IUTAM Symposium on Mesoscopic Dynamics of Fracture Process and Materials Strength pp 97-106 | Cite as
A New Model of Scale Dependent Crystal Plasticity Analysis
Abstract
Crystal plasticity analysis of slip deformation in metal microstructure enables one to calculate densities for the statistically stored (SS) and the geometrically necessary (GN) dislocations, and such densities are utilized to evaluate the critical resolved shear stresses for slip systems. In this paper, we propose a new model, where the mean free path of moving dislocations is defined as a function of the densities for SS and also, GN dislocations, and the critical resolved shear stresses for slip systems are given only by SSDs. Scale dependent characteristics of GN dislocations is transmitted to the SSDs via the mean free path and finally, to the slip resistance of slip systems. Tensile deformations of six-grained multicrystal models whose average grain diameter, d̅, ranges from 0.1 to 500 μm, are analyzed with this new model and microand macroscopicd aspects are examined. Plastic flow stresses increase almost linearly with d-1/2 within the range, 500 > d > 1 μm, showing the Hall-Petch relation, and this grain refinement effect is gradually reduced for finer microstructures.
Key words
metal microstructure crystal plasticity analysis dislocations scale dependent plasticityPreview
Unable to display preview. Download preview PDF.
References
- Acharya, A. and Beaudoin, A.J., 2000, J. Mech. Phys. Solids, 48, 2213.CrossRefMATHGoogle Scholar
- Fleck, N.A., et al., 1994, Acta metall. mater., 42, 475.MathSciNetCrossRefGoogle Scholar
- Hill, R. 1966, J. Mech. Phys. Sol., 14, 95–102.CrossRefGoogle Scholar
- Kuhlmann-Wilsdorf, D., 1989, Mat. Sci. Eng. A113, 1.CrossRefGoogle Scholar
- Needleman, A. and Gil Sevillano, J., 2003, Scripta Mat., 48, 109.CrossRefGoogle Scholar
- Ohashi, T. 1987, Trans. Japan Inst. Met. 28, 906.Google Scholar
- Ohashi, T. 1990, Colloque de Physique, Col. Cl, 51, c1–593.CrossRefGoogle Scholar
- Ohashi, T. 1994, Phil. Mag., A70, 793.CrossRefGoogle Scholar
- Ohashi, T. 1997, Phil. Mag. Lett., 75, 51.CrossRefGoogle Scholar
- Ohashi, T. 1999, J. Phys. IV France, 9, Pr9–279.CrossRefGoogle Scholar
- Weertman, J., 2002, Acta Mat., 50, 673.CrossRefGoogle Scholar