Abstract
A constitutive rate equation for grain boundary sliding (GBS), in the presence of grain boundary precipitates, is developed. Langdon’s GBS model is modified by incorporating physically de-fined back stresses opposing dislocation glide and climb and by modifying the grain size de-pendence of creep rate. The rate equation accurately predicts the stress dependence of minimum creep rate and change in activation energy occurring as a result of changing the grain boundary precipitate distribution in complex Ni-base superalloys. The rate equation, along with the math-ematical formulations for internal stresses, is used to derive a transient creep model, where the transient is regarded as the combination of primary and secondary stages of creep in constant load creep tests. The transient creep model predicts that the transient creep strain is dependent on stress and independent of test temperature. It is predicted that a true steady-state creep will only be observed after an infinitely long time. However, tertiary creep mechanisms are expected to intervene and lead to an acceleration in creep rate long before the onset of a true steady state. The model accurately predicts the strain vs time relationships for transient creep in IN738LC Ni-base superalloy, containing different grain boundary carbide distributions, over a range of temperatures.
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References
B. Burton and G.L. Reynolds:Phil. Mag., 1974, vol. 29, pp. 1359–70.
G.L. Reynolds, W.B. Beere, and B. Burton:Met. Sci. J., 1977, vol. 11, pp. 213–18.
R. Raj and M.F. Ashby:Metall. Trans., 1971, vol. 2, pp. 1113–27.
B Burton:Mater. Sci. Technol., 1989, vol. 5, pp. 1005–12.
R Raj:Metall. Trans. A, 1975, vol. 5A, pp. 1499–1509.
B. Burton:Diffusional Creep of Polycrystalline Materials, Trans Tech Publications, Aedermannsdorf, Switzerland, 1977.
G. Malakondaiah, N. Prasad, G. Sundararajan, and P. Rama Rao:Acta Metall., 1988, vol. 36, pp. 2167–81.
F. Garofalo:Fundamentals of Creep and Creep-Rupture in Metals, Macmillan Publishing Co., New York, NY, 1965.
B.F. Dyson and D. McLean:Met. Sci. J., 1977, vol. 11, pp. 37–45.
A.K. Koul and R. Castillo:Metall. Trans. A, 1988, vol. 19A, pp. 2049–66.
R Castillo, A.K. Koul, and J.-P.A. Immarigeon: inSuperalloys 1988 S Reichman, D.N. Duhl, G. Mauer, S. Antolovich, and C. Lund, eds., TMS-AIME, Warrendale, PA, 1988, pp. 805–13.
F.T. Furrillo, J.M. Davidson, J.K. Tien, and L.A. Jackman:Mater. Sci. Eng., 1979, vol. 39, pp. 267–73.
A.K. Koul and R. Castillo:ASM Materials Congress, Pittsburgh, PA, Oct. 1993.
T.G. Langdon:Phil. Mag., 1970, vol. 22, pp. 689–700.
R.C. Gifkins:J. Australian Inst. Met., 1973, vol. 18, pp.137–145.
F.W. Crossman and M.F. Ashby:Acta Metall., 1975, vol. 23, pp. 425–40.
S. P Temoshenko and J.N. Goodier:Theory of Elasticity, 3rd ed., McGraw-Hill, New York, NY, 1970.
E. Arzt, M.F. Ashby, and R.A. Verrall:Acta Metall., 1983, vol. 31, pp. 1977–89.
R.W. Bailey:J. Inst. Met., 1926, vol. 35, pp. 27–43.
E. Orowan:J. West Scot. Iron-Steel Inst., 1946–47, vol. 54, pp. 45–96.
A Seeger: inDislocations and Mechanical Properties of Crystals, Wiley, New York, NY, 1957, pp. 243–329.
W.G. Johnston:J. Appl. Phys., 1965, vol. 33, pp. 2716–30
A.S. Krausz and H. Eyring:Deformation Kinetics, Wiley Interscience, New York, NY, 1975.
H. Frost and M.F. Ashby:Deformation Mechanism Maps, Pergamon Press, Elmsford, NY, 1982.
J. Rösier and E. Arzt:Acta Metall., 1988, vol. 36, pp. 1043–51.
E. Arzt and J. Rösier:Acta Metall., 1988, vol. 36, pp. 1053–60.
F.R.N. Nabaroo:Theory of Crystal Dislocations, Oxford University Press, London, 1967.
E. Orowan:Proc. Phys. Soc., 1940, vol. 52, pp. 8–22.
R Raj and M.F. Ashby:Acta Metall., 1975, vol. 23, pp. 653–66.
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Wu, X.J., Koul, A.K. Grain boundary sliding in the presence of grain boundary precipitates during transient creep. Metall Mater Trans A 26, 905–914 (1995). https://doi.org/10.1007/BF02649087
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DOI: https://doi.org/10.1007/BF02649087