The in situ temperature and pressure of silicone (polydimethylsiloxane) grease at a ball-on-flat sliding contact was successfully measured by UV Raman spectroscopy. The ratio of Stokes and anti-Stokes Raman peaks from the 490 cm-1 Si-O-Si bending mode were used to calculate the grease temperature at 10 and 20 cm/s sliding speeds. The peak shifts detected during sliding were used to calculate the lubricant pressure. The results show that the silicone temperature at the contact area increased with the sliding speed. Under a stationary contact, the silicone temperature was measured to be 22°C. At 10 and 20 cm/s sliding speeds, the silicone temperatures were measured to be 45 and 62°C, respectively. The pressure, on the other hand, did not depend on the sliding speed and remained at 0.6 GPa. These results were found to be consistent with calculations based on Hertzian contact theory.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Electronic, Optical and Magnetic Materials
- Surfaces, Coatings and Films