Characterization and enhancement of the fiber-matrix adhesion in pitch-based carbon fiber/epoxy matrix composites

Thesis/Dissertation · Sun Jan 01 04:00:00 EST 1989

OSTI ID:5526029

King, T R

The level of fiber-matrix adhesion present in Tonen HM pitch-based carbon fiber/EPON 828 epoxy matrix composite materials was characterized. It was determined that the failure of a weak layer on the fiber surface was likely responsible for the poor base case fiber-matrix adhesion. A number of fiber treatments, designed to enhance the strength of the fiber-matrix interfacial bond were evaluated. Two classes of fiber treatments were considered. The first group was designed specifically to improve the chemical bonding between the fiber and matrix. The second group of treatments was designed to have the capability to remove weak regions on the fiber surface, in addition to increasing the degree of chemical interaction between the fiber and matrix. The treatments designed to enhance only the chemical bonding between the fiber and matrix were applied to unsized HM fibers which had previously received a proprietary, oxidative surface treatment by the manufacturer (i.e., HMS fibers). It was concluded that the effectiveness of these treatments was dependent upon the level of fiber-matrix adhesion present for the base fibers. An electrochemical treatment in ammonium sulfate, potentially capable of removing weak graphitic regions on the fiber surface, and also increasing the fiber-matrix chemical interactions, was subsequently developed. This treatment was observed (using the embedded single fiber and short beam shear tests) to produce strong fiber-matrix interfacial bonding, even when the base case adhesion was weak.

• Research Organization: Wyoming Univ., Laramie, WY (United States)
• OSTI ID: 5526029
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360601* -- Other Materials-- Preparation & Manufacture
360603 -- Materials-- Properties
ADHESION
BONDING
CARBON FIBERS
COMPOSITE MATERIALS
COMPRESSION STRENGTH
EPOXIDES
FABRICATION
FAILURES
FIBERS
INTERFACES
JOINING
MATERIALS
MECHANICAL PROPERTIES
ORGANIC COMPOUNDS
ORGANIC OXYGEN COMPOUNDS
SHEAR PROPERTIES
SURFACE TREATMENTS