Thin Solid Films, Vol.519, No.1, 24-30, 2010
Structure and mechanical properties of low temperature magnetron sputtered nanocrystalline (nc-)Ti(N,C)/amorphous diamond like carbon (a-C:H) coatings
This paper reports on the structure and mechanical properties of similar to 2 pm thick nanocomposite (nc-) Ti(N,C)/ amorphous diamond like carbon (a-C:H) coatings deposited on 100Cr6 steel substrates, using low temperature (similar to 200 degrees C) DC reactive magnetron sputtering. The carbon content was varied with acetylene partial pressure in order to obtain single layer coatings with different a-C:H carbon phase fractions. The nanocrystalline Ti(N,C) phase is approximately stoichiometric for all coatings and the a-C:H phase fraction increases from 31 to 47 at.% as the coatings stoichiometry changed from TiC1.34 N-0.51 to TiC2.48 N-0.48, respectively. TiC1.34 N-0.51 coatings showed the highest nanoindentation hardness (H) of similar to 14 GPa and a modulus (E-r) of similar to 144 GPa; H reduced to <6 GPa and E-r to <70 GPa for TiC2.45 N-0.48 coatings. nc-Ti(N,C)/a-C:H coatings are promising candidates for applications where better matching of the modulus between a relatively low modulus substrate, hard loading support layer and low modulus-high H/E ratio top layer is required. (C) 2010 Elsevier B.V. All rights reserved.
Keywords:Nanocomposite;Microstructures;Mechanical properties;Magnetron sputtering;Amorphous hydrogenated carbon;X-ray photoelectron spectroscopy;X-ray diffraction