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Tomography based numerical simulation of the demagnetizing field in soft magnetic composites

Authors :
Stefan Arzbacher
Alexander Ostermann
Jörg Petrasch
Thomas Loerting
Bernd Weidenfeller
Peter Amann
Source :
Journal of Applied Physics. 117:163905
Publication Year :
2015
Publisher :
AIP Publishing, 2015.

Abstract

The magneto-static behaviour of soft magnetic composites (SMCs) is investigated using tomography based direct numerical simulation. The microgeometry crucially affects the magnetic properties of the composite since a geometry dependent demagnetizing field is established inside the composite, which lowers the magnetic permeability. We determine the magnetic field information inside the SMC using direct numerical simulation of the magnetic field based on high resolution micro-computed tomography data of the SMC's microstructure as well as artificially generated data made of statistically homogeneous systems of identical fully penetrable spheres and prolate spheroids. Quasi-static electromagnetic behaviour and linear material response are assumed. The 3D magnetostatic Maxwell equations are solved using Whitney finite elements. Simulations show that clustering and percolation behaviour determine the demagnetizing factor of SMCs rather than the particle shape. The demagnetizing factor correlates with the slope of a 2-point probability function at its origin, which is related to the specific surface area of the SMC. Comparison with experimental results indicates that the relatively low permeability of SMCs cannot be explained by demagnetizing effects alone and suggests that the permeability of SMC particles has to be orders of magnitude smaller than the bulk permeability of the particle material.

Details

ISSN :
10897550 and 00218979
Volume :
117
Database :
OpenAIRE
Journal :
Journal of Applied Physics
Accession number :
edsair.doi...........543fdeeaa9a9d79d5da368275fbbfdfe
Full Text :
https://doi.org/10.1063/1.4917490