The Formation of Hybridized Porous Structure of Al Alloy by Alkali Surface Modification

To improve the filtration efficiency of porous materials used in filters, an extensive specific surface area is required to serve as a site for adsorption of impurities. In this paper, a method for creating a hybridized porous alloy using a powder metallurgical technique to build macropores in an Al-4 wt.% Cu alloy and subsequent surface modification for a microporous surface with a considerably increased specific surface area is suggested. The macropore structure was controlled by granulation, compacting pressure, and sintering; the micropore structure was obtained by a surface modification using a dilute NaOH solution. The specific surface area of surface- modified specimen increased about 10 times compare to as-sintered specimen that comprised of the macropore structure. Also, the surface-modified specimens showed a remarkable increase in micropores larger than 10 ���. Such a hybridized porous structure has potential for application in water and air purification filters, as well as membrane pre-treatment and catalysis