Hostname: page-component-586b7cd67f-vdxz6 Total loading time: 0 Render date: 2024-11-26T11:18:04.608Z Has data issue: false hasContentIssue false

Effect of a traveling magnetic field on freckle formation of directionally solidified Pb–Sn alloys

Published online by Cambridge University Press:  13 February 2017

Ling Qin
Affiliation:
State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, People’s Republic of China
Jun Shen*
Affiliation:
State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, People’s Republic of China
Qiudong Li
Affiliation:
State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, People’s Republic of China
Zhao Shang
Affiliation:
State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, People’s Republic of China
*
a) Address all correspondence to this author. e-mail: [email protected]
Get access

Abstract

Effects of traveling magnetic field (TMF) on freckle formation of directionally solidified Pb–Sn alloys were investigated experimentally and numerically. The experimental results demonstrated that freckles could form without any magnetic field and with the upward TMF. In the former case, the formation location is the center. In the latter case, it diverted from the center to the surface with the increasing intensity of TMF. However, freckle could not form under the downward TMF. Numerical results indicated that the change of the formation location under upward TMF should be attributed to the different solid/liquid interface shape, and no formation under downward TMF should be attributed to the convection intensity driven by TMF. These magnetic fields are used to modulate melt flow, which is similar to the effects of the gravity. For eliminating freckle, a microgravity environment can be established under the suitable downward TMF.

Type
Articles
Copyright
Copyright © Materials Research Society 2017 

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.)

Footnotes

Contributing Editor: Michael E. McHenry

References

REFERENCES

Sun, W.R., Hu, Z.Q., Lee, J.H., Ceo, S.M., and Choe, S.J.: Influence of solidification rate on precipitation and microstructure of directional solidification IN792 + Hf superalloy. J. Mater. Res. 14, 3873 (1999).Google Scholar
Xue, Y.L., Li, S.M., Zhong, H., Li, K.W., and Fu, H.Z.: Phase selection and mechanical properties of a directionally solidified Cr–20Nb–40Ti alloy. J. Mater. Res. 30, 3474 (2015).Google Scholar
Schneider, M.C. and Beckermann, C.: Formation of macrosegregation by multicomponent thermosolutal convection during the solidification of steel. Metall. Mater. Trans. A 26, 2373 (1995).CrossRefGoogle Scholar
Tin, S., Pollock, T., and Murphy, W.: Stabilization of thermosolutal convective instabilities in Ni-based single-crystal superalloys: Carbon additions and freckle formation. Metall. Mater. Trans. A 32, 1743 (2001).Google Scholar
Madison, J., Spowart, J., Rowenhorst, D., Aagesen, L.K., Thornton, K., and Pollock, T.M.: Modeling fluid flow in three-dimensional single crystal dendritic structures. Acta Mater. 58, 2864 (2010).Google Scholar
Lehmann, P., Moreau, R., Camel, D., and Bolcato, R.: Modification of interdendritic convection in directional solidification by a uniform magnetic field. Acta Mater. 46, 4067 (1998).Google Scholar
Utech, H.P. and Flemings, M.C.: Elimination of solute banding in indium antimonide crystals by growth in a magnetic field. J. Appl. Phys. 37, 2021 (1966).CrossRefGoogle Scholar
Li, X., Ren, Z.M., and Fautrelle, Y.: Effect of a vertical magnetic field on the dendrite morphology during Bridgman crystal growth of Al–4.5 wt% Cu. Acta. Mater. 54, 5349 (2006).Google Scholar
Zou, Q.C., Jie, J.C., Liu, S.C., Wang, T.M., Yin, G.M., and Li, T.J.: Effect of traveling magnetic field on separation and purification of Si from Al–Si melt during solidification. J. Cryst. Growth 429, 68 (2015).CrossRefGoogle Scholar
Wang, L., Shen, J., Qin, L., Feng, Z.R., Wang, L.S., and Fu, H.Z.: The effect of the flow driven by a travelling magnetic field on solidification structure of Sn–Cd peritectic alloys. J. Cryst. Growth 356, 26 (2012).Google Scholar
Lantzsch, R., Galindo, V., Grants, I., Zhang, C., Pätzold, O., Gerbeth, G., and Stelter, M.: Experimental and numerical results on the fluid flow driven by a traveling magnetic field. J. Cryst. Growth 305, 249 (2007).Google Scholar
Rudolph, P.: Travelling magnetic fields applied to bulk crystal growth from the melt: The step from basic research to industrial scale. J. Cryst. Growth 310, 1298 (2008).Google Scholar
Miyazawa, H., Liu, L., Hisamatsu, S., and Kakimoto, K.: Numerical analysis of the influence of tilt of crucibles on interface shape and fields of temperature and velocity in the unidirectional solidification process. J. Cryst. Growth 310, 1034 (2008).Google Scholar
Qin, L., Shen, J., Feng, Z.R., Shang, Z., and Fu, H.Z.: Microstructure evolution in directionally solidified Fe–Ni alloys under traveling magnetic field. Mater. Lett. 115, 155 (2014).Google Scholar
Karagadde, S., Yuan, L., Shevchenko, N., Eckert, S., and Lee, P.D.: 3-D microstructural model of freckle formation validated using in situ experiments. Acta Mater. 79, 168 (2014).Google Scholar
Tewari, S.N., Shan, R., and Song, H.: Effect of magnetic field on the microstructure and macrosegregation in directionally solidified Pb–Sn alloys. Metall. Mater. Trans. A 25, 1535 (1994).Google Scholar
Noeppel, A., Ciobanas, A., Wang, X.D., Zaïdat, K., Mangelinck, N., Budenkova, O., Weiss, A., Zimmermann, G., and Fautrelle, Y.: Influence of forced/natural convection on segregation during the directional solidification of Al-based binary alloys. Mater. Trans. B 241, 193 (2010).Google Scholar
Wang, L., Shen, J., Yin, X., Du, Y.J., Xiong, Y.L., and Fu, H.Z.: Influences of travelling magnetic field on the dendritic structures of Sn–1.8Cd peritectic alloy during directional solidification. Appl. Phys. A 112, 363 (2013).Google Scholar
Copley, S.M., Giamei, A.F., Johnson, S.M., and Hornbecker, M.F.: The origin of freckles in unidirectionally solidified castings. Metall. Trans. 1, 2193 (1970).Google Scholar
Yesilyurt, S., Motakef, S., Grugel, R., and Mazuruk, K.: The effect of the traveling magnetic field (TMF) on the buoyancy-induced convection in the vertical Bridgman growth of semiconductors. J. Cryst. Growth 263, 80 (2004).CrossRefGoogle Scholar
Min, Z.X., Shen, J., Feng, Z.R., Wang, L.S., Wang, L., and Fu, H.Z.: Effects of melt flow on the primary dendrite spacing of Pb–Sn binary alloy during directional solidification. J. Cryst. Growth 320, 41 (2011).Google Scholar
Hunt, J.D. and Lu, S.Z.: Numerical modeling of cellular/dendritic array growth: Spacing and structure predictions. Mater. Trans. A 27, 611 (1996).Google Scholar
Steinbach, I.: Pattern formation in constrained dendritic growth with solutal buoyancy. Acta Mater. 57, 2640 (2009).Google Scholar
Trivedi, R., Miyahara, H., Mazumder, P., Simsek, E., and Tewari, S.N.: Directional solidification microstructures in diffusive and convective regimes. J. Cryst. Growth 222, 365 (2001).CrossRefGoogle Scholar
Yuan, L. and Lee, P.D.: A new mechanism for freckle initiation based on microstructural level simulation. Acta. Mater. 60, 4917 (2012).Google Scholar