Effect of Thermomechanical Processes on Σ3 Grain Boundary Distribution in a Nickel Base Superalloy

Abstract:

According to various studies, Grain Boundary Engineering (GBE) is likely to enhance mechanical properties of polycrystalline materials. The present investigation highlights some relationships between thermomechanical process (TMP) parameters of a commercial nickel-base superalloy PER72, supplied by Aubert & Duval (equivalent to Udimet®720™) and the resulting microstructure. The long-term goal is to develop TMPs that modify the Grain Boundary Character Distributions (GBCD) in order to improve high temperature properties. In this context, Grain Boundary Engineering (GBE) techniques are considered, thinking of replacing standard forming processes by optimised thermomechanical treatments. Mechanical testing at high temperature (compression and torsion tests) has been carried out and it is shown that multi-step treatments promote twinning. Some clues are then presented in an attempt to explain when and how twins are created.

• Periodical: Materials Science Forum (Volumes 638-642)
• Pages: 2333-2338
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.638-642.2333
• Online since: January 2010
• Authors: Nadia Souaï, Roland E. Logé, Yvan Chastel, Nathalie Bozzolo, Vincent Maurel, Loic Nazé
• Keywords: Annealing Twin, Grain Boundary Engineering, Nickel-Based Superalloy, Thermomechanical Process

References

[1] C. Ducrocq, A. Lasalmonie, Y. Honnarat. Superalloys, TMS, (1988), 63.

[2] J. -Y. Guédou, I. Augustins-Lecallier, L. Nazé, P. Caron, D. Locq. Superalloys, TMS, (2008), 21.

[3] T. Watanabe. Res Mechanica: International Journal of Structural Mechanics and Material Science, 11: 47-84, (1984).

[4] M.L. Kronberg and F. H. Wilson. Metal Transactions, 185: 501-514, (1949).

[5] D.G. Brandon, B. Ralph, S. Ranganathan, and M.S. Wald. Acta Metallurgica, 12: 813-821, (1964).

DOI: 10.1016/0001-6160(64)90175-0

[6] V.Y. Gertsman and S.M. Bruemmer. Acta Materialia, 49: 1589-1598, (2001).

[7] Yong Gao, Mukul Kumar, R.K. Nalla, and R.O. Ritchie. Metallurgical and Material Transactions A, 36A: 3325-3333, (2005).

[8] E.M. Lehockey and G. Palumbo. Material Science & Engineering A, A237: 168-172, (1996).

[9] L. Tan, K. Sridharan, and T.R. Allen. Journal of Nuclear Materials, 348: 263-271, (2006).

[10] V. Randle. Acta Materialia, 52: 4067-4081, (2004).

[11] V. Randle. The Role of the Coincidence Site Lattice in Grain Boundary Engineering, Institute of Materials (1996).

[12] V. Randle. Journal of Material Science, 40: 853-859, (2005).

[13] C.T. Sims, N.S. Stoloff, and W.C. Hagel. Superalloys II, John Wiley & Sons (1987).

[14] D.G. Brandon. Acta Metallurgica, 14: 1479-1484, (1966).