Self-lubricating coating design strategy for titanium alloy by additive manufacturing

Abstract

Lowering the coefficient of friction (COF) and improving the wear resistance of titanium alloys are critical for expanding their industrial applications. Herein, we report a novel strategy endowing titanium alloys with superior tribological performance by combining surface texture and solid lubricant: a coating with honeycomb structure was prepared by laser powder-bed fusion and incorporated with polytetrafluoroethylene (PTFE) as solid lubricant. The hybrid coating exhibits stable low COF and zero-wear properties under various service environments: atmosphere, deionized water, seawater, and corrosive acid medium. Under the action of friction force, wear debris can be continuously captured by the hybrid coating while releasing equal volume PTFE lubricant to repair the damaged lubricating film, thereby achieving excellent tribological properties of the coating in various environments. Our findings provide a new approach to improve the friction and wear properties of metal and alloy components.