The effect of thermomechanical processing on the microstructure and creep behavior of Udimet alloy 188

S. C. Longanbach, C. J. Boehlert

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    • 3 Citations

    Abstract

    Udimet 188 alloy was subjected to thermomechanical processing in attempt to understand the effects of cold-rolling deformation on the microstructure and tensile-creep behavior. Commercially available sheet was cold rolled to varying amounts of deformation (between 5%-35% reduction in sheet thickness) followed by a solution treatment at 1191°C for one hour followed by air cooling. This sequence was repeated four times to induce a favorable grain boundary character distribution containing a high volume fraction of low-energy grain boundaries. The resultant microstructure was characterized using electron backscattered diffraction. The effect of the thermomechanical processing treatment on the high-temperature (760-815°C) creep behavior was evaluated. Conventional lever-arm creep experiments were performed in an open air environment. The measured creep stress exponents (5.7-6.4) suggested that dislocation creep was dominant at 760°C for stresses ranging between 100-220MPa. The material exhibited a significant extent of grain boundary cracking. The fhermomechanical processing treatments which resulted in the greatest fractions (∼0.8) of special grain boundaries (low-angle boundaries + coincident site lattice boundaries) also exhibited the lowest creep rates. Thus a correlation was exhibited between the grain boundary character distribution and the minimum creep rates. Creep rupture experiments were performed at T=815°C and σ= 165MPa and the thermomechanical processing treatment which resulted in the greatest special boundary fraction also resulted in the greatest average time-to-rupture.

    Original languageEnglish (US)
    Title of host publicationProceedings of the International Symposium on Superalloys
    Pages461-468
    Number of pages8
    StatePublished - 2008
    Event11th International Symposium on Superalloys, Superalloys 2008 - Champion, PA, United States

    Other

    Other11th International Symposium on Superalloys, Superalloys 2008
    CountryUnited States
    CityChampion, PA
    Period9/14/089/18/08

    Profile

    Creep
    grain boundaries
    microstructure
    Accessory Nerve
    Grain boundaries
    Microstructure
    Common Bile Duct Diseases
    Amoxapine
    Carbamyl Phosphate
    Addison Disease
    Air
    Experiments
    Udimet alloys
    tensile creep
    air cooling
    levers
    cold rolling
    electron diffraction
    exponents
    air

    Keywords

    • Cobalt-based alloy
    • Creep
    • Electron backscatter diffraction
    • Microstructure

    ASJC Scopus subject areas

    • Materials Science(all)
    • Condensed Matter Physics

    Cite this

    Longanbach, S. C., & Boehlert, C. J. (2008). The effect of thermomechanical processing on the microstructure and creep behavior of Udimet alloy 188. In Proceedings of the International Symposium on Superalloys (pp. 461-468)

    The effect of thermomechanical processing on the microstructure and creep behavior of Udimet alloy 188. / Longanbach, S. C.; Boehlert, C. J.

    Proceedings of the International Symposium on Superalloys. 2008. p. 461-468.

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

    Longanbach, SC & Boehlert, CJ 2008, The effect of thermomechanical processing on the microstructure and creep behavior of Udimet alloy 188. in Proceedings of the International Symposium on Superalloys. pp. 461-468, 11th International Symposium on Superalloys, Superalloys 2008, Champion, PA, United States, 14-18 September.
    Longanbach SC, Boehlert CJ. The effect of thermomechanical processing on the microstructure and creep behavior of Udimet alloy 188. In Proceedings of the International Symposium on Superalloys. 2008. p. 461-468.

    Longanbach, S. C.; Boehlert, C. J. / The effect of thermomechanical processing on the microstructure and creep behavior of Udimet alloy 188.

    Proceedings of the International Symposium on Superalloys. 2008. p. 461-468.

    Research output: Chapter in Book/Report/Conference proceedingConference contribution

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