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Investigation of PTFE transfer films by infrared emission spectroscopy and phase-locked ellipsometryWhen a PTFE sheet was rubbed unidirectionally over a smooth surface of stainless steel an essentially monomolecular transfer film was formed. by ellipsometric and emission infrared spectroscopic techniques it was shown that the film was 10 to 15 A thick and birefringent. From the intensity differences of infrared bands obtained with a polarizer passing radiation polarized in mutually perpendicular planes, it was possible to deduce transfer film orientation with the direction of rubbing. After standing in air for several weeks the transfer films apparently increased in thickness by as much as threefold. At the same time both the index of refraction and the absorption index decreased. Examination of the surfaces by optical and electron microscopies showed that the films had become porous and flaky. These observations were consistent with previous tribological measurements. The coefficients of friction decreased with the formation of the transfer film but increased again as the film developed breaks. The applicability of the ellipsometric and polarized infrared emission techniques to the identification of monomolecular tribological transfer films of polymers such as PTFE has been demonstrated.
Document ID
19880048341
Document Type
Reprint (Version printed in journal)
Authors
Lauer, James L. (Rensselaer Polytechnic Inst. Troy, NY, United States)
Bunting, Bruce G. (Rensselaer Polytechnic Institute, Troy, NY, United States)
Jones, William R., Jr. (NASA Lewis Research Center Cleveland, OH, United States)
Date Acquired
August 13, 2013
Publication Date
April 1, 1988
Publication Information
Publication: STLE Tribology Transactions
Volume: 31
ISSN: 0569-8197
Subject Category
NONMETALLIC MATERIALS
Funding Number(s)
CONTRACT_GRANT: DAAL03-86-K-0076
CONTRACT_GRANT: DAAL03-86-K-0042
Distribution Limits
Public
Copyright
Other