Effect of the Ball Milling Conditions, under Air, on the Preliminary Hydriding Properties of the Mixtures Mg-x Wt% Graphite. Role of Solvent

Abstract

The effect of wet milling on the hydriding properties of magnesium based mixture has been investigated. To prepare these mixtures, magnesium was ball milled with different weight percent of graphite (5, 10 and 25), at 300 rpm under air, for various duration using a ball miller apparatus Retsch S100 (R=12). Different solvents have been used such as benzene, heptane, styrene, DMSO. The hydriding properties were studied using a manual Sievert-type apparatus, at different temperatures (25°C, 100°C, 150°C and 200°C). The mixture Mg + 5wt% graphite milled during 6 hours in presence of 5mL heptane has shown the best hydriding properties at 150°C. The improvement of these properties has been related to the dielectric constant of the solvent and to the small size of the particles. The different mixtures have been analysed by means of scanning electron microscopy and laser granulometry.