Hostname: page-component-586b7cd67f-dsjbd Total loading time: 0 Render date: 2024-11-28T06:59:58.871Z Has data issue: false hasContentIssue false

Microstructure evolution of gas-atomized Fe–6.5 wt% Si droplets

Published online by Cambridge University Press:  13 February 2014

Kefeng Li
Affiliation:
Department of Metallurgical Engineering, School of Materials Science and Engineering, Shanghai University, Shanghai 200072, People’s Republic of China; and Institute for Complex Materials, Institute for Solid State and Materials Research Dresden, Dresden D-01069, Germany
Changjiang Song*
Affiliation:
Department of Metallurgical Engineering, School of Materials Science and Engineering, Shanghai University, Shanghai 200072, People’s Republic of China
Qijie Zhai
Affiliation:
Department of Metallurgical Engineering, School of Materials Science and Engineering, Shanghai University, Shanghai 200072, People’s Republic of China
Mihai Stoica
Affiliation:
Institute for Complex Materials, Institute for Solid State and Materials Research Dresden, Dresden D-01069, Germany
Jürgen Eckert
Affiliation:
Institute for Complex Materials, Institute for Solid State and Materials Research Dresden, Dresden D-01069, Germany; and Dresden University of Technology, Institute of Materials Science, Dresden D-01062, Germany
*
a)Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

The magnetic Fe–6.5 wt% Si powder was produced by gas atomization and its microstructure was also investigated. The secondary dendritic arm spacing (SDAS) is related to the droplet size, ${\rm{\lambda }} = 0.29 \cdot {D^{0.5}}$, and the numerical solidification model was applied to the system, giving rise to the correlation of microstructure to the solidification process of the droplet. It is found that the solid fraction at the end of recalescence is strongly dependent on the undercooling achieved before nucleation; the chances for the smaller droplets to form the grain-refined microstructures are less than the larger ones. Furthermore, the SDAS is strongly influenced by the cooling rate of post-recalescence solidification, and the relationship can be expressed as follows, ${\rm{\lambda }} = 74.2 \cdot {\left( {\dot T} \right)^{ - 0.347}}$. Then, the growth of the SDAS is driven by the solute diffusion of the interdendritic liquids, leading to a coarsening phenomenon, shown in a cubic root law of local solidification time, ${\rm{\lambda }} = 10.73 \cdot {\left( {{t_f}} \right)^{0.296}}$.

Type
Articles
Copyright
Copyright © Materials Research Society 2014 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

REFERENCES

Arai, K.I. and Ishiyama, K.: Recent developments of new soft magnetic materials. J. Magn. Magn. Mater. 133(1–3), 233 (1994).Google Scholar
Takada, Y., Abe, M., Masuda, S., and Inagaki, J.: Commercial scale production of Fe-6.5 wt. % Si sheet and its magnetic properties. J. Appl. Phys. 64(10), 5367 (1988).Google Scholar
Yamaji, T., Abe, M., Takada, Y., Okada, K., and Hiratani, T.: Magnetic properties and workability of 6.5% silicon steel sheet manufactured in continuous CVD siliconizing line. J. Magn. Magn. Mater. 133(1–3), 187 (1994).Google Scholar
Tsuya, K.I.A.N.: Ribbon-form silicon-iron alloy containing around 6.5 percent silicon. IEEE Trans. Mag. 16(1), 4 (1980).Google Scholar
Kasama, A.H., Moreira, A.J.J., Botta, F°.W.J., Kiminami, C.S., and Bolfarini, C.: Influence of the atomization gas on the microstructure and magnetic properties of spray-formed Fe–3%Si–3.5%Al alloys. Mater. Sci. Eng., A 477(1–2), 9 (2008).CrossRefGoogle Scholar
Shokrollahi, H. and Janghorban, K.: Soft magnetic composite materials (SMCs). J. Mater. Process. Technol. 189(1–3), 1 (2007).CrossRefGoogle Scholar
Sowter, G.A.V.: Soft magnetic materials for audio transformers: History, production, and applications. J. Audio Eng. Soc. 35, 760 (1987).Google Scholar
Bayraml, E., Gölgelioğlu, Ö., and Ertan, H.B.: Powder metal development for electrical motor applications. J. Mater. Process. Technol. 161(1–2), 83 (2005).Google Scholar
Tiedje, N., Hansen, P.N., and Pedersen, A.S.: Modeling of primary and secondary dendrites in a Cu-6 wt pct Sn alloy Metall. Mater. Trans. A 27(12), 4085 (1996).Google Scholar
Freyberg, A., Buchholz, M., Uhlenwinkel, V., and Henein, H.: Droplet solidification and gas-droplet thermal coupling in the atomization of a Cu-6Sn alloy. Metall. Mater. Trans. B 34(2), 243 (2003).Google Scholar
Levi, C.G. and Mehrabian, R.: Microstructures of rapidly solidified aluminum alloy submicron powders. Metall. Mater. Trans. A 13(1), 13 (1982).Google Scholar
Boettinger, W.J., Bendersky, L., and Early, J.G.: An analysis of the microstructure of rapidly solidified Al-8 wt pct Fe powder. Metall. Trans. A 17(5), 781 (1986).Google Scholar
Xu, R., Cui, Y.Y., Li, D., Xu, D.M., Li, Q.C., and Hu, Z.Q.: Solidification microstructure of super-α2 alloy prepared by gas atomization. J. Mater. Sci. 32(14), 3821 (1997).Google Scholar
Zheng, B., Lin, Y., Zhou, Y., and Lavernia, E.: Gas atomization of amorphous aluminum powder: Part II. Experimental investigation. Metall. Mater. Trans. B 40(6), 995 (2009).Google Scholar
Li, S., Wu, P., Fukuda, H., and Ando, T.: Simulation of the solidification of gas-atomized Sn-5mass%Pb droplets. Mater. Sci. Eng., A 499(1–2), 396 (2009).Google Scholar
Levi, C.G. and Mehrabian, R.: Heat-flow during rapid solidification of undercooled metal droplets. Metall. Trans. A 13(2), 221 (1982).Google Scholar
Lavernia, E.J., Gutierrez, E.M., Szekely, J., and Grant, N.J.: A mathematical model of the liquid dynamic compaction process. Part 1: Heat flow in gas atomization. Int. J. Rapid Solidification 4, 89 (1988).Google Scholar
Gutierrez-Miravete, E., Lavernia, E.J., Trapaga, G.M., Szekely, J., and Grant, N.J.: A mathematical model of the spray deposition process. Metall. Trans. A 20(1), 71 (1989).Google Scholar
Mathur, P., Apelian, D., and Lawley, A.: Analysis of the spray deposition process. Acta Metall. 37(2), 429 (1989).CrossRefGoogle Scholar
Lee, E-S. and Ahn, S.: Solidification progress and heat transfer analysis of gas-atomized alloy droplets during spray forming. Acta Metall. Mater. 42(9), 3231 (1994).Google Scholar
Bergmann, D., Fritsching, U., and Bauckhage, K.: A mathematical model for cooling and rapid solidification of molten metal droplets. Int. J. Therm. Sci. 39(1), 53 (2000).Google Scholar
Pryds, N.H. and Hattel, J.H.: Spray forming: A numerical investigation of the influence of the gas to melt ratio on the billet surface temperature. Int. J. Therm. Sci. 44(6), 587 (2005).Google Scholar
Heringer, R., Gandin, C.A., Lesoult, G., and Henein, H.: Atomized droplet solidification as an equiaxed growth model. Acta Mater. 54(17), 4427 (2006).CrossRefGoogle Scholar
Zeoli, N., Gu, S., and Kamnis, S.: Numerical modelling of metal droplet cooling and solidification. Int. J. Heat Mass Transfer 51(15–16), 4121 (2008).Google Scholar
Zheng, B., Lin, Y., Zhou, Y., and Lavernia, E.: Gas atomization of amorphous aluminum: Part I. Thermal behavior calculations. Metall. Mater. Trans. B 40(5), 768 (2009).Google Scholar
Okamoto, H.: Phase Diagrams for Binary Alloys, 2nd ed. (ASM International, 2000).Google Scholar
Trivedi, R. and Somboonsuk, K.: Constrained dendritic growth and spacing. Mater. Sci. Eng. 65(1), 65 (1984).Google Scholar
Hirth, J.P.: Nucleation, undercooling and homogeneous structures in rapidly solidified powders. Metall. Trans. A 9(3), 401 (1978).Google Scholar
Kurz, W. and Fisher, D.J.: Fundamentals of Solidification, 4th ed. (Trans. Tech. Publications, 1998).Google Scholar
Chang, K-C. and Chen, C-M.: Revisiting heat transfer analysis for rapid solidification of metal droplets. Int. J. Heat Mass Transfer 44(8), 1573 (2001).Google Scholar
Turnbull, D. and Cech, R.E.: Microscopic observation of the solidification of small metal droplets. J. Appl. Phys. 21(8), 804 (1950).Google Scholar
Herlach, D.M., Eckler, K., Karma, A., and Schwarz, M.: Grain refinement through fragmentation of dendrites in undercooled melts. Mater. Sci. Eng., A 304306(0), 20 (2001).Google Scholar
Pryds, N.H. and Pedersen, A.S.: Rapid solidification of martensitic stainless steel atomized droplets. Metall. Mater. Trans. A 33(12), 3755 (2002).CrossRefGoogle Scholar
Kattamis, T.Z. and Flemings, M.C.: Dendrite morphology, microsegregation, and homogenization of low-alloy steel. Trans. Metall. Soc. AIME 223, 8 (1965).Google Scholar
Marsh, S.P. and Glicksman, M.E.: Overview of geometric effects on coarsening of mushy zones. Metall. Mater. Trans. A 27(3), 557 (1996).Google Scholar