6Al-4V can be welded by most techniques: metal or tungsten inert gas, resistance, flash, friction, ultrasonic, or electron beam.
6Al-4V, like all titanium and titanium alloys, must be protected against contamination during welding. Oxygen and niotrogen from the atmosphere, surface residues, and imprities in the shielding gas readily dissolve in the molten weld metal and can produce embrittlement and porosity. Good shielding and careful edge preparation are therefore necessary. 6Al-4V sheet and plate are succesfully welded in open air with MIG or TIG techniques using an inert gas trailing shield plus underside or backup inert gas shielding.
Optimum welding parameters vary greatly with joint configuration and welding equipment. The recommendations are therefore presented as general guide lines only.
Titanium is an extremely active metal. Consequently, it easily reacts to the atmosphere and other, etc. during welding. Harmful chemical reaction occur when it comes into contact with various oxides. This can often erve to reduce the ductility of any welded zones. At the same time, a deterioration in corrosion resistance and the emergence of factors leading to the occurence of blow holes can also arise.
Therefore, when welding, it is necessary to maintain a clean working environment, use clean welding materials and, of course, totally seal the titanium.
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