Transmute: Titanium

Transmute: Titanium is a sub-skill of Alchemy which allows the Alchemist to create a Titanium Bar. Like all other Northrend transmutes, performing this skill is supposed to give the possibility of randomly discovering one of twelve different Eternal transmutes.

Source
The recipe is taught by any Northrend Alchemy trainer at skill level 395.

Alchemy Recipes from Transmute: Titanium
Transmuting Titanium allows for transmutation of Eternal Fire, Eternal Water, Eternal Life, Eternal Air and Eternal Earth into other kinds.