Mechanical Properties of Aluminium Foam and How Density, Temperature, and Strain Rate Affect Dynamic Strain–Stress Relationship

Abstract

Aluminium foam has been popular in engineering, and aluminium foam research has become a research hotspot. The strain–stress relationship of aluminium foam presents three distinct stages. In this paper, the mechanical behaviours of aluminium foam materials under dynamic and quasi-static compression are studied. The effects of density, strain rate and temperature on the dynamic mechanical behavior of aluminum foam were analyzed. Combined with the dynamic and static stress–strain curves of aluminium foam, the specific characteristics and the phenomena in every stage of the compression process were studied by high-speed photography and CT. The experimental results show that aluminium foam undergoes obvious collapse layerby-layer in the process of compression. The stress–strain curves include a considerable stress drop after the elastic stage. Moreover, the structural defects of the material will cause the plastic failure in advance, and the possibility of the existence of structural defects will be affected by the density. Under dynamic compression, with increasing density the strain rate sensitivity of aluminium foam increase, but with the temperature increasing, the strain rate sensitivity was decrease.