Innovative Material (and Application Method) for a Hydrophobic/Oleophobic Coating to an Aluminum-Bodied Heat Exchanger

Air-cooled exchangers are used in the V-22 Osprey and many other platforms where they provide a critical thermal management function. During operation, the outside environment brings in dust, grime, oil and sand which can foul the heat exchanger surface. Deposits on the surface create an insulating layer that increases the thermal resistance. Regular maintenance of the heat exchanger is required to clean off the surface, reducing military readiness by taking aircraft out of service and consuming funds on maintenance activities that could otherwise go for active missions. In this SBIR project, TDA will develop a hydrophobic and oleophobic (self-cleaning) surface coating that would repel dirt and fouling to prevent it from building up in the first place. The coating will be applied as a thin film layer, uniformly across the heater exchanger fins in a low-cost process that can be run either when the heat exchanger is built or during routine depot maintenance. In the Phase I we showed our new coating had excellent adhesion, high contact angle and maintained its hydrophobicity/oloephobicity even under abrasive conditions. In Phase II we will optimize the coating formulation and carry out a full coating evaluation of the finned heat exchanger.