Explosion welding is a solid state welding process in which welding is completed by the acceleration of one of the components at a very high velocity by using chemical explosives. This welding technique is most commonly used to join carbon steel plate with a thin layer of corrosion resistant material, such as stainless steel, nickel alloy, titanium or zirconium. Because of the nature of this welding process, the ability to produce different geometric welds are very limited. The welds performed must be simple in geometric design. The basic geometries that can be produced using this method include plates and tubing.
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Unlike other welding methods such as arc welding, explosion welding was developed following World War II. Its history can be traced further back to World War I where it was discovered that pieces of shrapnel that were sticking to armor plating were not just being embedded but were, in fact, being welded to the metal. Because the extreme heat used in other welding techniques were not being used to perform the welds, it was discovered that the welds created were caused by the explosive events that affected the shrapnel. The process was able to be duplicated later in laboratory tests and soon after the technique was perfected; it was patented in 1962 by DuPont and used in real world welding situations.
The process of explosion welding is able to create a bond between two metals that realistically should not be welded using standard welding techniques. The process of explosion welding does not cause either metal used to melt, it instead causes the surfaces of both metals to plasticize which then creates the weld. This welding process is similar to other non-fusion welding techniques being used today, such as friction welding. Explosion welding allows large areas of metal to be joined very quickly and the weld produced is very clean and strong due to fact that the surface material of both pieces of metal is violently expelled during the process.
The joining of multilaminates using explosion welding involves a working knowledge of the process and the ability to use them effectively in order to create composites of high quality. To produce a weld of high quality the weld the variables affecting the formation of the weld need to be tightly controlled. This means that the amps and periodicity of the wave pattern formed during explosion welding be controlled by making adjustments in three major areas: detonation velocity, explosive load and the interface spacing. The wave pattern that is formed at the bond line is commonly caused by a fluid flow collision that occurs during the welding process.
An important disadvantage of this welding method is that the welder needs to have an extensive knowledge of explosives before even attempting to perform the technique. This makes the process of explosion welding extremely dangerous and is used much less than other fusion welding techniques. If you are interested in becoming involved in this type of welding it is imperative that you receive the proper amount of training and are certified in the use of explosives and know all of the regulations that need to be used whenever this type of weld is performed. As with any welding technique the welder is in danger of becoming injured and should follow all of the recommended safety precautions and wear all of the proper safety gear to help them maintain their safety while welding. This is a highly demanding welding technique and should only be attempted by those who have received the proper training.
Explosion Welding Resources
- What is Explosion Welding? (blog article)
- Explosion Welding (www.wikipedia.org)
- Welding by Explosion Can Combine Any Metals Together (www.hight3ch.com)