This article discusses the effects of heavy metal impurities, environmental factors, the surface condition (such as as-cast, treated, and painted), and the assembly practice on the corrosion resistance of a magnesium or a magnesium alloy part. It provides information on stress-corrosion cracking and galvanic corrosion of magnesium alloys, as well as the surface protection of magnesium assemblies achieved by inorganic surface treatments.

This article begins with a discussion on the environmental factors that induce corrosion in magnesium alloys. It reviews the factors that determine the severity of different forms of localized corrosion, namely, galvanic corrosion, corrosion fatigue, and stress-corrosion. The article discusses corrosion protection in magnesium assemblies and the protective coating systems used in corrosion protection practices. Protection schemes for specific applications and the production of novel magnesium alloys with improved corrosion resistance are also reviewed. The article concludes with a discussion on the corrosion of bulk vapor-deposited alloys and magnesium-matrix composites.

Aluminum, a commonly used base material for brazing, can be easily fabricated by most manufacturing methods, such as machining, forming, and stamping. This article outlines non-heat-treatable wrought alloys typically used as base metals for the brazing process. It highlights chloride-active and fluoride-active types of fluxes that are used for torch, furnace, or dip brazing processes. The article explains the steps to be performed, including the designing of joints, preblaze cleaning, assembling, brazing techniques (dip brazing, furnace and torch brazing, fluxless vacuum brazing), flux removal techniques, and postbraze heat treatment processes. It concludes with information on the safety precautions to be followed during the brazing process.

Brazing technology is continually advancing for a variety of metals including aluminum and its alloys and nonmetals. This article discusses the key physical phenomena in aluminum brazing and the materials for aluminum brazing, including base metals, filler metals, brazing sheet, and brazing flux. It describes various aluminum brazing methods, such as furnace, vacuum, dip, and torch brazing. Friction, flow, induction, resistance, and diffusion brazing are some alternate brazing methods discussed. The article reviews the brazing of aluminum to ferrous alloys, aluminum to copper, and aluminum to other nonferrous metals. It also discusses post-braze processes in terms of post-braze heat treatment and finishing. The article concludes with information on the safety precautions considered in brazing aluminum alloys.

Mechanical joining by forming includes all processes where parts being joined are formed locally and sometimes fully. This article focuses on the types, advantages, disadvantages, and applications of the various mechanical joining methods, namely, riveting, crimping, clinching, and self-pierce riveting.

Most magnesium alloys can be joined by gas-tungsten arc welding (GTAW) and gas-metal arc welding (GMAW). This article describes relative weldability ratings and provides information on joint design and surface preparation and the use of filler metals and shielding gases suitable to arc welding of magnesium alloys. The article describes the repair welding of castings, with examples. It concludes with a discussion on heat treatment of castings after welding.

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 describes the influences of the operational environments of U.S. Navy aircraft during corrosion-control process. The most widely used materials in airframe structures and components, such as aluminum, steel, titanium, and magnesium alloy systems, are reviewed. The article provides information on the inspections steps, corrosion-control issues, and corrosion-prevention strategies for naval aircraft. It contains a table that lists typical locations of corrosion on the aircraft. The article also provides examples of aircraft corrosion damage.

This article provides information about the selection of brazing processes and filler metals and describes the brazing (heating) methods, including manual torch brazing, furnace brazing, induction brazing, dip brazing, resistance brazing and specialized brazing processes such as diffusion and exothermic brazing. The article explains joint design, filler materials, fuel gases, equipment, and fluxes in the brazing methods. The article also describes the brazing of steels, stainless steels, cast irons, heat-resistant alloys, aluminum alloys, copper and copper alloys, and titanium and titanium alloys.

This article provides information about the selection of brazing processes and filler metals and describes the brazing (heating) methods, including manual torch brazing, furnace brazing, induction brazing, dip brazing, resistance brazing and specialized brazing processes such as diffusion and exothermic brazing. The article explains joint design, filler materials, fuel gases, equipment, and fluxes in the brazing methods. The article also describes the brazing of steels, stainless steels, cast irons, heat-resistant alloys, aluminum alloys, copper and copper alloys, and titanium and titanium alloys.

Copper, copper alloys, and precious metals are probably the most easily brazed metals because of their resistance to oxidation at high temperatures. This article provides a brief discussion on the metallurgy of copper, copper alloys, and precious metals and discusses the filler metals, brazing fluxes, joint clearance and design, and different brazing processes used in brazing of copper, copper alloys, and precious metals.

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 describes the process and advantages of no-bond methods of vacuum molding and magnetic molding, with schematic illustrations. It also discusses the characteristics of plastic film and dimensional specifications of vacuum molding.

Cold extrusion is a push-through compressive forming process with the starting material (billet/slug) at room temperature. This article provides information on the different types of steels that can be cold extruded. Mechanical presses and hydraulic presses that are specifically designed for cold extrusion with high rigidity, accurate alignment, and long working strokes are described. The article details the factors that are critical in cold extrusion: punch design, die design, and tool design. It summarizes the role of lubricants during extrusion of steel, such as soap lubricant and polymer lubricants. The article describes several procedures for extruding specific steel parts such as tubular parts and stepped shafts. It lists problems such as tool breakage and galling or scoring of tools and explains cold extrusion of aluminum, copper, and nickel alloy parts. The article also discusses the impact extrusion of magnesium alloys.

This article focuses on the various criteria considered in the selection of product forms, joint types, solders, and filler metals for brazing and soldering of base material components.

This article provides a detailed account of the principles, instrumentation,and applications of x-ray photoelectron spectroscopy (XPS), a technique used for elemental and compositional analysis of surfaces and thin films. It reviews the nomenclature of energy states and sensitivity of electrons at the surface that are capable of producing peaks in XPS. Additionally, it presents information on the instrumentation and the preparation and mounting of samples for XPS analysis. The article explains qualitative analysis, namely, measuring of shifts in the binding energy of core electrons, multiplet splitting, and the Auger parameter; and quantitative analysis such as depth analysis carried out using XPS. It also discusses the applications of XPS with examples.

Machining serves as a more specialized supplement to the forging process, particularly in the formation of cavities and holes. This article provides information on the enclosures, cavities, and holes in hammer and press forgings. It provides a checklist that serves as a guide to the procedure for reviewing the design of cavities and holes to be incorporated in forgings. The article also describes forging designs in which cavities and holes are related to rib and web designs, punchout, piercing, extruding, and combinations of these processes.

This article discusses slurry molding that encompasses two distinct processes: plaster molding and ceramic molding. Plaster mold casting is a specialized casting process used to produce nonferrous castings that have greater dimensional accuracy, smoother surfaces, and more finely reproduced detail. The article describes three generally recognized plaster mold processes, namely, conventional plaster mold casting, the Antioch process, and the foamed plaster process. Ceramic molding techniques are based on processes that employ permanent patterns and fine-grained zircon and calcined, high-alumina mullite slurries for molding. The Shaw process and the proprietary Unicast processes are also discussed.

Aluminum alloys, particularly the heat-treatable alloys, are sensitive to weld cracking. Anticipation of these characteristics and general knowledge of these materials assist in selection of suitable method for welding heat-treatable aluminum alloys. This article provides a general description of the metallurgy, characteristics, and applications of heat-treatable aluminum alloys and a detailed discussion on the characteristics of heat-treatable aluminum alloys, their resulting impact on the weld quality and property, along with the methods of avoiding or reducing the impacts. The impact created in the weld quality includes crack sensitivity, liquation cracking, porosity, and heat-affected zone degradation. The article provides an overview of filler alloy selection for reducing weld crack sensitivity and increasing weld strength, ductility, and corrosion resistance in the welds of heat-treatable aluminum alloys.

This article commences with a discussion on the characteristics of stress-corrosion cracking (SCC) and describes crack initiation and propagation during SCC. It reviews the various mechanisms of SCC and addresses electrochemical and stress-sorption theories. The article explains the SCC, which occurs due to welding, metalworking process, and stress concentration, including options for investigation and corrective measures. It describes the sources of stresses in service and the effect of composition and metal structure on the susceptibility of SCC. The article provides information on specific ions and substances, service environments, and preservice environments responsible for SCC. It details the analysis of SCC failures, which include on-site examination, sampling, observation of fracture surface characteristics, macroscopic examination, microscopic examination, chemical analysis, metallographic analysis, and simulated-service tests. It provides case studies for the analysis of SCC service failures and their occurrence in steels, stainless steels, and commercial alloys of aluminum, copper, magnesium, and titanium.