Search Results for X-ray powder diffraction

This appendix explains how to identify crystallographic planes and directions. It shows how Miller indices, a system for specifying crystallographic planes within a unit cell, are determined for cubic and hexagonal systems. It also explains how x-ray diffraction techniques are used in the study of crystalline structures.

This chapter explains how to measure the shape, size, microstructure, and composition of powders as well as their flowability and crystallization behavior. It presents detailed workflows and calculations based on SEM, TEM, FESEM, and STEM imaging, x-ray diffraction, differential scanning calorimetry, EDS and EELS spectroscopy, and powder sieving. It also discusses the measurement of crystallite size, lattice mismatch, and crystallinity and the relationship between surface area and flowability.

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 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.

This appendix defines abbreviations, acronyms, and symbols presented within this book.

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.

This chapter covers the early studies and various discoveries by metals researchers to study the internal structure of metals. The topics covered include light microscopy, phase diagrams, X-ray diffraction, principles of precipitation hardening, and dislocation theory.

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 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.

This chapter examines boiler tube failures attributed to operation-related causes. It discusses failures due to rapid start-ups, excessive load swing, excessive heat inputs, poor water chemistry control, and water-treatment methods.

This article introduces procedures an engineer or materials scientist can use to investigate failures. It provides a brief survey of polymer systems and key properties that need to be measured during failure analysis. The article begins with an overview of the problem-solving approach pertinent to structure analysis. This is followed by a review of the characterization of plastics by infrared and nuclear magnetic resonance spectroscopy. The article then provides information on the distribution of molecular weight of an engineering plastic. It further discusses the methods used in thermal analysis, namely differential thermal analysis, thermogravimetric analysis, thermal-mechanical analysis, and dynamic mechanical analysis. The following sections provide details on X-ray diffraction for analyzing crystalline phases and on a minimal scheme for polymer analysis and characterization to assist the design engineer. The article ends with a discussion on the thermal-analytical scheme for analyzing the milligram quantities of polymer samples.

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 presents definitions of terms related to the metallurgy and metallographic study of irons and steels.

This appendix provides a detailed overview of the crystal structure of metals. It describes primary bonding mechanisms, space lattices and crystal systems, unit cell parameters, slip systems, and crystallographic planes and directions as well as plastic deformation mechanisms, crystalline imperfections, and the formation of surface or planar defects. It also discusses the use of X-ray diffraction for determining crystal structure.

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.