Competitive Growth of Degenerate Pattern and Dendrites During Directional Solidification of a Bicrystal Metallic Alloy


A degenerate pattern is seaweed-like morphology with its tip splitting continuously, differing from that the regular dendrite has a stable tip. Here, we carried out bicrystal (BC)-assembled experiments to investigate the competitive growth between a degenerate pattern and regular dendrites in a directionally solidified Al-4.5 wt pct Cu alloy. Using the electron backscattered diffraction (EBSD) technique, we characterized a degenerate pattern that solidified with a (100)[001]45 deg orientation and a dendrite growth comprising (100)[001]0 deg or (100)[001]15 deg orientations. The experimental results for the competitive growth show that the dendrites could overgrow the degenerate pattern completely at V = 15 and 25 µm/s. The grain boundary (GB) in between these two morphologies is not smooth, and its inclination angle θGB is slightly increased with an increase in the growth velocity. For the converging GBs, we find that the dendrites overgrow the degenerate pattern either by generating new primary arm dendrites through tertiary branching or being blocked by the growth of the existing primary arm dendrites, depending on the misorientation arrangement between these two morphologies. The limited growth stability of the degenerate pattern in comparison with the dendrite contributes to deepening the understanding of why the degenerate pattern is not widely prevailing in metallic alloy solidification microstructures.

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  1. 1.

    1. A. Pineau, G. Guillemot, D. Tourret, A. Karma, and C.A. Gandin: Acta Mater., 2018, vol. 155, pp. 286-301.

    CAS  Article  Google Scholar 

  2. 2.

    2. S.S. Hu, L. Liu, W.C. Yang, J. Zhang, T.W. Huang, Y.C. Wang, and X.D. Zhou: J. Alloy. Compd., 2018, vol. 735, pp. 1878-84.

    CAS  Article  Google Scholar 

  3. 3.

    3. Z.Y. Liu, M. Lin, D. Yu, X.W. Zhou, Y.X. Gu, and H.Z. Fu: Metall. Mater. Trans. A-Phys. Metall. Mater. Sci., 2013, vol. 44A, pp. 5113-21.

    Article  Google Scholar 

  4. 4.

    4. A.J. Clarke, D. Tourret, Y. Song, S.D. Imhoff, P.J. Gibbs, J.W. Gibbs, K. Fezzaa, and A. Karma: Acta Mater., 2017, vol. 129, pp. 203-16.

    CAS  Article  Google Scholar 

  5. 5.

    Y. Song, S. Akamatsu, S. Bottin-Rousseau, and A. Karma: Phys. Rev. Mater., 2018, vol. 2, p. 053403.

    CAS  Article  Google Scholar 

  6. 6.

    6. D. Walton, and B. Chalmers: Trans. Metall. Soc. AIME, 1959, vol. 215, pp. 447-57.

    CAS  Google Scholar 

  7. 7.

    7. M. Rappaz, and C.A. Gandin: Acta Metall. Mater., 1993, vol. 41, pp. 345-60.

    CAS  Article  Google Scholar 

  8. 8.

    8. S. Akamatsu, G. Faivre, and T. Ihle: Phys. Rev. E, 1995, vol. 51, pp. 4751-73.

    CAS  Article  Google Scholar 

  9. 9.

    9. Y.M. Wang, S.M. Li, Z.P. Liu, H. Zhong, L. Xu, and H. Xing: J. Mater. Sci. Technol., 2019, vol. 35, pp. 1309-14.

    Article  Google Scholar 

  10. 10.

    B. Utter, and E. Bodenschatz: Phys. Rev. E, 2005, vol. 72, p. 011601.

    Article  Google Scholar 

  11. 11.

    11. Y. Chen, B. Billia, D.Z. Li, H. Nguyen-Thi, N.M. Xiao, and A.A. Bogno: Acta Mater., 2014, vol. 66, pp. 219-31.

    CAS  Article  Google Scholar 

  12. 12.

    12. N. D’Souza, M.G. Ardakani, A. Wagner, B.A. Shollock, and M. McLean: J. Mater. Sci., 2002, vol. 37, pp. 481-87.

    Article  Google Scholar 

  13. 13.

    13. Y.Z. Zhou, A. Volek, and N.R. Green: Acta Mater., 2008, vol. 56, pp. 2631-37.

    CAS  Article  Google Scholar 

  14. 14.

    14. H.L. Yu, J.J. Li, X. Lin, L.L. Wang, and W.D. Huang: J. Cryst. Growth, 2014, vol. 402, pp. 210-14.

    CAS  Article  Google Scholar 

  15. 15.

    15. S.S. Hu, W.C. Yang, Q.W. Cui, T.W. Huang, J. Zhang, and L. Liu: Mater. Charact., 2017, vol. 125, pp. 152-59.

    CAS  Article  Google Scholar 

  16. 16.

    16. J. Eiken: Int. J. Cast. Metals Res., 2009, vol. 22, pp. 86-89.

    CAS  Article  Google Scholar 

  17. 17.

    17. J.J. Li, Z.J. Wang, Y.Q. Wang, and J.C. Wang: Acta Mater., 2012, vol. 60, pp. 1478-93.

    CAS  Article  Google Scholar 

  18. 18.

    18. C.W. Guo, J.J. Li, H.L. Yu, Z.J. Wang, X. Lin, and J.C. Wang: Acta Mater., 2017, vol. 136, pp. 148-63.

    CAS  Article  Google Scholar 

  19. 19.

    19. T. Takaki, M. Ohno, Y. Shibuta, S. Sakane, T. Shimokawabe, and T. Aoki: J. Cryst. Growth, 2016, vol. 442, pp. 14-24.

    Article  Google Scholar 

  20. 20.

    20. T. Takaki, M. Ohno, T. Shimokawabe, and T. Aoki: Acta Mater., 2014, vol. 81, pp. 272-83.

    CAS  Article  Google Scholar 

  21. 21.

    21. D. Tourret, Y. Song, A.J. Clarke, and A. Karma: Acta Mater., 2017, vol. 122, pp. 220-35.

    CAS  Article  Google Scholar 

  22. 22.

    F. Li, L. Jin, Z. Xu, and Z.Q. Guo: Rev. Sci. Instrum., 2009, vol. 80, p. 085106.

    Article  Google Scholar 

  23. 23.

    23. L.Y. Yang, S.M. Li, Y. Li, K. Fan, and H. Zhong: J. Mater. Res., 2019, vol. 34, pp. 240-50.

    CAS  Article  Google Scholar 

  24. 24.

    H. Xing, X.L. Dong, H.J. Wu, G.H. Hao, J.Y. Wang, C.L. Chen, and K.X. Jin: Sci Rep, 2016, vol. 6, p. 26625.

    CAS  Article  Google Scholar 

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This research is financially supported by the National Natural Science Foundation of China (No. 51474174), Research Funds of the State Key Laboratory of Solidification Processing in NWPU (No. 2019-TS-01). Yumin Wang thanks Ming Ma from Electronic Materials Research Laboratory of Xian Jiaotong University for his help on RO-XRD tests

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Correspondence to Shuangming Li.

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Manuscript submitted April 23, 2019.

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Wang, Y., Li, S., Liu, Z. et al. Competitive Growth of Degenerate Pattern and Dendrites During Directional Solidification of a Bicrystal Metallic Alloy. Metall Mater Trans A 50, 4677–4685 (2019).

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