This article outlines the basic steps to be followed and the range of techniques available for failure analysis, namely, background data assembling, visual examination, microfractography, chemical analysis, metallographic examination, electron microscopy, electron microprobe analysis, X-ray techniques, and simulations. It also describes the steps for analyzing the data, preparing the report, preservation of evidence, and follow-up on recommendations.

This article describes the methods and equipments involved in the preparation of specimens for examination by light optical microscopy, scanning electron microscopy, electron microprobe analysis for microindentation hardness testing, and for quantification of microstructural parameters, either manually or by the use of image analyzers. Preparation of metallographic specimens generally requires five major operations: sectioning, mounting, grinding, chemical polishing, and etching. The article provides information on the principles of technique selection in mechanical polishing, and describes the procedures, advantages, and disadvantages of electrolytic and chemical polishing. It also provides a detailed account of procedures, precautions, and composition for preparation and handling of etchants.

This article describes the operation and capabilities of surface analysis methods of metals, including scanning electron microscopy, electron probe microanalysis, transmission electron microscopy, secondary ion mass spectroscopy, and X-ray photoelectron spectroscopy. It provides information on the capabilities, typical uses, spatial resolution, elemental analysis detection threshold and precision, limitations, sample requirements, and operating principles of the scanning auger microprobe.

This article is a compilation of abbreviations and symbols related to metallography and microstructures.

Particle-induced x-ray emission (PIXE) is one of several quantitative analyses based on characteristic x-rays. This article provides a detailed account on the principles of PIXE, discussing the data-reduction codes used to identify, integrate, and reduce x-ray peaks into elemental concentrations. It provides information on the calibration of PIXE analysis, which is mostly performed using gravimetric standards to avoid serious absorption, refluorescence, or ion energy change corrections. A comparative study on PIXE and x-ray fluorescence is also included. Finally, the article discusses the applications of PIXE in three areas, namely, atmospheric physics and chemistry, external proton milliprobes and historical analysis, and PIXE microprobes.

This article provides a detailed account of particle-induced x-ray emission (PIXE), covering the basic principles of PIXE analysis and calibration and quality-assurance protocols employed. A comparative study on PIXE and x-ray fluorescence is then presented. The article also discusses the applications of PIXE in atmospheric physics and chemistry, external proton milliprobes and historical analysis, and PIXE microprobes.

Microstructural analysis is the combined characterization of the morphology, elemental composition, and crystallography of microstructural features through the use of a microscope. This article reviews three types of the most commonly used electron microscopies in metallurgical studies, namely scanning electron microscopy, electron probe microanalysis, and transmission electron microscopy. It briefly describes the operating principles, instrumentation which includes energy dispersive X-ray detectors, spatial resolution, typical use of the techniques, elemental analysis detection threshold and precision, limitations, sample requirements, and the capabilities of related techniques.

Chemical analysis is a critical part of any failure investigation. With the right planning and proper analytical equipment, a myriad of information can be obtained from a sample. This article presents a high-level introduction to techniques often used for chemical analysis during failure analysis. It describes the general considerations for bulk and microscale chemical analysis in failure analysis, the most effective techniques to use for organic or inorganic materials, and examples of using these techniques. The article discusses the processes involved in the chemical analysis of nonmetallics. Advances in chemical analysis methods for failure analysis are also covered.

This article provides a general introduction of materials characterization and describes the principles and applications of a limited number of techniques that are most commonly used to characterize the composition and structure of metals used in engineering systems. It briefly describes the classification of materials characterization methods including, bulk elemental characterization, bulk structural characterization, microstructural characterization, and surface characterization. Further, the article reviews the selection of materials characterization methods most commonly used with metals.

In secondary ion mass spectroscopy (SIMS), an energetic beam of focused ions is directed at the sample surface in a high or ultrahigh vacuum (UHV) environment. The transfer of momentum from the impinging primary ions to the sample surface causes sputtering of surface atoms and molecules. This article focuses on the principles and applications of high sputter rate dynamic SIMS for depth profiling and bulk impurity analysis. It provides information on broad-beam instruments, ion microprobes, and ion microscopes, detailing their system components with illustrations. The article graphically illustrates the SIMS spectra and depth profiles of various materials. The quantitative analysis of ion-implantation profiles, instrumental features required for secondary ion imaging, the analysis of nonmetallic samples, detection sensitivity, and the applications of SIMS are also discussed.

This article focuses on the principles and applications of high-sputter-rate dynamic secondary ion mass spectroscopy (SIMS) for depth profiling and bulk impurity analysis. It begins with an overview of various factors pertinent to sputtering. This is followed by a discussion on the effects of ion implantation and electronic excitation on the charge of the sputtered species. The design and operation of the various instrumental components of SIMS is then reviewed. Details on a depth-profiling analysis of SIMS, the quantitative analysis of SIMS data, and the static mode of operation of time-of-flight SIMS are covered. Instrumental features required for secondary ion imaging are presented and the differences between quadrupole and high-resolution magnetic mass filters are described. The article also reviews the optimum method for analysis of nonmetallic samples and high detection sensitivity of SIMS. It ends with a discussion on a variety of examples of SIMS applications.

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.

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 discusses the characterization of gray iron structures, following the sequence of structure formation, as it applies to unalloyed or low-alloyed gray iron. Austenite grains are the basic crystallographic entities of the metallic matrix in gray cast iron precipitated from the liquid melt. The article describes the macrostructure and dendrite morphology of primary austenite. Eutectoid transformation in the solid state causes the transformation of austenite to pearlite and/or ferrite, producing the as-cast structure. The article discusses the observations of the graphite and ferritic/pearlitic structure in as-cast gray iron.

This article describes the principles and applications of Auger electron spectroscopy (AES). It provides information on the instrumentation typically used in the AES, including an electron gun, an electron spectrometer, a secondary electron detector, and an ion gun. The article also describes experimental methods and limitations of the AES, including elemental detection sensitivity, electron beam artifacts, sample charging, spectral peak overlap, high vapor pressure samples, and sputtering artifacts.

Scanning electron microscopy (SEM) has unique capabilities for analyzing fracture surfaces. This article discusses the basic principles and practice of SEM, with an emphasis on its applications in fractography. The topics include an introduction to SEM instrumentation, imaging and analytical capabilities, specimen preparation, and the interpretation of fracture features. SEM can be subdivided into four systems, namely, illuminating/imaging, information, display, and vacuum systems. The article also describes the major criteria and techniques of SEM specimen preparation, and the general features of ductile and brittle fracture modes.

Coatings and thin films can be studied with surface analysis methods because their inherently small depth allows characterization of the surface composition, interface composition, and in-depth distribution of composition. This article describes principles and examples of common surface analysis methods, namely, Auger electron spectroscopy, X-ray photoelectron spectroscopy, ion scattering spectroscopy, secondary ion mass spectroscopy, and Rutherford backscattering spectroscopy. It also provides useful information on the applications of surface analysis.

This article introduces various techniques commonly used in the characterization of semiconductors, namely single-crystal, polycrystalline, amorphous, oxide, organic, and low-dimensional semiconductors and semiconductor devices. The discussion covers material classification, fabrication methods, sample preparation, bulk/elemental characterization methods, microstructural characterization methods, surface characterization methods, and electronic characterization methods.

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.

Electron probe microanalysis (EPMA) makes it possible to combine structural and compositional analysis in one operation. This article describes the basic concepts of microanalysis and the processing of EPMA that involves the measurement of the characteristic X-rays emitted from a microscopic part of a solid specimen bombarded by a beam of accelerated electrons. It provides information on the various aspects of energy-dispersive spectrometry (EDS) and wavelength-dispersive spectrometry (WDS), and elucidates the qualitative analysis of the major constituents of EDS and WDS. The article includes information on the analog and digital compositional mapping of elemental distribution, and describes the strengths and weaknesses of WDS and EDS spectrometers in X-ray mapping. It also outlines the application of EPMA for solving various problems in materials science.