Ceramic-matrix composites (CMCs) have ability to withstand high temperatures and have superior damage tolerance over monolithic ceramics. This article describes important processing techniques for CMCs: cold pressing, sintering, hot pressing, reaction-bonding, directed oxidation, in situ chemical reaction techniques, sol-gel techniques, pyrolysis, polymer infiltration, self-propagating high-temperature synthesis, and electrophoretic deposition. The advantages and disadvantages of each technique are highlighted to provide a comprehensive understanding of the achievements and challenges that remain in this area.

This article describes the analytical methods for analyzing surfaces for corrosion and corrosion inhibition processes as well as failure analysis based on surface structure and chemical identity and composition. The principles and applications of the surface-structure analysis techniques, namely, optical microscopy, scanning electron microscopy, scanning tunneling microscopy, and atomic force microscopy, are reviewed. The article discusses the principles and applications of chemical identity and composition analysis techniques. These techniques include the energy dispersive X-ray spectroscopy, Auger electron spectroscopy, X-ray photoelectron spectroscopy, ion scattering spectroscopy, reflectance Fourier transform infrared absorption spectroscopy, Raman and surface enhanced Raman spectroscopy, and extended X-ray absorption fine structure analysis.

This article discusses the application of amorphous and crystalline films through plasma-enhanced chemical vapor deposition (PECVD) from the view point of microelectronic device fabrication. It describes the various types of PECVD reactors and deposition techniques. Plasma enhancement of the CVD process is discussed briefly. The article also describes the properties of amorphous and crystalline films deposited by the PECVD process for integrated circuit fabrication.

This article provides information on basic chemical equilibria, wet analytical chemistry, and the appropriateness of classical wet methods. It focuses on nonoxidizing acids and oxidizing acids. The article includes information on the qualitative methods used to identify materials by wet chemical reaction. Gravimetry, in which a chemical species is weighed; titrimetry, which involves volume measurement of a liquid reactant; and a host of separation techniques, which require diverse forms of laboratory manipulation, are discussed. The article briefly describes the partitioning of oxidation states as well as those applications in surface studies and rapid material identification in which chemical techniques have proved useful.

Gas analysis by mass spectrometry, or gas mass spectrometry, is a general technique using a family of instrumentation that creates a charged ion from a gas phase chemical species and measures the mass-to-charge ratio. This article covers gas analysis applications that do not use chromatographic separation to physically isolate components of the sample prior to analysis. It is intended to provide an understanding of gas analysis instrumentation and terminology that will help make informed decisions in choosing an instrument and methodology appropriate for the data needed. Mass-analyzer technologies for gas mass spectrometry, namely quadrupole mass filters, magnetic sector mass filters, and time-of-flight mass analyzers are covered. Common factors to consider in choosing an analyzer for static or continuous gas measurement are also described. In addition, the article presents some examples of applications of gas mass spectrometry.

This article focuses on wet chemical methods that have stood the test of time in laboratories around the world. It begins with a description of the appropriateness of classical wet methods. This is followed by sections on sampling procedures, basic chemical equilibria, and wet analytical chemistry. Mechanical methods and nonoxidizing acids and/or acid mixtures for dissolving solid samples for wet chemical analysis are then reviewed. Qualitative methods that are used to identify materials by wet chemical reaction are also included. The article provides information on various methods for the separation of chemical mixtures and on the types of gravimetry and titrimetry. Strategies for removing inclusions are also included to aid in their compositional understanding. The article also briefly describes the processes involved in chemical surface studies and partitioning of oxidation states. It ends by presenting some examples of the applications of classical wet methods.

This article discusses the basic principles of and chemical effects in Auger electron spectroscopy (AES), covering various factors affecting the quantitative analyses of AES. The discussion covers instrumentation and sophisticated electronics typically used in AES for data acquisition and manipulation and various limitations of AES. Various examples highlighting the capabilities of the technique are also included.

This article describes the characteristics of thermoplastic composites and its material forms. It presents the steps and considerations in manufacturing the thermoplastic composites. The article describes the various techniques of manufacturing, such as consolidation, autoclave molding, diaphragm forming, compression molding, roll forming, bladder molding, liquid molding, filament winding, and pultrusion.

This article describes eight stages of the atomistic film growth: vaporization of the material, transport of the material to the substrate, condensation and nucleation of the atoms, nuclei growth, interface formation, film growth, changes in structure during the deposition, and postdeposition changes. It also discusses the effects and causes of growth-related properties of films deposited by physical vapor deposition processes, including residual film stress, density, and adhesion.

Ceramic-matrix composites (CMCs) are being developed for a number of high-temperature and high-performance applications in industrial, aerospace, and energy conservation sectors. This article focuses on processing, fabrication, testing, and characterization methods of CMCs, namely, discontinuously reinforced composites and continuous-fiber-reinforced composites. Processing methods include cold pressing, sintering, hot pressing, reaction bonding, melt infiltration, directed metal oxidation, sol-gel and polymer pyrolysis, self-propagating high-temperature synthesis and joining. A table summarizes the properties of various ceramic reinforcements and industrial applications of these composites.

This article describes the vapor-phase growth techniques applied to the epitaxial deposition of semiconductor films and discusses the fundamental processes involved in metal-organic chemical vapor deposition (MOCVD). It reviews the thermodynamics that determine the driving force behind the overall growth process and the kinetics that define the rates at which the various processes occur. The article provides information on the reactor systems and hardware, MOCVD starting materials, engineering considerations that optimize growth, and the growth parameters for a variety of Group III-V, II-VI, and IV semiconductors.

Metal transparency and interaction with X-rays have been recognized as obvious candidate principles from which methods for in situ monitoring of solidification processes could be developed. This article describes the use of X-ray imaging-based techniques to investigate interface morphology evolution, solute transport, and various process phenomena at spatiotemporal resolutions. It discusses the three viable imaging techniques made available by synchrotron radiation for the real-time investigation of solidification microstructures in alloys. These include two-dimensional X-ray topography, two-dimensional X-ray radiography, and ultra-fast three-dimensional X-ray tomography.

This article reviews the types of passivity and presents tactics that employ passivity to control corrosion. Thermodynamics provides a guide to the conditions under which passivation becomes possible. A valuable guide to thermodynamics is the potential-pH diagram and the Pourbaix diagram. The article presents a potential-pH diagram for the iron-water system and an illustration of an idealized anodic polarization curve for a metal surface, which serves as a basis for describing the kinetics of passivation. It discusses five properties of passive films: thickness, composition, structure, electronic properties, and mechanical properties. The article outlines three possible processes that can form passive films: direct film formation, dissolution precipitation, and anodic oxidation of metal ions in solution. It describes the breakdown of the passive film using various models and highlighting the effect of alloy composition and structure.

This article discusses the most common thermal analysis methods for thermosetting resins. These include differential scanning calorimetry, thermomechanical analysis, thermogravimetric analysis, and dynamic mechanical analysis. The article also discusses the characterization of uncured thermosetting resins as well as the curing process. Then, the techniques to characterize the physical properties of cured thermosets and composites are presented. Several examples of stress-strain curves are shown for thermosets and thermoplastic polymers.

Many applications of ceramics and glasses require them to be joined to each other or to other materials such as metals. This article focuses on ceramic joining technologies, including glass-metal sealing, glass-ceramic/metal joining, ceramic-metal joining, ceramic-ceramic joining, and the more advanced joining of nonoxide ceramics. It also discusses metallizing, brazing, diffusion bonding, and chemical bonding.

Corrosion is the deterioration of a material by a reaction of that material with its environment. The realization that corrosion control can be profitable has been acknowledged repeatedly by industry, typically following costly business interruptions. This article describes the electrochemical nature of corrosion and provides the typical analysis of environmental- and corrosion-related failures. It presents common methods of testing of laboratory corrosion and discusses the processes involved in the prevention of environmental- and corrosion-related failures of metals and nonmetals.

This article discusses the major methods of elemental analysis, namely, the combustion method for carbon, hydrogen, and nitrogen; the Kjeldahl method for nitrogen; and the Schoniger flask method for other common elements. It also discusses the methods of functional group analysis for acids, alcohols, aldehydes and ketones, amines, esters, aromatic hydrocarbons, peroxides, phenols, water (Karl Fischer method), and alkenes.

Gas porosity is a major factor in the quality and reliability of castings. The major cause of gas porosity in castings is the evolution of dissolved gases from melting and dross or slag containing gas porosity. Degassing is the process of removing these gases. This article describes the methods of degassing aluminum, magnesium, and copper alloys. It provides information on the sources of hydrogen in aluminum and gases in copper.

Ores, which consist of the primary valuable mineral, predominant gangue content, valuable by-products, and detrimental impurities, are extracted and directed to mineral processing. This article describes the mineral processing facilities, such as crushers, grinders, concentrators, separators, and flotation devices that are used for particle size reduction, separation of particles according to their settling rates in fluids and dewatering of concentrate particles. It explains the basic principles, flow diagrams, ore concentrate preparation methods, and equipment of major types of metallurgical processes, including pyrometallurgical, hydrometallurgical, and electrometallurgical processes.

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.