Thin Solid Films, Vol.503, No.1-2, 133-142, 2006
Chromium nitride/niobium nitride nano-scale multilayer coatings deposited at low temperature by the combined cathodic arc/unbalanced magnetron technique
CrN/NbN nano-scale multilayered coatings have been successfully grown at a deposition temperature of 250 degrees C. The coatings have been grown by the combined cathodic arc/unbalanced magnetron technique (Arc Bond Sputter) and were deposited at two different thicknesses namely similar to 1.0 and similar to 3.0 mu m at bias voltages U-B between -75 and -150 V. In all cases the stresses were compressive and increased from -4.4 GPa at U-B= -75 V to -9.5 GPa at U-B= -150 V. Coatings in all cases developed a pronounced {111}, texture that tended to a maximum at a bias voltage of -95 V The experiments indicated that the {111} texture developed by a competitive growth mechanism from a randomly oriented or 11001 initial starting texture. Measurements of coefficients of friction and sliding wear show a decrease in the coefficients of friction and sliding wear with increasing bias voltage. The coefficient of friction decreases from mu = 0.7 at U-B = -75 V to mu = 0.5 at U-B= -150 V while in parallel the coefficient of sliding wear decreased by an order of magnitude from 1.3 x 10(-14) at U-B = -75 V to 2.8 x 10(15) at U-B = -150 V. These decreases in coefficients of fiction and sliding wear appear to Mirror the increases in intensity of the {111} texture. The adhesion as measured by scratch test shows a distinct maximum of 72 N at a bias voltage U-B of - 95 V, which is a remarkably high value for a low temperature process in a coating with a compressive stress of -5.4 GPa. (c) 2005 Elsevier B.V. All rights reserved.