Effects of duty cycle on microstructure and mechanical properties of (AlCrNbSiTi)N high-entropy nitride hard coatings deposited by pulsed arc ion plating.

High entropy (AlCrNbSiTi)N hard coatings have been deposited by pulsed arc ion plating with various duty cycles. The effects of duty cycles on the morphology, chemical composition, microstructure and mechanical properties of coatings are studied. Higher duty cycles result in the increase of deposited particles and holes on the surface of the coatings. The coatings exhibited a single-phase face centered cubic structure with preferred orientation of (200). Appropriate duty cycle can significantly improve the comprehensive mechanical properties of the coatings. The coating exhibits highest hardness and elastic modulus of 43.4 GPa and 573.4 GPa, respectively. Formation of surface oxides during friction process are observed, which play a self-lubricating role. • The cross sections of all coatings are featureless and dense. • The coatings have typical single-phase B1–NaCl FCC solid solution crystal structure with (200) preferred orientation. • Coating deposited at 60 % duty cycle exhibits highest hardness of 43.4 GPa. [ABSTRACT FROM AUTHOR]