The effect of unbalanced coefficient of magnetron on the structure and properties of CN _x coatings

Abstract

The effect of unbalanced coefficient of magnetron (UCM) on the structure and tribological properties of CrN _x hard coatings was studied. The CrN _x coatings were deposited on both Si wafer and hardened tool steel substrates using a closed-field unbalanced magnetron sputtering ion plating technique in a gas mixture of Ar+N₂ under different unbalanced magnetron conditions. The coatings were characterized by means of XRD, XPS, SEM, microhardness tester and pin-on-disc tribometer to study respectively their structure, chemical bonding state, microstructure, hardness and tribological properties. The experimental results show that the UCM has a profound effect on the structure, hardness and tribological properties of the CrN_x coatings. With increasing the values of UCM, the dominant phases in the deposited coatings evolved from Cr+Cr₂N to Cr₂N+CrN, the microstructure became denser and the hardness increased; in addition, reduced coefficient of friction and improved wear resistance of CrN _x coatings were also observed under a larger UCM.

Keywords

magnetron sputtering / unbalanced coefficient / CrN _x coating / structure / properties

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