Modelling the coefficient of thermal expansion in Ni-based superalloys and bond coatings

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Karunaratne, M. S. A. ; Kyaw, Si ; Jones, A. ; Morrell, R. ; Thomson, R. C. (2016)

The coefficient of thermal expansion (CTE) of nickel-based superalloys and bond coat layers was modelled by considering contributions from their constituent phases. The equilibrium phase composition of the examined materials was determined using thermodynamic equilibrium software with an appropriate database for Ni-based alloys, whereas the CTE and elastic properties of the principal phases were modelled using published data. The CTEs of individual phases were combined using a number of approaches to determine the CTE of the phase aggregate. As part of this work, the expansion coefficients of the superalloy IN-738LC and bond coat Amdry-995 were measured as a function of temperature and compared with the model predictions. The predicted values were also validated with the published data for the single-crystal superalloy CMSX-4 and a number of other Ni-based alloy compositions at 1000 K. A very good agreement between experiment and model output was found, especially up to 800  $$^\circ $$ � C. The modelling approaches discussed in this paper have the potential to be an extremely useful tool for the industry and for the designers of new coating systems.
  • References (46)
    46 references, page 1 of 5

    1. Sims CT, Stoloff NS, Hagel WC (1987) Superalloys II: hightemperature materials for aerospace and industrial power. Wiley, New York

    2. Reed RC (2006) The superalloys: fundamentals and applications. Cambridge University Press, Cambridge

    3. Jena AK, Chaturvedi MC (1984) The role of alloying elements in the design of nickel-base superalloys. J Mater Sci 19(10):3121- 3139. doi:10.1007/BF00549796

    4. Tawancy HM, Sridhar N, Abbas NM, Rickerby DS (2000) Comparative performance of selected bond coats in advanced thermal barrier coating systems. J Mater Sci 35(14):3615-3629. doi:10.1023/A:1004825932601

    5. Evans HE, Taylor MP (1997) Creep relaxation and the spallation of oxide layers. Surf Coat Technol 94-95(1-3):27-33

    6. Liang JJ, Wei H, Zhu YL, Sun XF, Hu ZQ, Dargusch MS, Yao X (2011) Phase constituents and thermal expansion behavior of a NiCrAlYRe coating alloy. J Mater Sci 46(2):500-508. doi:10. 1007/s10853-010-4953-y

    7. Sung PK, Poirier DR (1998) Estimation of densities and coefficients of thermal expansion of solid Ni-base superalloys. Mater Sci Eng A 245(1):135-141

    8. Giamei AF, Pearson DD, Anton DL (1985) c: The key to superalloy behaviour. In: Koch CC, Liu CT, Stoloff NS (eds) High-temperature ordered intermetallic alloys. Materials Research Society Symposia Proceedings, vol. 39, p 294-308. Materials Research Society, Pittsburgh

    9. Hull FC, Hwang SK, Wells JM, Jaffee RI (1987) Effect of composition on thermal expansion of alloys used in power generation. J Mater Eng 9(1):81-92

    10. Morrow H, Sponseller DL, Semchyshen M (1975) The effects of molybdenum and aluminum on the thermal expansion coefficients of nickel-base alloys. Metall Mater Trans A 6(3):477-485

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