Accession Number : ADA331084

Title :   The Effect of Carbon Fiber Type on the Electrochemical Degradation of Carbon Fiber Polymer Composites, Tri-Service Committee on Corrosion Proceedings

Descriptive Note : Conference proceedings

Corporate Author : RHODE ISLAND UNIV KINGSTON DEPT OF CHEMICAL ENGINEERING

Personal Author(s) : Qin, J. ; Brown, R. ; Ghiorse, S. ; Shuford, R.

PDF Url : ADA331084

Report Date : JUN 1994

Pagination or Media Count : 20

Abstract : The galvanic interaction between metals and carbon fiber/polymer matrix composite degrades not only the metals but the composite itself. The objective of this study was to investigate if the fiber type influenced either the mechanism or form of damage. Two different composites were examined. Both have same epoxy matrix, 3501-6 epoxy, but contain different carbon fibers, either AS4 or IM6. The surfaces of the composite materials were exposed to 0.5 N NaCl solution to simulate sea water at open circuit condition or cathodic potentials to simulate galvanic coupling of metals. Electrochemical impedance spectroscopy (EIS) was employed to monitor changes in the behavior of the composites. Modeling of experimental data indicated that the parameter, Rp, representing the polymer resistance decreased with increasing time of exposure for both open circuit conditions and applied cathodic potentials. The value of Rp also decreased with increasingly cathodic applied potentials. This suggested that a damage process for the polymer involving increased access of solution to the carbon fibers. SEM examination showed that cracks and polymer separations on the exposed but not on the unexposed surfaces. The fiber type did not appear to influence the damage mechanism in this study.

Descriptors :   *SYMPOSIA, *DEGRADATION, *CARBON FIBERS, *EPOXY COMPOSITES, SCANNING ELECTRON MICROSCOPES, MICROSTRUCTURE, POLYMERS, ELECTROCHEMISTRY, CORROSION RESISTANCE, PH FACTOR, MICROCRACKING.

Subject Categories : Industrial Chemistry and Chemical Processing
      Laminates and Composite Materials
      Test Facilities, Equipment and Methods

Distribution Statement : APPROVED FOR PUBLIC RELEASE