Editing Welding (section)

===Solid-state welding===
[[File:Solid-state welding processes - AWS A3.0 2001.svg|thumb|300px|Solid-state welding processes [[classification chart]]<ref>AWS A3.0:2001, Standard Welding Terms and Definitions Including Terms for Adhesive Bonding, Brazing, Soldering, Thermal Cutting, and Thermal Spraying, American Welding Society (2001), p. 117. {{ISBN|0-87171-624-0}}</ref>]]

Like [[forge welding]] (the earliest welding process discovered), some modern welding methods do not involve the melting of the materials being joined. One of the most popular, [[ultrasonic welding]], is used to connect thin sheets or wires made of metal or thermoplastic by vibrating them at high frequency and under high pressure.<ref name="Weman8990">{{harvnb|Weman|2003|pp=89–90}}</ref> The equipment and methods involved are similar to that of resistance welding, but instead of electric current, vibration provides energy input.  When welding metals, the vibrations are introduced horizontally, and the materials are not melted; with plastics, which should have similar melting temperatures, vertically. Ultrasonic welding is commonly used for making electrical connections out of aluminum or copper, and it is also a very common polymer welding process.<ref name="Weman8990" />

Another common process, [[explosion welding]], involves the joining of materials by pushing them together under extremely high pressure. The energy from the impact plasticizes the materials, forming a weld, even though only a limited amount of heat is generated. The process is commonly used for welding dissimilar materials, including bonding aluminum to carbon steel in ship hulls and stainless steel or titanium to carbon steel in petrochemical pressure vessels.<ref name="Weman8990" />

Other solid-state welding processes include [[friction welding]] (including [[friction stir welding]] and [[friction stir spot welding]]),<ref name="NZ">
Stephan Kallee (August 2006) [https://www.twi-global.com/technical-knowledge/published-papers/nz-fabricators-begin-to-use-friction-stir-welding-to-produce-aluminium-components-and-panels-august-2006 "NZ Fabricators begin to use Friction Stir Welding to produce aluminium components and panels"]. ''New Zealand Engineering News''.</ref> [[magnetic pulse welding]],<ref name="EMPT">Stephan Kallee et al. (2010) ''[http://www.msm.cam.ac.uk/phase-trans/2010/IPM.pdf Industrialisation of Electromagnetic Pulse Technology (EMPT) in India]'' 38th Anniversary Issue of PURCHASE India.</ref> co-extrusion welding, [[cold welding]], [[diffusion bonding]], [[exothermic welding]], [[Radio-frequency welding|high frequency welding]], hot pressure welding, [[induction welding]], and [[roll bonding]].<ref name="Weman8990" />