Kaltverschweißen

Kaltverschweißen, also known as cold welding or contact welding, is a solid-state welding process where two or more workpieces are joined together without melting the base materials. This joining occurs at room temperature or below, hence the name "kalt" (cold). The process relies on applying sufficient pressure to the surfaces of the metals to be joined. This pressure causes the asperities, or microscopic irregularities, on the surfaces to break down, allowing the atoms of the two pieces to come into close atomic contact. If the surfaces are clean and the pressure is high enough, this intimate contact can lead to the formation of metallic bonds, effectively fusing the materials.

The effectiveness of Kaltverschweißen is highly dependent on the surface cleanliness of the materials. Oxides, oils, dirt, and other contaminants act as barriers, preventing direct atomic contact and thus inhibiting the welding process. Therefore, meticulous cleaning and preparation of the surfaces are crucial. The process is typically used for ductile metals such as aluminum, copper, and gold. It is often employed in applications where heat can damage the materials or where the ability to weld dissimilar metals without alloying is advantageous. Common applications include the joining of electrical wires and in the manufacturing of certain electronic components. The resulting weld is a purely mechanical bond formed through atomic forces.