Abstract
High-temperature tensile tests have been conducted on a magnesium alloy (Mg-1.5 pct Mn-0.3 pct Ce) with randomly mixed fine and coarse grains. The microstructural examinations clearly show that different mechanisms operate in the regions of coarse and fine grains. The coarse grains deform by dislocation slip, while grain boundary sliding occurs in the fine grains. The influence of these mechanisms on each other has also been observed in terms of dislocation density, intragranular slip lines, and grain boundary sliding. The analytical equations describing the interaction of two deformation mechanisms operative in materials with regions of fine and coarse grains were derived. The analysis is applicable for determining the controlling mechanism of two interacting mechanisms. It is predicted that at a critical volume fraction of fine grains of approximately 40 pct, a transition from superplastic to nonsuperplastic behavior occurs.
Similar content being viewed by others
References
K.A. Padmanabhan and G.J. Davis:Superplasticity, Springer- Verlag, Berlin, 1980.
J. Pilling and N. Ridley:Superplasticity in Crystalline Solids, The Institute of Metals, London, 1989.
O.D. Sherby and J. Wadsworth:Prog. Mater. Sci., 1989, vol. 33, p. 169.
A.K. Ghosh and R. Raj:Acta Metall., 1986, vol. 36, p. 447.
J. Cadek: Creep in Metallic Materials, Elsevier, 1988.
J.P. Poirier:Creep of Crystals, Cambridge University Press, Cambridge, United Kingdom, 1985.
O.A. Kaibyshev:Superplasticity of Commercial Alloys, Metallurgia, Moscow, 1984 (in Russian).
R.Z. Valiev, V.Yu. Gertcman, and O.A. Kaibyshev:Met. Phys. Metallogr., 1983, vol. 55, p. 554, (in Russian).
R.Z. Valiev and O.A. Kaibyshev:Phys. Status Solidi A, 1977, vol. 44, p. 65.
B.C. Snyder, J. Wadsworth, and O.D. Sherby:Acta Metall., 1984, vol. 32, p. 919.
R.C. Gifkins:J. Mater. Sci., 1970, vol. 5, p. 156.
T.G. Langdon and F.A. Mohamed:J. Austra. Inst. Met., 1977, vol. 22, p. 189.
L. Onsager:Phys. Rev., 1931, vol. 37, p. 405.
L. Onsager:Phys. Rev., 1931, vol. 38, p. 2265.
J.P. Hirth and J. Lothe:Theory of Dislocations, McGraw-Hill Book Company, New York, NY, 1968.
M.G. Zelin and R.Z. Valiev: Ufa Aviation Institute, Ufa, Russia, unpublished research, 1991.
N.G. Zaripov, A.R. Vagapov, and O.A. Kaibyshev:Met. Phys. Metallogr., 1987, vol. 63, p. 774.
Author information
Authors and Affiliations
Additional information
Formerly Associate Professor with the Ufa Aviation Institute
Rights and permissions
About this article
Cite this article
Zelin, M.G., Yang, H.S., Valiev, R.Z. et al. Interaction of high-temperature deformation mechanisms in a Magnesium Alloy with Mixed Fine and Coarse Grains. Metall Trans A 23, 3135–3140 (1992). https://doi.org/10.1007/BF02646132
Received:
Published:
Issue Date:
DOI: https://doi.org/10.1007/BF02646132