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Image analysis of magnetorheological elastomers microstructure

Stefan F. Awietjan ,  Anna Boczkowska 

Warsaw University of Technology, Faculty of Materials Science and Engineering (InMat), Wołoska 141, Warszawa 02-507, Poland


Magnetorheological elastomers (MREs) are solid analogues of magnetorheological fluids. These both consist of micrometer-sized magnetically permeable particles in a non-magnetic matrix material. As in the case of MR fluids, the particles try to arrange themselves in the direction of the magnetic field. The advantage of MREs over MR fluids is that ferrous particles do not undergo sedimentation. Due to the characteristic MRE microstructure, the response time and strain magnitude versus magnetic field intensity can be shortened. Interest in such intelligent materials has increased recently as they hold promise in enabling variable-stiffness devices and adaptive structures in aerospace, automotive, civil and electrical engineering applications.

The presented results are a part of the studies on development of MREs based on ferromagnetic particles in a polyurethane matrix. The influence of the amount of the ferromagnetic particles and their arrangement in relation to the external magnetic field was investigated. The amount of ferrous particles varied from 1.5 to 33 vol. %. Three types of particles were used; carbonyl iron in average sizes of 1-2 mm and 6-9 mm as well as 70 mm porous iron. Scanning electron and light microscopy were used to observe MREs microstructure. Obtained microstructures were analysed with image analysis using software Micrometer v.9.2. Images were analysed in two perpendicular directions to measure the microstructure anisotropy level. The largest microstructure anisotropy has been observed for samples with lower amounts of Fe particles. For samples with larger volume percentage of Fe the anisotropy has not been confirmed.


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Related papers

Presentation: Poster at E-MRS Fall Meeting 2008, Symposium C, by Stefan F. Awietjan
See On-line Journal of E-MRS Fall Meeting 2008

Submitted: 2008-05-09 16:58
Revised:   2009-06-07 00:48