A wide variety of brake materials are presently available for meeting the needs of today's vehicle brakes. One of the most demanding brake applications requiring use of materials with the best available properties is in the field of aircraft brakes. Aircraft brakes must be lightweight, while having high static and dynamic friction characteristics. They must produce consistent and smooth braking while demanding only relatively low pressure to produce the desired braking. The life of the brake material must be long enough to prevent constant changing of the brakes. Among the materials presently used for such brakes are organic substances, copper, steel and carbon.
One type of carbon aircraft brake is made from carbon/carbon composites. Carbon brakes are formed by a heated mold process into disks having very light weight and a relatively low coefficient of friction. The faces of the disks serve as the friction surfaces. Because carbon disks have a low coefficient of friction, the demands of aircraft brakes require that such disks be arranged in multiple disk brake systems so that sufficiently high braking ability is achieved. These brakes also suffer from inconsistent friction characteristics. Particularly, the dynamic coefficient of friction of carbon brakes is erratic at low speeds and the static coefficient of friction is erratic over broad temperature ranges.