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Effect of Precipitate Morphology on the Gradient-Dependent Behaviour of Two-Phase Single Crystals

Published online by Cambridge University Press:  15 February 2011

E. P. Busso ,
F. T. Meissonnier  and
N. P. O'Dowd
E. P. Busso
Affiliation:
Mechanical Engineering Department, Imperial College, London SW7 2BX, UK
F. T. Meissonnier
Affiliation:
Mechanical Engineering Department, Imperial College, London SW7 2BX, UK
N. P. O'Dowd
Affiliation:
Mechanical Engineering Department, Imperial College, London SW7 2BX, UK
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Abstract

In this work a recently proposed gradient and rate-dependent crystallographic formulation is used to investigate the macroscopic behaviour of a precipitated single crystal. It relies on strain gradient concepts to account for the additional strengthening mechanism caused by presence of interfacial and geometrically necessary dislocations (GNDs). The total slip resistance is assumed to be due to a mixed population of mobile and sessile forest obstacles arising from both statistically stored dislocations (SSDs) and GNDs. The non-local crystallographic theory is implemented numerically into the finite element method. It requires the calculation of the slip rate gradients at the element level to determine the evolutionary behaviour of the GND densities, and a fully implicit numerical algorithm within a large strain kinematics framework and non-isothermal conditions. The effects of the relevant microstructural features (precipitate size, morphology and volume fraction) and deformation gradient-related length scales on the macroscopic behaviour is investigated and compared with experimental results.

Type
Research Article
Information
MRS Online Proceedings Library (OPL) , Volume 578: Symposia A/C – Multiscale Phenomena in Materials - Experiments in Modeling , 1999 , 59
Copyright
Copyright © Materials Research Society 2000

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References

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