Tribology Testing of Advanced Aviation Oils, Bearing and Gear Materials

Long standing demands of advanced gas turbine engine oils to operate with increasing temperatures have resulted in formulations with reduced boundary lubrication. The desire to introduce corrosion resistance bearing and gear steels with more chemically benign surfaces compared to conventional steels presents significant challenges for boundary lubrication. A scuffing load capacity test method highlights oil and bearing steel response to mixed-film lubrication and wear. Through traction measurements the test method differentiates additive type and concentration with respect to wear and scuffing performance. The introduction of stainless steels 440C and Pyrowear 675 significantly reduces scuffing performance compared to conventional M50 bearing steel. The scuffing load capacity screening tests with advanced additive candidates show feasibility to significantly increase tribology performance with stainless steels.