Tribology properties of MoN-Cu adaptive coatings on L605 for variable cycle engine application

Abstract

The pressing demand for multi-mode propulsion systems stimulates the development of Variable Cycle Engines (VCEs). However, the severe friction conditions encountered by variable geometry components pose great challenges to the longevity of VCEs. Here, we synthesize MoN-Cu adaptive coatings on L605 using magnetron sputtering and investigate their tribological performance from room temperature to 800°C. We demonstrate that, despite the involvement of surface reactions of Co diffusing from the substrate at high temperatures, the coating displays commendable lubricity, except at medium temperatures where the coating’s mechanical properties deteriorate and thus severe abrasive wear. Our results provide critical insights into the tribological mechanism of the MoN-Cu coated cobalt-based alloy, knowledge vital for developing coating strategies against the persistent tribological issue in VCEs.