Materials engineer, National Aeronautics and Space Administration, Langley Research Center, Hampton, VA
Pages: 16 Published: Jan 1983
Celion® 6000/PMR-15, Celion 6000/LARC-160, and Celion 6000/RK-99 graphite/polyimides were aged in circulating air ovens at temperatures of 202, 232, 260, and 288°C for various times up to 15 000 h. Three unidirectional specimens were studied: short-beam-shear (SBS), flexure, and 153-mm square panels. The interior region of the square panels exhibited little or no property degradation. Based on the individually aged SBS specimen results, the relative thermal-oxidative stability from highest to lowest is as follows: PMR-15, LARC-160, RK-99. Celion 6000/PMR-15 and Celion 6000/LARC-160 laminates retained at least 80% of their initial flexural strengths for the duration of aging at each temperature. Celion 6000/RK-99 laminates exhibited a 20 to 50% loss of flexural strength at all aging temperatures. All three graphite/polyimide (Gr/PI) laminate materials degraded preferentially at the specimen edge perpendicular to the fibers.
composite materials, graphite composites, polyimides, thermal aging, composites
Paper ID: STP31824S