From WoWWiki
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 gives the possibility of randomly discovering one of thirteen different Eternal transmutes. This transmute has a 20 hour cooldown.
Source
The recipe is taught by any Northrend Alchemy trainer at skill level 395.
Notes
Titanium is a rare Northrend metal which can also be mined and smelted. On some servers the materials for this transmute are actually more expensive than the product. However, this is the first transmute that Grand Master Alchemists learn, making it the only way to discover new transmutes at least until skill level 425.
See also
Sources of Wrath alchemy recipes
External links