High-temperature polymer matrices under development have glass transition and potential use temperatures above 400oC. However, useful lifetime at elevated temperatures is reduced by oxidation of both matrices and fiber reinforcements of components. The goal of this project is to develop adherent, oxidation resistant coatings to extend high-temperature lifetimes of advanced polymer composites. Polymer matrices will be stabilized by thermal aging under inert gas atmospheres to drive anaerobic thermal decomposition reactions to completion. Thin-film barrier coatings will be applied by ion beam assisted deposition (IBAD) to stabilized test coupons in preparation for oxidation testing. The IBAD process uses high-energy ions to drive coating atoms into the substrate, thereby promoting extremely strong coating-substrate bonds. Extended elevated temperature oxidation testing of both coated and uncoated test coupons will be performed to assess the effectiveness of the oxygen barrier coatings. Post-test specimens will be subjected to optical and scanning electron microscopy to evaluate coating/matrix/fiber degradation.Polymer matrix composites with 400oC use temperatures would be suitable replacements for heavier metallic alloys in both commercial and military aeropropulsion systems.composites, coatings, oxidation-resistance, IBADSTATUS: Phase I Only
