Influence of Form and Structural Features of Open-Cell Hybrid Foam on the Remanent Magnetic Scanning

Abstract

Hybrid foams are promising materials for a wide range of applications due to their high strength and low weight. Due to the manufacturing process, the material properties are heterogeneous, therefore requiring characterization methods to quantify local coating layer thicknesses for both research and process scale-up. Compared to microscopy, remanent magnetic scanning enables shorter turnaround times for the estimation of coating thickness. This study aims to improve quantitative characterization with magnetic scanning measurements by proposing an equivalent model for open-cell hybrid foams. This model helps to identify possible sources of deviations in the thickness-magnetic correlation that can occur in hybrid foams. Simulations reveal that several geometrical features contribute ambiguously to the magnetic field. The level of influence on the magnetic signal varies depending on the feature under investigation and its proximity to the surface. High influence is observed for displaced cells in the depth and vertical struts at varying depths compared to adjacent cells on the surface. This should be considered when using remanent magnetic scanning for the quantitative estimation of local coating thickness. In the future, more experimental data may help to use this approach for quantitative characterization of layer thicknesses and reduce ambiguity of the measured data.