THE TRIBOLOGICAL BEHAVIOR OF TYPE-II TEXTURED MX2 (M = MO, W, X = S, SE) FILMS

The tribological properties of textured WS2, MoS2 and WSe2 films, whic h were prepared using an ultra-thin interlayer of Ni/Cr (van der Waals rheotaxy technique) on quartz substrate, were determined in ambient c onditions. Using scanning force microscope adapted for tribological me asurements, very low (0.04 and below) friction coefficients and little wear were measured on flat areas of the films, Macroscopic (engineeri ng) tribological measurements, using the reciprocating ball on flat tr ibometer, exhibit somewhat higher friction coefficients. Compactizatio n of the films under the load and little wear were observed for the fi lms even after a few hundred cycles. X-ray photoelectron spectroscopy of the WS, film after the wear experiment confirmed that some oxidatio n took place within the wear track, but the overall integrity of the f ilm was preserved. These measurements indicate that highly textured fi lms of this kind are promising candidates for tribological coatings, w here oil-free lubrication is required. (C) 1998 Elsevier Science S.A. All rights reserved.