Friction and Wear Characteristics of Candidate Foil Bearing Materials from 25°C to 800°C~©

摘要

The friction and wear behavior of unlubricated metal/metal sliding couples was investigated to screen potential candidates for high-temperature foil bearings. The tribo-tests were run in an induction-heated high-temperature pin-on-disk tribometer in an air atmosphere at a load of 4.9 N and at a sliding velocity of 1 m/s. The friction and wear properties of several nickel-based alloys (Rene' 41, Inconel X-750, Inconel 713C), iron-based alloys (MA956 and Inconel 909) and a ceramic (Al_2O_3) were tested at 25°, 500°, and 800°C. In general, the alloys oxidized at elevated temperatures and formed a tenacious and lubricous oxide surface film or layer. At 800°C, Inconel X-750 vs. Rene' 41 had the lowest friction coefficient (0.27) and, at 500°C, Inconel X-750 vs. Inconel 909 the lowest pin wear (2.84 × 10~(-6) mm~3/N-m). Gouging and severe wear of the softer material occurred whenever a significant difference in hardness existed between the pin and disk specimens.