Abstract
The present work is a study of the effect of humidity on the tribological behavior of carbon-carbon composites, including two-dimensional PAN/pitch (designated TM), PAN/CVI (designated E), and pitch/resin/CVI (designated A) formulae. Results indicate that there exist close relationships among friction coefficient, wear rate, and worn surface morphology. Whenever a morphological transition has occurred, transitions in friction and wear also occur. Three different debris morphologies are identified. The smooth type I and type III debris films can lubricate, but not the powdery type II debris. The relative humidity level has a strong effect on the tribological behavior of all three composites. Low humidity and high sliding speed generally accelerate the occurrence of type I-to-type II transitions in friction, wear, and debris morphology, whereas high humidity and low speed enhance the formation of type III debris. At any humidity level, the type I morphology is always accompanied by low friction and wear. After the type I-to-type II transition, higher friction coefficient and wear rate are observed in the low humidity than in the high humidity. Under the present conditions, composite E appears to be the most sensitive to the humidity effect, while composite A appears the least sensitive.
Original language | English |
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Pages (from-to) | 38-47 |
Number of pages | 10 |
Journal | Wear |
Volume | 193 |
Issue number | 1 |
DOIs | |
Publication status | Published - 1996 Jul 1 |
All Science Journal Classification (ASJC) codes
- Condensed Matter Physics
- Mechanics of Materials
- Surfaces and Interfaces
- Surfaces, Coatings and Films
- Materials Chemistry