Titanium offers an amazing corrosion resistance but is two times lighter than steel. Titanium also has a very high tendency to oxidize at higher temperatures. It extremely important to keep the molten metal away from atmospheric air while welding because even very little contamination of oxygen will lead to porosity. With the wide application of titanium and titanium alloy, the progress of welding technology gives us more choices. It not only saves the material, but also reduces the quality of the whole workpiece. Here we will introduce the 4 kinds of commonly used welding methods: Tungsten Inert Gas arc welding, metal inert gas welding, laser braze welding, vacuum electron beam welding and so on.
Tungsten Inert Gas arc welding（TIG）
TIG is the best-welded process for titanium alloy plate and tube with a thickness below 3mm. Tig welding can be divided into open welding and pool welding or manual welding and automatic welding according to the methods.
gas tungsten arc welding in the atmospheric environment is using the shielding and purge gas to welding nozzle, drag cover and backside protective device to separate the welding high-temperature area from the air, so as to prevent the air from invading and contaminating the metal in the welding area. This is a type of local gas protection welding method. When the welded parts are complex in structure and difficult to finish the protective cover or back side, the welding inside the weld pool should be adopted. The pool body should be vacuumed before welding and then filled with argon or argon helium mixture. then welding inside the pool conducted under an inert atmosphere, which is a welding method of overall gas protection. Often Titanium is welded in a gas chamber with pure argon gas to make sure that the weld pool gets proper protection.
Metal inert-gas welding
MIG works by using a continuously feeding of welding wire that burns, melts and fuses both the base and parent metals together. You can weld a variety of materials such as mild steel, stainless steel and titanium, obviously. In this process for welding titanium and titanium alloy, the welding material and its thickness needs to be selected strictly. Generally, thin titanium plate adopts the technology of droplet transition welding, while thick plate adopts the droplet spray transition method. The effect of melting argon arc welding is excellent compared with other welding methods, mainly used for welding thick titanium alloy plate. Protective gas content and pre-welding cleaning are key factors to MIG processing.