Heat Treatment Effect on Microstructure and Mechanical Properties of Re-Containing Inconel 718 Alloy


The effect of Rhenium additions to the standard Inconel 718 (ST IN718) alloy as well as solution and aging treatments on microstructure and hardness property were studied. The microstructure of Re-containing alloys has higher volume fraction of δ phase than standard alloy. Conventional solution treatment (CST) at 1273 K for 1h precipitates a thin film of δ phase at the grain boundaries as well as needle-like in γ matrix; however, after modified solution at 1440 K for 3 h long, both types of δ phase precipitates entirely vanish from the microstructure. Small colonies of needle-like δ phase start to appear with aging at 1023 K for 4 h, after CST. Prolonging the aging time to 50 h, these colonies enlarge in size and spread in the matrix. XRD and TEM observations were used to identify the precipitation of hard γ” and γ’ phases. The changing in hardness measurements were evidence about the precipitation of these hard phases. CST have higher rate to increase in hardness with aging time comparing to modified solution specimens.

Share and Cite:

N. El-Bagoury and M. Ramadan, "Heat Treatment Effect on Microstructure and Mechanical Properties of Re-Containing Inconel 718 Alloy," Journal of Minerals and Materials Characterization and Engineering, Vol. 11 No. 9, 2012, pp. 924-930. doi: 10.4236/jmmce.2012.119090.

Conflicts of Interest

The authors declare no conflicts of interest.


[1] T. S. Chester, S. S. Norman and C. H. William, “Superalloys ??,” John Willey & Sons, Inc., New York, 1976.
[2] P. Caron and T. Khan, “Evolution of Ni-Based Superalloys for Single Crystal Gas Turbine Blade Applications,” Aerospace Science and Technology, Vol. 3, No. 8, 1999, pp. 513-523. doi:10.1016/S1270-9638(99)00108-X
[3] Aerospace Structural Metals Handbook, Code 5201, 1963; Code 5206, 1966; Code 5208, 1967; Code 5209, 1971; Code 5211, 1973; U.S. Department of Defense, Mechanical Properties Data Center.
[4] Y. S. Song, W. F. Gao, C. Wang, X. W. Lei, H. L. Wang, “Effect of Heat Treatment Technology on Microstructure, Mechanical Property and Corrosion Resistance of Nickel-Base Alloy Inconel 718,” Cailiao Gongcheng, Journal of Materials Engineering, Vol. 6, 2012, p. 37.
[5] T. Carneiro and H. S. Moura, “Electron Beam Melting and Refining of Niobium at CBMM,” Paper Presented at the Electron Beam Melting and Refining, State of the Art 1998, Bakish Materials Corporation, Englewood, NJ, 11 December 1998, pp. 110-125.
[6] J. P. Gu, C. Beckermann and A. F. Giamei, “Motion and Remelting of Dendrite Fragments during Directional Solidification of a Nickel-Base Superalloy,” Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science, Vol. 28, No. 7, 1997, p. 1533.
[7] H. Murakami, H. Harada and H. K. D. H. Bhadeshia, “The Location of Atoms in Re- and V-Containing Multicomponent Nickel-Base Single-Crystal Superalloys,” Applied Surface Science, Vol. 76-77, 1994, pp. 177-183. doi:10.1016/0169-4332(94)90340-9
[8] H. Harada, A. Ishida, Y. Murakami, H. K. D. H. Bhadeshia and M. Yamazaki, “Atom-Probe Microanalysis of a Nickel-Base Single Crystal Superalloy,” Applied Surface Science, Vol. 67, No. 1-4, 1993, p. 299.
[9] J. He, S. Fukuyama and K. Yokogawa, “A Stacking Fault with a Series of Cross Fringes in Inconel 718 Ni-Base Superalloy,” Scripta Metallurgica et Materiala, Vol. 31, No. 10, 1994, p. 1421.
[10] D. Blavette, P. Caron and T. Khan, “An Atom Probe Investigation of the Role of Rhenium Additions in Improving Creep Resistance of Ni-Base Superalloys,” Scripta Metallurgica, Vol. 20, No. 10, 1986, pp. 1395-1400. doi:10.1016/0036-9748(86)90103-1
[11] S. Chambreland, A. Walder and D. Blavette, “Early Stages of Precipitation of γ’-Phase in a Nickel Base Superalloy: An Atom-Probe Investigation,” Acta Metallurgica, Vol. 36, No. 12, 1988, p. 3205.
[12] N. Wanderka and U. Glatzel, “Chemical Composition Measurements of a Nickel-Base Superalloy by Atom Probe Field Ion Microscopy,” Materials Science and Engineering: A, Vol. 203, No. 1-2, 1995, pp. 69-74. doi:10.1016/0921-5093(95)09825-9
[13] G. Appa Rao, M. Srinivas and D. S. Sarma, “Effect of Thermomechanical Working on the Microstructure and Mechanical Properties of Hot Isostatically Pressed Superalloy Inconel 718,” Materials Science and Engineering A, Vol. 383, No. 2, 2004, p. 201.
[14] W. C. Liu, F. R. Xiao, M. Yao, Z. L. Chen, Z. O. Jiang and S. G. Wang, “Relationship between the Lattice Constant of ? Phase and the Content of δ phase, γ’’ and γ’ Phases in Inconel 718,” Scripta Materialia, Vol. 37, No. 1, 1997, pp. 59-64. doi:10.1016/S1359-6462(97)00064-X
[15] C. Salama and M. Abdellaoui, “Structural Characterization of the Aged Inconel 718,” Journal of Alloys and Compounds, Vol. 306, No. 1-2, 2000, pp. 277-284. doi:10.1016/S0925-8388(00)00789-1
[16] G. Muralidharan, R. G. Thompson and S. D. Walack, “Analysis of Precipitation in Cast Alloy 718,” Ultramicroscopy, Vol. 29, No. 1-4, 1989, pp. 277-283. doi:10.1016/0304-3991(89)90255-6
[17] J. T. Goldstein and G. Ehrlich, “Atom and Cluster Diffusion on Re(0001),” Surface Science, Vol. 443, No. 1-2, 1999, pp. 105-115. doi:10.1016/S0039-6028(99)00950-4
[18] P. J. Warren, A. Cerezo and G. D. W. Smith, “An Atom Probe Study of the Distribution of Rhenium in a Nickel- Based Superalloy,” Materials Science and Engineering A, Vol. 250, No. 1, 1998, pp. 88-92. doi:10.1016/S0921-5093(98)00541-3

Copyright © 2023 by authors and Scientific Research Publishing Inc.

Creative Commons License

This work and the related PDF file are licensed under a Creative Commons Attribution 4.0 International License.