coldweld

Coldwelding is a solid-state welding process where two clean metal surfaces are joined together under pressure without the application of heat or filler material. This occurs when the surfaces are brought into such close contact that their atoms bond across the interface. The process relies on removing or preventing the formation of oxide layers or other contaminants that would inhibit direct metal-to-metal contact.

For coldwelding to be successful, the materials being joined must be ductile. The pressure applied forces the asperities on the surfaces to deform and break up any surface films, allowing the bulk metal to come into contact. This intimate contact enables intermolecular forces, specifically metallic bonding, to form a strong weld. The pressure required is significant and depends on the material's yield strength and ductility.

Common applications for coldwelding include joining dissimilar metals, particularly soft, ductile metals like aluminum and copper, often found in electrical connections and components. It is also used in the manufacturing of some seals and in specialized situations where heat would be detrimental to the materials' properties. The process can be performed manually or with specialized machinery, often involving dies or rollers to apply the necessary pressure. Coldwelding offers advantages such as avoiding heat-affected zones, preserving material properties, and creating a clean, often aesthetically pleasing joint.