Low-Cost Light-Weight Composite Metal Foams for Transportation Applications

Abstract

This paper is dealing with the production and investigation (structural and mechanical) of composite metal foams (CMFs) with AlSi9MgMn matrix and ~60 vol% of different nominal diameter light expanded clay particles (LECPs) filler. The main aim was to produce a cheap CMF grade for automotive industry. The samples were produced by liquid state low pressure infiltration. Cubic samples were manufactured from the produced CMF blocks for structural (optical microscopy, scanning electron microscopy and energy-dispersive x-ray spectrometry (EDS)) and for mechanical (compression) investigations and tests. The CMFs were investigated in as-cast and in T6 heat-treated conditions. The macrostructural investigations showed homogenous structure and sufficient quality infiltration. On the microscopic scale, the EDS investigations revealed a complex interface layer affected by chemical reactions between the matrix material and the filler particles. The compressive test proved the classic foam-like mechanical behavior of the CMFs (with long plateau region). A relationship (valid for both the as-cast and T6 heat-treated conditions) was found between the characteristic properties and the nominal diameter of the filler. Based on these results, the LECPs filled CMFs are ideal candidates for automotive applications with tailorable properties.