A study of aluminium foam formation - Kinetics and microstructure

Aluminium foams were produced by applying the powder compact melting method, i.e. by mixing metal powders and powdered gas-releasing blowing agents and pressing them to a foamable precursor material after this. The resulting precursor was then foamed by heating it up to above its melting point inside an expandometer, which allowed for the volume and temperature to be measured throughout the entire process. The present studies comprise the effects of the aluminium alloy composition (AlSi7 and 6061), some of the pressing parameters of the foamable precursor material, the foaming temperature and the heating rate during foaming on the expansion behaviour of the foam. Moreover, the morphological and microstructural evolution of metal foams is investigated. (C) 2000 Acta Merallurgica Inc. Published by Elsevier Science Ltd. All rights reserved.