Arc welding methods can be classified into shielded metal arc welding, flux-cored arc welding, submerged arc welding, gas metal arc welding, gas tungsten arc welding, plasma arc welding, plasma-metal inert gas (MIG) welding, and electroslag and electrogas welding. This article provides information on process capabilities, principles of operation, power sources, electrodes, shielding gases, flux, process variables, and advantages and disadvantages of these arc welding methods. It presents information about the arc welding procedures of hardenable carbon and alloy steels, cast irons, stainless steels, heat-resistant alloys, aluminum alloys, copper and copper alloys, magnesium alloys, nickel alloys, and titanium and titanium alloys.

This article focuses on the construction, operation of electric arc furnaces (EAF), and their auxiliary equipment in the steel foundry industry. It provides information on the power supply of EAF and discusses the components of the EAF, including the roof, furnace shell, spout and tap hole, water-cooling system, preheat and furnace scrap burners, and ladles. The article describes the acid and basic steelmaking practices. It discusses the raw materials used, oxidation process, methods of heat reduction, and deoxidation process in the practices. The article provides a discussion on arc melting of iron and EAF steelmaking.

This article describes the characteristics of continuous cathodic arc sources and filtering process for removing macroparticles from a cathodic arc. It provides information on the types of arc sources and the properties of deposited materials. The advantages, limitations, and applications of arc deposition are also discussed.

The vacuum arc remelting (VAR) process is widely used to improve the cleanliness and refine the structure of standard air melted or vacuum induction melted (VIM) ingots and also used in the triplex production of superalloys. This article illustrates the VAR process and the capabilities and variables of the VAR process. It also presents a discussion on the melt solidification, resulting structure, and ingot defects. The article concludes with a discussion on VAR process of superalloy, and titanium and titanium alloy.

This article discusses the principles of operation, equipment needed, applications, and advantages and disadvantages of various fusion welding processes, namely, oxyfuel gas welding, electron beam welding, stud welding, laser beam welding, percussion welding, high-frequency welding, and thermite welding.

Repair welding is a necessary operation for most fabricators and can cost more than the price of the original component if performed improperly. This article provides a discussion on the repair welding of castings for ferrous and nonferrous materials. The discussion focuses on surface preparation, weld repair process selection, joint selection, filler metal selection, weld repair considerations, deposition techniques, postweld heat treatment, and verification of weld repair quality.

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 addresses the cobalt and cobalt-base alloys most suited for aqueous environments and those suited for high temperatures. The performance of cobalt alloys in aqueous environments encountered in commercial applications is discussed. The article provides information on the environmental cracking resistance of the cobalt alloys. Three welding processes that are used for hardfacing with the high-carbon Co-Cr-W alloys, namely, oxyacetylene, gas tungsten arc, and plasma-transferred arc are also discussed. The article examines the effects of various modes of high-temperature corrosion. It describes the applications and fabrication of cobalt alloys for high-temperature service.

This article discusses the operating principles, types, and applications of shearing and slitting of different forms of steel, including plates, flat sheets, bars, coiled sheet and strips. In addition, it provides a detailed account of the cutting methods such as oxyfuel gas cutting, plasma arc cutting, oxygen arc cutting, laser beam cutting, and air carbon arc cutting and gouging, describing their process capabilities, equipment used, operating principles and parameters, and factors affecting their efficiency.

This article discusses different types of joining processes, including welding, brazing, soldering, mechanical fastening, and adhesive bonding. It examines two broad classes of welding: fusion welding and solid-state welding. The article discusses the process selection considerations for welding, brazing, and soldering. It also describes joint design considerations such as selection of weld joints and welds.

High-temperature corrosion can occur in numerous environments and is affected by various parameters such as temperature, alloy and protective coating compositions, stress, time, and gas composition. This article discusses the primary mechanisms of high-temperature corrosion, namely oxidation, carburization, metal dusting, nitridation, carbonitridation, sulfidation, and chloridation. Several other potential degradation processes, namely hot corrosion, hydrogen interactions, molten salts, aging, molten sand, erosion-corrosion, and environmental cracking, are discussed under boiler tube failures, molten salts for energy storage, and degradation and failures in gas turbines. The article describes the effects of environment on aero gas turbine engines and provides an overview of aging, diffusion, and interdiffusion phenomena. It also discusses the processes involved in high-temperature coatings that improve performance of superalloy.

This article introduces thermal spray coatings and describes the various types of coating processes and coating devices, including the flame spray, electric-arc spray, plasma spray, transferred plasma arc, high-velocity oxyfuel, and detonation gun. It provides information on the surface preparation methods and finishing treatments of coated parts. The article also explains the tests to evaluate the coating quality and the effects of coating structures and mechanical properties on coated parts. It concludes with a discussion on the uses of thermal spray coatings.

The structural efficiency of a composite structure is established by its joints and assembly. Adhesive bonding, mechanical fastening, and fusion bonding are three types of joining methods for polymer-matrix composites. This article provides information on surface treatment and the applications of adhesive bonding. It discusses the types of adhesives, namely, epoxy adhesives, epoxy-phenolic adhesives, condensation-reaction PI adhesives, addition-reaction PI adhesives, bismaleimide adhesives, and structural adhesives. The article provides information on fastener selection considerations, including corrosion compatibility, fastener materials and strength, head configurations, importance of clamp-up, interference fit fasteners, lightning strike protection, blind fastening, and sensitivity to hole quality. Types of fusion bonding are presented, namely, thermal welding, friction welding, electromagnetic welding, and polymer-coated material welding.

This article describes typical foundry practices used to commercially produce zirconium castings. The foundry practices are divided into two sections, namely, melting and casting. The article discusses various melting processes, such as vacuum arc skull melting, induction skull melting, and vacuum induction melting, and various casting processes, such as rammed graphite casting, static and centrifugal casting, and investment casting. It explains the evaluation and testing of the process. The article provides information on the mechanical and chemical properties of zirconium castings.

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.

Ceramic coatings are applied to metals to protect them against oxidation and corrosion at room temperature and at elevated temperatures. This article provides a detailed account of the factors to be considered when selecting a ceramic coating and describes the characteristics of various coating materials, namely, silicate glasses, oxides, carbides, silicides, and cermets. It reviews ceramic coating methods: brushing, spraying, dipping, flow coating, combustion flame spraying, plasma-arc flame spraying, detonation gun spraying, pack cementation, fluidized-bed deposition, vapor streaming, troweling, and electrophoresis. The article also includes information on the evaluation of the quality of ceramic coatings.

Sand mold and permanent mold castings are the major methods for shape casting of steels, with production closely split among green sand, chemically bonded sand, and permanent mold processes. This article describes the steel solidification characteristics, melting practices, melt treatment, and feeding of the molten steel into the mold used in steel foundries. It discusses the features of the melting furnaces used in direct arc melting, induction melting, and boiling. The article describes the sand casting and permanent mold casting of steel. The process design and castings of thin sections are also discussed.

This article reviews the bulk deformation processes for various aluminide and silicide intermetallic alloys with emphasis on the gamma titanium aluminide alloys. It summarizes the understanding of microstructure evolution and fracture behavior during thermomechanical processing of the gamma aluminides with particular reference to production scaleable techniques, including vacuum arc and cold-hearth melting, isothermal forging, conventional hot forging, and extrusion. The selection and design of manufacturing methods, in the context of processing-cost trade-offs for gamma titanium aluminide alloys, are also discussed.