Mechanisms and mechanics of compressive deformation in open-cell Al foams

• Published in: Mechanics of materials 2004-08, Vol.36 (8), p.781-797
• Main Authors: Zhou, J, Shrotriya, P, Soboyejo, W.O
• Format: Article
• Language: English
• Subjects: Applied sciences; Condensed matter: structure, mechanical and thermal properties; Deformation and plasticity (including yield, ductility, and superplasticity); Elasticity. Plasticity; Exact sciences and technology; Linear elastic deformation; Mechanical and acoustical properties of condensed matter; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Mechanical properties of solids; Mechanisms; Metals. Metallurgy; Physics; Plastic bending; Plastic buckling; Plastic collapse
• ISSN: 0167-6636; 1872-7743
• DOI: 10.1016/j.mechmat.2003.05.004

The paper presents the results of experimental study of compressive deformation in open-cell 6101-O aluminum alloy foams with three different pore sizes (10, 20 and 40 pores per inch or PPI). Samples of two dimensions (10 mm × 10 mm × 10 mm and 24.5 mm × 24.5 mm × 17.0 mm) were investigated. Linear elastic deformation was first observed in a small 10 PPI foam sample at small enough stress level (0.11 MPa). The onset and spread of plasticity in individual struts were studied by the observation of dislocation slip bands, which were examined during ex situ scanning electron microscopy (SEM). An in situ optical microscope, connected to a video camera, was also used to study the progressive deformation of the foam structure under compressive loading. Both plastic buckling and plastic bending of struts were observed to occur during compressive deformation of the foam blocks. However, plastic bending of struts was the dominant deformation mechanism.