Plastic deformation treated as material flow through adjustable crystal lattice

6th International Conference on Nanomaterials by Severe Plastic Deformation

材料科学;化学

Minakowski, P.^1 ; Hron, J.^2 ; Kratochvíl, J.^3 ; Kruík, M.^3,4 ; Málek, J.^2

University of Warsaw, Institute of Applied Mathematics and Mechanics, Banacha 2, 02-097 Warsaw, Poland^1

Charles University in Prague, Faculty of Mathematics and Physics, Mathematical Institute, Sokolovská 83, 186 75 Prague 8, Czech Republic^2

Czech Technical University, Faculty of Civil Engineering, Thákurova 7, 166 29 Prague 6, Czech Republic^3

Institute of Information Theory and Automation of the ASCR, Pod vodáenskou ví 4, 182 08 Prague 8, Czech Republic^4

关键词: Arbitrary Lagrangian Eulerian;    Crystal plasticity models;    Crystallographic plane;    Deformation process;    Finite-element discretization;    Highly viscous fluids;    Quasistatic process;    Severe plastic deformations;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/63/1/012130/pdf
DOI  :  10.1088/1757-899X/63/1/012130

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

Looking at severe plastic deformation experiments, it seems that crystalline materials at yield behave as a special kind of anisotropic, highly viscous fluids flowing through an adjustable crystal lattice space. High viscosity provides a possibility to describe the flow as a quasi-static process, where inertial and other body forces can be neglected. The flow through the lattice space is restricted to preferred crystallographic planes and directions causing anisotropy. In the deformation process the lattice is strained and rotated. The proposed model is based on the rate form of the decomposition rule: the velocity gradient consists of the lattice velocity gradient and the sum of the velocity gradients corresponding to the slip rates of individual slip systems. The proposed crystal plasticity model allowing for large deformations is treated as the flow-adjusted boundary value problem. As a test example we analyze a plastic flow of an single crystal compressed in a channel die. We propose three step algorithm of finite element discretization for a numerical solution in the Arbitrary Lagrangian Eulerian (ALE) configuration.