Crack Propagation in Fibrous Composite Materials Studied by SEM

Abstract

The modes of crack propagation, as well as the fracture surface of carbon Fiber-Reinforced composites were studied by means of a Scanning Electron Microscope (SEM). The composite specimens used were composed of an epoxy polymer matrix reinforced with unidirectional carbon fibers. In order to study the influence of the difference in the mechanical proper ties of the constituent materials on the overall crack propagation behavior of the composite, three different types of carbon fibers were used, while several amounts of plasticizer were added in the matrix material. From the crack propagation behavior observed from the microphotographs, conclu sions concerning the strength of the composite, the mode of failure, and the adhesion between the phases were derived.