Engineer, McDonnell Douglas Corporation, St. Louis, Mo.
Pages: 11 Published: Jan 1983
Current processing techniques for graphite/epoxy (Gr/Ep) composites require use of autoclaves. Because the autoclave is a major capital investment, materials that either eliminate the need for the autoclave or shorten autoclave cure times could reduce fabrication costs. The object of this study was to investigate composite materials that had short cure times and that were cured with vacuum-bag pressure only.
Two of the materials investigated were Hexcel HX565/T300 and Celanese diallyl phthalate (DAP)/C6000. Basic mechanical properties were determined initially for these systems. Because these initial results looked promising, the materials were further evaluated. These investigations included processing-time studies and fabrication and testing of a configured part. For the processing-time studies, viscosity profiles and interlaminar shear strengths were determined for several different cure cycles. The results did not indicate any advantage in altering the fast heat-up rate and short-cure-time cure cycle. The configured part evaluated was a hat-stiffened curved panel. Autoclave and vacuum-bag cured parts were tested in compression, in the post-buckling regime, and compared with a Gr/Ep system. The results from all tests indicate that the mechanical properties for these quick-cure and vacuum-bag cure systems are inferior to current Gr/Ep systems. However, the quick-cure and vacuum-bag cure materials might be cost effective in applications where minimum gage requirements make conventional Gr/Ep less efficient.
graphite/epoxy, epoxy, polyvinyl ether, diallyl phthalate, autoclave processing, vacuum-bag processing
Paper ID: STP28545S