Work of Adhesion Measurements of MoS2 Dry Lubricated 440C Stainless Steel Tribological Contacts. Issue 12 (10th August 2017)

• Record Type: Journal Article
• Authors: Pajovic, Simo; Colas, Guillaume; Saulot, Aurélien; Renouf, Mathieu; Filleter, Tobin
• Is Part Of: Advanced engineering materials. Volume 19:Issue 12(2017)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2017-08-10
• Subjects: work of adhesion -- AFM -- MoS2 -- roughness -- tribology; Materials -- Periodicals; 620.11
• DOI: 10.1002/adem.201700423
• Languages: English
• ISSNs: 1438-1656

Abstract

Abstract : The tribological behavior of dry lubricants depends on their mechanical and physicochemical environment, making it difficult to predict in practice. Discrete Element Method‐based modeling has been one successful approach to provide valuable insight into the tribology of dry lubricated contacts. However, it requires well‐defined interactions between discrete elements, in particular between those simulating different materials. Measuring the properties governing those interactions, such as the work of adhesion ( W ), is therefore critical. The present work describes a method for measuring the W between AISI440C steel and MoS2 ‐based coatings used in spacecraft. Using Atomic Force Microscopy local asperity and adhesion measurements, the W between steel microbeads and MoS2 coatings is determined at different stages in its wear life. The distributions of W values in the worn coatings and pristine coatings agree well with earlier Time‐of‐Flight Secondary Ion Mass Spectroscopy studies on the physicochemistry of the samples, as well as contact angle measurements. Additional measurements between the same materials on a ball bearing from a real life‐test unit of a spacecraft instrument also show a similar W distribution, suggesting that the approach used here provides relevant data for use in numerical simulations. Abstract : The study describes a method for measuring the work of adhesion ( W ) between AISI440C steel and MoS2 ‐based coatings. After morphological and chemical studies of the surfaces, W is determined at different stages of the coating's wear life by using Atomic Force Microscopy (AFM), local asperity detection, and adhesion measurements with steel microbeads.