Quantifying microstructural parameters has received considerable attention and success in developing procedures and using such data to develop structure/property relationships has been achieved. This article reviews many of the simple stereological counting measurements of volume fraction, grain structure (two-phase grain structures, and nonequiaxed grain structures), grain size, and inclusion content. It also reviews simple relationships between number of grains per unit area, number of intersections of a line of known length with particle or grain, and number of interceptions of particles or grains by a line of known length.

This article reviews many commonly used stereological counting measurements and the relationships based on these parameters. The discussion covers the processes involved in sampling and specimen preparation. Quantitative microstructural measurements are described including volume fraction, number per unit area, intersections and intercepts per unit length, grain size, and inclusion content.

This article focuses on aspects important for the commercial production of castings. It discusses the modification process in hypoeutectic and eutectic alloys that differ only in the relative volume fraction of primary aluminum and aluminum-silicon eutectic. The article explains how modification changes porosity formation in a casting. It describes the mechanisms responsible for silicon modification, as well as the modifications and changes in eutectic nucleation and eutectic grain structure. The article reviews the usage of strontium during process steps in foundry practices. The growth of silicon eutectic is described to explain effects ancillary to silicon modification. The article also discusses the effects of elements, such as phosphorus, antimony, bismuth, magnesium, boron, and calcium, on the silicon structure.

Spray casting, also known as spray forming, is a niche casting process for the manufacture of preforms. This article lists commercial examples of alloys manufactured by spray casting and provides sequential steps of the spray casting process. Gas atomization is a chaotic, stochastic process that always produces a wide range of droplet diameters. The article schematically illustrates typical log-normal droplet diameter probability density distribution on a mass or volume basis obtained by gas atomization. It also illustrates the changes in solid fraction during the spray casting process as a function of axial distance from the point of droplet atomization. The article concludes with a section on occurrence of macrosegregation and coarsening in spray cast preforms.

In the case of steels, heat treatment plays a fundamental role because no other process step can manipulate the microstructure in order to fulfill such a wide variety of possible in-service conditions. This article addresses heat treatment with regard to hardening and subsequent tempering of steel components in order to optimize tribological properties. It focuses on the heat treatment of tempering and bearing steels and on volume changes that take place due to phase transformations. Plastic deformations that occur due to shrinking and phase transformation are also discussed. The article also describes the generation of thermal, transformation, and hardening residual stresses.

Thin sections save weight and thus contribute to a more favorable strength-to-weight ratio. By requiring a smaller volume of metal, thin walls may also lower casting costs, particularly when an expensive alloy is being poured. This article discusses the design problems in thin-wall steel sand castings, thin-wall aluminum and magnesium castings, thin-wall permanent mold castings, and thin-wall investment castings, with schematic illustrations.

Ion-beam-assisted deposition (IBAD) refers to the process wherein evaporated atoms produced by physical vapor deposition are simultaneously struck by an independently generated flux of ions. This article discusses the energy utilization of this process. It describes the physical and chemical processes occurring at the film-vacuum interface during IBAD and dual-ion-beam sputtering with illustrations. The article also reviews the methods used for large-area, high-volume implementation of IBAD and the modes of film formation for IBAD. It contains a table that presents information on deposition and synthesis of inorganic compounds by IBAD and concludes with a discussion on the improved coating properties, advantages, limitations, and applications of IBAD.

Braiding is a textile process that is known for its simplicity and versatility. Braided structures are unique in their high level of conformability, torsional stability, and damage resistance. This article describes the braiding process and the mechanical properties of two-dimensional and three-dimensional braiding.

This article focuses on the modeling of microstructure evolution during thermomechanical processing in the two-phase field for alpha/beta and beta titanium alloys. It also discusses the mechanisms of spheroidization, the coarsening, particle growth, and phase decomposition in titanium alloys, with their corresponding equations.

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.

This article provides a detailed discussion on the causes of formation of shrinkage porosity and gas porosity along with the methods involved in eliminating them. It discusses the process of porosity formation and the factors affecting porosity formation, including alloy composition, external pressure, and cooling conditions.

This article presents the binary eutectic phase diagram to understand the various structures that evolve in a binary eutectic system during solidification. It describes the various classifications and solidification principles of the eutectic structures. Formation of halos in eutectic microstructures of most alloy systems is also discussed.

Nanofluids offer a completely different behavior of wetting kinetics and heat-removal characteristics, which are exploited in industrial heat treatment for quenching. This article provides information on the important thermophysical properties of nanofluids, namely, thermal conductivity, viscosity, specific heat, density, and surface tension. It reviews wetting and boiling heat-transfer characteristics of nanofluids as quenchants and highlights the importance of using nanofluids as effective quench media for the hardening process during heat treatment. The article describes the effect of nanoparticle addition on the microstructure, mechanical properties of components, wetting kinetics, and kinematics.

Thermal analysis is a classical method of determining phase diagrams and can be used to analyze the deviation from solidification under equilibrium conditions. This article discusses the use of thermal analysis in industrial processes and in research. It describes the theoretical basis of simplified and differential thermal analysis. The article explains how to determine the liquidus and solidus temperatures by using cooling curves.

The modeling and simulation of texture evolution for titanium alloys is often tightly coupled to microstructure evolution. This article focuses on a number of problems for titanium alloys in which such coupling is critical in the development of quantitative models. It discusses the phase equilibria, crystallography, and deformation behavior of titanium and titanium alloys. The article describes the modeling and simulation of recrystallization and grain growth of single-phase beta and single-phase alpha titanium. The deformation- and transformation-texture evolution of two-phase (alpha/beta) titanium alloys are also discussed.

Metal-matrix composites (MMCs) are a class of materials with potential for a wide variety of structural and thermal applications. This article discusses the mechanical properties of MMCs, namely aluminum-matrix composites, titanium-matrix composites, magnesium-matrix composites, copper-matrix composites, superalloy-matrix composites, and intermetallic-matrix composites. It describes the processing methods of discontinuous aluminum MMCs which include casting processes, liquid-metal infiltration, spray deposition and powder metallurgy. The article provides useful information on aluminum MMC designation system and also describes the types of continuous fiber aluminum MMCs, including aluminum/boron MMC, aluminum/silicon carbide MMC, aluminum/graphite MMC, and aluminum/alumina MMC.

This article describes the three solidification mechanisms of peritectic structures, namely, peritectic reaction, peritectic transformation, and direct precipitation. It discusses the theoretical analysis, which shows that the rate of the peritectic transformation is influenced by the diffusion rate and the extension of the beta-phase region in the phase diagram. The article provides information on peritectic transformations in multicomponent systems.

This article discusses the physical metallurgy of cast cobalt alloys with emphasis on crystallography, compositions, phases and microstructure, and properties. Cobalt alloys are cast by several different foundry methods. The article describes the argon-oxygen decarburization and continuous casting process. It provides information on castability and quality of the casted alloys. The article details postcasting treatment, including heat treatment, hot isostatic pressing, and coatings. It summarizes the applications of cast cobalt alloys.

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 phase field method and 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.