How do you mix the Titanium into the crystal, and does it bond in some way, or how does it strengthen and improve the durability?
Titanium has the highest strength-to-weight ratio of any metal which is why it's used in the most demanding applications like rockets.
Each glass manufacturer uses their own recipe and pretty much all of them use aluminum, rather than titanium, as their strengthening additive simply because it's exponentially cheaper.
From a layman's perspective all these metallic compounds seem really different from glass but in reality that's the magic of glass. I'm no chemist but SiO2 doesn't seem chemically very different from PbO or TiO2.