Integrated computational materials engineering
Encyclopedia
Integrated Computational Materials Engineering (ICME) is an approach to design products, the materials that comprise them, and their associated materials processing methods by linking materials models at multiple length scales. Key words are "Integrated", involving integrating models at multiple length scales, and "Engineering
", signifying industrial utility. The focus is on the material
s, i.e. understanding how processes produce material structures
, how those structures give rise to material properties, and how to select materials
for a given application. The key links are process-structures-properties-performance (see G. Olson 2000). The National Academies report describes the need for using multiscale materials modeling (Horstemeyer 2009) to capture the process-structures-properties-performance of a material.
There are some codes that operate on different length scales such as:
Engineering
Engineering is the discipline, art, skill and profession of acquiring and applying scientific, mathematical, economic, social, and practical knowledge, in order to design and build structures, machines, devices, systems, materials and processes that safely realize improvements to the lives of...
", signifying industrial utility. The focus is on the material
Material
Material is anything made of matter, constituted of one or more substances. Wood, cement, hydrogen, air and water are all examples of materials. Sometimes the term "material" is used more narrowly to refer to substances or components with certain physical properties that are used as inputs to...
s, i.e. understanding how processes produce material structures
Microstructure
Microstructure is defined as the structure of a prepared surface or thin foil of material as revealed by a microscope above 25× magnification...
, how those structures give rise to material properties, and how to select materials
Material selection
Material selection is a step in the process of designing any physical object. In the context of product design, the main goal of material selection is to minimize cost while meeting product performance goals. Systematic selection of the best material for a given application begins with properties...
for a given application. The key links are process-structures-properties-performance (see G. Olson 2000). The National Academies report describes the need for using multiscale materials modeling (Horstemeyer 2009) to capture the process-structures-properties-performance of a material.
- Structural scale: Finite elementFinite element methodThe finite element method is a numerical technique for finding approximate solutions of partial differential equations as well as integral equations...
, finite volumeFinite volume methodThe finite volume method is a method for representing and evaluating partial differential equations in the form of algebraic equations [LeVeque, 2002; Toro, 1999]....
and finite differenceFinite difference methodIn mathematics, finite-difference methods are numerical methods for approximating the solutions to differential equations using finite difference equations to approximate derivatives.- Derivation from Taylor's polynomial :...
partial differential equationPartial differential equationIn mathematics, partial differential equations are a type of differential equation, i.e., a relation involving an unknown function of several independent variables and their partial derivatives with respect to those variables...
are solvers used to simulate structural responses such as solid mechanicsSolid mechanicsSolid mechanics is the branch of mechanics, physics, and mathematics that concerns the behavior of solid matter under external actions . It is part of a broader study known as continuum mechanics. One of the most common practical applications of solid mechanics is the Euler-Bernoulli beam equation...
and transport phenomenaTransport PhenomenaTransport Phenomena is the first textbook that is about transport phenomena. It is specifically designed for chemical engineering students...
at large (meters) scales.- process modeling/simulations: extrusion, rolling, sheet forming, stamping, casting, welding, etc.
- product modeling/simulations: performance, impact, fatigue, corrosion, etc.
- Macroscale: constitutive (rheology) equations are used at the continuum level in solid mechanicsSolid mechanicsSolid mechanics is the branch of mechanics, physics, and mathematics that concerns the behavior of solid matter under external actions . It is part of a broader study known as continuum mechanics. One of the most common practical applications of solid mechanics is the Euler-Bernoulli beam equation...
and transport phenomenaTransport PhenomenaTransport Phenomena is the first textbook that is about transport phenomena. It is specifically designed for chemical engineering students...
at millimeter scales. - Mesoscale: continuum level formulations are used with discrete quantities at multiple micrometre scale. "Meso" is an ambiguous term that means "intermediate" so it has been used as representing different intermediate scales. In this context it can represent modeling from crystal plasticity for metals, Eshelby solutions for any materials, homogenization methods, and unit cell methods.
- Microscale: modeling techniques that represent the micrometre scale such as dislocation dynamics codes for metals and phase field models for multiphase materials. Phase field modelsPhase field modelsA phase field model is a mathematical model for solving interfacial problems. It has mainly been applied to solidification dynamics, but it has also been applied to other situations such as viscous fingering, fracture dynamics, vesicle dynamics, etc....
of phase transitionPhase transitionA phase transition is the transformation of a thermodynamic system from one phase or state of matter to another.A phase of a thermodynamic system and the states of matter have uniform physical properties....
s and microstructureMicrostructureMicrostructure is defined as the structure of a prepared surface or thin foil of material as revealed by a microscope above 25× magnification...
formation and evolution on nanometer to millimeter scales. - Nanoscale: semi-empirical atomistic methods are used such as Lennard-Jones, Brenner potentials, embedded atom method (EAM) potentials, and modified embedded atom potentials (MEAM) in molecular dynamicsMolecular dynamicsMolecular dynamics is a computer simulation of physical movements of atoms and molecules. The atoms and molecules are allowed to interact for a period of time, giving a view of the motion of the atoms...
(MD), molecular statics (MS), Monte CarloMonte Carlo methodMonte Carlo methods are a class of computational algorithms that rely on repeated random sampling to compute their results. Monte Carlo methods are often used in computer simulations of physical and mathematical systems...
(MC), and kinetic Monte CarloKinetic Monte CarloThe kinetic Monte Carlo method is a Monte Carlo method computer simulation intended to simulate the time evolution of some processes occurring in nature. Typically these are processes that occur with a given known rate...
(KMC) formulations. - Electronic scale: Schroedinger equations are used in computational framework as density functional theoryDensity functional theoryDensity functional theory is a quantum mechanical modelling method used in physics and chemistry to investigate the electronic structure of many-body systems, in particular atoms, molecules, and the condensed phases. With this theory, the properties of a many-electron system can be determined by...
(DFT) models of electron orbitals and bonding on angstrom to nanometer scales.
There are some codes that operate on different length scales such as:
- CALPHADCALPHADCALPHAD stands for CALculation of PHAse Diagrams. An equilibrium phase diagram is usually a diagram with axes for temperature and composition of a chemical system. It shows the regions where substances or solutions are stable and regions where two or more of them coexist...
computational thermodynamicsThermodynamicsThermodynamics is a physical science that studies the effects on material bodies, and on radiation in regions of space, of transfer of heat and of work done on or by the bodies or radiation...
for prediction of equilibrium phase diagramPhase diagramA phase diagram in physical chemistry, engineering, mineralogy, and materials science is a type of chart used to show conditions at which thermodynamically distinct phases can occur at equilibrium...
s and even non-equilibrium phases. - DatabaseDatabaseA database is an organized collection of data for one or more purposes, usually in digital form. The data are typically organized to model relevant aspects of reality , in a way that supports processes requiring this information...
s of processing parameters, microstructureMicrostructureMicrostructure is defined as the structure of a prepared surface or thin foil of material as revealed by a microscope above 25× magnification...
features, and properties from which one can draw correlations at various length scales
Integrating models
Model integration takes several forms, including the following:- Small scale models calculate material properties, or relationships between properties and parameters, e.g. yield strengthYield (engineering)The yield strength or yield point of a material is defined in engineering and materials science as the stress at which a material begins to deform plastically. Prior to the yield point the material will deform elastically and will return to its original shape when the applied stress is removed...
vs. temperatureTemperatureTemperature is a physical property of matter that quantitatively expresses the common notions of hot and cold. Objects of low temperature are cold, while various degrees of higher temperatures are referred to as warm or hot...
, for use in continuum models - CALPHADCALPHADCALPHAD stands for CALculation of PHAse Diagrams. An equilibrium phase diagram is usually a diagram with axes for temperature and composition of a chemical system. It shows the regions where substances or solutions are stable and regions where two or more of them coexist...
computational thermodynamics software predicts free energy as a function of composition; a phase field model then uses this to predict structure formation and development, which one may then correlate with properties. - Process models calculate spatial distribution of structure features, e.g. fiber density and orientation in a composite materialComposite materialComposite materials, often shortened to composites or called composition materials, are engineered or naturally occurring materials made from two or more constituent materials with significantly different physical or chemical properties which remain separate and distinct at the macroscopic or...
; small-scale models then calculate relationships between structure and properties, for use in a continuum models of overall part or system behavior - Large scale models explicitly fully couple with small scale models, e.g. a fractureFractureA fracture is the separation of an object or material into two, or more, pieces under the action of stress.The word fracture is often applied to bones of living creatures , or to crystals or crystalline materials, such as gemstones or metal...
simulation might integrate a continuum solid mechanics model of macroscopic deformation with an FD model of atomic motions at the crack tip