Filled/Reinforced Elastomers as Erosion Protection Materials for Rotor Blades - New Resin Systems

The recent experience during Desert Storm operations showed serious deficiencies in the use of exiting erosion protection systems in the helicopter rotor blades. The sand and rain erosions on the blade leading edges resulted in severe damages requiring extensive and frequent repairs. The contractor proposes to incorporate various fibers and self-lubricating powders into liquid castable polyurethane elastomer and develop new reinforced elastomeric materials with superior erosion resistance. Sub-micron sized fibers such as whiskers will create highly erosion resistant micro- or nano-structures in the elastomers. Other proposed fibers are either cut-resistant, self-lubricating, or reactive with the functional groups in the polyurethane, thus creating a highly durable interpenetrating chemical structure. Reinforcing fabrics and elastomeric films of different hardness will be impregnated with liquid polyurethane elastomer. Multi-layered elastomeric erosion protection laminates will be developed. Mixing and lamination techniques will be developed. Physical properties of reinforced resin formulations and the reinforced laminated structures will be measured. Rain erosion testing will be performed on selected systems.