The primary market for metal powder is the production of powder metallurgy (PM) parts, which are dominated primarily by iron and copper powders. This article reviews the chemical and pyrotechnics applications of ferrous and nonferrous powders. It describes the characteristics of iron powder used in oxygen scavengers and chemical reactive warmers and heaters. Metal powders used as fuels in solid propellants, pyrotechnic devices, explosives, and similar applications are reviewed. Atomized aluminum, magnesium, tungsten, and zirconium powders are also discussed.

Metal powders are used as fuels in solid propellants, fillers in various materials, such as polymers or other binder systems, and for material substitution. They are also used in food enrichment, environmental remediation market, and magnetic, electrical, and medical application areas. This article reviews some of the diverse and emerging applications of ferrous and nonferrous powders. It also discusses the functions of copier powders and the processes used frequently for copier powder coating.

Flash welding (FW) is a resistance welding process in which a butt joint weld is produced by a flashing action and by the application of pressure. Flash welding is used to join metallic parts that have similar cross sections in terms of size and shape. This article discusses flash-welding applications, including chain links, transmission bands, automotive flywheel ring gears, aircraft landing gear, band-saw blades, and crankshaft counter weights. It describes the components of a typical flash-welding machine. The article provides information on the electrical controls of flash-welding equipment. These include programmable controllers, welding current controllers, and either motor or servo-valve controllers.

Scanning electron microscopy (SEM) has shown various significant improvements since it first became available in 1965. These improvements include enhanced resolution, dependability, ease of operation, and reduction in size and cost. This article provides a detailed account of the instrumentation and principles of SEM, broadly explaining its capabilities in resolution and depth of field imaging. It describes three additional functions of SEM, including the use of channeling patterns to evaluate the crystallographic orientation of micron-sized regions; use of backscattered detectors to reveal grain boundaries on unetched samples and domain boundaries in ferromagnetic alloys; and the use of voltage contrast, electron beam-induced currents, and cathodoluminescence for the characterization and failure analysis of semiconductor devices. The article compares the features of SEM with that of scanning Auger microscopes, and lists the applications and limitations of SEM.

This article provides an overview of the composition and properties of powder metallurgy (P/M) aluminum powders for pressed and sintered parts. It includes the steps involved in the processing of high-performance P/M alloys. The article describes the classes of high-performance P/M alloys, including corrosion-resistant alloys (stress-corrosion cracking), elevated-temperature alloys, and low density/high-stiffness alloys.

This article discusses the melting and pouring practices, heat treatment, and applications of different types of high-alloy graphitic iron, namely, high-silicon gray irons, high-silicon ductile irons, nickel-alloyed austenitic irons, austenitic gray irons, austenitic ductile irons, and aluminum-alloyed irons.

Aluminum, the second most plentiful metallic element, is an economic competitor in various applications owing to its appearance, light weight, fabricability, physical properties, mechanical properties, and corrosion resistance. This article discusses the primary and secondary production of aluminum and classification system for cast and wrought aluminum alloys. It talks about various manufactured forms of aluminum and its alloys, which are classified into standardized products such as sheet, plate, foil, rod, bar, wire, tube, pipe, and structural forms, and engineered products such as extruded shapes, forgings, impacts, castings, stampings, powder metallurgy parts, machined parts, and metal-matrix composites. The article also reviews important fabrication characteristics in the machining, forming, forging, and joining of aluminum alloys. It concludes with a description of the major industrial applications of aluminum, including building and construction, transportation, consumer durables, electrical, machinery and equipment, containers and packaging, and other applications.

Flash welding, also called flash butt welding, is a resistance welding process in which a butt joint weld is produced by a flashing action and by the application of pressure. The flash welding process consists of preweld preparation, flashing, upsetting (forging), and postweld heat treatment. This article provides an overview of both flash welding and upset welding and describes the various process and failure origins of flash welding as well as the equipment used. It also explains the characteristics and advantages of solid-state upset welding.

Magnesium and magnesium alloys are used in a wide variety of structural and nonstructural applications. This article provides information on selection and application of magnesium and magnesium alloys, mainly, casting alloys and wrought alloys. It also provides tabulated data for the composition, properties of these alloys, including compressive strength, bearing strength, shear strength, hardness, wear resistance, and fatigue strength. The article describes the selection of product forms (castings, extrusions, forgings) for structural applications which is based on mechanical property requirements, cost, availability, and fabricability. It also discusses the types of inserts used in magnesium. The article also deals with the joining of magnesium alloys by welding, adhesive bonding, and riveting. It concludes by describing the formability and machinability of magnesium and magnesium alloys, and explains the role of magnesium in design and weight reduction.

This article discusses the production of aluminum and aluminum alloy powders with emphasis on the gas atomization method and the atomizing nozzle. It illustrates the particle formation mechanism and details the requisites for particle size distribution, control, and morphology. The article presents information on the mean oxide thickness formed on atomized powders. It also describes the mechanical and physical properties of aluminum and aluminum alloy powders, as well as their applications.

Magnesium and magnesium alloys have been employed in a wide variety of structural applications because of their favorable combination of tensile strength, elastic modulus, and low density. Providing a brief section on occurrence, production, and uses of magnesium, this article describes alloy and temper designations of cast and wrought magnesium alloys. The role of mechanical properties and fabrication characteristics in selection of product forms for structural applications is covered. The article explores the use of magnesium alloys as a substitution for heavier metals such as steel and aluminum alloys to reduce weight in structural parts.

This article presents a detailed account of ion chromatography (IC). It begins by describing the principles of common separation modes in IC. This is followed by a section on the different modes of detection, namely suppressed conductivity detection, nonsuppressed conductivity detection, spectrophotometric detection, and electrochemical detection. Various separation modes in IC are then described. The article further provides information on various eluents species, analyte range, and sample preparation techniques in IC. It ends by providing information on the instrumentation and applications and future directions of IC.

Ion chromatography (IC) is an analytical technique that uses columns packed with ion exchange resins to separate ions in aqueous solutions and dynamically elute them to a detector. This article provides information on the different modes of detection, namely, eluent-suppressed conductivity detection, single-column ion chromatography with conductivity detection, ion chromatography with spectrophotometric detection, and amperometric electrochemical detection. It describes the modes of separation techniques in IC and reversed-phase IC. The article discusses the detection capabilities of IC, the procedures for preparing solid and liquid samples, as well as the applications of IC.

This article reviews the applications of traditional glasses in architecture, transportation, construction, houseware, containers, and fibers. It also describes uses of specialty glasses for aerospace and military applications, biomedical and dental applications, chemical-resistant applications, lighting, information display, electronic processing and electronic devices, optical and ophthalmic products, and communications equipment.

This article discusses the chemical composition, mechanical, physical, thermal, electrical, optical, and magnetic properties of a variety of grades of wrought aluminum and aluminum alloys. It also discusses the standard specifications, mass and fabrication characteristics, corrosion resistance, and applications of a variety of grades of wrought aluminum and aluminum alloys.

Castability of alloys is a measure of their ability to be cast to a given shape with a given process without the formation of cracks/tears, pores/shrinkage, and/or other significant casting defects. This article discusses the factors which affect the fluidity of an iron melt: alloy composition and initial melt condition. Besides the basic alloy properties, the effective castability of high-alloy irons can be significantly improved through casting and casting system design. The article describes the product design and processing factors of high-alloy graphitic irons and high-alloy white irons. It explains the heat treatment of high-silicon irons for high-temperature service and concludes with a discussion on machining and finishing of high-alloy iron castings.

This article reviews the production stages of iron foundry casting, with particular emphasis on the melting practices, molten metal treatment, and feeding of molten metal into sand molds. It discusses the molten metal treatments for high-silicon gray, high-nickel ductile, and malleable irons. Foundry practices are also described for compacted graphite, high-silicon ductile, and high-alloy white irons.