High-temperature compression of closed cell aluminium foams

Abstract

The compression behaviour of closed cell aluminium foams (Al99.5, AlMg1Si0.6 and AlSi12 matrix alloys, TiH2 foaming agent) prepared by powder metallurgy was studied in the temperature range of 20–550◦C. It was observed that the temperature increase results in the decrease of the compression strength and energy absorption and increase of densification strain (plateau length) at constant density. The dependence of compression strength on foam density and temperature was successfully modelled using new proposed equation. The activation energy for compression of aluminium foams seems to be density dependent with a maximum at certain density range depending on foam composition. It was also found that the characteristic exponent Tf for the compression strength of aluminium foams is temperature dependent variable. The strain at compression strength (deformation up to the macroscopic failure of foam) is nearly temperature independent or decreases at constant density depending on aluminium alloy matrix. The absorbed energy per unit volume of aluminium foams decreases with increasing temperature significantly due to the decrease in the value of plateau/compression strength at constant density.