This article provides a discussion on various types of glasses: traditional glasses, specialty glasses, and glass ceramics. It provides information on glazes and enamels and reviews the broad classes of ceramic materials. These include whitewares, structural clay products, technical ceramics, refractories, structural ceramics, engineering ceramics, and electronic and magnetic ceramics. General processing variables that can affect structure and compositional homogeneity are discussed. Traditional ceramics that include both oxide and nonoxide ceramics are also reviewed. The article concludes with several examples of engineering ceramics.

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.

This article focuses on the production methods, properties, and applications of two main types of commercially available continuous-length ceramic fibers, namely, oxide fibers based on the alumina-silica system and on alpha-alumina, and nonoxide fibers based primarily on beta-phase silicon carbide. It provides a discussion on factors that are considered in understanding thermostructural capability of ceramic fiber for high-temperature ceramic-matrix composites (CMC) applications. The article tabulates other commercial oxide and nonoxide fiber types for CMC reinforcement.

This article provides a discussion on the structural ceramics used in gas turbine components, the automotive and aerospace industries, or as heat exchangers in various segments of the chemical and power generation industries. It covers the fundamental aspects of chemical corrosion and describes the corrosion resistance characteristics of specific classes of refractories and structural ceramics. The article also examines the prevention strategies that minimize corrosion failures of both classes of materials.

This article provides an overview of the steps that are used in ceramics processing and related mechanical design considerations. It discusses various design approaches, such as the empirical design, the deterministic design, and the probabilistic design. The article presents a general process design flowchart for ceramic processing. Information on traditional ceramics and advanced ceramics is also provided. The article describes various ceramic forming processes, such as wet processing, plastic forming, dry processing, and machining. The factors for evaluating different ceramic forming processes are summarized in a table. The article discusses vitrification and sintering that generally pertain to ceramic firing and concludes with a discussion on firing process factors.

Reinforcing fibers are a key component of polymer-matrix composites (PMCs), ceramic-matrix composites (CMCs), and metal-matrix composites (MMCs). This article discusses the mechanical and nonmechanical properties of these composites. It presents an overview of PMC, CMC, and MMC reinforcing fibers. The article describes cost-considered value-in-use of the ultimate-use temperature of selected fibers in three fiber categories: metal fibers or wires, oxide ceramic fibers, and non-oxide ceramic fibers.

Microstructural analysis reveals many important details about the qualities and capabilities of high-performance ceramics. This article explains how to prepare ceramic samples for imaging and the imaging technologies normally used. It describes sectioning, mounting, grinding, and polishing as well as ceramographic etching. It discusses common imaging approaches, including scanning electron microscopy and thin-section polarized light techniques, a type of optical microscopy. The article also addresses microstructural classification, examining detailed micrographs from samples of aluminum oxide, zirconium dioxide, aluminum nitride, silicon carbide, and piezoelectric ceramics.

Corrosion is often thought of as rusting, the process of deterioration undergone by a metal when it is exposed to air or water. This article provides the fundamentals of joints corrosion and primarily addresses the various forms of corrosion observed in brazed and soldered joints and their causes. It describes the role of proper brazing procedures in controlling corrosion. The article concludes with information on the corrosion resistance of various brazing alloy systems.

For the reinforcement of metal-matrix composites, four general classes of materials are commercially available: oxide fibers based primarily on alumina and alumina silica systems, nonoxide systems based on silicon carbide, boron fibers, and carbon fibers. This article discusses the key aspects of aluminum oxide fibers, silicon carbide fibers, boron fibers, and carbon fibers. The commercial fibers for reinforcement of metal-matrix composites are presented in a table. A tabulation of the coating schemes for silicon carbide monofilament fibers is also provided.

This article discusses the mechanisms for enhancing the reliability of three types of ceramic-matrix composites: discontinuously reinforced ceramic-matrix composites, continuous fiber ceramic composites, and carbon-carbon composites. It also presents examples of their mechanical and physical properties. Examples that illustrate the properties of commercially available materials are also provided.

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.

Sintering provides the interparticle bonding that generates the attractive forces needed to hold together the otherwise loose ceramic powder mass. It also improves hardness, strength, transparency, toughness, electrical conductivity, thermal expansion, magnetic saturation, corrosion resistance, and other properties. This article discusses the fundamentals of sintering and its effects on pore structures and particle density. It addresses some of the more common sintering methods, including solid-state, liquid-phase, and gas pressure sintering, and presents alternative processes such as reaction sintering and self-propagating, high-temperature synthesis. It also describes several pressure densification methods, including hot isostatic pressing, gas pressure sintering, molten particle deposition, and sol-gel processing. The article concludes with a section on grain growth that discusses the underlying mechanisms and kinetics and the relationship between grain growth and densification.

This article focuses on the process methods and matrix chemistries of ceramic-matrix composites. These methods include pressure-assisted densification, chemical vapor infiltration, melt infiltration, polymer infiltration and pyrolysis, and sol-gel processing. The article discusses the use of a ceramic, preceramic, or metal phase as a fluid or vapor phase reactant to form the matrix. Emphasis is placed on microstructural features that influence ultimate composite properties.

Carbon-carbon is a unique composite material in which a nonstructural carbonaceous matrix is reinforced by carbon fibers to create a heat-resistant structural material that finds application in the aerospace and defense industries. This article provides a detailed account of the fundamentals of protecting carbon-carbon composites and explains the various coating deposition techniques, namely, pack cementation, chemical vapor deposition, and slurry coatings. It includes information on the practical limitations of coatings for the carbon-carbon composites.

This article explains how ceramic powders are made. It begins by briefly describing the raw materials used in structural clay products, whitewares, refractories, and advanced ceramics. It then examines various additives that promote uniformity at different stages of the process. After a description of the comminution process (wet and dry milling methods), it discusses batching and mixing operations and granulation methods. The article also deals with the effect of process variables and the steps involved in chemical synthesis, including preparation from solution and gas-phase reactions, filtration and washing, and powder recovery techniques. It concludes with a discussion on characterization, centering on size distribution analysis, specific surface area, density, porosity chemical composition, phase, and surface composition.

This article is intended to assist the development of procedures for the brazing of ceramic-to-ceramic or ceramic-to-metal joints for service under elevated temperatures, mechanical or thermal stresses, or corrosive atmospheres. It describes the factors considered in preparing a procedure for the brazing of graphitic materials.

This article focuses on the various techniques for removing contaminants in the surface preparation of steel for hot-dip coatings: wet cleaning methods, including alkaline cleaning, electrolytic cleaning, chemical pickling, and electrolytic pickling; flame cleaning and furnace-atmosphere techniques, such as Sendzimir oxidation/reduction method; other specialized methods, namely, fluxes, mechanical cleaning, and ultrasonic methods; or a combination of these.

This article provides a broad overview of sliding and adhesive wear, its processes, and its control, with special attention to three general classes of materials: metals, ceramics, and polymers. It discusses the ways in which materials can be damaged and removed during sliding contact. The article explains the physical and chemical nature of sliding surfaces. It presents wear equations, design criteria, and criteria for selection of materials. The article also describes the factors that affect wear performance of hybrid sliding systems. It concludes by providing general guidelines to prevent the sliding and adhesive wear in metals, polymers, and ceramics.

This article describes the factors considered in the analysis of brazeability and solderability of engineering materials. These are the wetting and spreading behavior, joint mechanical properties, corrosion resistance, metallurgical considerations, and residual stress levels. It discusses the application of brazed and soldered joints in sophisticated mechanical assemblies, such as aerospace equipment, chemical reactors, electronic packaging, nuclear applications, and heat exchangers. The article also provides a detailed discussion on the joining process characteristics of different types of engineering materials considered in the selection of a brazing process. The engineering materials include low-carbon steels, low-alloy steels, and tool steels; cast irons; aluminum alloys; copper and copper alloys; nickel-base alloys; heat-resistant alloys; titanium and titanium alloys; refractory metals; cobalt-base alloys; and ceramic materials.

This article describes the manufacture, post-processing, fabrication, and properties of carbon-carbon composites (CCCs). Manufacturing techniques with respect to the processibility of different geometries of two-directional and multiaxial carbon fibers are listed in a table. The article discusses matrix precursor impregnants, liquid impregnation, and chemical vapor infiltration (CVI) for densification of CCCs. It presents various coating approaches for protecting CCCs, including pack cementation, chemical vapor deposition, and slurry coating. Practical limitations of coatings are also discussed. The article concludes with information on the mechanical properties of CCCs.