Fabrication and characterization of Al foam through powder metallurgy rout by using acrylic powder as space holder

Metal foams are a new class of materials with low density and novel physical, mechanical, thermal, electrical and acoustic properties. Among the metal foams, Al-alloys are commerciallythe most exploited ones due to their low density, high ductility, high thermal conductivity and competitive cost. In this study open cell aluminum foams with varying porosities (50-80vol %)sintered at different temperature have been made through powder metallurgy route using acrylicpowder as a space holder and their properties are compared with each other. In order to mix the aluminum and space holder powders; ball mill with ball to powder ratio of 15 were used.Powder compaction performed in a 12.8 mm diameter steel die by uniaxial cold pressing.Samples were sintered in argon atmosphere to avoid oxidation of aluminum. Also in order to avoid sample’s destruction; low heating rate were applied. TG and DSC analysis were used todetermine range of decomposition temperature of acrylic powder and aluminum melting point,respectively and XRD analysis was used to show if any reaction happen between acrylic and aluminum powders. The observed SEM images show increasing network connection by going up sintering temperature in the range of 640 to 750°C and also by increasing relative density of foams between 0.22 to 0.3, absorbed energy showed an increasing trend from 1.5 to 6.8 MJ/m3

Keywords:

foam , aluminum , acrylic , powder metallurgy