Fiber-matrix Interface Mechanical Properties of Carbon-Carbon Composites

Abstract

Fiber-matrix interface mechanical properties are the key design point for the composites, however, methodology for evaluating interface properties of C/Cs are not still well established. In this study, capability of the fiber bundle push-out method was demonstrated as a measurement technique of fiber-matrix interfacial mechanical properties of various C/Cs. First, to carefully determine the experimental conditions to give proper interface mechanical properties, the influences of a radius of an indenter and the thickness of specimens on the measured results were examined. From the experimental result, interface debonding stress, τd, and sliding stress, τs, could be obtained as a constant value independent from specimen thickness as long as tested using the same indenter size and the proper specimen thicknesses of 2273 K by the structure change of the interface from the graphitization of matrices. Finally, The fiber bundle push-out method was proved to be a strong tool to investigate fiber-matrix interface mechanical properties of C/Cs.