Abstract
Transmission electron microscopy (TEM) was performed on cross-sectional samples of tapered roller bearing cone surfaces that were tested at two levels of local boundary lubrication severity, A ∼ 1.1 and 0.3. Unlike ourpreviously reported work in which a base mineral oil was used, the bearing tests were conducted in mineral oil with sulfur- and phosphorus-containing gear oil additives. Structural and compositional characterization of undetached antiwear surface layers on the base steel (cone raceway) revealed that thefilms contained crystalline and amorphous regions. A sharp interface (< ∼ 10 nm) that separated the surface layer and base steel was imaged. The surface layer for the cone tested at Δ ∼ 1.1 consisted of Fe, O, and P whereas thatfor the cone tested at Δ ∼ 0.3 consisted of Fe, O, P, C, Ca, and S. Various TEM analytical techniques were used to study the segregation of these elements throughout the antiwear surface layer volume.
| Original language | English |
|---|---|
| Pages (from-to) | 299-307 |
| Number of pages | 9 |
| Journal | Tribology Transactions |
| Volume | 48 |
| Issue number | 3 |
| DOIs | |
| State | Published - Jul 2005 |
Funding
We would like to thank The Timken Company for approval to publish the findings of this study and support of this work. Thanks go to J. L. Maloney III, M. R. Hoeprich, R. L. Widner, and R. V. Fryan for guidance and support; to D. E. McClintock, J. Z. Russell, A. J. Hussar, and the bearing test lab technicians; to H. E. Chappie and R. Aubrey for lubricant analyses; to D. A. Clouse and M. Frank for metrology lab work; to J. Nisely and J. Wingert for help in sample preparation; and to W. Jennings at the Center for Surface Analysis of Materials at Case Western Reserve University for XPS analysis. Special thanks go to D. W. Coffey and T. Brummet for FIB specimen preparation at Oak Ridge National Laboratory (ORNL). In addition, we would like to thank P. J. Blau (ORNL) for reviewing the manuscript and submitting valuable comments. Research was partially sponsored by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of FreedomCAR and Vehicle Technologies, as part of the High Temperature Materials Laboratory User Program, ORNL, managed by UT-Battelle, LLC, for the U. S. Department of Energy under contract number DE-AC05-00OR22725.
| Funders | Funder number |
|---|---|
| Office of FreedomCar | |
| U.S. Department of Energy | DE-AC05-00OR22725 |
| Office of Energy Efficiency and Renewable Energy | |
| Oak Ridge National Laboratory |
Keywords
- Additives
- Boundary lubrication
- Oxides
- Surface films
- Tapered roller bearing
- Transmission Electrom Microscopy (TEM)
- Wear