Hostname: page-component-84b7d79bbc-g7rbq Total loading time: 0 Render date: 2024-07-28T12:23:02.191Z Has data issue: false hasContentIssue false

Elemental Mapping at Grain Boundaries in Alloy X-750 by EFTEM

Published online by Cambridge University Press:  02 July 2020

J. Bentley
Affiliation:
Metals & Ceramics Division, Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN37831-6376
N. D. Evans
Affiliation:
Oak Ridge Institute for Science and Education, PO Box 117, Oak Ridge, TN37831-0117
E. A. Kenik
Affiliation:
Metals & Ceramics Division, Oak Ridge National Laboratory, PO Box 2008, Oak Ridge, TN37831-6376
Get access

Extract

Alloy X-750 is a γ -strengthened, nickel-base alloy used in demanding high-temperature applications. The HTH commercial heat treatment condition provides excellent strength and good corrosion resistance. However, the resultant precipitate structure is complex with fine (˜20 nm) intragranular γ' phase and copious intergranular precipitation of at least four phases (γ', M23C6, M23B6, and TiN). The intergranular precipitation causes localized grain boundary migration and results in a convoluted grain boundary structure. Such complex grain boundary microstructures increase the difficulty of phase identification and interfacial composition measurements by traditional analytical electron microscopy methods. Elemental mapping by EFTEM is a useful additional or alternative technique for characterizing such structures. A Gatan Imaging Filter (GIF) on a Philips CM30 (LaB6) was used in the current investigation. Experimental details have been summarized elsewhere.

Elemental maps of Cr, Ti, and Ni (net L23 intensities) are presented in Fig. la-c for a typical grain boundary region of a HTH heat treated specimen.

Type
Analytical Electron Microscopy
Copyright
Copyright © Microscopy Society of America 1997

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1 Kenik, E.A., these proceedings; also Mater. Res. Soc. Symp. Proc. 439, in press.Google Scholar

2 Hall, E.L. and Bentley, J., Mater. Res. Soc. Symp. Proc. 458, in press.Google Scholar

3 Bentley, J.et al. Proc. Microscopy and Microanalysis 1996, 542.CrossRefGoogle Scholar

4 Evans, N.D. and Bentley, J., Proc. Microscopy and Microanalysis 1996, 544.CrossRefGoogle Scholar

5 Research at the ORNL SHaRE User Facility sponsored by the Division of Materials Sciences, U.S. Department of Energy, under contracts DE-AC05-96OR22464 with Lockheed Martin Energy Research Corp., and DE-AC05-76OR00033 with Oak Ridge Associated Universities.Google Scholar