mechanical Attrition Treatments for Improved Gradient Structures: Processing Parameters and Surface Reactivity

“…8. It should be recalled here that the powder were formed "naturally" by a fragmentation mechanism, known as hydrogen pulverization, 141,142) which is governed by the repeated expansion/contraction of the lattice volume induced by the hydrogen diffusion. Figure 8(c) shows a SEM image taken directly at the surface that was previously peened by the SMAT process (marked with a triangle) and easily recognisable by its undulated aspect generated by the shot impacts.…”

Measure of the hydride breathing while cyclically absorbing and desorbing hydrogen

“…near the bottom of the vessel than the mean stress. The geometry of the vessel is predominant in previous work [6][7][8]. All the stresses have the same behavior with an increase during loading time (absorption) and decreases for desorption.…”

Mechanical Properties of Packed Bed of Hydrogen Storage Alloys in Loading and Unloading Processes

“…However, hydrogen absorption/desorption causes volume expansion of the hydrogen storage alloy and pulverization, and those particles are moved, rearranged, and then segregated in the packed bed (van Mal, 1976). Okumura et al (2012b) visualized that the pulverized particles were segregated at the bottom of the packed bed after hydrogen absorption/desorption in the packed bed of hydrogen storage alloy using X-ray CT. Since the particle segregation causes deformation and/or breakage of the vessel of the alloy particles (van Mal, 1976;Qin et al, 2008;Lototskyy et al, 2014), the stress on the vessel wall is important for using the hydrogen storage alloy safely.…”