Effects of cell wall property on compressive performance of aluminum foams
(1. School of Materials Science and Engineering, Tsinghua University, Beijing 100084, China;
2. Key Laboratory for Advanced Materials Processing Technology, Ministry of Education,
Tsinghua University, Beijing 100084, China)
2. Key Laboratory for Advanced Materials Processing Technology, Ministry of Education,
Tsinghua University, Beijing 100084, China)
Abstract: The effects of cell wall property on the compressive performance of high porosity, closed-cell aluminum foams prepared by gas injection method were investigated. The research was conducted both experimentally and numerically. Foam specimens prepared from conditioned melt were tested under uniaxial compressive loading condition. The cell wall microstructure and fracture were observed through optical microscope (OM) and scanning electron microscope (SEM), which indicates that the cell wall property is impaired by the defects in cell walls and oxide films on the cell wall surface. Subsequently, finite element (FE) models based on three-dimensional thin shell Kelvin tetrakaidecahedron were developed based on the mechanical properties of the raw material and solid material that are determined by using experimental measurements. The simulation results show that the plateau stress of the nominal stress-strain curve exhibits a linear relationship with the yield strength of the cell wall material. The simulation plateau stress is higher than the experimental data, partly owing to the substitution of solid material for cell wall material in the process of the establishment of FE models.
Key words: aluminum foams; cell wall property; uniaxial compressive performance; FE analysis