Precipitation Behavior during Ageing Treatment of a Single Crystal Nickel-Base Superalloy


Article Preview

The precipitation behavior during ageing treatment of a single crystal nickel-base superalloy was investigated by SEM and TEM. The results showed that tetragonal needle-like σ phase and blocky -W phase precipitated during low temperature ageing treatment after this testing alloy was completely solution heat treated. σ and -W phases robbed of solid solution strengthening alloying element W、Mo in the matrix and degraded high temperature creep rupture property severely. The creep curve of the crystal tested at 1010 °C and 248 MPa exhibited that the steady state creep rate ε was as high as 9.46 × 10-3/h. The creep-rupture life was only 25 hours. -W phase was not formed by decrease of W content properly. A relatively low level of Co could inhibit σ phase precipitation and improve microstructural stability.



Materials Science Forum (Volumes 475-479)

Main Theme:

Edited by:

Z.Y. Zhong, H. Saka, T.H. Kim, E.A. Holm, Y.F. Han and X.S. Xie




D.Y. Yang et al., "Precipitation Behavior during Ageing Treatment of a Single Crystal Nickel-Base Superalloy", Materials Science Forum, Vols. 475-479, pp. 673-676, 2005

Online since:

January 2005




[1] Q.Y. Huang and H.K. Li: Superalloy (Metallurgy Industry Press, Beijing 2000), p.2.

[2] C.M.F. Rae, M.S.A. Karunaratne, C.J. Small, R.M. Broomfield, C.N. Jones and R.C. Reed: Superalloys 2000 (The Minerals, Metals & Materials Society, New York 2000), p.767.

[3] T.M. Pollock: Mater. Sci. Eng. Vol. 32B (1995), p.255.

[4] A.F. Giamei and D.L. Anton: Metall. Trans. Vol. 16A (1985), p. (1997).

[5] R. Darolia, D.F. Lahrman, R.D. Fiele and R. Sisson: Superalloys 1988 (The Metallurgical Society, New York 1988), p.255.

[6] G.L. Chen: Superalloy (Metallurgy Industry Press, Beijing 1988), p.167.

[7] G.L. Erickson: Superalloys 1996 (The Minerals, Metals & Materials Society, New York 1996), p.35.

[8] Y.R. Zheng and D.T. Zhang: Color Metallographic Investigation of Superalloys and Steels (Defence Industry Press, Beijing 1999), p.197 1µm Fig. 6 Microstructure of the new alloy after ageing at 870 ℃ for 500h.