Rolling Contact Testing of Vapor Phase Lubricants—Part III: Surface Analysis©

Abstract

Infrared microscopy (μ-FTIR), Raman spectroscopy, Auger electron spectroscopy (AES), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) were used to characterize bearing surfaces lubricated from the vapor phase. Results are presented for surface films generated with a tertiary-butyl phenyl phosphate (TBPP) and a polyphenylether (5P4E). Infrared bands consistent with inorganic poly-phosphates and phosphites were detected in deposition films generated with the TBPP lubricant. Raman shifts consistent with graphite of short range order were detected in films deposited by both lubricants. However, specimens lubricated by the 5P4E had several Raman shifts consistent with Fe₂O₃ and Fe₃O₄. Iron oxides were not detected in deposition films generated with the TBPP lubricant. AES depth profiles indicate a predominant mixture of iron and carbon in the TBPP deposition film; whereas, the 5P4E film predominately consists of iron and oxygen. Localized corrosion pitting generated with the TBPP lubricant was analyzed using AES, SEM, and EDS. The results indicate that a modified matrix rich in phosphorus, oxygen and carbon, with a corresponding depletion of iron, transcends to depths of at least 10 microns in the substrate in damaged regions. Lubrication and failure mechanisms of vapor lubricated bearings are proposed based on the results.

Presented at the 51st Annual Meeting in Cincinnati, Ohio May 19–23, 1996

KEY WORDS:

• Vapor Phase Lubrication
• Lubricants, Vapor Phase Lubricants
• Surface Analytical Techniques, Chemical
• Auger Electron Spectroscopy
• Fourier Transform Infrared Spectroscopy
• Raman Spectroscopy
• Energy Dispersive X-Ray Fluorescence

Notes

Presented at the 51st Annual Meeting in Cincinnati, Ohio May 19–23, 1996