Peering inside metal foams: Exploiting sinogram-based X-ray microscopy and CT to reveal the evolution of foam microstructure during thermomechanical loading

Metal foams manifest a unique combination of properties, including light weight, high specific stiffness and excellent energy absorption when deformed.

These characteristics make metal foams ideally suited to applications in, for example, the automotive and aerospace industries. The strength of individual foam cells is governed by microstructural features like grains, particles, pores and cracks.

The evolution of these features—and the interaction between them—has largely been neglected in prior foam studies, which have focused primarily on changes in cell structure.

The present project aims to remedy this deficit by applying synchrotron-based 3D scattering and imaging techniques to metal foams subjected to thermal and mechanical loading.

The goal is to gain a predictive understanding of the mechanical response of metal foams that spans both length and time scales.

To that end, a thermomechanical load rig will be installed at the P21.2 beamline of PETRA III, with the setup being used to develop and deploy a novel sinogram-based acquisition scheme that will double or even triple the effective field of view, thus making in situ CT and 3DXRD characterization feasible for a wide range of foam pore sizes.

Routines implementing this correlated imaging protocol will be developed as open-source software tools, and the experimental results will be combined with numerical modeling to shed new light on the microstructural evolution of metal foams during thermomechanical loading.