The effect of Cu content on the microstructures, mechanical and antibacterial properties of Cr-Cu-N nanocomposite coatings deposited by pulsed DC reactive magnetron sputtering

The nanocomposite Cr-Cu-N thin films with Cu content ranging from 1.6 to 24.3 at.% have been deposited by a bipolar asymmetric pulsed DC reactive magnetron sputtering system. A strong CrN (200) texture is found for each coating. The columnar structure was replaced by a dense and compact morphology when the coating contained more than 8.2 at.% Cu. An unusual hardness enhancement is observed on the coating with 15.7 at% Cu, which is possibly due to its grain refinement effect. For the coating containing 15.7 at.% Cu, a combination of high hardness, low coefficient of friction and good antibacterial properties are achieved. The Cr-Cu-N nanocomposite thin film developed in this study with sufficient hardness and antibacterial abilities can be used as a promising candidate to deposit on the surfaces of medical apparatus and food processing equipments. (C) 2007 Elsevier B.V. All rights reserved.