A Numerical Method for Microstructure Generation of a Binary Aluminum Alloy and Study of Its Mechanical Properties Using the Finite Element Method HAMID SHARIFI and DANIEL LAROUCHE A numerical method for the generation of the microstructure of a binary aluminum copper alloy is presented. This method is based on the repeated addition of some basic grain shapes into a representative volume element. Depending of the orientation of adjacent grains, different type of grain boundaries can be formed. The primary and secondary phases are distinguishable in our model and have distinct properties, reflecting the heterogeneous nature of the microstructure. The digital microstructure was then transformed into a finite element model. Using the finite element software ABAQUS, the stress distribution inside our heterogeneous material model has been studied and its mechanical properties have been found. That also makes possible to study and to visualize the cracks generated during the loading of the material where the local stress was sufficiently high. As a result of these analyses, the elastic modulus of such a heterogeneous domain and the effect of crack formation on ductility were evaluated. DOI: 10.1007/s11661-014-2446-3 Ó The Minerals, Metals & Materials Society and ASM International 2014 I. INTRODUCTION THE classical stress analysis approaches based on continuum mechanics give the modeling tools for computation of stress field inside a homogeneous material. This type of modeling is not able to give the localized stress concentration inside a real material because it cannot take into account its microstructure. As an example, a fracture apparition and nucleation cannot be explained adequately based on continuum mechanics theories. A lot of engineering materials have polycrystalline and multiphase structures. The overall mechanical properties of these materials depend on the properties of these crystals (grains). An old fundamental principle in the analysis of materials is the structure-properties relationship which states that there is an undeniable relation between the structure of a material and its properties. [1] The structure can be interpreted at the atomic, the crystal lattice, or at the grain microstructure level. An important scale which affects the mechanical properties and stress distribution inside a material is the grain microstructure of the material. An individual crystal could be anisotropic in both elastic and plastic behaviors, but if a volume of material contains a large numbers of grains with random crystal lattice orienta- tions, it could present isotropic characteristics. Even if the overall mechanical property of a material is consid- ered as isotropic, the stress distribution inside a volume of the material depends on its grain microstructure. As a result, the geometrical grain structures of a material at the microstructural scale can help us to understand stress field variations inside a material. Several authors have worked on the development of microstructure models for the simulation of recrystalli- zation and grain growth problems. These models can be divided into two groups. [2] The geometrical and topo- logical model of the first group is based on combining the elementary geometry of nucleation, grain growth, and impingement. [3–6] These models are mostly con- structed by employing the Voronoi’s structure where the initial nucleation points are seeds in the Voronoi’s diagram. The second group, which is called component methods, is an extension of the first group to include several components like for example the grain orienta- tions. [7,8] Nucleation and growth conditions are defined for each component. Different texture components grow independently and the final microstructure is formed when growing grains impinged and prevent their further growth. The nuclei can be distributed initially or they can be added continuously. The component method can be used for a three-dimensional (3D) simulation too. An interesting method for modeling microstructure evolu- tion processes is the phase-field method. This method defines a microstructure as a whole using some field variables which are functions of space. [9] Microstructure model can also be captured directly from microstructure photography for creating a digital microstructure model, here image processing techniques are used to produce such granular models. [10,11] When an acceptable microstructure geometric with distinguishable solid phases has been produced, the overall mechanical properties of the material can be HAMID SHARIFI, Research Associate, is with the Department of Mechanical Engineering, Aluminum Research Center – REGAL, Laval University, 1065, Ave de la Me´decine, Quebec, QC G1V 0A6, Canada. Contact e-mail: hamid.sharifi@gmn.ulaval.ca DANIEL LAROUCHE, Professor, is with the Department of Mining, Metal- lurgy and Materials Engineering, Aluminum Research Center – REGAL, Laval University. Manuscript submitted January 24, 2014. Article published online September 16, 2014 5866—VOLUME 45A, DECEMBER 2014 METALLURGICAL AND MATERIALS TRANSACTIONS A