Damage kinetics and compression behavior of Al alloy foam using in situ SRμCT

We have developed a synchrotron-based in situ X-ray micro-tomography facility for 3D imaging of material deformation under compression and tensile loads. In this report, we have discussed the details of this experimental facility, and as a case study, the quasi-static, elasto-plastic compression behavior of open-cell aluminum (Al) alloy foam is studied under in situ load conditions. Micro-tomography images obtained at different levels of compressive strains reveal damage kinetics of the cellular microstructure, observed in the form of strut bending and fracture, cell size reduction, shape distortion, cell wall collapse, etc. These morphological and structural changes are found to be closely correlated with specific variations in the stress–strain curve, which explain its macroscopic deformation behavior. The experimental stress–strain behavior is compared to a constitutive model for metal foams, and observed deviations are discussed for structure–property relations.