Gold-Titanium, he does say it out loud and the alloy exists. I'm just saying they've gone down the usual route of saying the name of a real metal, then making it do something it can't do in real life anyway.
The same with the Avengers, Iridium exists in proper ingots in various locations all over the Earth. It's incredibly rare, but when it is found it's nearly always immediately refined to the base metal. There was no need to go to Germany except to do the Hitler jokes, and what the hell that "rock" was supposed to be I don't know.
But yeah, true to old school "suits of armour" his is designed with the idea of multiple intertlocking parts, used ablatively, when one piece is damaged it's replaced. He had regular damage in mind when he designed them.