dsio
··Ash @ ΩFKind of...PVD is a process not a material. The "Phantom" Aquaracer 300 has a titanium case with titanium-carbide coating- same as the Heuer-01.
TAG Heuer doesn't make ceramic cases- just bezels 😉
The scratch resistance is in fact not down to the coating, but rather how hard the surface is that's being coated. That's why Sinn use "Tegimented" steel, ie hardened steel.
Here's one I wrote a while back:
http://timeandtidewatches.com/guide-to-black-watches/