Was Mithril Titanium?

Short answer: No, probably not.

Let's go over what we know about mithril:

"For here alone in the world was found Moria-silver, or true-silver as some have called it: mithril is the Elvish name. The Dwarves have a name which they do not tell. Its worth was ten times that of gold, and now it is beyond price; for little of is left above ground, and even the Orcs dare not delve here for it...

All folk desired it. It could be beaten like copper, and polished like glass; and the Dwarves could make of it a metal, light and yet harder than tempered steel. Its beauty was like to that of common silver, but the beauty of mithril did not tarnish or grow dim."

Does that sound like titanium? Titanium is certainly not as shiny as silver, and thus there isn't much to tarnish. Titanium can be found in other European countries than Germany. Titanium is the ninth-most abundant element in Earth's crust. Titanium is less strong at high temperatures than iron.

Let's face it, folks. Mithril was not titanium.