Ceramic Composite Air Cooled Clutch Development

Refractory Composites, Inc. (RCI) proposes to develop air cooled clutch friction materials based on SiC composites. These materials possess higher friction factors that SOA carbon-carbon friction materials and can be operated at higher peak temperatures without oxidative damage. Consequently, much higher power and energy levels per unit friction area and per unit mass can be achieved than the SOA friction materials. Areal power and energy densities may be double the SOA and mass specific power and energy levels may be a factor of 1.6 higher. These materials also have superior mechanical properties particularly shear and out of plane properties. RCI plans to perform brake dynamometer testing of a baseline SiC composite material whose performance including wear and structural durability will be assessed using operational clutch performance criteria provided by rotorcraft and turboshaft engine companies. Disk on disk dynamometer testing will be performed at approximately 1/3 to 1/2 scale at surface speeds up to 80% of the maximum level desired.