Fluids, Lubrication, Fuels and Related Materials

Oxidation studies with a variety of fluids at high temperatures are presented. These studies emphasize the evaluation of oxygen tolerance of the fluids as opposed to conventional tests measuring the stable life or induction period of fluids. Oxygen assimilation rates are measured using gas chromatographic methods. Temperature-programmed gas chromatography using an internal standard is used for the quantitative evaluation of the oxidized product. Temperature measurements are being made for both the liquid and the vapor space in the reaction zone. The effect of the volatility of the fluid and of the volatile oxidation products on the rate of oxygen assimilation is determined. Procedures for the recovery and analysis of the debris formed at the wear surfaces in a four-ball wear tester are presented. A lubrication model based on metal-fluid interaction in the concentrated contact is proposed. Environmental conditions in the concentrated contact are shown to be capable of providing fluid degradation products. A material balance used to quantify the lubrication debris recovered is discussed. Atomic absorption spectrophotometry is used to obtain the metal content of the various fractions of the wear debris. Some preliminary data on the effect of several materials on the wear behavior of steel-on-titanium and titanium-on-titanium are presented. Bulk modulus measurements for some Spec. MIL-H-83282 fluids are given.