Titanium Smelter

Titanium is a highly reactive metal. When welding it, you have to completely shield the weld zone and the cooling material with shielding gas (argon or helium). If the shielding isn't enough, titanium picks up oxygen and nitrogen from the air and becomes brittle and cracky. The weld then often looks blue or gray discolored – that's a sure sign of poor shielding. Don't forget to also flood the back side of the weld with shielding gas, and let the part cool under gas.