AlCrN (aluminum chromium nitride) is a cathodic-arc PVD hard nitride built on the (Al,Cr)N system. It exists to push past the oxidation ceiling of TiN and AlTiN: the high aluminum fraction forms a stable, self-protecting alumina-rich surface oxide at temperature, which is what lets the coating hold up under the thermal and oxidative load that destroys lower-temperature nitrides. The chromium contributes adhesion and toughness, making the layer a practical fit for hot-work tooling rather than just cutting edges.
What the numbers say
- Hardness lands in a tight band, roughly 2900-3500 HV with a typical near 3200 HV. The spread comes from a flat 3000 HV figure on one sheet and a 3200 +/- 300 HV band on another [ionbond25, eifeler_crosalplus, surftech_alcrona].
- Max service temperature is high for a nitride: 1050-1100 C, with 1100 C the dominant published figure across three sources. The basis is oxidation onset rather than a melting limit [eifeler_crosalplus, oerlikon_alcrona_evo, surftech_alcrona].
- Friction against steel is reported 0.35-0.55, typical around 0.45. Only one source explicitly states dry sliding (0.55); the others say "vs steel" without naming lubrication or the counterface alloy, so treat this as indicative, not specified [ionbond25, eifeler_crosalplus, surftech_alcrona].
- Layer thickness runs 2-5 um (typical ~3 um), deposited around 450-550 C, low enough to follow most hardened tool steels without retempering [ionbond25, eifeler_crosalplus, oerlikon_alcrona_evo].
Where it fits
AlCrN earns its place wherever heat is the failure mode. It is the default on hot-work forging dies, die-casting tooling, and stamping or sheet-forming tools that see sustained high surface temperatures, and it doubles as a workhorse on carbide cutting tools for dry and high-speed milling, drilling, and turning. The deciding question is usually thermal: if a job runs hot enough that TiN or AlTiN oxidizes away, AlCrN is the next step up.
These are general process properties published to help understand tradeoffs between coatings, not a specification for your application. Actual performance depends on substrate, surface prep, edge geometry, and service conditions — confirm requirements with your coater.