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.

Friction welding (FRW) can be divided into two major process variations: direct-drive or continuous-drive FRW and inertia-drive FRW. This article describes direct-drive FRW variables such as rotational speed, duration of rotation, and axial force and inertia-drive FRW variables such as flywheel mass, rotational speed, and axial force. It lists the advantages and limitations of FRW and provides a brief description on categories of applications of FRW such as batch and jobbing work and mass production. A table of process parameters of direct-drive FRW systems relative to inertia-drive FRW systems is also provided.

This article discusses the principles of the press-brake forming process and its applicability with an example. It describes the types of press brakes and examines some considerations, which help in the selection of machine. The article provides information on flattening dies, gooseneck punches, wiping dies, channel dies, arbor-type punches, box-forming dies, curling dies, beading dies, and cam-driven dies, with illustrations. It discusses the tool material selection for various operations. The article explains the procedures used for producing different shapes, including simple boxlike parts, panels, flanged parts, architectural columns, fully closed parts, and semicircular parts. It examines the effect of work metal variables on results in press-brake operations. The article also reviews stock tolerances, design, and condition of machines and tools, which help in obtaining good dimensional accuracy.

This article describes the presses that are mechanically or hydraulically powered and used for producing sheet, strip, and plate from sheet metal. It also presents the JIC standards for presses, compares the presses based on power source, details the selection criteria and provides information on the various drive systems and the auxiliary equipment. It describes the selection of die materials and lubricants for sheet metal forming and provides information on the lubrication mechanisms and selection with a list of lubricant types for forming of specific sheet materials of ferrous or nonferrous metals. The article reviews the various types of forming processes such as blanking, piercing, fine-edge blanking, press bending, press forming, forming by multiple-slide machines, deep drawing, stretch forming, spinning, rubber-pad forming, three-roll forming, contour roll forming, drop hammer forming, explosive forming, electromagnetic forming, and superplastic forming.

This article focuses on the mechanical and nonmechanical cutting methods used in metal fabrication industries. The most prevalent equipment used for mechanical cutting includes shears, iron workers, nibblers, and band saws. Nonmechanical methods of cutting include gas cutting, electric arc cutting, and laser cutting. The article concludes with information on the advantages of abrasive waterjet cutting, which is an alternative to laser cutting, gas cutting, and plasma cutting.

This article reviews the selection and formability characteristics of steels, with an emphasis on low-carbon steels and some coverage on the forming of high-carbon steels. It describes the key factors that affect the formability of steels in terms of steelmaking practices, surface finishes, metal thicknesses, and alloying. The article explains the bending and forming operations with some examples. It also describes the formation of various shells, including doubly contoured shells, deep recessed shells, and deep circular shells.

This article discusses the selection of types of stainless steel for various methods of forming based on the formability and on the power required for forming. It reviews the requirements of lubrication, blanking, and piercing. The article describes various forming methods, namely, press-brake forming, press forming, multiple-slide forming, deep drawing, spinning, rubber-pad forming, drop hammer forming¸ three-roll forming, contour roll forming, stretch forming, and bending of tubing.

This article describes the formability and surface contamination of the refractory metals such as niobium, tantalum, molybdenum, tungsten, and titanium-zirconium-molybdenum alloys. It reviews the factors that affect mechanical properties and formability during rolling and heat treatment. The effect of temperature on the formability of refractory metals is discussed. The article provides a description of the forming methods of sheet and preformed blanks using refractory metals. It also discusses the types of lubricants, including oils, soaps, waxes, silicones, graphite, and molybdenum disulphide, used in the forming of refractory metals.

This article explains how to design a joint or conduct a joining process so that components can be produced most efficiently and without defects. The joining processes include mechanical fastening, adhesive bonding, welding, brazing, and soldering. The article discusses the selection and application of good design practices based on the understanding of process-related manufacturing aspects such as accessibility, quality, productivity, and overall manufacturing cost. It provides several examples of selected parts and joining processes to illustrate the advantages of a specific design practice in improving manufacturability.

This article focuses on environmental and application factors in solid friction. It covers the tribology of contact between a soft and hard material, including mechanisms and testing. The article describes the tribology of contact between a metal and tool during metalworking processes. It also discusses the tribology of metal friction at elevated temperatures.

Finite element analysis is a computer-based numerical method for solving engineering problems in bodies of user-defined geometry. This article introduces the important issues of finite elements (especially accuracy and efficiency) in a nonacademic manner. It describes the Rayleigh-Ritz procedure for solving structural problems based on the principle of virtual work. The article discusses continuum elements, such as hexahedra, pentahedra, tetrahedra, quadrilaterals, and triangles, commonly used in three- or two-dimensional domains. It considers structural elements such as beam element, plate element, shell element, and elbow element. The article presents three examples to illustrate the types of problems that can be addressed and the decisions that must be made when using finite element analysis.

Sheet forming comprises deformation processes in which a metal blank is shaped by tools or dies, primarily under the action of tensile stresses. This article discusses the classification of sheet-forming processes for obtaining desired dimensional features. It describes different process-related developments, namely, superplastic forming of aluminum, forming of tailor-welded blanks, rubber-pad forming, and high-velocity metal forming. The article explains cost-effective approaches of evaluating tooling designs prior to the manufacture of expensive steel dies and dieless forming techniques such as thermal forming and peen forming. It provides information on the application of advanced high-strength steels, magnesium alloys, and various ultrafine-grain materials for superplastic sheet forming. The article concludes with information on the development and application of simulation, design, and control of sheet-forming processes.

This article is a comprehensive collection of terms related to metalworking operations that produce shapes from forging, extrusion, drawing, and rolling operations.

This article is a compilation of definitions of the terms related to sheet metal forming and fabrication.

This article is concerned with gear tooth failures influenced by friction, lubrication, and wear, and especially those failure modes that occur in wind-turbine components. It provides a detailed discussion on wear (including adhesion, abrasion, polishing, fretting, and electrical discharge), scuffing, and Hertzian fatigue (including macropitting and micropitting). Details for obtaining high lubricant specific film thickness are presented. The article describes the selection criteria for lubricants, such as oil, grease, adhesive open gear lubricant, and solid lubricants. It discusses the applications of oil and gear lubricants and the types of standardized gear tests. The article presents some recommendations for selecting lubricants and lubricant viscosity for enclosed gear. It provides some examples of failure modes that commonly occur on gears and bearings in wind turbine gearboxes.

This article lists the system parameters of the friction welding process and describes the four categories of monitoring and control of the manufacturing process. It discusses the monitoring methods of a rotary friction welded sample, for determining in-process quality of ferrous alloys, and dissimilar metals using acoustic emission. The article reviews the feasibility of detecting the presence of ferrite during microstructural evolution of friction welding of three austenitic stainless steels: 310, 304, and 255. It also explains the in-process quality control of friction welding.

The selection of the best material for a particular design is intimately associated with the decisions of how to process the material or manufacture a part. This article describes the basic characteristics of manufacturing processes such as material factors, shape factors, and process factors. The influence of materials on the manufacturing cost is described with a specific example. The article discusses the design for manufacturability to minimize the total number of parts, use readily processed materials, and eliminate machining and finishing operations. It reviews the factors influencing the selection of a material for production, including material composition, heat-treated condition, surface finish, and cost of material. The article describes the material characteristics, such as terms formability, workability, castability, machinability, and weldability, that aid or hinder the production of a part without defects.

Stretch forming is the forming of sheet, bars, and rolled or extruded sections over a die or form block of the required shape while the workpiece is held in tension. This article discusses the applicability, advantages, and machines and accessories of stretch forming. It provides a detailed discussion on four methods of stretch forming, namely, stretch draw forming, stretch wrapping, compression forming, and radial draw forming.