Yield behavior of magnetorheological suspensions

• Published in: Journal of magnetism and magnetic materials Vol. 258; pp. 456 - 458
• Main Authors: Bossis, G., Khuzir, P., Lacis, S., Volkova, O.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-03-2003
• Subjects: Magnetic particles; Magnetorheological suspensions; Yield stress; Yield stress; Magnetic particles; Magnetorheological suspensions
• ISSN: 0304-8853
• DOI: 10.1016/S0304-8853(02)01096-X

The rheology of suspensions containing magnetic particles of micrometer size is strongly modified by the application of a magnetic field. We first describe a model experiment where the suspension is made of spheres of millimeter size and we show that the experimental dependence of the yield stress is well predicted by a non-affine model where the chains of particles break in the middle. Then we compare these predictions with some experimental results obtained on suspensions of carbonyl iron; it is shown that this model does not apply in this case. We propose a mechanism where after some friction on the walls the aggregates begin to rotate and break at a strain smaller than unity, due to the interactions with other aggregates.