Portal:Engineering/Selected picture/34

San Diego (Jan. 4, 2007) Navy Diver 1st Class Josh Moore welds a repair patch on the submerged bow of amphibious transport dock USS Ogden (LPD 5) while the ship was in port at Naval Base San Diego.

Welding

Credit: Mass Communication Specialist Senior Chief Andrew McKaskle

Welding is a fabrication or sculptural process that joins materials, usually metals or thermoplastics, by causing fusion, which is distinct from lower temperature metal-joining techniques such as brazing and soldering, which do not melt the base metal. In addition to melting the base metal, a filler material is often added to the joint to form a pool of molten material (the weld pool) that cools to form a joint that can be as strong, or even stronger, than the base material. Pressure may also be used in conjunction with heat, or by itself, to produce a weld.