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.

This article reviews forge welding and illustrates the typical joint configurations used for manual and automatic forge welding applications.

Nickel alloys can be joined reliably by all types of welding processes or methods, with the exception of forge welding and oxyacetylene welding. This article discusses the heat treatment of nickel alloys and tabulates nominal compositions of selected weldable wrought nickel and nickel alloys. It provides information on gas-tungsten arc welding, gas-metal arc welding, plasma arc welding, shielded metal arc welding, and submerged arc welding for welding nickel alloys. The article reviews the defects encountered in the arc welding of nickel alloys, including porosity, cracking, and stress-corrosion cracking. It provides information on the factors that influence the choice of filler metal and welding process of nickel alloys.