Thermo-oxidative performance of metal-coated polymers and composites

This paper presents the design, fabrication and oxidation resistance performance of metal barrier coatings on high temperature polymers and their composites. The metal thin-films are selected for their ductility, low oxygen solubility and diffusivity. The coatings are fabricated with thermal and e-beam evaporation processes. The bond between the metal topcoats and the polymeric substrates is enhanced with surface roughening and other metallic interlayers. The retardation in oxidation in coated specimens is characterized with isothermal aging studies. Experimental characterization results are presented for bismaleimide resin (BMI) and unidirectional carbon-fiber reinforced composites with aluminum, alumina, titanium, and silver coatings. Results show that the oxidation resistance is strongly related to coating durability and durable coatings substantially decelerate the oxidative degradation.