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Structural and magnetic characterization of spark plasma sintered Fe-50Co alloys

Published online by Cambridge University Press:  20 December 2012

Mahesh Kumar Mani*
Affiliation:
Wolfson Centre for Magnetics, Cardiff School of Engineering, Cardiff University, UK
Giuseppe Viola
Affiliation:
School of Engineering and Materials Science, Queen Mary University of London, London, UK Nanoforce Technology Ltd., London, U.K
Mike J Reece
Affiliation:
School of Engineering and Materials Science, Queen Mary University of London, London, UK Nanoforce Technology Ltd., London, U.K
Jeremy P Hall
Affiliation:
Wolfson Centre for Magnetics, Cardiff School of Engineering, Cardiff University, UK
Sam L Evans
Affiliation:
Institute of Medical Engineering and Physics, Cardiff University, UK
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Abstract

Fe-50 wt% Co alloy powders with average particle size of 10 μm were compacted by spark plasma sintering (SPS) at 700, 800, 900 and 950oC by applying 40, 80, 100 MPa uniaxial pressures for 2, 5, 10 minutes. The densities of the samples were found to increase with temperature from 700 to 900oC for constant sintering pressure and time and to decrease for the material sintered at 950oC. The effects of sintering time on density were more significant in samples sintered at 700oC and 800oC than those densified at 900oC. The consequences of small increases in mechanical pressure during sintering on density values were significant for samples sintered at 700oC. The coercivity (Hc) of the compacts decreased significantly with increasing sintering temperature, and with increasing dwell time at sintering temperatures lower than 700oC. The sample sintered at 950oC, which contains the largest grains among the prepared samples and porous microstructure, exhibited the minimum coercivity. Unlike Hc, the remanence (Br) and saturation induction (Bsat) values were more strongly affected by the specimen density than by grain size. Br and Bsat values were found to vary linearly with sintering temperature and pressure owing to increasing density. An increase in soaking time at 800 and 900 oC, although enabling higher density, exhibited contradicting effects on Bsat values. The SPS parameters to obtain maximum density and optimum magnetic properties for Fe-50% Co alloy were found to be 900oC, 80 MPa and 2-5 minutes.

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Articles
Copyright
Copyright © Materials Research Society 2012 

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References

REFERENCES

Quigley, R.E, Proc. of IEEE Applied Power Electronics Conf. ‘More electric aircraft’, 906911 (1993).CrossRefGoogle Scholar
Jones, R.I, Proc. of the Institution of Mech. Engineers, Part G: J of Aerospace Engineering 216, 259269 (2002).CrossRefGoogle Scholar
Sundar, R. S. and Deevi, S. C., International Mater. Reviews 50, 157192 (2005).CrossRefGoogle Scholar
Zhao, L. and Baker, I., Acta Metall. Mater. 42, 1953–58 (1994).10.1016/0956-7151(94)90020-5CrossRefGoogle Scholar
Sourmail, T., Progress in Mat. Sci. 50, 816880 (2005).CrossRefGoogle Scholar
Kawahara, K, J Mater. Sci. 18, 1709–18 (1983).CrossRefGoogle Scholar
Silva, A., Wendhausen, P., Machado, R. and Ristow , W. Jr, Mater. Sci. Forum 534-536 1353–56 (2007).CrossRefGoogle Scholar
Yamagishi, W., Hashimoto, K., Sato, T., Ogawa, S. and Henmi, Z., IEEE Trans. on Magnetics Mag–22, 641643(1986).CrossRefGoogle Scholar
Turgut, Z, Huang, M, Horwath, J.C., and Fingers, R.T., J. App. Physics 103, 07E7241–3 (2008).CrossRefGoogle Scholar
Hanejko, F., Rutz, H. and Oliver, C., Advances in Powder Metallurgy & Particulate Materials 6, 375404 (1992), Metal Powder Industries Federation, Princeton, NJ.Google Scholar
Mamedov, V., Powder Metallurgy 45, 322328 (2002).CrossRefGoogle Scholar
Nygren, M. and Shen, Z., Key Engineering Materials 264-268, 719724 (2004).CrossRefGoogle Scholar
Nicula, R., Cojocaru, V.D., Stir, M., Hennicke, J. and Burkel, E., J. of Alloys & Compounds 434435, 362366 (2007).CrossRefGoogle Scholar
Kim, Y.D., Chung, J.Y., Kim, J. and Jeon, H., Mater. Sci. & Engg. A291, 1721 (2000).CrossRefGoogle Scholar
Milsom, B, Viola, G, Gao, Z, Inam, F, Peijs, T and Reece, M.J, Journal of the European Ceramic Society 32, 41494156 (2012).CrossRefGoogle Scholar
Anderson, P, J Mag. & Mag. Mater. 320, e589e593 (2008).CrossRefGoogle Scholar
Bas, J.A., Calero, J.A. and Dougan, M.J., Journal of Magnetism and Magnetic Materials 254255, 391398 (2003).CrossRefGoogle Scholar
Lee, P.W., ASM Handbook - Powder Metal Technologies and Applications 7, ed. (American Society for Metals, 1998) p 2523.Google Scholar