Characterizing Tribo-Surface Chemistry


Wear additives are often added to lubricants to increase the useable lifetime of metal parts and increase lubricity. PHI surface analysis instruments are ideally suited to characterize small features with significant topography such as wear tracks. Displayed below (Fig. 1) is a scanning x-ray beam induced secondary electron image of a wear track. The XPS images (Fig. 2) show that a lubricant additive, molybdenum disulfide, has bonded to the metal surface in the wear track. PHI XPS instruments provide the ability to probe micro areas and provide quantitative chemical state information from the surface. Thin film depth profile analysis can also be performed in the wear track to further characterize the nature of the tribo film.

Sample is courtesy of Thierry Le Mogne, Laboratoire de Tribologie et Dynamique des Systèmes, Lyon, France