Comparison of tribological properties of industrial low friction coatings

Abstract

MX2(M = Mo, W; X = S, Se) and DLC (a-C: H and WC/C) are the two kinds of typical low friction coatings widely used in industry. The friction and wear properties of these two kinds of coatings marked as MOVIC, MOST, MoSe2/Ni, WSe2, a-C: H and WC/C coatings were determined by fretting tests in ambient air of different humidity. The results show that the coefficient of friction Of MX2 coatings increases when the relative humidity of air increases whereas the coefficient of friction DLC coatings decreases with the increasing of relative humidity. MOVIC and WSe2 coatings have a poor friction and wear resistance because of non-basal planes ( 100) and ( 101) parallel to the surface in the MOVIC coating, or the rough and porous surface of WSe2 coatings. Among these six coatings, MoSe2/Ni and WC/ C coatings have the highest wear resistance which seems to be unaffected by the relative humidity.