Early Investigation in Porous Aluminum Development via Powder Metallurgy Technique
Porous aluminum (Al) has gained significant attention owing to its peculiar properties including lightweight, high strength to weight ratio as well as excellent impact energy absorption. In spite of these advantages, early investigation prior to satisfactory porous Al development is rarely reported in open literature. Therefore, the current study was initiated to perform an early investigation on porous Al development via powder metallurgy technique. In this study, 30 wt. % of polymethylmetacrylate (PMMA) was introduced as a temporary space holder to create a desirable porous structure. The effects of milling time on the morphology and densities of elemental powder mixture and porous Al were evaluated systematically. Prolong milling time to 12 hr resulted in smaller elemental powder particle size with improved powder mixture agglomeration along with a broad distribution of powder mixture particle size. In line with this, a reduction in peaks intensity was demonstrated by x-ray diffraction (XRD) analysis when the milling time was increased from 4 hr to 12 hr, confirming powder particle size reduction. Apart from these, a decreased in green densities from 1.742 g/cm3 to 1.736 g/cm3 were recorded with increasing milling time from 3 hr to 9 hr in which a slight increased to 1.743 g/cm3 was recorded with after 12 hr milling. On the other hand, maximum milling time of 12 hr reduced the total porosity of porous Al from 31.75% to 30.45% whereas its density was found to increase from 1.465 g/cm3 to 1.471 g/cm3, respectively. Therefore, it can be emphasized that milling time of 12 hr was sufficient to design a desirable porous structure with satisfactory results of green and sintered densities as well as porosity level.