High Temperature Solid Lubricant Coatings for Air Foil Bearings

This purpose of this project is to demonstrate the feasibility of using solid lubricant coatings in high temperature air foil bearings. Both the journal and foil components of the bearing will be coated. The journal will be coated with an innovative graded, nanocomposite structure while the foil will be coated with a proven CuAl alloy.  The nanocomposite journal coating provides (1) lubricating properties over a broad temperature range (-40°F up to 1200°F), (2) thermal stability in air over this temperature range, (3) excellent loading capability without failure, (4) and excellent wear characteristics. The nanocomposite is deposited on top of a metal nitride with excellent adhesion to the substrate, oxidation resistance and thermal stability. The foil coating will be a CuAl alloy. The coating provides thermal stability and resistance against spallation over the temperature range of -40 to 1200°F.  The ductile Cu assists in the bearing run-in to yield an aerodynamically smooth surface, maximizing the bearings loading capacity. BENEFIT: The development of new high-temperature solid lubricant coatings will allow the introduction of air foil bearings into new applications for turbo machinery.  This will lead to improvements in engine performance, safety, and reliability.