This article discusses the numerical simulation of the forming of aluminum alloy sheet metals. The macroscopic and microscopic aspects of the plastic behavior of aluminum alloys are reviewed. The article presents constitutive equations suitable for the description of aluminum alloy sheets. It explains testing procedures and analysis methods that are used to measure the relevant data needed to identify the material coefficients. The article describes the various formulations of finite element methods used in sheet metal forming process simulations. Stress-integration procedures for both continuum and crystal-plasticity mechanics are also discussed. The article also provides various examples that illustrate the simulation of aluminum sheet forming.

Microstructure and crystallographic texture are the key material features used in the continuous endeavor to relate the processing of a metal with its final properties. This article emphasizes several aspects of deformation microstructures, namely, microstructural evolution, dislocation boundaries, and macroscopic properties. It discusses three different microstructural types: cell blocks, TL blocks, and equiaxed subgrains. The article also emphasizes the behavior of metals and single-phase alloys processed under plastic deformation (dislocation slip) conditions. It provides information on the microstructural parameters, measurement techniques, and microstructural relationships, which assist in predicting the mechanical properties and recrystallization behavior of materials. The article concludes with an analysis of the general relationship between the microstructural parameters and properties.

This article describes various evaluation techniques of fractography such as visual inspection, macroscopic and microscopic examinations that are used to resolve different aspects of failure. It gives a brief description and pictorial representation of various defects leading to fracture of metals, including laps, seams, cold shuts, cracks, inclusions, porosity, fatigue, and stress corrosion cracking.

Coextrusion is defined as the simultaneous extrusion of two or more metals to form an integral product that can be carried out using conventional extrusion or drawing equipment at a temperature appropriate to the metal system being formed. This article discusses the applications, billet configurations, and metal flow modes of coextrusion. It presents the analytical studies of coextrusion: deformation energy methods, lower-bound (slab) analyses, upper-bound analyses, and finite-element analyses. These studies are used to identify the regime of material properties and process variables for which sound extrusions can be obtained. The article concludes with a discussion on the state-of-the-art of coextrusion that assists in developing process models, which accurately describe both the macroscopic and microscopic aspects of a process.

This article discusses the process details of metal powder injection molding of microcomponents and the powder particle characteristics of feedstock and property requirements of binders. It reviews important characteristics to be considered in the processing steps: venting, channel diameters, binder segregation, binder degradation, feedstock supply, temperature control, demolding, debinding, and sintering. Finally, the article provides information on powder injection molding mold-filling simulation and two-component powder injection molding, offering a method for high-volume production of microcomponents made of multifunctional materials.

This article focuses on the various technology drivers for finishing methods, namely, tolerance, consistency, surface quality, and productivity. Every finishing method may be viewed as a manufacturing system consisting of four input categories: machine tool, processing tool, work material, and operational factors. The article provides a classification of finishing as a surface generation process and addresses the characteristics of the generated surfaces and the methods used to measure them. It describes the thermomechanical interactions occurring between the processing tool and the work material in the presence of machine tool and operational factors.

This article commences with a summary of fatigue processes and mechanisms. It focuses on fractography of fatigue. Characteristic fatigue fracture features that can be discerned visually or under low magnification are described. Typical microscopic features observed on structural metals are presented subsequently, followed by a brief discussion of fatigue in nonmetals. The article reviews the various macroscopic and microscopic features to characterize the history and growth rate of fatigue in metals. It concludes with a description of fatigue of polymers and composites.

This article provides an explanation on how crystal plasticity is implemented within finite element formulations by the use of physical length scales: crystal scale and continuum scale. It provides theoretical formulations for kinematic framework for deforming crystals and polycrystals, elastic and plastic behaviors of single crystals, refinements to the single-crystal constitutive, and crystal-scale finite-element. The article also presents examples that illustrate the capabilities of the formulations at the length scales.

Fatigue failure of engineering components and structures results from progressive fracture caused by cyclic or fluctuating loads. Fatigue is an important potential cause of mechanical failure, because most engineering components or structures are or can be subjected to cyclic loads during their lifetime. This article focuses on fractography of fatigue. It provides an abbreviated summary of fatigue processes and mechanisms: fatigue crack initiation, fatigue crack propagation, and final fracture,. Characteristic fatigue fracture features that can be discerned visually or under low magnification are then described. Typical microscopic features observed on structural metals are presented subsequently, followed by a brief discussion on fatigue in polymers and polymer-matrix composites.

This article focuses on the modeling and simulation of cavitation phenomena. It summarizes the experimental observations of cavitation and reviews the modeling of cavity nucleation and growth. The article discusses the modeling of the cavity growth based on mesoscale and microscale under uniaxial versus multiaxial tensile-stress conditions. Mesoscale models incorporate the influence of local microstructure and texture on cavitation. The article outlines the descriptions of cavity coalescence and shrinkage. It also describes the simulation of the tension test to predict tensile ductility and to construct failure-mechanism maps.

Integrated computational materials engineering refers to the use of computer simulations that integrate mathematical models of complex metallurgical processes with computer models used in component and process design. This article outlines an example of a computer-aided engineering tool, such as virtual aluminum castings (VAC), developed and implemented for quickly developing durable cast aluminum power train components. It describes the procedures for the model development of the VAC system. These procedures include linking the manufacturing process to microstructure, linking microstructures to mechanical properties, linking material properties to performance prediction, and model validation and integration into the engineering process. The article discusses the benefits of the VAC system in process selection, process optimization, and improving the component design criteria.

This article begins with balance equations for mass, momentum, energy, and solute and the necessary boundary conditions for solving problems of interest in casting and solidification. The transport phenomena cover a vast range of length and time scales, from atomic dimensions up to macroscopic casting size and from nanoseconds for interface attachment kinetics to hours for casting solidification. The article describes how to determine which phenomena are most important at the particular length and time scale for the problem. It concludes with several examples of the application of transport phenomena in solidification, focusing on microstructure formation.

Modeling of structure formation in casting of alloys involves several length scales, ranging from the atomic level to macroscopic scale. Intermediate length scales are used to define the microstructure of the growing phases and the grain structure. This article discusses the principles and applications of the phase field method and the cellular automaton method for modeling the direct evolution of structure at the intermediate length scales, where transport phenomena govern the spatial and temporal evolution of the structure that involves nucleation and growth.

This article focuses on the intermediate length scales, where transport phenomena govern the spatial and temporal evolution of a structure. It presents the cellular automaton (CA) and phase field (PF) methods that represent the state of the art for modeling macrostructure and microstructure. The article describes the principles of the PF method and provides information on the applications of the PF method. The CA model is introduced as a computationally efficient method to predict grain structures in castings using the mesoscopic scale of individual grains. The article discusses the coupling of the CA to macroscopic calculation of heat, flow, and mass transfers in castings and applications to realistic casting conditions.

This article begins with a description of indirect and direct semisolid metalworking processes. It then provides information on alloy compositions of common aluminum semisolid metalworking alloys and primary die-cast magnesium alloys in a tabular form. The article describes the macroscopic examination of defects, which occur in semisolid metalworking with illustrations. It discusses the macroscopic examination of gating systems and semisolid feedstocks. The article also provides information on feedstock microstructures, direct semisolid metalworking component microstructures, and indirect semisolid metalworking component microstructures of series 300 aluminum casting alloys and magnesium die-casting alloys.

In cast iron, residual stresses normally arise due to hindered thermal contraction, meaning that they are associated with the presence of constraints that prevent the natural, free volumetric variation of the material upon solid-state cooling. This article explains their mechanism of formation by introducing the scalar relation, known as the additive strain decomposition. The main factors influencing casting deformation are volume changes during solidification and cooling, phase transformations, alloy composition, thermal gradients, casting geometry, and mold stability. The article reviews the dimensional stability in cast iron and discusses macroscopic and microscopic stresses in cast iron.

The microstructure that develops during the solidification stage of cast iron largely influences the subsequent solid-state transformations and mechanical properties of the cast components. This article provides a brief introduction of methods that can be used for simulating the solidification microstructure of cast iron. Analytical as well as numerical models describing solidification phenomena at both macroscopic and microscopic scales are presented. The article introduces macroscopic transport equations and presents analytical microscopic models for solidification. These models include the dendrite growth models and the cooperative eutectic growth models. The article provides some solutions using numerical models to simulate the kinetics of microstructure formation in cast iron. It concludes with a discussion on cellular automaton (CA) technique that can handle complex topology changes and reproduce most of the solidification microstructure features observed experimentally.

Optical metallography, one of the most common materials characterization techniques, uses visible light to magnify structural features of interest. This article discusses the use of optical methods to evaluate micro and macrostructure and relate it to process conditions and material behavior. It covers the steps involved in sample preparation, including sectioning, mounting, grinding, polishing, and etching, and presents several examples of macro and microanalysis on various metals and alloys.

Tribology is the science and technology of interacting surfaces in relative motion. This article describes in detail the basic structural, operational, and interaction parameters of a tribosystem. The interaction parameters, which characterize the action of the operational parameters on the structural components in the system, consist of three important aspects: contact parameters, friction parameters, and wear parameters. These three aspects embody the complex mechanisms and relationships between the constituents of a tribosystem. The article concludes with information on the selection criteria of a material for wear applications.

This article provides an overview of the origin of metallography. It presents information on how to select a section from a specimen and prepare it for macroscopic analysis. The article describes the macroscopic analysis of steel fracture surfaces with emphasis on ductile, brittle, and fatigue fracture with illustrations. It discusses microanalysis with a focus on the method of light microscopy and includes information of scanning electron microscope in fractography. The article also explains the characteristics of solidification, transformation, deformation structures, and discontinuities that are present in a microstructure. It concludes with information on image analysis.