Host: The Japan Society of Mechanical Engineers
Name : [in Japanese]
Date : March 04, 2024 - March 05, 2024
Heat-resistance of lubricants (Perfluorinated polyether system) for HAMR (Heat-Assisted Magnetic Recording) system of HDD was examined using Near Infrared Raman Spectroscopy (NIRRS) and Surface-Enhanced Raman Spectroscopy (SERS). Heating of lubricant creates fluorescence which disturbs Raman analysis as a result of thermal degradation. NIRRS with 1064nm laser in wavelength is useful to analyze Raman spectrum of heated lubricant because there is no fluorescence in that wavelength region. Another method to avoid fluorescence disturbance is SERS, because enhanced Raman intensity is much larger than fluorescence intensity. As a result, Demnum type backbone structure, C3F6O-, is thermally stronger than Fomblin type backbone, -C2F4O-. Also, phenyl group improves heat-resistance of lubricant. Lubricant with OH groups and with three or six phenyl groups exhibits high heat-resistance over 250℃. A lot of unknown peaks are observed for lubricant with fluorescence. There peaks are decomposed by-products by heating. Carbon peaks are also observed for decomposed lubricants. Carbonization also occurred by thermal decomposition. Those by-products may create smear which causes head crushing.
