Graphite Filament Reinforced Plastics.
Abstract
The results of an investigation on graphite filament reinforced plastics are presented. The properties of a quasi-isotropic laminate construction were experimentally determined and analyzed. The analysis indicates the elastic properties should be isotropic but neither the experimental strength or modulus were isotropic. Two surface treatments were developed which improved composite performance. A pyrolytic carbon coating increased the interfacial bond slightly and increased fatigue resistance appreciably. A small amount of boron added to the pyrolytic carbon increased interlaminar shear to approximately 9,000 psi without deterioration of yarn strand tensile strength. A polyphenylquinoxaline was evaluated as a binder for high temperature resistant composite. Difficulties were encountered in adhesion to the steel mold after the 400 C molding temperature and the panels were damaged. An attempt was made to determine the initial crack formations in a bidirectional composite by applying various cyclic loads. It was found that transverse cracks were present before any stresses were applied. Analyses indicated resin contraction during cooling and low interfacial bond strength caused the cracks. The cracks have not proven detrimental to composite performances. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 1969
- Accession Number
- AD0856661
Entities
People
- Douglas R. Doner
- Nelson E. Quakenbush