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.

Friction welding (FRW) is a solid-state welding process in which the heat for welding is produced by the relative motion of the two interfaces being joined. This article provides an outline of the mechanisms of friction heating and discusses the two principal FRW methods: direct-drive welding and inertia-drive welding. It summarizes the similar and dissimilar metals that can be joined by FRW and discusses the metallurgical considerations that govern the properties of the resulting weld.

Friction welding (FRW) is a solid-state welding process in which the heat for welding is produced by the relative motion of the two interfaces being joined. This article describes two principal FRW methods: direct-drive welding and inertia-drive welding. The direct-drive FRW uses a motor running at constant speed to input energy to the weld. The inertia-drive FRW uses the energy stored in a flywheel to input energy to the weld. The article summarizes some of the metals that have been joined by FRW and discusses the metallurgical considerations that govern the properties of the resulting weld. It also presents a schematic illustration of the effect of welding parameters on the finished weld nugget obtained when similar metals are welded using inertia-drive FRW equipment.

Friction welding (FRW) is a solid-state welding process that uses the compressive force of the workpieces that are rotating or moving relative to one another, producing heat and plastically displacing material from the faying surfaces to create a weld. This article reviews practice considerations for the two most common variations: inertia welding and direct-drive friction welding. Direct-drive friction welding differs from inertia welding, primarily in how the energy is delivered to the joint. The article discusses the parameter calculations for inertia welding and direct-drive friction welding. It provides information on friction welding of carbon steels, stainless steels, aluminum-base alloys, and copper-, nickel-, and cobalt-base materials.

This article provides information on the practice considerations for the inertia and direct-drive rotary friction welding processes. It presents the tooling and welding parameter designs of these processes. The article discusses the welding of different material family classes to provide a baseline for initial development of a welding parameter set. Common material family classes, including steels, nonferrous metals, and dissimilar metals, are discussed.

This article discusses the significant factors in the selection of forging equipment for a particular process. It describes the characteristics of forging hydraulic presses, mechanical presses, screw presses, and hammers. The article discusses the significant characteristics of these machines that comprise all machine design and performance data, which are pertinent to the economic use of the machines, including the characteristics for load and energy, time-related characteristics, and characteristics for accuracy.

This article describes the various types of press construction and the factors that influence the selection of mechanically or hydraulically powered machines for producing parts from sheet metal. Presses are broadly classified, according to the type of frame used in their construction, into two main groups: gap-frame presses and straight-side presses. The article describes the various components of mechanical presses and hydraulic presses. It discusses important factors, such as the size, force, energy, and speed requirements, that influence the selection of a press. The article describes the roles of automatic handling equipment that can be categorized as feeding equipment, unloading equipment, and transfer equipment. It concludes with information on the common types of high-production presses, such as dieing machines, multiple-slide machines, transfer presses, fine blanking presses, and flexible-die forming presses.

Hammers and high-energy-rate forging machines are classified as energy-restricted machines as they deform the workpiece by the kinetic energy of the hammer ram. This article provides information on gravity-drop hammers, power-drop hammers, die forger hammers, counterblow hammers, and computer-controlled hammers. It describes the three basic designs of high-energy-rate forging (HERF) machines: the ram and inner frame, two-ram, and controlled energy flow. The article reviews forging mechanical presses, hydraulic presses, drive presses, screw presses, and multiple-ram presses.

Friction welding is based on the rapid introduction of heat, causing the temperature at the interface to rise sharply and leading to local softening. This article illustrates the basic principles of direct-drive rotational friction welding and inertia friction welding. Modeling the effective friction response of the materials is central to simulating the welding process. The article discusses a series of distinct frictional stages during continuous drive friction welding. Modeling of the evolution of the thermal field has been an important objective since the early days of rotational friction welding. The article describes analytical thermal models and numerical thermal models for rotational friction welding. It concludes with information on the modeling of residual stresses.

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.

Roll forging is a process for simultaneously reducing the cross-sectional area and changing the shape of heated bars, billets, or plates. This article provides an overview of the process capabilities, production techniques, machines and machine size selection considerations, and types of roll dies and auxiliary tools for the roll forging. It concludes with information on the production examples of roll forging.

Forging machines use a wide variety of hammers, presses, and dies to produce products with the desired shape, size, and geometry. This article discusses the major types of hammers (gravity-drop, power-drop, high speed, and open-die forging), and presses (mechanical, hydraulic, screw-type, and multiple-ram). It further discusses the technologies used in the design of dies, terminology, and materials selection for dies for the most common hot-forging processes, particularly those using vertical presses, hammers, and horizontal forging machines. A brief section is included on computer-aided design in the forging industry. Additionally, the article reviews specific characteristics, process limitations, advantages, and disadvantages of the most common forging processes, namely hot upset forging, roll forging, radial forging, rotary forging, isothermal and hot-die forging, precision forging, and cold forging.

Powder metallurgy compacting presses usually are mechanically or hydraulically driven, but they can incorporate a combination of mechanically, hydraulically, and pneumatically driven systems. This article provides a comparison of mechanical and hydraulic presses based on the cost, production rate, and machine overload protection. The article lists the classification of powder metallurgy parts based on complexity of shapes as suggested by the Metal Powder Industries Federation, such as Class I parts, Class II parts, Class III parts, and Class IV parts. It describes rigid tooling compaction and details the powder-fill ratio considerations for these classes. The article elaborates on the types of tooling systems and presses used for these classes. Some important factors and components used in designing a tool are also described. Finally, the article considers tool materials, including punches, core rods, and punch clamp rings.

This article defines performance indices in a formal way and specifies how they are derived. The performance indices for a light, strong tie and a light, stiff beam are presented. The article presents two case studies that illustrate the use of material indices, shape factors, and selection charts to select materials.

Health and safety are critically important issues, and there are numerous aspects of the production and use of metal powders that may entail exposure to hazardous conditions. This article provides a discussion on the issues associated with the safe production and handling of metal powders and the safe operation of continuous mesh belt sintering furnaces with combustible atmospheres. It also provides a comprehensive high-level overview of the safety-related issues and concerns related to the use of compacting presses in the manufacturing sector.

Sand mold and permanent mold casting 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 key aspects of the steel casting process, including 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 melting furnaces used in direct arc melting and induction melting. It reviews factors such as wall thickness and designing for avoidance of hot spots. The article explains the sand casting and permanent mold casting of steel. The process design and casting of thin sections are also discussed.

The effective integration of aluminum metal-matrix composites (Al-MMCs) into useful structures and devices often requires an understanding of the weldability of Al-MMCs that includes a thorough knowledge on the effects of various interactions between matrix and reinforcement. This article provides a detailed discussion on weldability and the effect of viscosity, chemical reactions, and solidification on weldability. It discusses different welding processes, namely, gas-tungsten arc welding, gas-metal arc welding, laser-beam welding, electron-beam welding, resistance welding, friction welding, transient liquid phase bonding, and capacitor discharge welding.

This article discusses the operation of upset forging machines and selection of the machine size. It describes several types of upsetter heading tools and their materials. The article reviews the cold shearing and hot shearing methods for preparing blanks for hot upset forging. It deals with various upsetting processes: offset upsetting, double-end upsetting, upsetting with sliding dies, upsetting pipe and tubing, and electric upsetting. The article also provides information on hot forging and cold forging.

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.

Scanners are the most versatile and flexible of the equipment available to the heat treating industry for induction hardening. This article provides a general overview of scanners, and describes various critical factors, including scan speeds, rotational speeds, and center total indicator runout of vertical scanners. It presents information on the frequency selection parameters for scanning applications. The article also discusses the critical parameters and production rates in specifying and developing a tooth-by-tooth hardening process.