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.

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.

Thermomechanical analysis (TMA) is a thermal analysis technique in which the length of a specimen is precisely measured versus temperature and time as the specimen is subjected to controlled heating and cooling. This article discusses the various factors and processes involved in TMA. The discussion covers the general principles, equipment used, specimen preparation process, calibration conditions, data analysis steps, and examples of the applications and interpretation of TMA.

This article provides a brief account of glow discharge mass spectrometry (GDMS) for direct determination of trace elements in solid samples and for fast depth profiling in a great variety of innovative materials. It begins by describing the general principles of GDMS. This is followed by a discussion on the various components of a GDMS system as well as commercial GDMS instruments. A description of processes involved in specimen preparation and cleaning in GDMS is then presented. Various problems pertinent to multielemental calibrations in GDMS are discussed along with measures to overcome them. The article further provides information on the processes involved in the analytical setup of parameters in GDMS, covering the steps involved in the analysis of GDMS data. It ends with a section on the application and interpretation of GDMS in the metals industry.

Differential scanning calorimetry (DSC) is the most common thermal technique for polymer characterization. This article provides a detailed account of the various factors and processes involved in DSC. The discussion covers the equipment used, specimen preparation process, calibration requirements, data analysis, and provides examples of the applications and interpretation of DSC.

Thermogravimetric analysis (TGA) is a thermal analysis technique that measures the amount and rate of change in the weight of a material as a function of temperature or time in a controlled atmosphere. This article provides a detailed account of the concepts of TGA, covering the various criteria to be considered for specimen preparation and calibration of TGAs. The use of thermogravimetric analysis data in the assessment of failure analysis of plastics and the combined usage of TGA with other techniques to understand the changes in the sample are also covered. The article provides examples of applications and provides information on the interpretation of TGA.

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 the principles and applications of X-ray photoelectron spectroscopy (XPS) for the analysis of elemental and chemical composition. The discussion covers the nomenclature, instruments, and specimen preparation process of XPS. Some of the factors pertinent to the calibration of materials for accurate measurements using XPS are provided, along with some aspects of the accuracy in quantitative analysis by XPS. In addition, the article presents examples of how XPS data can be used to solve problems with surface interactions.

This article focuses on the principles and applications of thermal desorption spectroscopy (TDS) use to study adsorption, desorption, and reaction of adsorbed atoms and molecules on surfaces. The discussion provides information on various components of and specimen preparation processes for a TDS experiment. The factors that must be considered when performing TPD experiments and several methods of analyzing TPD data are covered. A few studies where TPD was used to elucidate surface reactions that impact the tribological performances of materials are also discussed.

Dynamic mechanical analysis (DMA) is a powerful tool for studying the viscoelastic properties and behavior of a range of materials as a function of time, temperature, and frequency. This article describes various systems and equipment used in DMA setup and discusses the processes involved in preparation of test specimen for DMA measurements. Some factors to be considered when calibrating the DMA instrument are provided, along with a description on processes for interpreting the temperature and frequency dependence of DMA curves as well as the applications of DMA.

Transmission electron microscopy (TEM) approach enables essentially simultaneous examination of microstructural features through imaging from lower magnifications to atomic resolution and the acquisition of chemical and crystallographic information from small regions of the thin specimen. This article discusses fundamentals of the technique, especially for solving materials problems. Background information is provided to help understand basic operations and principles, including instrumentation, the physics of signal generation and detection, image formation, electron diffraction, and spectrometry techniques with data analysis.

X-ray powder diffraction (XRPD) techniques are used to characterize samples in the form of loose powders, aggregates of finely divided material or polycrystalline specimens. This article provides a detailed account of XRPD. It begins with a discussion on XRPD instrumentation and the techniques used to characterize samples. The article then describes the principles, advantages, and disadvantages of various types of powder diffractometers. A section on the Rietveld method of diffraction analysis is then presented. The article discusses various methods and procedures for qualifying and quantifying phase mixtures in powder samples. It provides information on typical sensitivity and experimental limits on precision of XRPD analysis and other systematic sources of errors that affect accuracy. Some of the factors pertinent to the estimation of crystallite size and defects are also presented. The article ends with a few application examples of XRPD.

This article provides detailed information on the instrumentation and principles of the scanning electron microscope (SEM). It begins with a description of the primary components of a conventional SEM instrument. This is followed by a discussion on the advantages and disadvantages of the SEM compared with other common microscopy and microanalysis techniques. The following sections cover the critical issues regarding sample preparation, the physical principles regarding electron beam-sample interaction, and the mechanisms for many types of image contrast. The article also presents the details of SEM-based techniques and specialized SEM instruments. It ends with example applications of various SEM modes.

This article provides a detailed account of X-ray spectroscopy used for elemental identification and determination. It begins with an overview of the operating principles of X-ray fluorescence (XRF) spectrometer, as well as a comparison of the operating principles of wavelength-dispersive spectrometer (WDS) and energy-dispersive spectrometer (EDS). This is followed by a discussion on the mechanism and effects of X-ray radiation, X-ray emission, and X-ray absorption. The article then discusses components used, operation, and applications of WDS and EDS. Some of the factors and processes involved in sample preparation for XRF analysis are also included. The article further provides information on the practical procedure for and the applications of WDS and EDS qualitative and quantitative analyses.

This article discusses various concepts of micro x-ray diffraction (XRD) used for the examination of materials in situ. The discussion covers the principles, equipment used, sample preparation procedure, considerations for calibrating a detector, steps for performing data analysis, and applications and interpretation of micro-XRD.

This article focuses on laboratory atomic force microscopes (AFMs) used in ambient air and liquid environments. It begins with a discussion on the origin of AFM and development trends occurring in AFM. This is followed by a section on the general principles of AFM and a comprehensive list of AFM scanning modes. There is a brief description of how each mode works and what types of applications can be made with each mode. Some of the processes involved in preparation of samples (bulk materials and those placed on a substrate) scanned in an AFM are then presented. The article provides information on the factors applicable to the accuracy and precision of AFM measurements. It ends by discussing the applications for AFMs in the fields of science, technology, and engineering.

This article provides a brief introduction to neutron diffraction as well as its state-of-the-art capabilities. The discussion covers the general principles of the neutron, neutron-scattering theory, generation of neutrons, types of incident radiation, and purposes of single-crystal neutron diffraction, powder diffraction, and pair distribution function analysis. The relationship between detector space and reciprocal space are presented. Various factors involved in sample preparation, calibration, and techniques used for analyzing diffraction data are described. The article also presents application examples and possible future developments in neutron diffraction.

The electron backscatter diffraction (EBSD) technique has proven to be very useful in the measurement of crystallographic textures, orientation relationships between phases, and both plastic and elastic strains. This article focuses on backscatter diffraction in a scanning electron microscope and describes transmission Kikuchi diffraction. It begins with a discussion on the origins of EBSD and the collection of EBSD patterns. This is followed by sections providing information on EBSD spatial resolution and system operation of EBSD. Various factors pertinent to perform an EBSD experiment are then covered. The article further describes the processes involved in sample preparation that are critical to the success or usefulness of an EBSD experiment. It also discusses the applications of EBSD to bulk samples and the development of EBSD indexing methods.

The reflected light microscope is the most commonly used tool to study the microstructure of metals, composites, ceramics, minerals, and polymers. For the study of the microstructure of metals and alloys, light microscopy is employed in the reflected-light mode using either bright-field illumination, dark-field illumination, polarized light illumination, or differential interference contract, generally by the Nomarski technique. This article concentrates on how to reveal microstructure properly to enable the proper identification of the phases and constituents and, if needed, measuring the amount, size, and spacing of constituents, using the light optical microscope. The discussion covers the examination of microstructures using different illumination methods and includes a comparison between light optical images and scanning electron microscopy images of microstructure.

This article briefly discusses popular techniques for metals characterization. It begins with a description of the most common techniques for determining chemical composition of metals, namely X-ray fluorescence, optical emission spectroscopy, inductively coupled plasma optical emission spectroscopy, high-temperature combustion, and inert gas fusion. This is followed by a section on techniques for determining the atomic structure of crystals, namely X-ray diffraction, neutron diffraction, and electron diffraction. Types of electron microscopies most commonly used for microstructural analysis of metals, such as scanning electron microscopy, electron probe microanalysis, and transmission electron microscopy, are then reviewed. The article contains tables listing analytical methods used for characterization of metals and alloys and surface analysis techniques. It ends by discussing the objective of metallography.