Mechanical properties and high temperature oxidation of CrAlSiN/TiVN hard coatings synthesized by cathodic arc evaporation

• The multilayered CrAlSiN/TiVN coatings possessed the highest hardness of 33 GPa.
• CrAlSiN and CrAlSiN/TiVN coatings had better oxidation resistance than TiVN.
• The multilayered CrAlSiN/TiVN coating exhibited the best impact resistance.

Wear resistant hard coatings are highly demanded in modern manufacturing industry to ensure good performance of cutting and forming tools. In this study, TiVN, CrAlSiN and multilayered CrAlSiN/TiVN coatings were synthesized by cathodic-arc evaporation (CAE). TiV and CrAlSi alloy cathodes were used for the deposition of multilayered CrAlSiN/TiVN coatings. The cathode current and bias voltage of both TiV and CrAlSi cathodes were controlled at 70 A and − 120 V, respectively. By controlling the rotation speed of 4 rpm, a stepwise columnar structure containing periodic CrAlSiN and TiVN layers was found in this multilayered CrAlSiN/TiVN coating. The modulation period of the deposited CrAlSiN/TiVN coatings was 9 nm. The CrAlSiN/TiVN coatings possessed higher hardness of 33 GPa as compared to TiVN and CrAlSiN (24 GPa26 GPa). After oxidation at 500 °C, the TiVN revealed the presence of TiO2, V2O5 and VO2 on the surface. Small fraction of oxygen displaced nitrogen. Titanium and vanadium oxides were formed. The XPS, XRD and SEM analyses only suggested small amounts of titanium and vanadium oxides on the surface of the multilayered CrAlSiN/TiVN after oxidation at 500 °C. To study the impact fracture resistance, an impact test using a cyclic loading was conducted. The multilayered CrAlSiN/TiVN coating exhibited the best impact resistance (higher than 4 × 105 impacts) at room temperature and 500 °C, indicating the best resistance to impact fracture, among the studied coatings. The multilayered structure with TiVN and CrAlSiN is responsible for the enhanced mechanical properties, oxidation resistance and impact resistance.