Coupling Effect of Porosity and Cell Size on the Deformation Behavior of Al Alloy Foam under Quasi-Static Compression

Closed-cell AlCu5Mn alloy foam with porosity range of ~45–90% were fabricated by the melt-foaming route. The pore structure of the fabricated Al alloy foam was analyzed and the coupling effect of porosity and cell size on the quasi-static compression behavior of the foam was investigated. The results show that the cell size of the foam decreases with the porosity decline from the view of the contribution rate to the porosity and the hierarchical pore structure characteristics becomes obvious when the foam porosity is low; the compression stress–strain curves of the foams with high porosity (>74%) are serrated due to the large cell size being easy to deform and more strain needed to let the stress recover. Meanwhile, the compression curve of the foams with low porosity (<74%) are smooth without serration, which is attributed to the hierarchical pore structure and less strain needed to let the stress recovery.

Mechanical Properties and Energy Absorption Capability of Closed-Cell Al Alloy Foam

Based on compression tests of closed-cell Al alloy foam measured, mchanical properties and energy absorption capability had been investigated. The compressive stress-strain curve of closed-cell Al foam consists of three distinct regions, i.e., the linear elasticity region, the plastic collapse region or brittle crushing region, and the densification region. Formula on energy absorption capability of closed-cell Al alloy foam was presented, which could provide theoretical support for its engineering application.

New Type Spherical Pores Al Foam and its Properties

Based on compression curves of spherical pores Al foam measured, compressive yield strength, the densification starting pointand energy absorption had been investigated. The compressive stress-strain curve of spherical pores Al foam consists of three distinct regions, i.e., the linear elasticity region, yield platform stage and the densification region. The way to determine the densification starting pointεDof high density metal foam has been presented. Spherical pores Al foam is a cellular metal material of high plastic performance, so energy absorption capability of it is bigger than that of spherical pores Al alloy foam. Compressive yield stress was in good agreement with Gibson-Ashby model’s expectation．