Aluminum Oxide Films for Thermo-Oxidative Protection of Polyimide-Based Composites

Abstract

AbstractPolyimide-based composites offer one of the best opportunities to bring the advantages of high modulus-to-density ratio materials to higher temperature applications, such as jet engines. In the present work, thin films (1000 - 2000Å) of aluminum oxide have been deposited by plasma-enhanced chemical vapor deposition from aluminum triisopropoxide precursor on polyimide composite substrates. The films were characterized for stoichiometry, thickness uniformity, and adhesion, and their effectiveness in the prevention of thermo-oxidative degradation of the composite at temperatures up to 371 °C has been examined and compared to that provided by other thin film materials. These preliminary results indicate that Al2O3 is not as successful as SiO2 at preventing oxidative degradation, although significant variability in the quality of the polyimide composite substrate makes precise comparison difficult.