Accession Number : AD0489187

Title :   SURFACE TREATMENTS FOR FIBROUS CARBON REINFORCEMENTS.

Descriptive Note : Technical rept. Jul 65-Apr 66,

Corporate Author : AVCO MISSILES SPACE AND ELECTRONICS GROUP LOWELL MA AVCO SPACE SYSTEMS DIV

Personal Author(s) : Herrick, John W. ; Gruber, Philip E., Jr. ; Mansur, Frank T.

Report Date : JUL 1966

Pagination or Media Count : 138

Abstract : Studies have been conducted to improve the performance of structural and ablative composites composed of graphite- and carbon-fiber reinforced epoxy and tested for changes in interlaminar shear strength. Carbon fibers were coated with nickel and several oxides, and the oxidation resistance measured by thermogravimetric analyses in air. Chemical oxidation by nitric acid and thermal oxidation in air of graphite fibers were performed and found to increase the interlaminar shear strength of graphite/epoxy composites. These treatments also increased the surface activity of the fibers as measured by chemical group analysis and surface area. The surface cleaning treatments of solvent extraction and degassing were less effective in increasing composite shear strength, as were several chemical finishes applied to graphite and carbon fibers. The nickel coating of fibers had little effect on composite shear strength; a nylon coating produced a moderate increase. Of several oxides deposited on carbon fibers, the application of silica by vapor-phase deposition yielded the best coating and resulted in a moderate increase in oxidation resistance of the fibers. Deposition by electrophoresis and from organosilicates were attempted, but uniform fiber coatings were not obtained. Nickel, platinum, and rhodium were coated on carbon fibers electrochemically, with electroless nickel producing the best coatings. (Author)

Descriptors :   (*COMPOSITE MATERIALS, SHEAR STRESSES), FIBERS, GRAPHITE, CARBON, METAL COATINGS, COATINGS, CORROSION INHIBITION, NICKEL COMPOUNDS, OXIDES, THERMOGRAVIMETRIC ANALYSIS, NITRIC ACID, OXIDATION, REINFORCING MATERIALS, PHENOLIC PLASTICS, ABLATION, SURFACE PROPERTIES, EPOXY RESINS, NYLON, SILICON COMPOUNDS, PLATINUM COMPOUNDS, RHODIUM COMPOUNDS, ELECTROPHORESIS, POLYMERS, OPTIMIZATION, SELECTION.

Subject Categories : Laminates and Composite Materials
      Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE