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Two-phase separated growth and peritectic reaction during directional solidification of Cu–Ge peritectic alloys

  • Shujie Wang (a1), Liangshun Luo (a1), Yanqing Su (a1), Fuyu Dong (a1), Jingjie Guo (a1) and Hengzhi Fu (a1)...

Abstract

During directional solidification of Cu–Ge peritectic alloys, a two-phase separated structure has been observed. With proper growth conditions, the peritectic ζ-Cu5Ge and primary α-Cu phases completely separate and form cylindrical layered structures. It is found that the formation of the separated structure is closely related to double diffusive convection and growth conditions. In the two-phase separated structure, a large trijunction region of peritectic reaction forms around the cylindrical α-Cu phase. During peritectic reaction, the morphological instabilities of ζ-Cu5Ge occur under high pulling velocities and are explained by the constitutional undercooling criterion. A new coupling growth between the ζ-Cu5Ge-phase and the groove of α-Cu phase near the trijunction is observed. Different from peritectic coupling growth, the diffusion coupling is established below the peritectic temperature. This two-phase separated growth process creates new opportunities for the fabrication of functionally layered materials.

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Corresponding author

a)Address all correspondence to this author. e-mail: suyq@hit.edu.cn

References

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1.Lo, T.S., Karma, A., and Plapp, M.: Phase-field modeling of microstructural pattern formation during directional solidification of peritectic alloys without morphological instability. Phys. Rev. E 63, 031504 (2001).
2.Kerr, H.W. and Kurz, W.: Solidification of peritectic alloys. Int. Mater. Rev. 41, 129 (1996).
3.Ding, X.F., Lin, J.P., Zhang, L.Q., Su, Y.Q., Hao, G.J., and Chen, G.L.: A closely-complete peritectic transformation during directional solidification of a Ti-45Al-8.5Nb alloy. Intermetallics 19, 1115 (2011).
4.Chen, Y.Z., Liu, F., Yang, G.C., and Zhou, Y.H.: Nonequilibrium effects of primary solidification on peritectic reaction and transformation in undercooled peritectic Fe–Ni alloy. J. Mater. Res. 25, 1025 (2010).
5.Kaya, H., Engin, S., Böyük, U., Çadırlı, E., and Maraşlı, N.: Unidirectional solidification of Zn-rich Zn-Cu hypoperitectic alloy. J. Mater. Res. 24, 3422 (2009).
6.Hu, X.W., Li, S.M., Gao, S.F., Liu, L., and Fu, H.Z.: Peritectic transformation and primary α-dendrite dissolution in directionally solidified Pb–26%Bi alloy. J. Alloys Compd. 501, 110 (2010).
7.Vandyoussefi, M., Kerr, H.W., and Kurz, W.: Two-phase growth in peritectic Fe-Ni alloys. Acta Mater. 48, 2297 (2000).
8.Dobler, S., Lo, T.S., Plapp, M., Karma, A., and Kurz, W.: Peritectic coupled growth. Acta Mater. 52, 2795 (2004).
9.Park, J.S. and Trivedi, R.: Convection-induced novel oscillating microstructure formation in peritectic systems. J. Cryst. Growth 187, 511 (1998).
10.Kohler, F., Germond, L., Wagnière, J-D., and Rappaz, M.: Peritectic solidification of Cu–Sn alloys: Microstructural competition at low speed. Acta Mater. 57, 56 (2009).
11.Trivedi, R. and Park, J.S.: Dynamics of microstructure formation in the two-phase region of peritectic systems. J. Cryst. Growth 235, 572 (2002).
12.Mazumder, P., Trivedi, R., and Karma, A.: A model of convection-induced oscillatory structure formation in peritectic alloys. Metall. Trans. A 31, 1233 (2000).
13.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).
14.Hu, X.W., Li, S.M., Gao, S.F., Liu, L., and Fu, H.Z.: Effect of melt convection on primary dendrite arm spacing in directionally solidified Pb-26%Bi hypo-peritectic alloys. Trans. Nonferrous Met. Soc. China 21, 65 (2011).
15.Drevet, B., Nguyen Thi, H., Camel, D., Billia, B., and Dupouy, M.D.: Solidification of aluminium-lithium alloys near the cell/dendrite transition-influence of solutal convection. J. Cryst. Growth 218, 419 (2000).
16.Trivedi, R., Liu, S., Mazumder, P., and Simsek, E.: Microstructure development in the directionally solidified Al-4.0 wt% Cu alloy system. Sci. Technol. Adv. Mater. 2, 309 (2001).
17.Fredriksson, H. and Nylen, T.: Mechanism of peritectic reactions and transformations. Metal. Sci. 16, 283 (1982).
18.Stjohn, D.H.: The peritectic reaction. Acta Mater. 38, 631 (1990).
19.Phelan, D., Reid, M., and Dippenaar, R.: Kinetics of peritectic reaction and transformation in Fe-C alloys. Mater. Sci. Eng., A 477, 226 (2008).
20.Wang, J., Jin, S., Leinenbach, C., and Jacot, A.: Thermodynamic assessment of the Cu–Ge binary system. J. Alloys. Compd. 504, 159 (2010).
21.Jamgotchian, H., Nguyen Thi, H., Bergeon, N., and Billia, B.: Double-diffusive convective modes and induced microstructure localisation during solidification of binary alloys. Int. J. Therm. Sci. 43, 769 (2004).
22.Worster, M.G.: Instabilities of the liquid and mushy regions during solidification of alloys. J. Fluid. Mech. 237, 649 (1992).
23.Coriell, S.R., Cordes, M.R., Boettinger, W.J., and Sekerka, R.F.: Convective and interfacial instabilities during unidirectional solidification of a binary alloy. J. Cryst. Growth 49, 13 (1980).
24.Caroli, B., Caroli, C., Misbah, C., and Roulet, B.: Solutal convection and morphological instability in directional solidification of binary alloys. J. Phys. 46, 401 (1985).
25.Nguyen Thi, H., Billia, B., and Jamgotchian, H.: Influence of thermosolutal convection on the solidification front during upwards solidification. J. Fluid. Mech. 204, 581 (1989).

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