FIBER PULLOUT PROCESSES AND MECHANISMS OF A CARBON-FIBER REINFORCED SILICON-NITRIDE CERAMIC COMPOSITE

Details of fiber pullout processes and mechanisms are addressed for a carbon fiber reinforced silicon nitride ceramic composite. The energy for fiber pullout, gamma(po), is experimentally measured by the work-of-fracture technique using test specimens with a circumferential notch. A precise determination of the distribution of pullout fibers combined with the experimental results of the pullout energy provides an important insight into the micromechanical processes and mechanisms of the composite fracture. Various energy dissipation processes associated with the composite fracture, the frictional interface shear stress, the Weibull modulus of the reinforcing fibers, and composite designs for improved toughening are discussed.