High Density Bands of GN Dislocations Formed by Multi Body Interaction in Compatible Type Multi Crystal Models


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Slip deformation phenomena in compatible type multi crystal models subjected to tensile load are analyzed by a finite element crystal plasticity analysis code, and accumulation of geometrically-necessary and statistically-stored dislocations (GNDs and SSDs) are evaluated in detail. Crystal orientations for the grains are chosen so that mutual constraint of deformation through grain boundary planes does not take place. We call these models as compatible type multi crystals, because “compatibility requirements” at grain boundaries are automatically maintained by slip deformation only on the primary systems and uniform deformation is expected to occur in each grain. Results of the analysis, however, show non-uniform deformation with high density of GNDs accumulated in a form of band. Growth of such kind of structure of GNDs caused localized accumulation of SSDs at grain boundary triple junctions. Mechanism for the band-shaped accumulation of GNDs in the compatible type multi crystals are discussed from the viewpoint of multi body interactions which arise from shape change of crystal grains after slip deformation.



Key Engineering Materials (Volumes 340-341)

Edited by:

N. Ohno and T. Uehara




R. Kondou and T. Ohashi, "High Density Bands of GN Dislocations Formed by Multi Body Interaction in Compatible Type Multi Crystal Models", Key Engineering Materials, Vols. 340-341, pp. 187-192, 2007

Online since:

June 2007




[1] Livingston, J. D. and Chalmers, B., Acta Met., Vol. 5, No. 6 (1957) pp.322-327.

[2] Hirth, J. P., Metall. Trans., Vol. 3 (1972) pp.3047-3067.

[3] Hook, R. E., and Hirth, J. P., Acta Metall., Vol. 15 (1967) pp.535-551.

[4] Ashby M. F., Phil. Mag., Vol. 21 (1970) pp.399-424.

[5] Kondou R., and Ohashi T., Trans. JSME, Vol. 72, No. 718 (2006) pp.937-944.

[6] Hill R., J. Mech. Phys. Sol., Vol. 14 (1966) 95-102.

[7] Ohashi T., Phil. Mag. A, Vol. 70, No. 5 (1994) 793-803.

[8] Ohashi T., The Iron and Steel Institute of Japan, 180�181 Nishiyama anniversary technique lecture (2004) pp.73-95.

[9] Ohashi T., IUTAM Symposium on Mesoscopic Dynamics of Fracture Process and Materials Strength (2004) pp.97-106.

[10] Ohashi T., Phil. Mag. Lett. Vol. 75, No. 2 (1997) pp.51-57.

[11] Ohashi T., et al., J. Japan Inst. Metals Vol. 44, No. 8 (1980) pp.876-883.

[12] Kondou R., et al., T., Trans. JSME, A, Vol. 72, No. 716 (2006) pp.582-589.