Hostname: page-component-cd9895bd7-gxg78 Total loading time: 0 Render date: 2024-12-28T21:49:12.407Z Has data issue: false hasContentIssue false

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

Published online by Cambridge University Press:  28 December 2012

Takahiro Sumitani
Affiliation:
Department of Mechanics, Kobe University, Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
Katsushi Tanaka
Affiliation:
Department of Mechanics, Kobe University, Rokkodai-cho, Nada-ku, Kobe 657-8501, Japan
Haruyuki Inui
Affiliation:
Department of Materials Science and Engineering, Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan
Get access

Abstract

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.

Type
Articles
Copyright
Copyright © Materials Research Society 2012 

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

Sato, J., Omori, T., Oikawa, K., Ohnuma, I., Kainuma, R. and Ishida, K., Science 312, 90 (2006).CrossRefGoogle Scholar
Miura, S., Ohkubo, K. and Mohri, T., Mater. Trans. 48, 2403 (2007).10.2320/matertrans.MAW200734CrossRefGoogle Scholar
Suzuki, A., DeNolf, G. C. and Pollock, T. M., Scripta Mater. 56, 385 (2007).10.1016/j.scriptamat.2006.10.039CrossRefGoogle Scholar
Tanaka, K., Ohashi, T., Kishida, K. and Inui, H., Appl. Phys. Lett. 91, 181907 (2007).10.1063/1.2805020CrossRefGoogle Scholar
Shinagawa, K., Omori, T., Sato, J., Oikawa, K., Ohnuma, I., Kainuma, R. and Ishida, K., Mater. Trans. 49, 1474 (2008).CrossRefGoogle Scholar
Suzuki, A. and Pollock, T. M., Acta Mater. 56, 1288 (2008).10.1016/j.actamat.2007.11.014CrossRefGoogle Scholar
Osaki, M., Ueta, S., Shimizu, T., Omori, T. and Ishida, K., Denkiseikou 79, 197 (2008).Google Scholar
Chinen, H., Omori, T., Oikawa, K., Ohnuma, I., Kainuma, R. and Ishida, K., J. Phase Equi. Diffusion 30, 587 (2009).CrossRefGoogle Scholar
Kobayashi, S., Tsukamoto, Y., Takasugi, T., Chinen, H., Omori, T., Ishida, K. and Zaefferer, S., Intermetallics 17, 1085 (2009).10.1016/j.intermet.2009.05.009CrossRefGoogle Scholar
Shinagawa, K., Omori, T., Oikawa, K., Kainuma, R. and Ishida, K., Scripta Mater. 61, 612 (2009).CrossRefGoogle Scholar
Pollock, T. M., Dibbern, J., Tsunekane, M., Zhu, J. and Suzuki, A., JOM 62, 58 (2010).CrossRefGoogle Scholar
Chen, M., Wang, C. Y., Physics Letters A374, 3238 (2010).CrossRefGoogle Scholar
Bauer, A., Neumeier, S., Pyczak, F. and Göken, M., Scripta Mater. 63, 1197 (2010).10.1016/j.scriptamat.2010.08.036CrossRefGoogle Scholar
Ooshima, M., Tanaka, K., Okamoto, N. L., Kishida, K. and Inui, H., J. Alloys Comp. 508, 71 (2010).CrossRefGoogle Scholar
Inui, H., Oohashi, T., Okamoto, N. L., Kishida, K. and Tanaka, K., Mater. Sci. Forum 638642, 1342 (2010).10.4028/www.scientific.net/MSF.638-642.1342CrossRefGoogle Scholar
Copley, S. M. and Kear, B. H., Trans. Metall. Soc. AIME 239, 977 (1967).Google Scholar
Bauer, A., Neumeier, S., Pyczak, F., Singer, R. F. and Göken, M., Mater. Sci. Eng. A550, 333 (2012).CrossRefGoogle Scholar
Titus, M. S., Suzuki, A. and Pollock, T. M., Scripta Mater. 66, 574 (2012).10.1016/j.scriptamat.2012.01.008CrossRefGoogle Scholar
Thornton, P. H., Davis, R. G. and Johnston, T. L., Metall. Trans. 1, 207 (1970).Google Scholar
Paidar, V., Pope, D. P., Vitek, V., Acta Metall. 32, 435 (1984).CrossRefGoogle Scholar
Knowles, D. M. and Chen, Q. Z., Mater. Sci. Eng. A356, 352 (2003).Google Scholar