Effects of Ru Additions on the Microstructures and Stress Rupture Life of a Directionally Solidified Ni-Based Cast Superalloy

Abstract:

Two directionally solidified (DS) Ni-based cast superalloys without and with 3wt. % Ru were prepared. The effects of Ru addition on the microstructures and stress rupture properties of the heat treated superalloys were investigated. It is shown that the amount of eutectic in 3wt. % Ru alloy was less than that in alloy without Ru. The incipient melting structure was found after quenching followed by 1295°C and 1300°C solid solution treatments in 3wt. % Ru alloy and in the alloy without Ru, respectively. The temperature at which the eutectic pools dissolved completely was higher than the temperature at which incipient melting appears. In order to obtain the better mechanical properties, double aging treatment was carried out for both alloys to optimize the sizes, morphologies and distribution of the γ′ phase. The stress rupture lives of the alloys were 55h and 108h under the condition of 1070°C and 137MPa the alloys without Ru and with 3wt. % Ru respectively. It is suggested that 3wt. % Ru addition can prolong the stress rupture life of the alloy.

• Periodical: Materials Science Forum (Volumes 546-549)
• Pages: 1201-1206
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.546-549.1201
• Online since: May 2007
• Authors: Xiao Lei Han, Ya Fang Han, Shu Suo Li, Wen You Ma
• Keywords: Aging Treatment, DS Ni Base Superalloy, Ru, Solid Solution Treatment, Stress-Rupture Properties

References

[1] Koizumi Y, Kobayashi T, Yokokawa T, et al. Development of 4 th generation Ni-base single crystal superalloys [A]. Pro Second Int Symposium on High Temperature Materials 2001 [C]. Tsukuba Science City: National Institute for Materials Science, 2001, 30-31.

[2] G L., Erickson, In Pro 8 th Int Symp on Superalloys . Pennsylvania: TMS, 1996, 35-44.

[3] Feng Q, Nandy T K, Tin S, et al: Acta Materialia, 2003, 51: 269-284.

[4] C. M. F. Race, M�S�A. Karumaratne, C. J. Small, Superalloys 2000, eds, by T.M. Pollock, TMS, 2000, 767-776.

[5] L. Zheng. The Effects of Ta and Ru on the Microstructures and Properties of Low Cr and High W Content Cast Ni-base Superalloys [D].

[6] Nguyen-Dinh X. Phase stable single crystal materials [p], US 4935072, Jun. 19, (1990).

[7] Y. Murata, R. Hashizume etal. , Superalloys 2000, eds. By T.M. Pollock, TMS, 2000, 285-294.

[8] Y. Koizumi, T. Kobayashi, Yokokawa T, etal. In Pro Second Int Symposium on High Temperature Materials 2001. Tsukuba Science City: National Institute for Materials Science, 2001. 30-31.

[9] Q.Y. Huang, H.K. Li. Superalloys [M], Beijing, Metallurgical Industry Press, 2002: 144.

[10] C.X. Wu, C.Q. Sun, Q.J. Li: Journal of Aeronautical Materials, 2002, 22 (3): 1.

[11] R.Z. Chen, L.B. Wang, Y.P. Wang: Acta Aeronautica Et Astronautica Sinica, 1988, 9 (9): A308.

[12] W.Y. Ma, S.S. Li, M. Qiao: The Chinese Journal of Nonferrous Metals, 2006, 6; 937.

[13] Q.Z. Hu, L.R. Liu, T. Jin: Aeroengine, 2005, 31(3): 4.

[14] H. Murakami, T. Honma et al., Distribution of Platinum Group Metals in Ni-Base Single Crystal Superalloys. Superalloys 2000, Eds. T.M. Pollock et al., TMS, 2000: 747.

DOI: 10.7449/2000/superalloys_2000_747_756

[15] T. Murakumo et al., TEM Observation of Microstructures in Ni-base Single Crystal Superalloys with and without Re. The 2 nd International Symposium on High Temperature Materials 2001, Tsukuba: NIMS, 2001: 18-20.