International Journal of Hydrogen Energy, Vol.45, No.8, 5375-5383, 2020
Hydrogen storage properties of filings of the ZK60 alloy modified with 2.5 wt% mischmetal
In this study, a commercial Mg-based ZK60 alloy was modified with 2.5 wt% mischmetal (ZK60-2.5 wt%Mm) and further processed by cold rolling followed by manual filing. The chips obtained by manual filing process were collected from the as cast (AC) and the cold rolled (CR) materials. The hydrogen storage properties were evaluated by kinetics measurements at 350 degrees C. A full microstructural characterization including optical, scanning and transmission electron microscopy (MO, MEV and TEM), X-ray diffraction (XRD) and differential scanning calorimetry (DSC) was performed in the samples. For the first absorption of both filed samples the H storage capacity showed a value around 6.0 wt% after 1 h while for the CR sample it was close to 1.25 wt% after the same time. The manual filing produced samples with higher hydrogenation kinetics compared with that of the CR sample. Besides, their hydrogen storage capacity was maintained close to the theoretical value (6.75 wt%). The breakage and pulverization of the intermetallic phases gave the chips from the CR alloy the faster hydrogenation kinetics, especially for H-desorption. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.