Dislocation Micromechanisms and Scale-Free Flow in Microcrystals (Preprint)
Abstract
A frontier topic in computational materials science and mechanics is the development of a plasticity-modeling framework that naturally and accurately represents evolving length-scale effects and the consequences of the dislocation structure. Current studies show that important intrinsic "size effects" exist separately from an evolving excess dislocation density at mesoscopic scales. Understanding those effects forms an essential foundation for representing microstructural effects within predictive computational frameworks. Our studies focused on simulation, analysis and measurements of the plastic phenomena occurring in microcrystals having dimensions at the lower end of the mesoscopic domain, wherein the discrete and stochastic nature of the dislocation ensemble is visible. In prior work, we reported on selected experimental results for Ni crystals. The present studies examined the athermal flow response of micron-scale single crystals using large-scale discrete dislocation simulations (DDS) in 3d, under conditions closely related to our experimental methods.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 2009
- Accession Number
- ADA502793
Entities
People
- Christopher F. Woodward
- Dennis M. Dimiduk
- E. Nadgorny
- M. D. Uchic
- Paul A. Shade
- S.I. Rao
Organizations
- Air Force Research Laboratory