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.

Ion-beam-assisted deposition (IBAD) refers to the process wherein evaporated atoms produced by physical vapor deposition are simultaneously struck by an independently generated flux of ions. This article discusses the energy utilization of this process. It describes the physical and chemical processes occurring at the film-vacuum interface during IBAD and dual-ion-beam sputtering with illustrations. The article also reviews the methods used for large-area, high-volume implementation of IBAD and the modes of film formation for IBAD. It contains a table that presents information on deposition and synthesis of inorganic compounds by IBAD and concludes with a discussion on the improved coating properties, advantages, limitations, and applications of IBAD.

Nanotechnology and smart-coating technologies have been reported to show great promise for improved performance in critical areas such as corrosion resistance, durability, and conductivity. This article exemplifies nanofilms and nanomaterials used in coatings applications, including carbon nanotubes, silica, metals/metal oxides, ceramics, clays, buckyballs, graphene, polymers, titanium dioxide, and waxes. These can be produced by a variety of methods, including chemical vapor deposition, plasma arcing, electrodeposition, sol-gel synthesis, and ball milling. The application of nanotechnology and the development of smart coatings have been dependent largely on the availability of analytical and imaging techniques such as Raman spectroscopy, scanning and transmission electron microscopy, atomic force microscopy, and scanning tunneling microscopy.

Metallic glasses can be prepared by solidification of liquid alloys at cooling rates sufficient to suppress the nucleation and growth of competing crystalline phases. This article presents a historical survey of the study of metallic glasses and other amorphous metals and alloys. This includes a discussion of synthesis and processing methods, structure and morphology, and a description of the electronic, magnetic, thermodynamic, chemical, and mechanical properties of metallic glasses. In addition, the article describes the development of metallic glasses as materials for technical applications.

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 focuses on transport phenomena and modeling approaches that are specific to vapor-phase processes (VPP). It discusses the VPP for the synthesis of materials. The article reviews the basic notions of molecular collisions and gas flows, and presents transport equations. It describes the modeling of vapor-surface interactions and kinetics of hetereogeneous processes as well as the modeling and kinetics of homogenous reactions in chemical vapor deposition (CVD). The article provides information on the various stages of developing models for numerical simulation of the transport phenomena in continuous media and transition regime flows of VPP. It explains the methods used for molecular modeling in computational materials science. The article also presents examples that illustrate multiscale simulations of CVD or PVD processes and examples that focus on sputtering deposition and reactive or ion beam etching.

This article introduces the fundamental concepts and the essential components of liquid chromatography (LC). It discusses the different modes of LC, such as liquid-solid chromatography, liquid-liquid chromatography, bonded-phase chromatograph, normal-phase chromatography, reversed-phase chromatography, ion-exchange chromatography, ion-pair chromatography, and size-exclusion chromatography. The article also includes a discussion on the qualitative and quantitative analyses and the applications of LC.

This article discusses the methods and procedures used to extract, purify, and synthesize tungsten carbide powder, metal, and other refractory carbide/nitride powders used in hard metal production. Selection of powders, additives, equipment, and processes for making ready-to-press hard metal powders is also discussed. The article also provides information on the emerging technologies for tungsten carbide synthesis and binders in hard metal production, such as cobalt, iron, and nickel.

Synthetic diamond and cubic boron nitride are among a class of superhard materials from the boron-carbon-nitrogen-silicon family of elements. This article focuses on the two materials, the forms in which they are produced, and their respective properties. Synthetic diamond and cubic boron nitride compounds are available in the form of grit and sintered polycrystalline blanks of various size, shape, and composition. The article explains how superabrasive grains made from these materials can be used in lapping, polishing, and grinding applications, and how diamond and boron nitride blanks can be mounted to suitable substrates to form ultrahard cutting edges and tools.

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.

The chemical process being catalyzed should have a high productivity within a specified reactor volume with high reaction rates for the desired reactions and low rates for undesired reaction pathways. This article reviews the general catalyst preparation procedures, namely, impregnation, ion exchange, and precipitation. Catalyst carriers are usually high-surface-area inorganic materials with complex pore structures, into which catalytic materials such as palladium, platinum, cobalt, chromium oxide, and vanadium pentoxide are deposited using these procedures. The article also provides information on catalyst powder processing.

This article focuses on lubricants classified as either internal combustion engine or nonengine lubricants, and the lubricant additives. The functional groups of chemically active and inert additives, as well as friction modifiers and other additives, are described in detail. The chemically active additives include dispersants, detergents, antiwear, and extreme-pressure agents, oxidation inhibitors, and rust and corrosion inhibitors. The chemically inert additives include emulsifiers, demulsifiers, pour-point depressants, foam inhibitors, and viscosity improvers. The article also discusses the multifunctional nature of additives and concludes with information on lubricant formulation.

This article discusses the properties and applications of two types of polyimide resins: condensation polyimides and addition-type polyimides. It describes the chemistry of condensation-type polyimides during synthesis, processing of polyamide acid precursor solution to polyimide, and preparation of polyimide films from thermoplastic polyamic acid precursors. The article reviews the chemistry of several addition-type polyimides, including phenylethynyl-containing imide oligomers, nadic end-capped polyimides, and LARC RP46. It explains the preparation processes of nadic end-capped amic acid oligomer resin solutions, including the preparation of resin powder and resin disks, adhesive film, adhesive bond specimens, and films.

Lasers evolved as a versatile materials processing tool due to their advantages such as rapid, reproducible processing, chemical cleanliness, ability to handle variety of materials, and suitability for automation. This article focuses on state-of-the-art laser applications to improve tribological performance of structural materials in lubricated and nonlubricated environments. It discusses the fundamentals of various laser materials interactions and reviews laser-based surface-modification strategies, including laser surface heating and melting, laser-synthesized coatings, and laser-based design approaches such as laser patterning and dimpling. Laser-surface modification of novel materials, such as high-entropy alloys and metallic glasses, is explored. The article provides an overview of hybrid techniques involving laser as a secondary tool, as well as a discussion on the improved capabilities of laser surface engineering for tribological applications by means of integrated computational process modeling.

Ammonia and ammonium hydroxide are not particularly corrosive in themselves, but corrosion problems can arise with specific materials, particularly when contaminants are present. This article discusses the corrosion resistance of materials used for the manufacture, handling, and storage of ammonia. These materials include aluminum alloys, iron and steel, stainless steels, nickel and its alloys, copper and its alloys, titanium and its alloys, zirconium and its alloys, niobium, tantalum, and nonmetallic materials.

Consolidation of titanium powders at room temperature may be performed by low-cost conventional powder metallurgy processes. This article provides information on various consolidation methods, namely, die pressing, direct powder rolling, and cold isostatic pressing. It also describes the sintering of blended elemental powders, high-strength titanium alloys, and porous material as well as the sintering of titanium powders by microwave heating.

Metal contamination of the environment reflects both natural sources and industrial activity, affecting human health. This article begins with a discussion on the level of metal exposure resulting in toxicological effects, the factors influencing toxicity of metals, and carcinogenicity of metal compounds. It discusses some commonly used chelating agents for treating metal intoxication, and clinical effectiveness in treating poisoning by different metals. The metals discussed are grouped into four categories: (1) major toxic metals with multiple effects, including arsenic, beryllium, cadmium, chromium, lead, mercury, and nickel; (2) essential metals with potential for toxicity, including cobalt, copper, iron, manganese, molybdenum, selenium, and zinc; (3) metals with toxicity related to medical therapy, including aluminum, bismuth, gallium, gold, lithium, and platinum; and (4) minor toxic metals, including antimony, barium, indium, magnesium, silver, tellurium, thallium, tin, titanium, uranium, and vanadium. The main factors included in the discussion are their disposition, toxicity, biological factors and treatment.

Value analysis (VA) is a team problem-solving process to improve the value of a product from the viewpoint of a user. This article presents a comparison between VA and total quality management in materials selection and design. It discusses the key attributes, concepts, and activities of the VA. The application of value engineering in U.S. government contracts and the construction industry is reviewed. The article describes the eight phases of the VA process: preparation, information, analysis, creation, synthesis, development, presentation and report, and implementation and follow-up. It presents case studies that illustrate the materials-related aspects of the VA process.

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 introduces the structure, tribological properties, advantages, and applications of ionic liquids (ILs) as lubricating media. It discusses the mechanisms of IL lubrication for different contacts. The advances in studies focusing on tribological properties of a wide range of ILs are reviewed. The article concludes with the challenges that limit the applications of ILs in tribology engineering.