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.

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 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.

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 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.

This article provides information on radial friction welding, which adopts the principle of rotating and compressing a solid ring around two stationary pipe. The process evolution of this welding is illustrated. The article also examines the equipment used and operating steps. It also illustrates a prototype of radial friction-welding machine and concludes with a discussion on applications that would be suitable for radial friction welding.

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.

A key differentiator between friction stir welding (FSW) and other friction welding processes is the presence of a nonconsumable tool in FSW, often referred to as a pin tool to differentiate it from other tooling associated with the process. This article discusses materials for friction stir welding (FSW) pin tools, various tool geometries that have been used, designs for specific applications, predicting and measuring tool performance, and other considerations in FSW pin tool design. The tool materials include tool steels, superalloys, refractory metals, carbides and ceramics, and superabrasives.