Thermatanium

There's Thermatanium in them thar hills.

Thermatanium is a mineral substance used in the construction of Cybertronian spacecraft. When combined with Cybertronian metals, it gains resistance to heat and pressure. It's very orange.

Fiction

2015 Robots in Disguise cartoon

Saberhorn was sent to obtain thermatanium by Scorponok and Glowstrike. He managed to find some raw thermatanium in a quarry near Crown City, but when he was interrupted by Bumblebee's team of Autobots, he was only able to get away with a few chunks. He took his prize to a steel mill where he started smelting it, only for the Autobots to again catch up with him and as a result he was forced to abandon the thermatanium. Metal Meltdown