Elemental mapping at grain boundaries in alloy X-750 by EFTEM
- Oak Ridge National Lab., TN (United States). Metals and Ceramics Div.
- Oak Ridge Inst. for Science and Education, TN (United States)
Alloy X-750 is a {gamma}{prime}-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 ({approximately}30 nm) intragranular {gamma}{prime} phase and copious intergranular precipitation of at least four phases ({gamma}{prime}, M{sub 23}C{sub 6}, M{sub 23}B{sub 6}, 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 (LaB{sub 6}) was used in the current investigation. Experimental details have been summarized elsewhere. Elemental maps of Cr, Ti, and Ni (net L{sub 23} intensities) are presented for a typical grain boundary region of a HTH heat treated specimen.
- Research Organization:
- Oak Ridge National Lab., TN (United States)
- Sponsoring Organization:
- USDOE Office of Energy Research, Washington, DC (United States)
- DOE Contract Number:
- AC05-96OR22464
- OSTI ID:
- 505347
- Report Number(s):
- CONF-970834--14; ON: DE97005142
- Country of Publication:
- United States
- Language:
- English
Similar Records
Effect of heat treatment on SCC and HEC of precipitate-hardenable alloy in sour gas environment
Irradiation-induced precipitation in direct-aged alloy 625