X-ray micro-tomographic characterization of field-structured magnetorheological elastomers

Anisotropic magnetorheological elastomers (MREs) with four different mass percentages of iron powder were prepared in an external magnetic field. The inner structure of the samples was characterized by using computed tomography. It has been shown that this kind of non-destructive analysis of MRE samples can be efficiently used for a detailed structural investigation. It was found that even small changes in the mass content of the magnetic filler led to the formation of completely different morphologies, which were reproducible for all samples. There were the familiar column formations in patterns with a mass content of ~ 5% iron powder. Increasing the mass fraction to ~ 14% resulted in the formation of tubular structures. Samples with ~ 23 and ~ 33 wt% had a densely packed structure, where the particle formations broke up: meanders without particles penetrate the samples over the entire height like canyons.