Development of New Bond Coat System in Ni-Base Alloys


Article Preview

Ni-base single crystal (SC) superalloys containing high concentrations of refractory elements are prone to generate a diffusion layer called Secondary Reaction Zone (SRZ) beneath their bond coating during exposure at high temperatures. SRZ causes a reduction of the load bearing cross section and is detrimental to the creep properties of thin-wall turbine airfoils. In this study, a new coating system – “EQ coating”, which is in thermodynamic equilibrium with the substrate, has been proposed and the formation behavior of SRZ beneath bond coat materials was investigated on the 5th generation Ni-base SC superalloy developed by NIMS. Diffusion couples of several alloys were made and were heat treated at 1100°C for 300 h, 1000 h. The concentration profiles were analyzed by EPMA. Also, cyclic oxidation tests were carried out at 1100°C in air.



Materials Science Forum (Volumes 522-523)

Edited by:

Shigeji Taniguchi, Toshio Maruyama, Masayuki Yoshiba, Nobuo Otsuka and Yuuzou Kawahara




A. Sato et al., "Development of New Bond Coat System in Ni-Base Alloys", Materials Science Forum, Vols. 522-523, pp. 361-368, 2006

Online since:

August 2006




[1] Y. Koizumi, T. Kobayashi, T. Yokokawa, J. X. Zhang, M. Osawa, H. Harada, Y. Aoki and M. Arai: Superalloy 2004, (TMS, 2004) pp.35-43.

[2] W. S. Walston, J. C. Schaeffer and W. H. Murphy: Superalloy 1996, (TMS, 1996) pp.9-18.

[3] O. Lavigne, C. Ramusat, S. Drawin, P. Caron, D. Boivin and J. -L. Pouchou: Superalloy 2004, (TMS, 2004) pp.667-675.

[4] I. E. Locci, R. A. Mackay, A. Grag and F. J. Ritzert: NASA/TM-2004-212920, March (2004).

[5] Y. Matsuoka, Y. Aoki, K. Matsumoto, A. Satou, T. Suzuki, K. Chikugo and K. Murakami: Superalloy 2004, (TMS, 2004) pp.637-642.

[6] L. S. Darken: Trans AIME., 175 (1948), 184.

[7] T. Narita, S. Hayashi, H. Yakuwa, M. Noguchi and M. Miyasaka: U.S. Patent, 6, 830, 827, Dec. 14, (2004).

[8] I. T. Spitsberg, R. Darolia, M. R. Jackson, J. C. Zhao and J. C. Schaeffer: U.S. Patent, 6, 306, 524, Oct. 23, (2001).

[9] R. G. Wing: U.S. Patent, 6, 080, 246, June. 27, (2000).

[10] B. Gleeson, W. Wang, S. Hayashi and D. Sordelet: Materials Science Forum, 461-464 (2004), pp.213-222.

[11] S. Hayashi, W. Wang, D. J. Sordelet and B. Gleeson: Metallurgical and Meterials Transactions A, 36A (2004), pp.1769-1775.

[12] J. R. Nicholls, N. J. Simms, W. Y. Chan and H. E. Evans: Surface and Coatings Technology, 149 (2002) pp.216-244.

[13] D. Zhong, J. J. Moore, E. Sutter and B. Mishra: Surface and Coatings Technology, 200 (2005), pp.1236-1241.

[14] T. Hino, T. Kobayashi, Y. Koizumi, H. Harada and T. Yamagata: Superalloys 2000 (TMS, 2000), pp.729-736.

[15] H. Harada, T. Yokokawa, K. Ohno, T. Yamagata and M. Yamazaki: Proceedings of Conference on Creep and Fracture of Engineering Materials and Structure, (The Institute of Materials, 1990) pp.255-264. Diffusion Zone.