Solid State Welding process

A solid-state welding process is a set of welding processes in which welding is performed with the application of pressure and at temperatures below the melting point of the parent metal. The filler material is not required in these processes.

Types of Solid State Welding process

Cold welding process

Cold welding is a solid-state welding process wherein an external force is used at room temperature. Pressure causes substantial deformation in the weld.

when two surfaces are pressed together, the oxide film from the high spots fragments and the metal behind that suffer plastic formation; melt-to-metal contact occurs because of the fragmentation of oxide film.
any metal can be made to weld by shearing the two surfaces together at sufficiently high normal pressure.

Solid state welding is a group of welding processes which produces coalescence at temperatures essentially below the melting point of the base materials being joined, without the addition of brazing filler metal.

Total material

The following types of materials can be welded by cold welding

Cu and its alloys.
Aluminum alloys.
Pure aluminum
Cd,Pb,Cu,Ni,Zn,Ag.
Al to Cu.
Ni to Fe, etc.

Joint design for Cold welding

The following types of joints are used in the cold welding process,

Butt joint

Usually, the butt joint in cold welding is used extensively in the manufacture of aluminum wire and cable. The most common use is to join successive reels of wire for continuous drawing to smaller diameters.

Lap joint

Lap joints are used for sheet or foil joining, packing as well as electrical applications that cover large distribution transformers into small electronic devices.