Investigation of the Nanostructure and Wear Properties of Physical Vapour Deposited CrCuN Nanocomposite Coatings

This article presents results on CrCuN nanocomposite coatings deposited by physical vapour deposition. The immiscibility of Cr containing a supersaturation of nitrogen and Cu offers the potential of depositing a predominantly metallic and therefore tough nanocomposite, composed of small CrN metallic and/or beta-Cr2N ceramic grains interdispersed in a minority Cu matrix. A range of CrCuN compositions have been deposited using a hot-filament enhanced unbalanced magnetron sputtering system. The stoichiometry and nanostructure have been studied by x-ray photoelectron spectroscopy, transmission electron microscopy, scanning electron microscopy, and x-ray diffraction. Hardness, wear resistance, and impact resistance have been determined by nanoindentation, reciprocating-sliding, and ball-on-plate high-frequency impact. Evolution of the nanostructure as a function of composition and correlations of the nanostructure and mechanical properties of the CrCuN coatings are discussed. A nanostructure comprised of 1–3 nm alpha-CrN and beta-Cr2N grains separated by intergranular regions of Cu gives rise to a coating with significantly enhanced resistance to impact wear.JRC.I.4-Nanotechnology and Molecular Imagin