Equal channel angular pressing as a means of improving the hydrogen absorption/desorption properties of alloy ZK60

In the present work, an attempt was undertaken to achieve an enhancement of the desorption rate of hydrogen in a Mg alloy by using equal channel angular pressing (ECAP) alone or in combination with high-energy ball milling (HEBM). The object of the study was the commercial magnesium alloy ZK60 (Mg-4.95 wt.%Zn-0.71 wt. % Zr). ECAP was shown to have a significant accelerating effect on the hydrogen absorption/desorption kinetics, comparable with or even exceeding that of HEBM. An interesting feature associated with combined ECAP/HEBM processing is the disappearance of pressure hysteresis with respect to hydrogen absorption/desorption. This hydrogenation behavior is explained in terms of the microstructure of bulk samples and the morphology of dehydrogenated powders as observed by high resolution scanning electron microscopy.