Morphology of γ' Precipitates in Second Stage High Pressure Turbine Blade of Single Crystal Nickel-Based Superalloy after Serviced

Abstract:

The morphology of the ’ precipitates in the single crystal nickel-based superalloy serviced as the second stage high pressure turbine blade of the aircraft engine was examined. The aim of this work was to estimate the temperature and the stress distribution, and the stress direction of the blade in service. The blade was cut into three parts parallel to (001) plane at 8, 40 and 64mm from the tip. These parts were named as the tip, middle and root parts. Furthermore, these three parts were cut into six parts parallel to {100} which were almost normal to the surface from the leading to the trailing edge at interval of 6mm. Microstructure observations by a FE-SEM were carried out on the thirty portions of each part parallel to (001) and {100} planes at the vicinity of the interface between the coating layer and the matrix in the suction and pressure sides. Most of the ’ precipitates contacted each other toward almost parallel to the surface at the vicinity of the interface in the blade. Especially, at the leading edge of the pressure side of the tip and middle parts, the rafted /’ structures start to collapse. Consequently, the blade in service, at the leading edge of the pressure side of the tip and middle parts were exposed to the highest temperature and stress conditions. And the multi-axial compressive stresses parallel to the blade surface were expected to act on the blade in service.

• Periodical: Materials Science Forum (Volumes 638-642)
• Pages: 2291-2296
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.638-642.2291
• Online since: January 2010
• Authors: N. Miura, K. Nakata, M. Miyazaki, Y. Hayashi, Y. Kondo
• Keywords: Rafted γ / γ' Structure, Superalloy, Turbine Blade, γ' Precipitate

References

[1] H. Harada : JSPS Rep. of the 123rd Committee on Heat Res. and Alloys, Vol. 48 (2007), p.357.

[2] Y. Yoshioka : JSPS Rep. of the 123rd Committee on Heat Res. and Alloys, Vol. 48 (2007), p.365.

[3] R. J. R. Glenny, J. E. Northwood and A. B. Smith : Int. Met. Rev. Vol. 20 (1997), p.257.

[4] M. Masuoka : Jet Engine (JAEA, Tokyo, 2003).

[5] T. M. Pollock and A. S. Argon : Acta Metall. Mater., Vol. 42 (1994), p.1859.

[6] V. Sass, V. Glatzel and M. F. Kniepmeier : Acta Metall. Mater. Vol. 44 (1996), p. (1967).

[7] L. Shin, S. Tian, T. Jin and Z. Hu : Mater Sci. and Eng. A, Vol. 418 (2006), p.229.

[8] N. Miura, Y. Kondo and T. Matsuo : Proc. of 9th Int'l. Conf. on Creep and Fracture Eng. Mater. and Structures, (2001), p.437.

[9] N. Miura, K. Kurita, Y. Kondo and T. Matsuo : Mater. Sci. Forum Vol. 539-543 (2007), p.3024.

[10] N. Miura, N. Harada, Y. Kondo and T. Matsuo : Proc. of the 7th Liege Conf. on Mater. for Adv. Power Eng. 2002, (2002), p.245.

[11] U. Tetzlatt and H. Mughrabi : Proc. of the 9 th Int. Conf. on Superalloys 2000, (2000), p.273.

[12] L. Shui, S. Tian, T. Jin. and Z. Hu : Mater. Sci. and Eng. A, Vol. 418 (2006), p.229.

[13] K. Nakata, A. Kugimiya, Y. Hayashi, N. Miura and Y. Kondo : CAMP-ISIJ, Vol. 22(2009), p.561. Fig. 6 Schematic illustration of the distribution of the temperature and the stress, and the stress directions of the 2nd HPT blade in service.