Study of thermal stability and mechanical properties of amorphous Zr19W18N63 coatings deposited by DC/RF reactive magnetron sputtering

Thermal stability and mechanical properties of Zr-W-N films have been studied. Zr-W-N films of various structure have been deposited on Si substrates by DC/RF reactive magnetron sputtering at various substrate temperatures T-s (100 degrees-600 degrees C) and at constant N-2 partial pressure (0.27 Pa). For 100 degrees C <= T-s <= 300 degrees C, X-ray diffraction patterns show an amorphous structure of the films which is further confirmed by transmission electron microscopy measurements. For 400 degrees C <= T-s <= 600 degrees C, a crystalline fcc phase with (111) and (200) orientation has been observed. Maximum wear resistance (H/E-r similar to 0.22) and maximum resistance to fatigue fracture (H-3/E-r(2) similar to 1.1 GPa) have been obtained for the amorphous films deposited at T-s = 200 degrees C. Post annealing of films deposited at 200 degrees C has been carried out in air from 100 degrees to 600 degrees C. Oxygen starts to be incorporated in the films at 300 degrees C annealing temperature (T-n) and its content increases with increasing T-n. No crystalline oxide phases are observed up to T-n = 600 degrees C. The hardness of the annealed films decreases with increasing oxygen incorporation. (C) 2013 Elsevier B.V. All rights reserved.