SBIR-STTR Award

The Navy operates its helicopters and other aircraft in dust, salt, and water-laden environments. The impact of sand and water droplets on the rotor blades at high velocities causes rotor life to drop drastically. The cost of replacing and maintaining rotor blades is a significant factor. The current solution is to use metallic abrasion strips that offer limited protection; however, the strips limit the fatigue life of composite rotors. AS&M has developed a coating that provides superior erosion protection without reducing fatigue life. AS&M’s coating is comprised of a fine dispersion of very hard particles in a resilient matrix. The coating partly absorbs the energy and reflects back the impacting particles without deformation or cratering. In Phase I, we propose to demonstrate the applicability of AS&M’s coating on composite material for adhesion, uniformity, smoothness, erosion, and cavitation properties. In the Phase I option, we propose to establish a field repair kit for maintenance and extending the coating life. In Phase II, we propose to coat airfoil shapes for simulated erosion test and also to carry out a full-fledged fatigue test on a coated rotor. In Phase III, we will work with a rotor blade manufacturer and transition the technology to a rotary-wing platform

The Navy's helicopters and aircraft encounter dust, salt and water laden environments. The impact of sand and water droplets onto the rotor blades at high velocities causes rotor life to drop drastically. The cost of replacing and maintaining rotor blades is a significant factor. The current solution is to use metallic abrasion strips that offer limited protection. AS&M has been developing a coating that provides superior erosion protection. AS&M's coating is a nano-composite reinforced elastomer with superior erosion resistance. The coating resists erosion by absorbing a part of the impact energy. In Phase I, the applicability of AS&M's coating on composite material was demonstrated. AS&M's coating was found to have adequate adhesion, uniformity, smoothness, high velocity sand erosion and cavitation properties. It was also found to be applicable on a range of substrates - aluminum, stainless steel, nickel, titanium and steel. In Phase II, we propose to further develop the material to improve its thermal conductivity and optimize the composition to demonstrate combined sand and rain erosion resistance in the whirling arm test. The up-scaling capabilities will be established by standardizing the technology-related issues that include specification of raw materials, mixing, spray processing, finishing, field applicability and repair.

Keywords:
SAND EROSION, RAIN EROSION, CAVITATION, PROTECTIVE COATING, HELICOPTER ROTOR, LEADING EDGE