Abstract
Transmission electron microscopy (TEM) was performed on the near-surface material (depth <500 nm) of tapered roller bearing inner rings (cones) that were tested at two levels of boundary-lubricated conditions in mineral oil with no additives. Site-specific thinning of cross section cone surface sections for TEM analyses was conducted using the focused ion beam (FIB) milling technique. High-resolution structural and compositional characterization of near-surface material and surface layers was performed on an untested cone as well as cones tested at Λ ∼ 1.1 and 0.3. This approach revealed near-surface microstructural distortion and grain size gradients that were attributed to surface finishing operations during manufacture. The characteristics of oxide surface layers and micro-cracks on the tested bearing surfaces were evaluated and found to depend on lubrication conditions.
| Original language | English |
|---|---|
| Pages (from-to) | 430-439 |
| Number of pages | 10 |
| Journal | Tribology Transactions |
| Volume | 47 |
| Issue number | 3 |
| DOIs | |
| State | Published - Jul 2004 |
Funding
Research was partially sponsored by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Freedom-CAR and Vehicle Technologies, as part of the High Temperature Materials Laboratory User Program, Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the U. S. Department of Energy under contract number DE-AC05-00OR22725. We would like to thank The Timken Company for approval to publish the findings of this study and the support of this work. Thanks to J. L. Maloney III, M. R. Hoeprich, and R. L. Widner for guidance and support. Thanks to D. E. McClintock, J. Z. Russell, A. J. Hussar, and the bearing test lab technicians. Thanks also to M. Petraroli for metallography, H. E. Chappie and R. Aubrey for lubricant analyses, D. A. Clouse and M. Frank for metrology lab work, J. Nisely and J. Wingert for help in sample preparation, and W. Jennings at the Center for Surface Analysis of Materials at Case Western Reserve University for XPS analysis. Special thanks to D. W. Coffey and T. Brummet for FIB specimen preparation at ORNL. In addition, we would like to thank D. A. Rigney (The Ohio State University) and P. J. Blau (ORNL) for reviewing the manuscript and submitting valuable comments.
| Funders | Funder number |
|---|---|
| Office of Freedom-CAR | |
| Timken Company | |
| U. S. Department of Energy | DE-AC05-00OR22725 |
| Office of Energy Efficiency and Renewable Energy | |
| Oak Ridge National Laboratory |
Keywords
- Boundary lubrication
- Oxides
- Surface films
- Tapered roller bearing
- Transmission electron microscopy (TEM)
- Wear