Explosion welding (EXW) is a solid state (solid-phase) process where welding is accomplished by accelerating one of the components at extremely high velocity through the use of chemical

explosives An explosive (or explosive material) is a reactive substance that contains a great amount of potential energy that can produce an explosion if released suddenly, usually accompanied by the production of light, heat, sound, and pressure. An expl ...

. This process is often used to clad

carbon steel Carbon steel is a steel with carbon content from about 0.05 up to 2.1 percent by weight. The definition of carbon steel from the American Iron and Steel Institute (AISI) states: * no minimum content is specified or required for chromium, cobalt ...

aluminium Aluminium (aluminum in AmE, American and CanE, Canadian English) is a chemical element with the Symbol (chemistry), symbol Al and atomic number 13. Aluminium has a density lower than those of other common metals, at approximately o ...

plate with a thin layer of a harder or more corrosion-resistant material (e.g.,

stainless steel Stainless steel is an alloy of iron that is resistant to rusting and corrosion. It contains at least 11% chromium and may contain elements such as carbon, other nonmetals and metals to obtain other desired properties. Stainless steel's corros ...

, nickel alloy, titanium, or zirconium). Due to the nature of this process, producible geometries are very limited. Typical geometries produced include plates, tubing and tube sheets.

Development

Unlike other forms of welding such as arc welding (which was developed in the late 19th century), explosion welding was developed relatively recently, in the decades after World War II. Its origins, however, go back to World War I, when it was observed that pieces of

shrapnel Shrapnel may refer to: Military * Shrapnel shell, explosive artillery munitions, generally for anti-personnel use * Shrapnel (fragment), a hard loose material Popular culture * ''Shrapnel'' (Radical Comics) * ''Shrapnel'', a game by Adam ...

sticking to armor plating were not only embedding themselves, but were actually being welded to the metal. Since the extreme heat involved in other forms of welding did not play a role, it was concluded that the phenomenon was caused by the explosive forces acting on the shrapnel. These results were later duplicated in laboratory tests and, not long afterwards, the process was patented and put to use. In 1962,

DuPont DuPont de Nemours, Inc., commonly shortened to DuPont, is an American multinational chemical company first formed in 1802 by French-American chemist and industrialist Éleuthère Irénée du Pont de Nemours. The company played a major role in ...

applied for a patent on the explosion welding process, which was granted on June 23, 1964 under US Patent 3,137,937 and resulted in the use of the ''Detaclad''

trademark A trademark (also written trade mark or trade-mark) is a type of intellectual property consisting of a recognizable sign, design, or expression that identifies products or services from a particular source and distinguishes them from oth ...

to describe the process. On July 22, 1996, Dynamic Materials Corporation completed the acquisition of DuPont's Detaclad operations for a purchase price of $5,321,850 (or about $ million today). The response of inhomogeneous plates undergoing explosive welding was analytically modeled in 2011.

Advantages and disadvantages

Explosion welding can produce a bond between two metals that cannot necessarily be welded by conventional means. The process does not melt either metal, instead plasticizing the surfaces of both metals, causing them to come into intimate contact sufficient to create a weld. This is a similar principle to other non-fusion welding techniques, such as

friction welding Friction welding (FRW) is a solid-state welding process that generates heat through mechanical friction between workpieces in relative motion to one another, with the addition of a lateral force called "upset" to plastically displace and fuse the m ...

. Large areas can be bonded extremely quickly and the weld itself is very clean, due to the fact that the surface material of both metals is violently expelled during the reaction. Explosion welding can join a wide array of compatible and non-compatible metals, with more than 260 metal combinations possible. A disadvantage of this method is that extensive knowledge of explosives is needed before the procedure may be attempted safely. Regulations for the use of high explosives may require special licensing.

References

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Development

Advantages and disadvantages

See also

References

Further reading