Grain size refinement due to relaxation of disclination junction configurations in the course of plastic deformation of polycrystals. / Orlova, T. S.; Nazarov, A. A.; Enikeev, N. A.; Alexandrov, I. V.; Valiev, R. Z.; Romanov, A. E.
In: Physics of the Solid State, Vol. 47, No. 5, 01.01.2005, p. 845-851.Research output: Contribution to journal › Article › peer-review
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TY - JOUR
T1 - Grain size refinement due to relaxation of disclination junction configurations in the course of plastic deformation of polycrystals
AU - Orlova, T. S.
AU - Nazarov, A. A.
AU - Enikeev, N. A.
AU - Alexandrov, I. V.
AU - Valiev, R. Z.
AU - Romanov, A. E.
PY - 2005/1/1
Y1 - 2005/1/1
N2 - A model is proposed for the formation of the substructure in polycrystals during plastic deformation. According to this model, fragmentation of a grain occurs through the formation of a system of diagonal low-angle boundaries, which originate at the edges of a rectangular grain. Misorientation boundaries form through relaxation of a nonsymmetric junction quadrupole disclination configuration accumulated at the grain corners under severe deformation when the disclination strength reaches a certain critical value. The energetics of this process is analyzed. A general case is considered where the disclinations at the junctions of the chosen grain differ in strength. The energetic approach used makes it possible to determine the misorientation angle ωx of the resulting boundaries corresponding to the maximum energy gain and to find the dependence of this angle on the degree of asymmetry of the quadrupole configuration of junction disclinations. According to the proposed model, the splitting of a grain with a short edge greater than 0.5 μm is energetically favorable and decreases the latent energy of the grain for any ratio between the junction disclination strengths if the grain length-to-width ratio is less than 30. It is shown that the minimum possible grain size in the proposed model does not exceed 0.1 μm.
AB - A model is proposed for the formation of the substructure in polycrystals during plastic deformation. According to this model, fragmentation of a grain occurs through the formation of a system of diagonal low-angle boundaries, which originate at the edges of a rectangular grain. Misorientation boundaries form through relaxation of a nonsymmetric junction quadrupole disclination configuration accumulated at the grain corners under severe deformation when the disclination strength reaches a certain critical value. The energetics of this process is analyzed. A general case is considered where the disclinations at the junctions of the chosen grain differ in strength. The energetic approach used makes it possible to determine the misorientation angle ωx of the resulting boundaries corresponding to the maximum energy gain and to find the dependence of this angle on the degree of asymmetry of the quadrupole configuration of junction disclinations. According to the proposed model, the splitting of a grain with a short edge greater than 0.5 μm is energetically favorable and decreases the latent energy of the grain for any ratio between the junction disclination strengths if the grain length-to-width ratio is less than 30. It is shown that the minimum possible grain size in the proposed model does not exceed 0.1 μm.
UR - http://www.scopus.com/inward/record.url?scp=18744374249&partnerID=8YFLogxK
U2 - 10.1134/1.1924843
DO - 10.1134/1.1924843
M3 - Article
AN - SCOPUS:18744374249
VL - 47
SP - 845
EP - 851
JO - Physics of the Solid State
JF - Physics of the Solid State
SN - 1063-7834
IS - 5
ER -
ID: 45792252