Effect of crystallographic orientation on fretting wear behaviour of MoS sub(x) coatings in dry and humid air

• Published in: Thin solid films Vol. 396; no. 1-2; pp. 69 - 77
• Main Authors: Zhang, X, Vitchev, R G, Lauwerens, W, Stals, L, He, J, Celis, J-P
• Format: Journal Article
• Language: English
• Published: 21-09-2001
• ISSN: 0040-6090

The tribological behaviour of MoS sub(2) coatings in air of high humidity is critical for their application in air. An improved friction and wear resistance of sulfur-deficient MoS sub(x) coatings in humid air is reported based on fretting wear tests. For random-oriented MoS sub(x) coatings, the coefficient of friction and the wear volume are still significantly dependent on the relative humidity. On the contrary, basal-oriented MoS sub(x) coatings show an interesting low sensitivity to humidity. MoO sub(3) and SO super(2) sub(4) super(-) have been detected in the wear track and the debris. The amount of MoO sub(3) and SO super(2) sub(4) super(-) is related to the crystallographic orientation of the coatings and the relative humidity in the fretting wear tests. However, the structure and grain size of the MoO sub(3) debris are not dependent on the relative humidity and the crystal orientation of the coatings. The effect of humidity on the friction and wear of these sulfur-deficient MoS sub(x) coatings with different crystallographic orientations is discussed. copyright 2001 Elsevier Science B.V. All rights reserved.