Durable Hydrophobic Barrier Coating for the Remote Minehunting Tow Cable

The outer cable strands used to tow the AQS-20A from the RMMV are made from Nitronic 50, an austenitic stainless steel that, under normal circumstances, exhibits excellent corrosion resistance and strength over a wide temperature range. Unfortunately, the cables are experiencing early life corrosion problems due to salt water deposit buildup that occurs over repeated operations and subsequent system stowage. To achieve the corrosion and abrasion resistance necessary for the AQS-20A tow cable, Luna is collaborating with Lockheed Martin to develop a hydrophobic watershedding coating that is mechanically durable, optically transparent, and easy to apply. Numerous accomplishments were made in the Phase I effort that demonstrated the excellent performance of Luna’s coating system. Coatings were formulated that provided excellent abrasion resistance, high flexibility, optical transparency, and good corrosion protection of coated Nitronic 50 flat substrates, as well as actual tow cable test articles. In the Phase II, Luna will further improve performance and processing of the hydrophobic coating, validate its use as a robust and cost-effective solution for the RMS tow cable corrosion problem, and transition an application process for implementation testing.