Welding is a metal fabrication technique used to fuse metal parts together to create unique structures. Typically, the parts being welded together are of the same metal material. But that is not always the case. Sometimes, the manufacturing process may call for fusing of metal parts that are not of the same material. For example, metal fabricators may need to fuse steel to aluminum alloys, stainless steel to carbon steel, titanium to carbon steel, or stainless steel to nickel base alloys. This is known as welding of dissimilar metals. The techniques used in this kind of welding are not usually the same as those used when welding metal parts of the same material.
If you want to venture into the business of welding dissimilar metals, you need to be aware of the various types of dissimilar metal welds available out there. Here are a few common ones you should learn about before you get started.
Explosion welding: This solid-state welding technique, which is also referred to as explosion cladding or bonding, uses an explosive detonation to create a metallurgical bond between dissimilar metal parts. The different metals become atomically bonded. It is this attribute that makes it possible to weld just about any metal combination when using explosion welding, including those metals that are traditionally considered to be metallurgically compatible. Explosion welding is commonly used in tube cladding, for flat plates and in many other industrial-based applications.
Cold welding: This is another solid-state welding technique that applies mechanical pressure alone to bring dissimilar metals into intimate contact. Cold welding is performed in vacuum-tight enclosures. The interiors of the enclosures don't get contaminated from dusts and vapours. This means the metal weld is very clean. In addition, the workpieces in the enclosure aren't subjected to variations in temperature, as no heat is neither required nor produced during the welding process.
Friction welding: What happens when you continuously rub your hands together for a couple of seconds? Your hands will feel warmer, right? That's the exact same principle that applies to friction welding, which uses frictional heat to fuse dissimilar metal members into one. The heat is generated by rubbing two different metals against each other. As no burning fuel is required to produce the heat, nor is any filler used, friction welding leads to cheaper cost per weld. It is an ideal welding technique for mass production of welded metal products.