Titanium is one of the most fascinating metals. It has strength similar to steel, but it is 45% lighter. Also, it maintains its mechanical properties at a wide range of temperatures. Titanium will work in below freezing temperatures without losing its toughness. But it also resists creep and oxidation at temperatures up to 600 C.
Titanium is reactive metal and forms a thin layer of titanium dioxide on its surface. This oxide layer offers excellent corrosion resistance and endures indefinitely in acidic, chloride, and saltwater environments. While expensive initially, the lifetime cost titanium is actually quite low because of its extensive service life and reduced (or even non-existent) maintenance and repair costs.
There are 31 grades of titanium based on mechanical and chemical properties. The weldability of titanium grades is one thing considered.
These grades are divided up into four classes: Commercially Pure (CP, or unalloyed), Alpha, Alpha-Beta, and Beta.
The elements in the titanium determine the crystal structure of the material. Oxygen, nitrogen, and aluminum encourage an alpha structure. Whereas vanadium, molybdenum and silicon act as beta stabilizers. The addition of other elements to the alloy can precisely control the crystal structure. Therefore the alloy’s properties and weldability can be controlled.
Consequently, the first step to successful titanium welding is to familiarize yourself with the various alloys, their properties, and the considerations in choosing filler metal for each.