Zybanium was a substance used by the Time Lords for materials tasks needing durability and resistance to temporal energy.
The Temporal Reactors in a Class 7C Time Station were shielded with Zybanium. (AUDIO: Neverland)
Rassilon's Foundry contained a number of containment cells with triple-thick Zybanium shielding. They contained entire star systems, and in one case, the Divergent Universe. (AUDIO: Zagreus)
Nepenthe muzzled K9 Mark I with a Zybanium band when K9 tried to break into the Free Time enclave on Gryben. (AUDIO: Weapon of Choice)