Three-dimensional microscopy can be used to reveal the shape, distribution, and connectivity of three-dimensional (3D) features that lie buried within an opaque material. This article discusses several experimental techniques that can be used to generate 3D images. These include serial sectioning, focused ion beam tomography, atom probe tomography, and X-ray microtomography. Nine case studies are presented that represent the work of the various research groups currently working on 3D microscopy using serial sectioning and illustrate the variants of the basic experimental techniques. The article also discusses the techniques for reconstruction and visualization of 3D microstructures with advanced computer software and hardware.

This article is an overview of the division Surface Analysis of this volume. The division covers various developed surface-analysis techniques, such as scanning probe and atomic force microscopy. The division focuses on the analysis of surface layers that are less than 100 nm. A quick reference summary of surface-analysis methods is presented in this article.

This article describes the effects of alloying and heat treatment on the metastable transition precipitates that occur in age hardenable aluminum alloys. Early precipitation stages are less well understood than later ones. This article details the aging sequence and characteristics of precipitates that occur in the natural aging and artificial aging of Al-Mg-Si-(Cu) alloys, Al-Mg-Cu alloys, microalloyed Al-Mg-Cu-(Ag, Si) alloys, aluminum-lithium-base alloys, and Al-Zn-Mg-(Cu) alloys. Crystal structure, composition, dimensions, and aging conditions of precipitates are detailed. Effects of reversion, duplex annealing, and retrogression and re-aging are included.

This article is intended to provide the reader with a good understanding of the underlying science, technology, and the most common applications of focused ion beam (FIB) instruments. It begins with a survey of the various types of FIB instruments and their configurations, discusses the essential components, and explains their function only to the extent that it helps the operator obtain the desired results. An explanation of how the components of ion optical column shape and steer the ion beam to the desired target locations is then provided. The article also reviews the many diverse accessories and options that enable the instrument to realize its full potential across all of the varied applications. This is followed by a detailed analysis of the physical processes associated with the ion beam interacting with the sample. Finally, a complete survey of the most prominent FIB applications is presented.

Ultrasonic additive manufacturing (UAM) is a solid-state hybrid manufacturing technique that leverages the principles of ultrasonic welding, mechanized tape layering, and computer numerical control (CNC) machining operations to create three-dimensional metal parts. This article begins with a discussion on the process fundamentals and process parameters of UAM. It then describes metallurgical aspects in UAM. The article provides a detailed description of a wide range of mechanical characterization techniques of UAM, namely tensile testing, peel testing, and pushpin testing. The article ends with information on sensor embedding.

Computed tomography (CT) is an imaging technique that generates a three-dimensional (3-D) volumetric image of a test piece. This article illustrates the basic principles of CT and provides information on the types, applications, and capabilities of CT systems. A comparison of performance characteristics for film radiography, real-time radiography, and X-ray computed tomography is presented in a table. A functional block diagram of a typical computed tomography system is provided. The article discusses CT scanning geometry that is used to acquire the necessary transmission data. It also provides information on digital radiography, image processing and analysis, dual-energy imaging, and partial angle imaging, of a CT system.

This article reviews the characterization methods for producing 3-D microstructural data sets. The methods include serial sectioning by mechanical material removal method and focused ion beam tomography method. The article describes how these data sets are used in realistic 3-D simulations of microstructural evolution during materials processing and materials response. It also explains how the 3-D experimental data are actually input and used in the simulations using phase-field modeling and finite-element modeling.

Metal transparency and interaction with X-rays have been recognized as obvious candidate principles from which methods for in situ monitoring of solidification processes could be developed. This article describes the use of X-ray imaging-based techniques to investigate interface morphology evolution, solute transport, and various process phenomena at spatiotemporal resolutions. It discusses the three viable imaging techniques made available by synchrotron radiation for the real-time investigation of solidification microstructures in alloys. These include two-dimensional X-ray topography, two-dimensional X-ray radiography, and ultra-fast three-dimensional X-ray tomography.

Radiography is a nondestructive-inspection method that is based on the differential absorption of penetrating radiation by the part or test piece (object) being inspected. This article discusses the fundamentals and general applications of radiography, and describes the sources of radiation in radiographic inspection, including X-rays and gamma rays. It deals with the characteristics that differentiate neutron radiography from X-ray or gamma-ray radiography. The geometric principles of shadow formation, image conversion, variation of attenuation with test-piece thickness, and many other factors that govern the exposure and processing of a neutron radiograph are similar to those for radiography using X-rays or gamma rays.

Retrogression and reaging (RRA) is an established form of postquench aging heat treatment. RRA treatments can be applied to precipitation-hardened aluminum alloys that are used in aerospace applications. This article provides information on the development background of RRA and the steps involved in the RRA treatments. It discusses the process descriptions, applications, microstructural consequences, and limitations of RRA. In addition, the article describes the influence of RRA on mechanical properties.

This article introduces the principal methodologies and some advanced technologies that are being applied for nondestructive evaluation (NDE) of fiber-reinforced polymer-matrix composites. These include acoustic emission, ultrasonic, eddy-current, computed tomography, electromagnetic acoustic transducer, radiography, thermography, and low-frequency vibration methods. The article also provides information on NDE methods commonly used for metal-matrix composites.

This article introduces the principal methodologies and some technologies that are being applied for nondestructive evaluation of composite materials. These include ultrasonic testing (UT), air-coupled UT, laser UT, ultrasonic spectroscopy, leaky lamb wave method, acousto-ultrasonics, radiography, X-ray computed tomography, thermography, low-frequency vibration methods, acoustic emission, eddy current testing, optical holography, and shearography. The article presents some examples are for fiber-reinforced polymer-matrix composites. Many of the techniques have general applicability to other types of composites such as metal-matrix composites and ceramic-matrix composites.

Copper steels are precipitation-strengthened steels that are designed to have a unique combination of physical and mechanical properties. This article provides an overview of copper precipitate-strengthened steels and their applications, and discusses appropriate ASTM International standards. It describes the common phases and alloying elements present in copper precipitate-strengthened steels, and reviews the influences of alloying elements on processing, phase diagrams, microstructures, and mechanical properties. The article also discusses the thermomechanical process, solutionizing heat treatment, and isothermal aging in detail. It concludes with a review of the interrelationships between heat treatments, microstructures, and mechanical properties.