Search Results for electron probe X-ray microanalysis

This chapter elucidates the indispensable role of characterization in the development of cold-sprayed coatings and illustrates some of the common processes used during coatings development. Emphasis is placed on the advanced microstructural characterization techniques that are used in high-pressure cold spray coating characterization, including residual-stress characterization. The chapter includes some preliminary screening of tool hardness and bond adhesion strength, as well as a distinction between surface and bulk characterization techniques and their importance for cold spray coatings. The techniques covered are optical microscopy, X-Ray diffraction, scanning electron microscopy, focused ion beam machining, electron probe microanalysis, transmission electron microscopy, and electron backscattered diffraction. The techniques also include electron channeling contrast imaging, X-Ray photoelectron spectroscopy, X-ray fluorescence, Auger electron spectroscopy, Raman spectroscopy, oxygen analysis, and nanoindentation.

Several specialized instruments are available for the metallographer to use as tools to gather key information on the characteristics of the microstructure being analyzed. These include microscopes that use electrons as a source of illumination instead of light and x-ray diffraction equipment. This chapter describes how these instruments can be used to gather important information about a microstructure. The instruments covered include image analyzers, transmission electron microscopes, scanning electron microscopes, electron probe microanalyzers, scanning transmission electron microscopes, x-ray diffractometers, microhardness testers, and hot microhardness testers. A list of other instruments that are usually located in a research laboratory or specialized testing laboratory is also provided.

The overall chemical composition of metals and alloys is most commonly determined by x-ray fluorescence (XRF) and optical emission spectroscopy (OES). High-temperature combustion and inert gas fusion methods are typically used to analyze dissolved gases (oxygen, nitrogen, and hydrogen) and, in some cases, carbon and sulfur in metals. This chapter discusses the operating principles of XRF, OES, combustion and inert gas fusion analysis, surface analysis, and scanning auger microprobe analysis. The details of equipment set-up used for chemical composition analysis as well as the capabilities of related techniques of these methods are also covered.

This chapter discusses the use of electron microscopy in metallographic analysis. It explains how electrons interact with metals and how these interactions can be harnessed to produce two- and three-dimensional images of metal surfaces and generate crystallographic and compositional data as well. It discusses the basic design and operating principles of scanning electron microscopes, transmission electron microscopes, and scanning transmission electron microscopes and how they are typically used. It describes the additional information contained in backscattered electrons and emitted x-rays and the methods used to access it, namely wavelength and energy dispersive spectroscopy and electron backscattering diffraction techniques. It also describes the role of focused ion beam milling in sample preparation and provides information on atom probes, atomic force microscopes, and laser scanning microscopes.

This chapter discusses some of the methods and measurements used to construct phase diagrams. It explains how cooling curves were widely used to determine phase boundaries, and how equilibrated alloys examined under controlled heating and cooling provide information for constructing isothermal and vertical sections as well as liquid projections. It also explains how diffusion couples provide a window into local equilibria and identifies typical phase diagram construction errors along with problems stemming from phase-boundary curvatures and congruent transformations.

After the fault-tree, a failure-cause identification method has identified potential failure causes and the failure analysis team has prepared a failure mode assessment and assignment (FMA&A). The team knows specifically what to search for when examining components and subassemblies from the failed system. There are numerous techniques and technologies available for examining and analyzing components and subassemblies, which are categorized as follows: optical approaches, dimensional inspection and related approaches, nondestructive test approaches, mechanical and environmental approaches, and chemical and composition analysis for assessing material characteristics. This chapter is a detailed account of the working principle and the steps involved in these techniques and technologies.

This chapter discusses the basic steps of a failure investigation. It explains that the first step is to gather and document information about the failed component and its operating history. It advises investigators to visit the failure site as soon as possible to record damages and collect test specimens for subsequent examination and chemical analysis. It also discusses the role of mechanical property testing, the use of nondestructive evaluation, and the final step of generating a report.

This chapter provides perspective on the physical dimensions associated with the microstructure of steel and the instruments that reveal grain size, morphology, phase distributions, crystal defects, and chemical composition, from which properties and behaviors derive. The chapter also reviews the definitions and classifications used to identify and differentiate commercial steels, including the AISI/SAE and UNS designation systems.

The ultimate goal of the failure analysis process is to find physical evidence that can identify the root cause of the failure. Transmission electron microscopy (TEM) has emerged as a powerful tool to characterize subtle defects. This article discusses the sample preparation procedures based on focused ion beam milling used for TEM sample preparation. It describes the principles behind commonly used imaging modes in semiconductor failure analysis and how these operation modes can be utilized to selectively maximize signal from specific beam-specimen interactions to generate useful information about the defect. Various elemental analysis techniques, namely energy dispersive spectroscopy, electron energy loss spectroscopy, and energy-filtered TEM, are described using examples encountered in failure analysis. The origin of different image contrast mechanisms, their interpretation, and analytical techniques for composition analysis are discussed. The article also provides information on the use of off-axis electron holography technique in failure analysis.

This article covers common techniques for surface characterization, including the modern scanning electron microscopy and methods for the chemical characterization of surfaces by Auger electron spectroscopy, X-ray photoelectron spectroscopy, and time-of-flight secondary ion mass spectrometry. The principles of surface analysis and some of the applications of the technique in polymer failure studies are also provided.

With the commercialization of heavier and lighter ion beams, adoption of focused ion beam (FIB) use for analysis of challenging regions of interest (ROI) has grown. In this chapter, the authors focus on highlighting commercially available and complementary FIB technologies and their implementation challenges and application trends.

This chapter describes some of the most effective tools for investigating boiler tube failures, including scanning electron microscopy, optical emission spectroscopy, atomic absorption spectroscopy, x-ray fluorescence spectroscopy, x-ray diffraction, and x-ray photoelectron spectroscopy. It explains how the tools work and what they reveal. It also covers the topic of image analysis and its application in the measurement of grain size, phase/volume fraction, delta ferrite and retained austenite, inclusion rating, depth of carburization/decarburization, scale thickness, pearlite banding, microhardness, and hardness profiles. The chapter concludes with a brief discussion on the effect of scaling and deposition and how to measure it.

This article provides an overview of how to use the scanning electron microscope (SEM) for imaging integrated circuits. The discussion covers the principles of operation and practical techniques of the SEM. The techniques include sample mounting, sample preparation, sputter coating, sample tilt and image composition, focus and astigmatism correction, dynamic focus and image correction, raster alignment, and adjusting brightness and contrast. The article also provides information on achieving ultra-high resolution in the SEM. It concludes with information on the general characteristics and applications of environmental SEM.

This chapter discusses the techniques applicable to the diagnosis of corrosion failures, including visual and microscopic examination of corroded surfaces and microstructure; chemical analysis of the metal, corrosion products, and bulk environment; nondestructive evaluation methods; corrosion testing techniques; and mechanical testing techniques. A guide to investigative techniques used in corrosion failure analysis is provided in a table, describing the advantages and limitations of each technique. The principal stages of the investigation and analysis of corrosion failures discussed in the chapter are: collection of background information and sampling; preliminary laboratory examination; detailed metallographic and fractographic examinations; chemical analysis of corrosion products and bulk materials; corrosion testing for quality control; mechanical testing for quality control; and analysis of results and report writing.

This chapter explains what some of the terms used in physical metallurgy are intended to mean and how these meanings affect the manner in which the subject is treated throughout the book.

This chapter discusses the principles of scanning transmission electron microscopy (STEM) as implemented using conventional scanning electron microscopes (SEMs). It describes the pros and cons of low-energy imaging and diffraction, addresses basic hardware requirements, and provides information on imaging modes, detector positioning and alignment, and the effect of contrast reversal. It also discusses beam convergence and angular selectivity, the use of application-specific masks, and how to generate grain orientation maps for different material systems.

Circuit edit has been instrumental to the development of focused ion beam (FIB) systems. FIB tools for advanced circuit edit play a major role in the validation of design and manufacture. This chapter begins with an overview of value, role, and unique capabilities of FIB circuit edit tools for first silicon debug. The etching capabilities of circuit edit FIB tools are then discussed, providing information on chemistry assisted etching in silicon oxides and low-k dielectrics. The chapter also discusses the requirements and procedures involved in edit operation: high aspect ratio milling, endpointing, and cutting copper. It then provides an introduction to FIB metal/conductor deposition and FIB dielectric deposition. Edit design rules that can facilitate prototype production from first silicon are also provided. The chapter concludes with a discussion on future trends in circuit edit technology.