Abstract
The rate of diffusional creep varies with grain size x, either as 1/x 2 or 1/x 3, depending on whether lattice or grain boundary diffusion is dominating. Since the rate of grain growth is proportional to 1/x p, where p⩾1, the creep and grain growth relationships can be combined to predict the transient creep that results from the two processes operating concurrently. An important result is obtained for grain boundary diffusion creep (Coble creep), where two regimes of behaviour are predicted depending on the value of p. For normal grain growth (p=1) and up to a critical value p=2, the transient gives rise to an upper limit to the grain boundary diffusional creep strain. For p>2, no limiting strain is predicted. The role of the limiting strain is discussed in the context of the various experimental attempts that have been made to verify the Coble mechanism.
Similar content being viewed by others
References
F. R. N. Nabarro, Report on Conference on Strength of Solids (Physical Society, London, 1948).
C. Herring, J. Appl. Phys. 21 (1950) 437.
R. L. Coble, ibid. 34 (1963) 1679.
B. Burton and G. W. Greenwood, Met. Sci. J. 4 (1970) 215.
N. Prasad, G. Malakondaiah and P. Rama Rao, Scripta Metall. 26 (1992) 541.
J. Fiala, L. Kloc and J. Cadek, Mater. Sci. Engng A136 (1991) 9.
B. Burton and G. W. Greenwood, Mater. Sci. Technol. 1 (1985) 1029.
A. M. Brown and M. F. Ashby, Acta Metall. 28 (1980) 1085.
B. Burton, “Diffusional Creep of Polycrystalline Materials” (Trans Tech, Aedermannsdorf, Switzerland, 1977).
J. E. Harris, M. O. Tucker and G. W. Greenwood, Met. Sci. J. 8 (1974) 310.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Burton, B. A theoretical upper limit to Coble creep strain resulting from concurrent grain growth. JOURNAL OF MATERIALS SCIENCE 28, 4900–4903 (1993). https://doi.org/10.1007/BF00361153
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/BF00361153