Reaction and Evaporation Rates of High Temperature Candidate Fluids from a TFOST Test

Abstract

Five high temperature fluids have been evaluated in a thin-film oxidation sealed tube (TFOST) test at 300°C to assess their capability for high temperature application. Degradation maps were constructed for each individual lubricant based on the amount of fresh lubricant remaining. Liquid-phase and gas-phase reaction rates and evaporation rate were then calculated and plotted against test time to illustrate their temporal functionalities. Composite plots of the test fluids were made in both global-rate and specific-rate forms, which are then used jointly to explain a number of important mechanisms concerning lubricant behavior in this experimental system. In general, lubricant evaporation rates are an order of magnitude larger than their reaction rates, and chemical reaction rates in the gas phase are higher than those from the liquid phase.

Presented at the 51st Annual Meeting in Cincinnati, Ohio May 19–23, 1996

KEY WORDS:

• Oxidation
• Lubricant Degradation/Stability
• Bench Tests
• Synthetic Lubricants

Notes

Presented at the 51st Annual Meeting in Cincinnati, Ohio May 19–23, 1996