TiAlN (titanium aluminum nitride) is a hard PVD nitride built on the (Ti,Al)N system. It exists to extend the working temperature of plain TiN: substituting aluminum for part of the titanium forms a stable, alumina-rich surface oxide at temperature, so the coating resists oxidation and holds its hardness in the heat generated at a cutting edge or a working die face. Relative to higher-aluminum AlTiN, the lower Al fraction trades some oxidation ceiling for more toughness, which makes it a practical pick for roughing and interrupted work.
What the numbers say
- Hardness sits roughly 2600-3300 HV, typical near 3200 HV. Only two sources actually publish an HV figure (Wikipedia's 2600-3300 band and MiniTools' 3200 +/- 50); a peer-reviewed paper reports 2972.91 HV0.5 separately from a 46.39 GPa nanoindentation value, which is not converted to HV [wikipedia, minitools, richter, fcva_paper].
- Max service temperature runs 750-900 C, typical around 850 C, on an oxidation-onset basis. The spread is real and reflects differing definitions: oxidation starts near 800 C with phase stability to ~850 C, while vendor "max working" figures range from 748 C up to 900 C [wikipedia, brycoat, calico, minitools, richter].
- Friction against steel is reported 0.3-0.5, typical ~0.4, but the only confirmed steel-counterface value is MiniTools' 0.40 dry against 100Cr6 bearing steel. The wider envelope rests on unverified vendor figures, so treat it as soft, not specified [minitools, richter].
- Layer thickness runs 1-7 um (typical ~3 um), deposited around 375-480 C (typical ~450 C) for conventional arc/sputter PVD; low-temperature variants down to 200-300 C exist but are not the standard process [wikipedia, brycoat, calico, minitools, richter].
Where it fits
TiAlN is a general-purpose high-temperature coating. Its home is dry and near-dry machining: end mills, drills, and taps cutting steel, stainless, cast iron, and superalloys, where the heat at the edge would soften an uncoated or TiN-coated tool. Because it is tougher than higher-Al AlTiN, it suits roughing and interrupted cuts as well as forming, stamping, and die or punch tooling that sees abrasive wear, plus highly stressed precision parts needing wear and erosion resistance at elevated temperature. The deciding question is usually how hot the job runs and how much shock the edge takes.
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.