Deposition of nanolayered CrN/AlBN thin films by cathodic arc deposition: Influence of cathode arc current and bias voltage on the mechanical properties

Thin films of CrAlBN were deposited on SKD 11 tool steel substrate using Cr and AlB cathodes in a cathodic arc plasma deposition system. The influence of AlB cathode arc current and substrate bias voltage on the mechanical and the structural properties of the films was investigated. The CrAlBN thin films had a multilayered structure in which the nano-crystalline CrN layer alternated with the amorphous AlBN layer. The hardness of the films increased as the AlB cathode arc current was raised from 35 to 45 A, and then decreased with further increase of the current. The hardness of the films increased rapidly with the increase of the bias voltage from − 50 to − 150 V. Further increase in the bias voltage decreased the hardness. The maximum hardness of 48 GPa was obtained at the bias voltage of − 150 V. With the increase of bias voltage, a good correlation between the residual stress and the hardness of the films was observed.