Atomistic and mean-field estimates of effective stiffness tensor of nanocrystalline copper

Abstract

The full elasticity tensor for nano-crystalline copper is derived in molecular simulations by performing numerical tests for a set of generated samples of the polycrystalline material. The results are analysed with respect to the anisotropy degree of the overall stiffness tensor resulting from the limited number of grain orientations and their spatial distribution. The dependence of the overall bulk and shear moduli of an isotropized polycrystal on the average grain diameter is analysed. It is found that while the shear modulus decreases with grain size, the bulk modulus shows negligible dependence on the grain diameter and is close to the bulk modulus of a single crystal. A closed-form mean-field model of effective elastic properties for a bulk nano-grained polycrystal with cubic grains, i.e. made of a material with cubic symmetry, is formulated. In the model all parameters are based on the data for a single crystal and on the averaged grain size without any need for additional fitting. It is shown that the proposed model provides predictions of satisfactory qualitative and quantitative agreement with atomistic simulations.

arXiv comment28 pages, 33 figures

References in corpus (5)

• Structure identification methods for atomistic simulations of crystalline materials
• Atomic-scale modeling of the deformation of nanocrystalline metals
• The closest elastic tensor of arbitrary symmetry to an elasticity tensor of lower symmetry
• Studying the elastic properties of nanocrystalline copper using a model of randomly packed uniform grains
• Three-dimensional Random Voronoi Tessellations: From Cubic Crystal Lattices to Poisson Point Processes

Cited by in corpus (3)

• Atomistic and mean-field estimates of effective stiffness tensor of nanocrystalline materials of hexagonal symmetry
• Atomistic and mean-field estimates of effective stiffness tensor of nanocrystalline materials of cubic symmetry
• Atomistic investigation of deformation and fracture of individual structural components of metal matrix composites