The introduction of focused ion beam (FIB) microscopy in the 1990s added the capability of studying fracture surfaces in the third dimension and making site-specific and stress-free transmission electron microscope (TEM) specimens in situ. This article reviews the methods for preparing replicas and the site-specific FIB thin-foil preparation technique. It provides an overview of FIB-TEM specimen preparation.

This article discusses the importance of the care and handling of fracture specimens and what to look for during the preliminary field or laboratory observation and collection, the preservation of specimens, and the cleaning and preparation of fracture specimens for additional analyses. The preservation of nonmetallic specimens, medical devices, oversized components, light alloys, nondestructively tested components, and materials that are part of legal proceedings is addressed.

Visual examination, using the unaided eye or a low-power optical magnifier, is typically one of the first steps in a failure investigation. This article presents the guidelines for selecting samples for scanning electron microscope examination and optical metallography and for cleaning fracture surfaces. It discusses damage characterization of metals, covering various factors that influence the damage, namely stress, aggressive environment, temperature, and discontinuities.

X-ray diffraction (XRD) residual-stress analysis is an essential tool for failure analysis. This article focuses primarily on what the analyst should know about applying XRD residual-stress measurement techniques to failure analysis. Discussions are extended to the description of ways in which XRD can be applied to the characterization of residual stresses in a component or assembly and to the subsequent evaluation of corrective actions that alter the residual-stress state of a component for the purposes of preventing, minimizing, or eradicating the contribution of residual stress to premature failures. The article presents a practical approach to sample selection and specimen preparation, measurement location selection, and measurement depth selection; measurement validation is outlined as well. A number of case studies and examples are cited. The article also briefly summarizes the theory of XRD analysis and describes advances in equipment capability.

The metallographic specimen preparation process for microstructural investigations of cast iron specimens usually consists of five stages: sampling, cold or hot mounting, grinding, polishing, and etching with a suitable etchant to reveal the microstructure. This article describes the general preparation of metallographic specimens and the methods of macroscopic and microscopic examination. Usually, gray-scale (black-and-white) metallography is sufficient for microstructural analysis of cast irons. The article discusses the use of color metallography of gray irons and ductile irons. It also presents application examples of color metallography.

Metallographic analysis is primarily a collection of visual and imaging techniques that provide an insight into the background of a material or part and its behavior. Metallic specimens, both porous and pore-free, are opaque, and as a result, an optical examination must be performed on carefully prepared planar (two-dimensional) surfaces. This article discusses the preparation sequence of ferrous powders, which is normally separated into several well-defined steps: sample selection, sectioning, mounting, grinding, polishing, drying, and chemical etching and/or coating. It provides several suggestions to promote and encourage the safety of those performing metallographic preparation and analysis.

Particle size and size distribution have a significant effect on the behavior of metal powders during their processing. This article provides an overview of the sample preparation process for particle size measurement, which is a key step in the measurement of particle size distributions. Common particle size measuring techniques discussed in this article include sieve analysis, quantitative image analysis, laser diffraction, sedimentation methods, aerodynamic time-of-flight method, electrical zone sensing, and photon correlation spectroscopy. The advantages and disadvantages of these methods are reviewed.

This article summarizes the terminology for gas reactions, and discusses low-temperature nitriding and nitrocarburizing of stainless steels. It describes the various nitriding processes, namely, high- and low-pressure nitriding, oxynitriding, sulfonitriding, oxysulfonitriding, ferritic nitrocarburizing and austenitic nitrocarburizing. The article includes a discussion on the difficulties in specimen cleaning, importance of furnace purge, uses of pre and post oxidation, depassivation, or activation, and requirements for perfect nucleation in nitriding process. In nitriding, the successful atmosphere control depends on various potentials. The article summarizes the methods of measuring potentials in nitriding and nitrocarburizing, provides useful information on the furnaces used, and the safety precautions to be followed in the nitriding process. It also describes the sample preparation procedures and testing methods to ensure the quality of the sample.

Materials resulting from thermal spray processes are often different from their wrought, forged, and cast counterparts. Assessing the usefulness of thermal spray coatings requires understanding, developing, and using appropriate testing and characterization methods that are generally borrowed from other materials science disciplines. This article focuses on commonly used testing and characterization methods: metallography, image analysis, hardness, tensile adhesion testing, corrosion testing, x-ray diffraction, non-destructive testing, and powder characterization. It provides information on how the materials themselves respond to the various test methods. The article focuses on the test methods themselves, including those test parameters that can be varied and the influence of each on the results obtained.

Metallographic examination is a critical step in the assessment of thermal spray coating characteristics. This article discusses the major steps involved in metallographic examination: sectioning, mounting, grinding, polishing, optical microscopy, and image analysis. It provides a discussion on etching to reveal grain structure. The article also provides recommendations for metallographic examination of some standard coatings.

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.

This article outlines the beam/sample interactions and the basic instrumental design of a scanning electron microscopy (SEM), which include the electron gun, probeforming column (consisting of magnetic electron lenses, apertures, and scanning coils), electron detectors, and vacuum system. It discusses the contrasts mechanisms used for imaging and analyzing materials in the SEM. These include the topographic contrast, compositional contrast, and electron channeling pattern and orientation contrast. Special instrumentation and accessory equipment used at elevated pressures and during the X-ray microanalysis are reviewed. The article also provides information on the sample preparation procedure and the materials applications of the SEM.

This article describes the metallographic specimen preparation procedures for cast iron test samples, including mounting, grinding, polishing, and etching. It discusses the makeup and use of black-and-white and selective color etchants and where one might be preferred over the other. The article provides information on nearly 100 micrographs, discussing the microstructure of flake graphite in gray iron, nodular graphite in ductile iron, and temper graphite in malleable iron. It also examines the matrix microstructures of gray, ductile, compacted, and malleable cast iron samples.

This article reviews how process variations influence the characteristics of thermal spray coatings. It describes various specimen preparation techniques, which allow accurate microstructural analysis. These techniques include sectioning, cleaning, mounting, planar grinding, fine grinding, rough polishing, and etching. The article provides information on the problems associated with specimen preparation. It concludes with a discussion on the various methods of analysis for thermal spray coatings.

This article describes how composite specimens are sectioned, documented, and labeled during sample preparation. The mounting procedures for the specimen are summarized. The article explains sample clamping, which involves not mounting the specimens using an adhesive or casting resin and corresponds to clamped samples used in automated polishing heads. It details that cavity molds involve mounting the composite specimens using a casting resin in a preset mold. The article also discusses the mounting of composite materials for hand polishing.

This article describes the various specimen preparation procedures for lead, lead alloys, and sleeve bearings, including sectioning, mounting, grinding, polishing, and etching. The microscopic examination and microstructures of lead and lead alloys are discussed. The article also provides information on the microstructures of sleeve bearing materials.

This article discusses the specimen preparation techniques for zinc and its alloys and zinc-coated specimens, namely, sectioning, mounting, grinding and polishing, and etching. It describes the characteristics of lead, cadmium, iron, copper, titanium, aluminum, magnesium, and tin, which are present in the microstructure of zinc alloys. The article also provides information on microexamination that helps to determine the dendrite arm spacing, as well as the grain size, grain boundaries, and grain counts.

Rough grinding and polishing of specimens are required to prepare fiber-reinforced composite samples for optical analysis. This article discusses the consumables, process variables, and the equipment that influence the sample preparation procedure. It describes the hand and automated grinding methods. The article summarizes the rough and final polishing steps for both hand and automated techniques. Common artifacts that may be created during grinding and polishing steps of composite samples are reviewed. These include scratches, fiber pull-out, matrix smears, streaks, erosion of different phases, and fiber and sample edge rounding and relief.