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Microstructural evolution of monocrystalline Co–Al–W-based superalloys by high-temperature creep deformation

  • Takahiro Sumitani (a1), Katsushi Tanaka (a1) and Haruyuki Inui (a2)


Creep tests of monocrystalline Co–Al–W-based alloys with a tensile stress of 137 MPa at 1000 °C were carried out. The microstructures of the crept specimens were investigated by scanning electron microscope (SEM) and transmission electron microscope (TEM). The γ′ phase in the specimens was not only elongated along the stress direction as expected by the sign of the lattice misfit but also elongated in one of the <100> directions perpendicular to the stress direction. As a result, the shape of the γ′ phase is not a rod but a plate. In the TEM images, it was observed that many SISFs are induced in the γ′ phase by creep. A similar microstructure is also observed in Ni-based superalloys, but the microstructure was formed under relatively lower temperatures and higher applied stresses. The observation of numerous stacking faults in the γ′ phase is a clear indication that the γ′ phase precipitated in the present alloy is weaker than that in many modern Ni-based superalloys.



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1. Sato, J., Omori, T., Oikawa, K., Ohnuma, I., Kainuma, R. and Ishida, K., Science 312, 90 (2006).
2. Miura, S., Ohkubo, K. and Mohri, T., Mater. Trans. 48, 2403 (2007).10.2320/matertrans.MAW200734
3. Suzuki, A., DeNolf, G. C. and Pollock, T. M., Scripta Mater. 56, 385 (2007).10.1016/j.scriptamat.2006.10.039
4. Tanaka, K., Ohashi, T., Kishida, K. and Inui, H., Appl. Phys. Lett. 91, 181907 (2007).10.1063/1.2805020
5. Shinagawa, K., Omori, T., Sato, J., Oikawa, K., Ohnuma, I., Kainuma, R. and Ishida, K., Mater. Trans. 49, 1474 (2008).
6. Suzuki, A. and Pollock, T. M., Acta Mater. 56, 1288 (2008).10.1016/j.actamat.2007.11.014
7. Osaki, M., Ueta, S., Shimizu, T., Omori, T. and Ishida, K., Denkiseikou 79, 197 (2008).
8. Chinen, H., Omori, T., Oikawa, K., Ohnuma, I., Kainuma, R. and Ishida, K., J. Phase Equi. Diffusion 30, 587 (2009).
9. Kobayashi, S., Tsukamoto, Y., Takasugi, T., Chinen, H., Omori, T., Ishida, K. and Zaefferer, S., Intermetallics 17, 1085 (2009).10.1016/j.intermet.2009.05.009
10. Shinagawa, K., Omori, T., Oikawa, K., Kainuma, R. and Ishida, K., Scripta Mater. 61, 612 (2009).
11. Pollock, T. M., Dibbern, J., Tsunekane, M., Zhu, J. and Suzuki, A., JOM 62, 58 (2010).
12. Chen, M., Wang, C. Y., Physics Letters A374, 3238 (2010).
13. Bauer, A., Neumeier, S., Pyczak, F. and Göken, M., Scripta Mater. 63, 1197 (2010).10.1016/j.scriptamat.2010.08.036
14. Ooshima, M., Tanaka, K., Okamoto, N. L., Kishida, K. and Inui, H., J. Alloys Comp. 508, 71 (2010).
15. Inui, H., Oohashi, T., Okamoto, N. L., Kishida, K. and Tanaka, K., Mater. Sci. Forum 638642, 1342 (2010).10.4028/
16. Copley, S. M. and Kear, B. H., Trans. Metall. Soc. AIME 239, 977 (1967).
17. Bauer, A., Neumeier, S., Pyczak, F., Singer, R. F. and Göken, M., Mater. Sci. Eng. A550, 333 (2012).
18. Titus, M. S., Suzuki, A. and Pollock, T. M., Scripta Mater. 66, 574 (2012).10.1016/j.scriptamat.2012.01.008
19. Thornton, P. H., Davis, R. G. and Johnston, T. L., Metall. Trans. 1, 207 (1970).
20. Paidar, V., Pope, D. P., Vitek, V., Acta Metall. 32, 435 (1984).
21. Knowles, D. M. and Chen, Q. Z., Mater. Sci. Eng. A356, 352 (2003).



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