Projection welding is a variation of resistance welding in which current flow is concentrated at the point of contact with a local geometric extension of one (or both) of the parts being welded. This article focuses on the process fundamentals, advantages, and limitations of projection welding and reviews the equipment used in the process. It discusses projection welding of copper and copper alloys, aluminum and aluminum alloys, and steels. The article provides several specifications and recommended weld schedules and practices for projection welding. It describes the embossed-projection welding of heavy-, intermediate-, and thin-gage sheet mild steel as well as the welds between dissimilar thickness joints. The article also considers the solid-projection welding of steels: annular, nut, and cross-wire projection configurations. It also details the various tests that can be used to validate projection weld quality.

Projection welding (PW) is a variation of resistance welding in which current flow is concentrated at the point of contact with a local geometric extension of one (or both) of the parts being welded. This article discusses the applications of PW generally categorized as either embossed-projection welding or solid-projection welding. Different projection-welding configurations are schematically presented and the common variations of solid-projection welding are described. The article describes equipment used and the process requirement for the PW. The process requirements for projection welding of a range of intermediate-gage low-carbon steels are presented in a table.

This article provides a fundamentals-based description of solid-state resistance projection welding. It details simple analytical tools to understand the variety of mechanisms that occur during resistance projection welding. Factors relating to the quality of solid projection are discussed, in addition to an explanation of the mechanisms of bonding for solid projection welding. The article reviews how these mechanisms are affected by heat balance, current profile, and mechanical characteristics of the welding equipment. It also presents the design of projection welding mechanical systems.

This article presents a detailed account of the welding parameters, equipment needed, applications, advantages, limitations, and the process variables affecting various types of resistance welding operations, namely, resistance spot welding, resistance seam welding, resistance projection welding, and flash welding.

This article presents a detailed account of the welding parameters, equipment needed, applications, advantages, limitations, and the process variables affecting various types of resistance welding operations, namely, resistance spot welding, resistance seam welding, resistance projection welding, and flash welding.

Resistance welding (RW) encompasses a group of processes in which the heat for welding is generated by the resistance to the flow of electrical current through the parts being joined. The three major resistance welding processes are resistance spot welding (RSW), resistance seam welding (RSEW), and projection welding (PW). This article addresses the considerations for using these processes to join specific types of materials. It discusses the process variations, applicability, advantages, and limitations of these resistance welding processes. The article provides information on flash welding, high-frequency resistance welding, and capacitor discharge stud welding. It concludes with a discussion on resistance welding of stainless steels, aluminum alloys, and copper and copper alloys.

Multiple-slide forming is a process in which the workpiece is progressively formed in a combination of units that can be used in various ways for the automated fabrication of a large variety of simple and intricately shaped parts from coil stock or wire. This article discusses the components of multiple-slide rotary forming machines involved in the blanking and forming of strip stock. It describes a complicated application of the two-level forming, with an example.

Porcelain enamels are glass coatings applied primarily to products or parts made of sheet steel, cast iron, and aluminum to improve appearance and to protect the metal surface. This article describes the types of porcelain enamels, and details enamel frits for these materials. It provides a list of steels suitable for porcelain enameling and discusses the most important factors considered in the selection of steel for porcelain enameling. The article briefly presents the preparation methods of these materials for porcelain enameling and covers the methods, and furnaces of porcelain enameling. It examines the role of coating thickness, firing time and temperature, metal substrate, and color on the performance of enameled surfaces. The article concludes with a discussion on the properties of enameled surfaces, factors considered in process control, and test procedures for evaluating the quality of enameled surfaces.

This article emphasizes the traits that are common to high-velocity forming operations. It describes general principles on how metal forming is accomplished and analyzed when inertial forces are large. The article discusses the principal methods of high-velocity forming, such as explosive forming, electrohydraulic forming, and electromagnetic forming. It provides examples that illustrate how these methods can be practically applied. The article concludes with information on the status and development potential for the technology.

This article discusses the conceptual and configuration design of special-purpose parts that are designed and manufactured especially for use in a particular application. It provides a discussion on the issues considered in designing of parts, including, functionality; the relationship of the part to the whole assembly or subassembly; material and process selection; configuration; and tolerances. The article discusses the qualitative physical reasoning and qualitative reasoning that assist in developing part configuration alternatives.

Weldability is a function of three major factors: base material quality, welding process, and design. This article focuses on base-metal weldability of aluminum alloys in terms of mechanical property degradation in both the weld region and heat-affected zone, weld porosity, and susceptibility to solidification cracking and liquation cracking. It provides an overview on welding processes, including gas metal arc welding, gas tungsten arc welding, resistance spot and seam welding, laser beam welding, and various solid-state welding processes. A review on joint design is also included, mainly in the general factors associated with service weldability (fitness). The article also provides a discussion on the selection and weldability of non-heat-treatable aluminum alloys, heat treatable aluminum alloys, aluminum-lithium alloys, and aluminum metal-matrix composites.

This article provides an overview of surface-texturing techniques. It describes the texturing parameters, namely, shape, depth, and width of the textured pattern, its aspect ratio (depth over width), texture area density, and orientation. The article explains the effect of these parameters on tribological behavior of textured surfaces. It provides information on various modeling approaches for surface texture. The article also discusses the beneficial effect of surface texturing.

This article provides a discussion on the two basic steps of the batch hot dip galvanizing process: surface preparation and galvanizing. It describes the factors affecting coating thickness and coating structure. The mechanical properties of the coating and steel substrate are also discussed. The article also provides information on the various factors that should be considered before galvanizing a material. It examines the performances of galvanized coatings in corrosion service. The joining of galvanized structural members by bolting and welding is also discussed. The article describes the synergistic effects of galvanized and painted systems. It explains the applications of hot dip galvanized steel. The article concludes with information on pertinent galvanizing specifications under the authority of the American Society for Testing and Materials.

This article overviews the classification of welding processes and the key process embodiments for joining by various fusion welding processes: fusion welding with chemical sources for heating; fusion welding with electrical energy sources, such as arc welding or resistance welding; and fusion welding with directed energy sources, such as laser welding, electron beam welding. The article reviews the different types of nonfusion welding processes, regardless of the particular energy source, which is usually mechanical but can be chemical, and related subprocesses of brazing and soldering.

This article introduces the basic characteristics, processes, and product forms associated with the five major categories of aluminum wrought products, namely, flat-rolled products (sheet, plate, and foil); rod, bar, and wire; tubular products; profiles; and forgings. It summarizes the various product forms in which commonly used wrought aluminum alloys are available. The article also provides design guidelines for aluminum extrusions and discusses various forming methods.

This article discusses the general formability considerations of aluminum alloys. To conduct a complete analysis of a formed part, the required mechanical properties, as determined by several standard tests, must be considered. The article describes tension testing and other tests designed to simulate various production forming processes, including cup tests and bend tests, which help in determining these properties. It provides information on the equipment and tools, which are used in the forming of aluminum alloys. The article presents a list of lubricants that are most widely used in the forming. It also analyzes the various forming processes of aluminum alloys. The processes include blanking and piercing, bending, press-brake forming, contour roll forming, deep drawing, spinning, stretch forming, rubber-pad forming, warm forming, superplastic forming, explosive forming, electrohydraulic forming, electromagnetic forming, hydraulic forming, shot peening, and drop hammer forming.

Rapid prototyping (RP) techniques in the sheet-metal forming industry is developed to quickly test the form and fit of new sheet-metal products on a prototype basis as well as for production runs characterized by small lot sizes. This article provides an overview of some of the technologies used for RP and low-volume production of sheet-metal parts. It discusses low-cost tooling and flexible sheet-forming processes and reviews the various aspects of incremental sheet forming.