Accession Number : ADA304559

Title :   Long-Term Thermal Aging of Two Graphite/Polyimide Composite Materials.

Descriptive Note : Technical rept.,

Corporate Author : NATIONAL AERONAUTICS AND SPACE ADMINISTRATION HAMPTON VA LANGLEY RESEARCH CEN TER

Personal Author(s) : Nelson, James B.

PDF Url : ADA304559

Report Date : NOV 1984

Pagination or Media Count : 26

Abstract : A general conclusion of this study was that thermal aging of small graphite/polyimide composite specimens can yield results quite different from results for larger panels more representative of structural parts. Individually aged short beam shear and flexure specimens exhibited large reductions in strengths after aging; the interior regions of the square panels, on the other hand, exhibited only minor property degradation. Aging of small test specimens indicated that the usable lifetime at 2320C is 10000 hours for PMR-15 laminates and 5000 hours for LARC-160 laminates. However, larger panels of both of these materials exhibited usable lifetimes of at least 25000 hours when aged unstressed at 2040C and 2320 C. Unidirectional laminates, large or small, of both LARC-160 and PMR-15 cracked. (KAR) p. 8

Descriptors :   *THERMAL PROPERTIES, *AGING(MATERIALS), *GRAPHITED MATERIALS, SHEAR PROPERTIES, DEGRADATION, LAMINATES, PANELS, LONG RANGE(TIME), REGIONS, INTERNAL, FLEXURAL PROPERTIES, STRUCTURAL COMPONENTS, UNIDIRECTIONAL, POLYIMIDE RESINS.

Subject Categories : Laminates and Composite Materials
      Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE