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The role of the dispersed-phase remnant magnetization on the redispersibility of magnetorheological fluids

Published online by Cambridge University Press:  31 January 2011

Pradeep P. Phulé
Affiliation:
Department of Materials Science and Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
Matthew P. Mihalcin
Affiliation:
Department of Materials Science and Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
Seval Genc
Affiliation:
Department of Materials Science and Engineering, University of Pittsburgh, Pittsburgh, Pennsylvania 15261
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Abstract

The influence of the remnant magnetization of the soft magnetic particulates, used as a dispersed phase, on the redispersibility of magnetorheological (MR) fluids is discussed. Calculations of the magnetic interaction energy showed that for 33-vol% MR fluids based on particles of iron (∼6 μm), manganese zinc ferrite (∼2.3 μm), and nickel zinc ferrite (∼2.1 μm), the ratios of the magnetic interaction energy to the thermal energy were 161,000, 6400, and 3900, respectively. These calculations showed that even the seemingly small levels of remnant magnetization, associated with particulates employed in MR fluids, introduced significant dipole–dipole interparticle interactions. It is proposed that this interaction causes most MR fluids to show a tendency for “cake formation,” which makes it difficult to redisperse these fluids. Our modeling presented here also suggests practical strategies to enhance the redispersibility of MR fluids.

Type
Articles
Copyright
Copyright © Materials Research Society 1999

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References

REFERENCES

1.Ginder, J.M., in Encyclopedia of Applied Physics, edited by Immergut, E. (VCH, New York, 1996), Vol. 16, p. 487.Google Scholar
2.Phulé, P.P., MRS Bull. 23(8), 23 (1998).CrossRefGoogle Scholar
3.Phulé, P.P. and Ginder, J.M., Intl. J. Mod. Phys. (in press).Google Scholar
4.Rabinow, J., AIEE Trans. 67, p. 1308 (1948).Google Scholar
5.Rabinow, J., U.S. Patent No. 2 675 360 (1951).CrossRefGoogle Scholar
6.Rabinow, J., SAE National Transportation Meeting, Cleveland, OH (1949).Google Scholar
7.Ozaki, M., Egami, T., Sugiyama, N., and Matijevic, E., J. Coll. Interface Sci. 125(1), p. 212 (1988).CrossRefGoogle Scholar
8.Chacko, A.P. and Nikles, D.E., IEEE Trans. Magnetics 32, 4043 (1996).CrossRefGoogle Scholar
9.Phulé, P.P., Jatkar, A.D., and Ginder, J.M., in Materials for Smart Systems, MRS Proc. Vol. 459, edited by George, E.P., Gotthardt, R., Otsuka, K., Trolier-McKinstry, S., and Wun Fogle, M., (Mat. Res. Soc., 1997), p. 99.Google Scholar
10.Zhang, L. and Manthiram, A., IEEE Trans. 32(5), 4481 (1996).Google Scholar
11.Muench, G.J., Arajs, S., and Matijevic, E., J. Appl. Phys. 52, 2493 (1981).CrossRefGoogle Scholar
12.Bate, G., in Concise Encyclopedia of Magnetic and Superconducting Materials, edited by. Evettes, J., (Pergamon Press, Elmsford, NY, 1992), p. 247.Google Scholar
13.Lemaire, E., Meunier, A., Bossis, G., Liu, J., Felt, D., Bashtovoi, P., and Matoussevitch, N., J. Rheol. 39, 1011 (1995).CrossRefGoogle Scholar
14.Bossis, G. and Lemaire, E., J. Rheol. 35, 1345 (1991).CrossRefGoogle Scholar
15.Rosensweig, R.E. in Concise Encyclopedia of Magnetic and Superconducting Materials, edited by Evettes, J. (Pergamon Press Inc., Elmsford, NY, 1992), p. 141.Google Scholar
16.Fertman, V.E., Magnetic Fluids Guidebook: Properties and Applications (Hemisphere Publishing Corp., New York, 1990).Google Scholar
17.Kormann, Cl., Laun, L., and Klett, G., in Electrorheological Fluids, Magnetorheological Suspensions, and Associated Technology, edited by Bullough, W.A. (World Scientific, Sheffield, UK, 1996), p. 362.Google Scholar
18.Kordonsky, W.I. and Jacobs, S.D., in Electrorheological Fluids, Magnetorheological Suspensions, and Associated Technology, edited by Bullough, W.A. (World Scientific, Sheffield, UK, 1996), p. 1.Google Scholar
19.Rosensweig, R., Ferrohydrodyanmics (Dover Publications, Inc., New York, 1985).Google Scholar