Fabrication of lotus-type porous magnesium through thermal decomposition of magnesium hydride

Abstract

Lotus-type porous magnesium was fabricated through thermal decomposition of MgH2 powders as a source of hydrogen. Liquid magnesium was cast into a mold in which MgH2 powders were placed and solidified unidirectionally in the mold, which achieved the growth of unidirectional elongated pores in magnesium matrix. The fabrication method is safer than a conventional method using pressurized hydrogen atmosphere, because the risk of explosion can be avoidable. The effect of the amount of MgH2 powders and the distance from the bottom of the ingot on the porous structure was investigated, which clarified that the two factors have the large influence on the pore growth. © 2009 IOP Publishing Ltd.