THE PERMITTIVITY AT X-BAND FREQUENCIES OF NICKEL-COATED GRAPHITE FIBERS IN AN EPOXY MATRIX

In this study, we have investigated the microwave dielectric behavior of a composite formed by embedding nickel-coated graphite fibers in an epoxy matrix. Permittivities of composites in the X-band frequency ra nge as a function of fiber concentration, fiber length, and the degree of fiber aggregation were studied, Fiber aggregation was reduced sign ificantly by the addition of silica particles to the composite mixture before epoxy curing. Predictions from the mean field theory fit the e xperimental data well at dilute fiber concentrations.