Thin Film Rheology of Boundary Lubricating Surface Films. Part I.
Abstract
The objectives of the work are to obtain a more quantitative understanding of the behavior and properties of liquid films on solid substrates and to apply this understanding to the formulation of better lubricants. A qualitative model based on the formation of a chemisorbed film and a resulting ordering of solvent and additive molecules was found to fit almost all of the experimental data. In the most highly ordered case, the model predicts layered structures. Quantitative calculations of the interaction energy between two layers were performed and the results agreed well with experiment and other published theory of monolayer lubrication. The experimental work in the program consisted of measurements of film thickness and attempts to determine degree of ordering by nuclear magnetic resonance measurements. Capacitance measurements of film thickness of hydrocarbon-stearic acid films confirmed the theory by demonstrating the necessity of both a reactive substrate and fatty acid additive for the formation of a film. Films some 2000 A thick were obtained from a 0.1 weight percent stearic acid in benzene solution. By means of capacitance measurements, it was also found that a nonadditive synthetic diester gas turbine lubricant did not form a stable film whereas the same fluid with an antiwear additive forms a stable film some 700 A thick. Similar results were obtained with a synthetic paraffin base lubricant. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1970
- Accession Number
- AD0721176
Entities
People
- C. M. Allen
- E. Drauglis
- J. M. Genco
- N. F. Hartman
- W. H. Jones Jr.
Organizations
- Battelle Memorial Institute