Title: Cold welding - Wikipedia
Headings: Cold welding
Cold welding
Contents
In space
Nanoscale
See also
References
Further reading

Content: Cross-section of cold welding – before and after the weld
Cold welding or contact welding is a solid -state welding process in which joining takes place without fusion or heating at the interface of the two parts to be welded. Unlike in the fusion-welding processes, no liquid or molten phase is present in the joint. Cold welding was first recognized as a general materials phenomenon in the 1940s. It was then discovered that two clean, flat surfaces of similar metal would strongly adhere if brought into contact while in a vacuum. Newly discovered micro- and nano-scale cold welding has shown potential in nanofabrication processes. The reason for this unexpected behavior is that when the atoms in contact are all of the same kind, there is no way for the atoms to "know" that they are in different pieces of copper. When there are other atoms, in the oxides and greases and more complicated thin surface layers of contaminants in between, the atoms "know" when they are not on the same part. — Richard Feynman, The Feynman Lectures, 12–2 Friction
Applications include wire stock and electrical connections (such as insulation-displacement connectors and wire wrap connections). Contents
1 In space
2 Nanoscale
3 See also
4 References
5 Further reading
In space
Mechanical problems in early satellites were sometimes attributed to cold welding. In 2009 the European Space Agency published a peer reviewed paper detailing why cold welding is a significant issue that spacecraft designers need to carefully consider.