Tribological properties of Cr-Si-N nanocomposite film adherent silicon under various environments

Chromium nitride thin films have good corrosion resistance and mechanical properties. However, their hardness is slightly lower than that of other hard coatings. The concept of nanocomposite thin films is employed by adding silicon to form Cr-Si-N thin films with enhanced hardness and wear resistance. In this study, Cr-Si-N films with various Si contents were coated on silicon wafer to enhance the tribological properties and anticorrosion by a bipolar symmetry pulsed DC reactive magnetron sputtering process. The tribological properties were studied by a pin-on-disk tester. The tests were conducted with the same operating condition under three different environments. They were performed in the ambient atmosphere (in 55% humid air), DI water, and 0.01 M NaCl aqueous solution, respectively. The wear tests revealed that, as the silicon content was increased, even though the Cr-Si-N films had a better anticorrosion property they had an inferior performance on wear resistance. The results were concluded to be mainly due to Cr-Si-N films' microstructures and adhesion to the Si substrate rather than their hardness and toughness. (C) 2010 Elsevier B.V. All rights reserved.