Use of Exoelectrons to Study Solid Films.
Abstract
Two new applications of exoelectron emission to tribology were studied, both involving non-metallic films (which emit few or no exoelectrons) on metallic substrates. The first application dealt with hard, wear-resistant coatings. Experiments were conducted to determine if exoelectrons could be used as a new technique to help detect premature defects and localized film failure. Plots of emission versus location could then be used to determine coating quality and the wear process involved. The second application was concerned with soft, organic coatings and the measurement of their wear-out and possible migration along a wear track. In order to facilitate these studies, a new apparatus was constructed which allows the sliding experiment to be carried out in the exoelectron-detection chamber. Thus, exoelectron emission, as well as friction can be measured continuously during the sliding test. This new testing procedure is much more flexible than the previous method, which involved frequent removals of the test specimen from the friction apparatus to the exoelectron test chamber and back again. The results show that exoelectron emission is an excellent means of determining localized film failure due to wear. Solid films incorporating graphite and molybdenum disulfide were found to wear monotonically, while some migration was observed with Teflon-containing coatings.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 31, 1979
- Accession Number
- ADA080627
Entities
People
- Ernest Rabinowicz
- Mark Connelly
Organizations
- Massachusetts Institute of Technology