Production of Porous Metallic Glass Granule by Optimizing Chemical Processing

Abstract

Abstract In this study, we optimized dissolution the dissolution conditions of porous amorphous powder to havehigh specific surface area. Porous metallic glass(MG) granules were fabricated by selective phase dissolution, in whichbrass is removed from a composite powder consisting of MG and 40 vol.% brass. Dissolution was achieved throughvarious concentrations of H 2 SO 4 and HNO 3 , with HNO 3 proving to have the faster reaction kinetics. Porous powderswere analyzed by differential scanning calorimetry to observe crystallization behavior. The Microstructure of milledpowder and dissolved powder was analyzed by scanning electron microscope. To check for residual in the dissolvedpowder after dissolution, energy dispersive X-ray spectroscory and elemental mapping was conducted. It was confirmedthat the MG/brass composite powder dissolved in 10% HNO 3 produced a porous MG granule with a relatively high spe-cific surface area of 19.60 m 2 /g. This proved to be the optimum dissolution condition in which both a porous internalgranule structure and amorphous phase were maintained. Consequently, porous MG granules were effectively fabricatedand applications of such structures can be expanded.Keywords: Porous granule, Selective phase dissolution, High specific surface area