Finite element investigation of size effects on the mechanical behavior of nickel single crystals

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:550

Article

Keller, C.¹  Habraken, A. M.²  Duchene, L.² 

[1] Univ Rouen, Ermeca GPM, UMR 6634, CNRS,INSA Rouen, F-76800 St Etienne, France

[2] Univ Liege, Dept ArGEnCo, Div MSF, B-4000 Liege, Belgium

关键词: Finite element method;    Crystal plasticity;    Size effects;    Single crystal;    Boundary conditions;   

DOI  :  10.1016/j.msea.2012.04.085

来源: Elsevier

【 摘 要 】

The influence of dimensions on the mechanical behavior of f.c.c. single crystals with dimensions larger than a few micrometers has been the topic of many experimental investigations and controversies during the 1970s and this question is still open. The objective of this article is to shed new light on this point by performing finite element simulations thanks to a strain gradient crystal plasticity model. Based on the model identification for nickel, several single crystal samples with various thicknesses and orientations were tested numerically in tension. The effect of dimensions was then analyzed considering the spatial distribution of dislocation densities. Near loading boundaries, dislocation density gradients appeared perpendicular to the Burgers vector direction of the primary activated slip system which modified the mechanical behavior. These gradients are discussed in terms of boundary conditions, crystal orientation and dislocation interactions with surfaces. (C) 2012 Elsevier B.V. All rights reserved.

【 授权许可】

Free