Benzoxazine Matrix Composite Bearing Materials for Arresting Gear Components

Carrier aviation is dependent on the ability to recover aircraft expeditiously and safely aboard ship. The system that arrests the aircraft, the Arresting Gear system, utilizes slippers or bearing materials between moving components. The Arresting Gear system on Navy carrier aircraft utilizes slippers or bearing materials between moving components. These materials bear the weight of the various arresting gear components and function as the sliding medium between components to allow free movement during arrestments. The current slipper material is a cotton-fabric reinforced graphite phenolic-based composite material. A major shortcoming of this material is it's swelling when exposed to ethylene glycol, which causes clearance issues in the operating equipment. As a result, replacement is often required outside of scheduled maintenance, which is undesirable due to the labor-intensive nature of some of these replacements. Consequently, the Navy is seeking a new slipper material that would maintain dimensional stability throughout its lifetime, and have low wear rates compared to the existing material. It is desired for the slippers to have a life of 20,000 arrestments, with no shelf life limitations. Improving the life of the slippers will result in labor savings and greater equipment availability. During the Phase I program, Composite Technology Development (CTD) will develop a new composite bearing material comprised of either glass or carbon reinforcing fibers and a benzoxazine resin chemistry in place of the current phenolic resin to replace the current cotton/phenolic composite bearing material. Nano-scale additives such as clays, silica, silicon carbide, and carbon will also be incorporated to improve the wear resistance and friction characteristics of the resulting composites.