| Publication Date |
1983 |
| Personal Author |
Faut, O. D.; Wheeler, D. R. |
| Page Count |
14 |
| Abstract |
A pin-on-disk tribometer equipped with an induction heater was used to study the coefficient of friction as a function of temperature for tricresylphosphate (TCP) on continuous vacuum melted (CVM) M-50 tool steel when the TCP was present in a liquid reservoir (bulk lubrication), and when it was applied as a liquid layer directly to the disk (limited lubrication). Under limited lubrication conditions, experiments were performed in dry ( 100 ppm H2O) air, dry ( 20 ppm H2O) nitrogen, dry nitrogen with the disks heated to 700 C then cooled to room temperature before the TCP was applied and the measurements made (preheated disks), and moist nitrogen using preheated disks. When the coefficient of friction was plotted as a function of the disk temperature, the friction decreased at a characteristic temperature, T sub r whose observed values were 265 C for bulk lubrication conditions in dry air, 225 C for limited lubrication conditions in dry air, and 215 C for limited lubrication conditions in dry nitrogen. No decrease in friction was observed with preheated disks; instead a sharp failure temperature was observed at 218 C, which was taken as the temperature about which the behavior of TCP should be judged, X-ray photoelectron spectroscopy confirmed the presence of phosphate on the surface of the iron pins used in the tribometer under TCP lubrication. Depth profile studies support the idea that a chemical reaction occurs between the TCP and the metal surface at T sub r. |
| Keywords |
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| Source Agency |
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| NTIS Subject Category |
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| Corporate Authors |
National Aeronautics and Space Administration, Cleveland, OH. Lewis Research Center. |
| Supplemental Notes |
Presented at the Asle Lubrication Conf., Washington, D.C., 5-7 Oct. 1982. |
| Document Type |
Technical Report |
| NTIS Issue Number |
198314 |
