Forge welding is a solid-state joining process in which the workpieces are heated to the welding temperature and then sufficient blows or force are applied to cause permanent deformation and bonding at the faying surfaces. Coextrusion welding is a solid-state process that produces a weld by heating two or more workpieces to the welding temperature and forcing them through an extrusion die. This article illustrates typical joint configurations used for manual and automatic forge welding applications. It provides information on the common metals welded by coextrusion welding, such as low-carbon steel, aluminum, copper, and copper alloys. The article also explains the common coextrusion behaviors.

Polymeric materials that possess similar solubility parameters can be joined using a variety of polymer joining techniques. This article describes commonly available fusion-welding techniques such as joining methods, key joining parameters, and the application areas of each joining method. The techniques are hot-tool, hot-gas, extrusion, focused infrared, laser, friction, vibration, spin, ultrasonic, and electromagnetic welding techniques (resistance, induction, dielectric, and microwave welding). The article concludes with a discussion on welding evaluation methods.

Cold pressure welding can be accomplished by deforming in a lap or butt configuration, drawing, extrusion, and rolling. This article provides a discussion on cold pressure lap welding, cold pressure butt welding and cold pressure welding in drawing process with illustrations. It provides information on the combinations of metals that can be successfully cold welded.

Coextrusion welding (CEW) is a solid-state process that produces a weld by heating two or more workpieces to the welding temperature and forcing them through an extrusion die. This article describes cold and hot CEW for common metals such as low-carbon steel, aluminum, aluminum alloys, copper, and copper alloys. Additional applicable materials include nickel, nickel-base alloys, zirconium, titanium, tantalum, and niobium.