Selective plating, also known as brush plating, differs from traditional tank or bath plating in that the workpiece is not immersed in a plating solution (electrolyte). Instead, the electrolyte is brought to the part and applied by a handheld anode or stylus, which incorporates an absorbent wrapping for applying the solution to the workpiece (cathode). This article focuses on the selective plating systems that include a power pack, plating tools, anode covers, specially formulated plating solutions, and any auxiliary equipment required for the particular application. It provides a detailed account of the applications of selective plating, with examples. The article describes the advantages, limitations, key process elements, and health and safety considerations of selective plating. It also includes the most important industrial, government, and military specifications.

A wide variety of stop-off technologies for heat treatment are used to selectively prevent the diffusion of carbon and/or nitrogen during atmosphere carburizing, carbonitriding, vacuum carburizing, and various forms of nitriding. In addition to selective stop-off, technologies are also available for scale prevention in open-fired furnaces. This article describes two stop-off technologies, mechanical masking and copper plating, along with stop-off paints/compounds. Prior to the application of stop-off paints, the part surface of the furnaces should be properly cleaned and dried. The article also describes the usage of stop-off paints in different heat treating processes, namely, carburizing and carbonitriding, deep carburizing, vacuum carburizing, nitriding and nitrocarburizing, and plasma nitriding. The article concludes by reviewing the application methods of stop-off paints: brushing, dipping, dispensing, spraying and stamping.

The selection of surface treatments for copper and copper alloys is generally based on application requirements for appearance and corrosion resistance. This article describes cleaning, finishing, and coating processes for copper and copper alloys. These processes include pickling and bright dipping, abrasive blast cleaning, chemical and electrochemical cleaning, mass finishing, polishing and buffing, electroless plating, immersion plating, electroplating, passivation, coloring, and organic coatings.

Electrical contacts are metal devices that make and break electrical circuits. This article provides information on materials selection criteria and failure modes of make-break contacts. It describes the property requirements for make-break arcing contacts, namely, electrical conductivity, mechanical properties, chemical properties, fabrication properties, and thermal properties. The article presents a brief note on brush contact materials and their interdependence factors for sliding contacts. It also describes the type of commercial contact materials for electrical contacts, namely, copper metals, silver metals, gold metals, metals of the platinum group, precious metal overlays, tungsten and molybdenum, aluminum, and composite materials. Finally, the article provides information on composite manufacturing methods, and tabulates the physical, and mechanical properties of electrical contact materials, including copper, silver, gold, platinum, palladium, and composites.

Electrodeposits of cadmium are used to protect steel and cast iron against corrosion. This article provides an overview of the surface preparation of, and brighteners used in, cyanide baths. It focuses on the anode system, current density, deposition rates, and bath temperature of cadmium plating with attention to the materials of construction and equipment used. The article provides a description of the selection of plating method with examples, applications, and several postplating processes of cadmium plating.

This article presents general design principles for different types of surface-finishing processes, such as cleaning, organic coatings, and inorganic coatings applied by a variety of techniques. It discusses the factors that influence the selection of surface-finishing processes. These include fabrication processes, size, weight, functional requirements, and design features. The article discusses the design as an integral part of manufacturing. It contains tables that summarize the design limitations for selected surface-preparation, organic finishing, and inorganic finishing processes.

Mechanical finishes usually can be applied to aluminum using the same equipment used for other metals. This article describes the two types of grinding used in mechanical finishing: abrasive belt grinding and abrasive wheel grinding. It reviews the binders and fluid carriers used in buffing, and discusses satin finishing and barrel finishing. It also describes lapping and honing techniques that are of special interest in treating aluminum parts that have received hard anodic coatings. Honing recommendations for aluminum alloys are presented in a table.

Zirconium and its alloys are available in two general categories: commercial grade and reactor grade. This article discusses the welding processes that can be used for welding any of the zirconium alloys. These include gas-tungsten arc welding (GTAW), gas-metal arc welding (GMAW), plasma arc welding (PAW), electron-beam welding (EBW), laser-beam welding (LBW), friction welding (FRW), resistance welding (RW), resistance spot welding (RSW), and resistance seam welding (RSEW). The article reviews the selection of shielding gases and filler metals for welding zirconium alloys. It concludes with a discussion on process procedures for welding zirconium alloys.

Aluminum or aluminum alloy products have various types of finishes applied to their surfaces to enhance appearance or improve functional properties. This article discusses the procedures, considerations, and applications of various methods employed in the cleaning, finishing, and coating of aluminum. These include abrasive blast cleaning, barrel finishing, polishing, buffing, satin finishing, chemical cleaning, chemical brightening, electrolytic brightening, chemical etching, alkaline etching, acid etching, chemical conversion coating, electroplating, immersion plating, electroless plating, porcelain enameling, and shot peening.

Painting is a generic term for the application of a thin organic coating to the surface of a material for decorative, protective, or functional purposes. This article provides a detailed account of the types and selection factors of paints and the various application methods, including conventional air atomized, airless, and electrostatic spray; roller coating; dip coating; flow coating; curtain coating; tumble coating; electrocoating; and powder coating. Surface preparation methods and prepaint treatments for coating systems are also discussed. The article includes information on quality control procedures, causes of paint film defects, cost calculation, and safety and environmental precautions. The composition and characteristics of organic coatings, coating system selection factors, the types of paints for structural steel, and the applications of paint on structural steel are also reviewed.

Ultrasonic welding (USW) is effectively used to join both similar and dissimilar metals with lap-joint welds. This article describes procedure considerations for the ultrasonic welding of specific material types. It reviews difficult-to-weld alloys, such as carbon and low-alloy steels, high-strength steels, and stainless steel, and provides information on the applications of weldable alloys such as aluminum alloys and copper alloys. The article concludes with a discussion on welding of dissimilar metal (nonferrous-to-nonferrous) combinations and its applications.

Surface treatments are applied to magnesium parts primarily to improve their appearance and corrosion resistance. Mechanical and chemical cleaning methods are used singly or in combination, depending on the specific application and product involved to ensure repetitive reliability. This article focuses on mechanical finishing methods, namely, barrel tumbling, polishing, buffing, vibratory finishing, fiber brushing, and shot blasting. It provides useful information on process control and difficulties with chemical and anodic treatments of magnesium alloys. The use and applications of plating and organic finishing of magnesium alloys are also reviewed. The article concludes with a description of health and safety precautions to be followed during the surface treatment process.

The process of transferring coating materials from the container to the surface to be coated can be accomplished in a number of ways. This article describes seven methods of coating application: brushes, rollers, and daubers; conventional air spray; high-volume low-pressure spray; airless spray; air-assisted airless spray; plural-component spray; and electrostatic spray. Factors to be considered when deciding on an application method include the size and configuration of the surfaces to be coated, the type of coating being applied, environmental regulations/restrictions, the proximity to other operations or personnel, and the recommendations of the coating manufacturer.

Rust-preventive compounds are removable coatings used for the protection of the surfaces of iron, steel, coated or galvanized products, and other alloys. This article describes the basic parts of rust-preventive compounds, namely, carrier, film former, polar materials, and specialty additives. It explains types of rust-preventive compounds, including dry films and water-based dry films. The article also discusses the methods of application of various compounds, such as petrolatum compounds and emulsion compounds. It contains tables that provide information on the characteristics, applications, and physical properties of rust-preventive materials covered by military specifications. Finally, the article describes the various considerations and parameters for selecting rust-preventive materials.

The necessary precursor to a proper and durable finish is the preparation of the active aluminum surface to receive the desired protective finish that will allow it to have a long and attractive service life. This article helps those who work with aluminum in the many varieties of applications of such products. It describes the two main categories of cleaning that can be used with most any metal, namely, mechanical cleaning and chemical cleaning. The article provides a discussion on the laboratory evaluation of cleaners, field testing of cleaners, and cleaner types and procedures. It also describes the special cleaning procedures for aluminum alloys, such as steam cleaning and rotary wire-brush cleaning. The article reviews the use of temporary coatings and the use of maintenance coatings on aluminum. It provides information on the handling and storage procedures of aluminum alloys and the cleaning of specific applications of aluminum.

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.

Roll welding (ROW) is a process in which two or more sheets or plates are stacked together and then passed through the rolls until sufficient deformation has occurred to produce solid-state welds. This article begins with a process description of two modes of roll welding, including pack rolling. It describes a patented roll welding process for fabrication of heat exchangers. The article presents a table showing the typical properties of common roll welded clad laminates. The relative weldability of selected dissimilar metals and alloys roll welded into clad-laminate form are also tabulated. The article concludes with information on cladding of metals by strip roll welding.

This article discusses the characteristics, properties, and production methods of copper powders and copper alloy powders. Bulk of the discussion is devoted to production and applications of powder metallurgy (P/M) parts, including pure copper P/M parts, bronze P/M parts, brass and nickel silver P/M parts, copper-nickel P/M parts, copper-lead P/M parts, copper-base P/M friction materials, copper-base P/M electrical contact materials, copper-base P/M brush materials, infiltrated parts, and oxide-dispersion-strengthened copper P/M materials.

Electrical contacts are metal devices that make and break electrical circuits. This article describes the property requirements such as electrical conductivity, mechanical properties, chemical properties, fabrication properties, and thermal properties of make-break arcing contacts. The article also focuses on brush contact materials and their interdependence factors for sliding contacts. In addition, the article discusses the properties, manufacturing methods, and applications of electrical contact materials, including wrought materials such as copper metals, silver metals, gold metals, precious metal overlays, tungsten, molybdenum, and aluminum, and composite materials. It concludes by discussing the composite manufacturing methods such as infiltration, press-sinter, press-sinter-repress process, press-sinter-extrude process, internal oxidation, and preoxidized-press-sinter-extrude process, and coprecipitation.

Zinc and zinc alloys require surface engineering prior to coating or use to improve adhesion and corrosion resistance. Die-cast zinc parts, in addition, must be trimmed and finished to remove flash and parting lines. This article covers zinc cleaning procedures as well as coating and finishing processes. It explains how to remove parting lines and presents several mechanical finishing methods, including surface polishing, brushing, controlled shot peening, and buffing. It also provides information on solvent cleaning, emulsion cleaning, aqueous detergent or alkaline cleaning), electrocleaning, acid dipping, and zinc conversion coating treatments.