Influence of substrate rotation speed on the structure and mechanical properties of AlTiN/CrN coatings

AlTiN/CrN coatings were deposited on Si (100) and cemented carbide substrates using Cr and Al0.67Ti0.33 cathodes in an industrial‐scale cathodic arc plating system. The influence of substrate rotation speed (Srs) on the structural and mechanical properties of the coatings was investigated. The AlTiN/CrN coatings had a superlattice structure in which the AlTiN layer alternated with the CrN layer. With the increase of Srs, the modulation period of the coatings decreased from 21.9 nm to 2.40 nm. The hardness of the coatings increased as the Srs was raised from 1.5 to 3.0 rpm, and then decreased with further increase of the Srs. The maximum hardness of 3211 HV0.05 was obtained at 3 rpm. The coatings exhibited high friction coefficients against Si3N4 and lower values against cemented carbide under different normal loads.

► Superlattices AlTiN/CrN coatings were deposited by home-made industrial‐scale cathode arc ion plating system.
► The hardness of AlTiN/CrN coatings is larger than 3211 HV.
► The friction coefficient is 0.8 lower against Si3N4 and 0.4 against cemented carbide.