The primary goal of quality control in electron beam (EB) welding is to consistently produce defect-free and structurally sound welds. This article discusses the common procedures for controlling the EB welding process, the control of the essential machine parameters, and the introduction of closed-loop controls and diagnostic feedback systems in the EB welding systems. It reviews the beam diagnostic tools that interrogate the beam to produce a reconstruction of the power density distribution and provide additional information on the size and shape of the EB. Knowledge of these beam parameters can be used to improve process understanding and control. The article also describes the application areas of beam diagnostics: machine characterization, weld parameter transfer, and weld quality control.

This article introduces the operating principles and modes of operation for high-vacuum (EBW-HV), Medium-vacuum (EBW-MV), and nonvacuum (EBW-NV) electron beam welding. Equipment, process sequence, part preparation, process control, and weld geometry are described for electron beam welding. Advantages are described in terms of welding near heat sensitive components or materials and producing deep penetration or shallow welds with the same equipment.

Electron-beam welding (EBW) is a high-energy density fusion process that is accomplished by bombarding the joint to be welded with an intense (strongly focused) beam of electrons that have been accelerated up to velocities 0.3 to 0.7 times the speed of light at 25 to 200 kV, respectively. This article discusses the principles of operation, as well as the advantages and limitations of EBW. It reviews the basic variables employed for controlling the results of an electron-beam weld. These include accelerating voltage, beam current, welding speed, focusing current, and standoff distance. The article reviews the operation sequence and safety aspects of EBW.

Safety is an important consideration in all welding, cutting, and related work. This article discusses the basic elements of safety general to all welding, cutting, and related processes. It includes safety procedures common to a variety of applications. The most important component of an effective safety and health program is management support and direction. The article reviews the role of management, training, housekeeping, and public demonstrations in welding safety to minimize personal injury and property damage. It provides information on the safety measures for eye and face protection in various welding and cutting operations. Injuries and fatalities from electric shock in welding and cutting operations can occur if proper precautionary measures are not followed. The article discusses the electrical safety aspects to be considered for various welding and cutting operations.

This article presents an overview of the rules, regulations, and techniques implemented to minimize the safety hazards associated with welding, cutting, and allied processes. Safety management, protection of the work area, process-specific safety considerations, and robotic and electrical safety are discussed. The article explains the use of personal protective equipment and provides information on protection against fumes, gases, and electromagnetic radiation. It concludes with a discussion on safe handling of compressed gases as well as the prevention and protection of fire and explosion.

This article provides a history of electron and laser beam welding, discusses the properties of electrons and photons used for welding, and contrasts electron and laser beam welding. It presents a comparison of the electron and laser beam welding processes. The article also illustrates constant power density boundaries, showing the relationship between the focused beam diameter and the absorbed beam power for approximate regions of keyhole-mode welding, conduction-mode welding, cutting, and drilling.

Electron-beam welding (EBW) can produce deep, narrow, and almost parallel-sided welds with low total heat input and relatively narrow heat-affected zones in a wide variety of common and exotic metals. This article discusses the joint configurations and shrinkage stresses encountered in various joint designs for electron-beam welding, as well as special joints and welds including multiple-pass welds, tangent-tube welds, three-piece welds, and multiple-tier welds. It provides a comparison of medium vacuum EBW with high-vacuum EBW. Scanning is a method of checking the run-out between the beam spot and the joint to be welded. The article describes various scanning techniques for welding dissimilar metals and provides information on the application of electron-beam wire-feed process for repairs. It concludes with a discussion on EBW of heat-resistant alloys, refractory metals, aluminum alloys, titanium alloys, copper and copper alloys, magnesium alloys, and beryllium.

This article focuses on the use of electron beam (EB) for near-net shape processing based on the wire feed material-delivery method. EB deposition processes start with a 3-D model designed in a computer-aided design (CAD) environment, where the deposition path and process parameters are generated. The article provides a description of the electron beam direct manufacturing (EBDM) system used for manufacturing of target parts with the aid of a case study. The control of the essential variables of dynamic beam deflection is also reviewed. The article also includes information on the applications of high-frequency multibeam processes, namely, selective surface treatment, multiple-pool welding, and pre- and post-heat treating.

Electron beam welding (EBW) can produce deep, narrow, and almost parallel-sided welds with low total heat input and relatively narrow heat-affected zones in a wide variety of common and exotic metals. This article focuses on essential parameters of EBW, namely, weld and surface geometry, part configuration, melt-zone configuration, weld atmosphere (vacuum and nonvacuum), and joint design. It describes various aspects considered in EBW of thin and thick metal sections and poorly accessible joints. An overview of scanning and joint tracking techniques for inspection of electron beam-welded joints is also included. The article concludes with discussions on EBW defects, the use of filler metal for weld repair, and the control plans, codes, and specifications of the EBW process.

Power sources are apparatuses that are used to supply current and voltages that are suitable for particular welding processes. This article describes power sources for arc welding, resistance welding, and electron-beam welding. The more-common welding processes that use constant-current and constant-voltage power sources are listed in a table. The article describes the open-circuit voltage characteristics and power source control methods. The control methods employ either pulse width modulation (PWM) or frequency modulation (FM).

This article describes the joint preparation, fit-up and design of various types of laser beam weld joints: butt joint, lap joint, flange joint, kissing weld, and wire joint. It explains the use of consumables for laser welding and highlights the special laser welding practices of steel, aluminum, and titanium engineering alloys. Laser weld quality and quality assessment are described with summaries of imperfections and how its operations contribute to providing repeatable and reliable laser welds. Relevant laser weld quality specifications are listed.

This article provides an overview of the types of weld discontinuities that are characteristic of specialized welding processes. These welding processes include electron-beam welding, plasma arc welding, electroslag welding, friction welding, resistance welding, and diffusion welding. The article also describes the common inspection methods used to detect these discontinuities.

Refractory metals are typically processed from powders into ingots that are subsequently swaged into round bars or rolled into plates. Secondary operations are required to fabricate more complex refractory metal components. This article discusses two such secondary operations, namely, machining and joining processes for tungsten, tungsten heavy alloys, molybdenum, tantalum, niobium, and rhenium components. It describes the various types of metal joining processes, including mechanical fastening, brazing, and welding.

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 presents a detailed account of directed-energy deposition (DED) processes that are used for additive manufacturing (AM) of metallic materials. It begins with a process overview and a description of the components of DED systems followed by sections providing information on the process involved in DED and the materials used for DED. The postprocessing applied to the material after deposition is then covered. The article discusses the properties of metallic materials produced by using DED and ends with a discussion on applications for DED processes in various industries.

Electron beam hardening (EBH), with some special characteristics in comparison to other heat treatment technologies, allows beam deflection frequencies of up to 100 kHz. This article illustrates the principles of different thermal electron beam technologies, including beam-deflection, continuous EB interaction, EB flash, as well as multifield EB-deflection and multiprocess techniques. It characterizes the technical and technological possibilities for EBH in comparison to other surface-layer hardening processes. The article also discusses the technical design of electron beam facilities and the applications of EBH.

Additive manufacturing is a collection of manufacturing processes, each of which builds a part additively based on a digital solid model. The solid model-to-additive manufacturing interface and material deposition are entirely computer-controlled. The traditional additive manufacturing applications have been used for low production runs of parts with complex shapes and geometric features. Additive manufacturing is also used for topology optimization and it impacts the process and supply chain. This article discusses processes, including vat photopolymerization, material jetting, powder bed fusion, directed energy deposition, material extrusion, binder jetting, and sheet lamination.

This article briefly reviews the forming of steel tailor-welded blanks (TWB) with a discussion on the effects of welding on forming. It presents the parameters that are monitored to control the stamping operation for tailor-welded blanks. The article discusses weld factors such as the orientation of weld relative to metal movement in dies, the formability of TWB materials, die and press considerations, and specific factors for the drawing, stretching, and bending of steel tailor-welded blanks.

All refractory metals, except osmium and iridium, have the highest melting temperatures and lowest vapor pressures of all metals. This article discusses the commercial applications, and production procedures of refractory metals and alloys. These procedures include fabrication, machining, forming, cleaning, joining, and coatings. The article also presents information on, and specifications for, the following metals and their alloys: niobium, tantalum, molybdenum, tungsten, rhenium, and refractory metal fiber-reinforced composites. It discusses the processes involved in their production, their mechanical properties, physical properties, thermal properties, electrical properties, chemical properties, applications, and corrosion resistance.