Influence of processing conditions on morphology of metal foams produced from metal powder

The influence of the processing conditions on the evolution of the cell mor phology of aluminium foams is investigated. The precursor material, a compa cted mixture of aluminium and titanium hydride powder, is foamed to differe nt degrees by heating it to different maximum temperatures. The pressure of the surrounding argon atmosphere is varied from low pressure to overpressu re. The cell morphology is characterised by the mean cell diameter, its cir cularity, and the gas/metal interface length per unit area. The cell morpho logy is found to be primarily determined by the density and cannot be influ enced by the outside pressure. The morphology is governed by one simple evo lution law: the mean cell wall thickness is constant during expansion, MST/ 4544 (C) 2000 IoM Communications Ltd.