Evaluation of commercial oleophobic coatings for aerospace applications in harsh environments: Analytical approach to determine the coefficient of friction at nano-level through lateral or friction force microscopy

This paper investigates the coefficient of friction at nano-levels of commercially available oleophobic coatings when applied over Inconel 718, which has widespread applications in the aerospace industry. The coatings were investigated in simulated sand-storm conditions, using uni-directional controlled sand blasting. The particle size and speed of collision during the sand-blasting procedure was carefully selected to simulate sand-storm conditions. The value for nano level coefficient of friction has been determined using lateral or friction force microscopy (LFM/FFM). The analysis has been used to formulate a value of friction coefficient which in turn is associative of the amount of wear the coating can bear before the exposure of the base substrate to the harsh environment. The analysis aims to validate the coefficient of friction value as marketed by the coating manufacturers and more importantly test the coating in real-life aerospace applications to justify its use.