Development of Phosphorus Based Migration Resistant Anti-Oxidants for Carbon-Carbon Composite Aircraft Brakes

Matthew Levi Bolin, Southern Illinois University Carbondale

Abstract

Carbon-Carbon is a composite material made from a carbon fibrous substrate organized tightly into a carbon based matrix. Anti-oxidants are applied to the non-rubbing surfaces of the C/C composite brakes of aircrafts to prevent oxidation. Research performed by Dr. Jarlen Don and Z. Wang found problems with existing anti-oxidant systems. High relative humidity allows the anti-oxidant to migrate from the non-rubbing surfaces to the rubbing surfaces of the brake composite. This eventually results in a drop in the coefficient of friction and loss of braking properties. In order to fix the problems associated with migration, we have found the precise temperature char profile and formulating a precise chemical composition needed to reduce migration of the anti-oxidant to the rubbing surfaces when introduced to high relative humidity environments. Since Carbon-carbon (C/C) composites have retention of strength at high temperatures, they have been used for many government and private applications. Upon finding the proper temperature char profile and precise chemical composition, anti-oxidant migrations have been reduced significantly therefore improving the braking capability of aircraft brakes.