Failure analysis of cast open-cell iron based foams from the submicron to the macro-scale
Final Report Abstract
We produced grey cast iron foams by a modified investment casting process. The structural characteristics of the produced micro-geometries, foam segments and single struts were investigated by light and electron microscopy in 2D, and synchrotron micro-computed tomography in 3D, and the mechanical properties were characterised by macro/micro- mechanical testing and nanoindentation. The microstructure of the grey cast iron struts exhibits high amounts of graphite in both, flake-like coarse type A and, locally, fine undercooled type D morphologies with a heterogeneous distribution which we assume to be the reason for the large scatter of the mechanical properties of the single struts. Consequently, the struts behave in a brittle way, leading to strong serrations in the stress-strain curves of the foams. This leads to a relatively low energy absorption efficiency of below 50 %. The mechanical properties of the foams are further influenced by scale effects, due to the small specimen size. Further improvement in the fabrication of grey cast iron foams is needed to tailor graphite distributions and optimize performance of cast iron-based foams.
Publications
- Casting and mechanical properties of gray cast iron open cell foams; CellMAT 2018, 24-26/10/2018, Bad Staffelstein, D
A.C. Kaya, P. Zaslansky, A. Rack, S.F. Fischer, C. Fleck
- Foams of grey cast iron as efficient energy absorption structures: a feasibility study, Advanced Engineering Materials 2019, 1900080
A.C. Kaya, P. Zaslansky, A. Rack, S.F. Fischer, C. Fleck
(See online at https://doi.org/10.1002/adem.201900080)
