Fabrication of hybrid ceramic matrix composites by tape casting and lamination

Hybrid ceramic matrix composites consisting of continuous aligned SiC fibers and partially aligned SiC whiskers distributed in a cordierite matrix are fabricated with the tape casting and lamination technique. Continuous fiber reinforced ceramic matrix composites, whisker reinforced ceramic matrix composites and monolithic cordierite are also produced. Sintering to near theoretical density for fiber volume fractions up to 35% is achieved by hot pressing. Fiber and whisker volume fractions are adjusted and maintained with a high degree of control resulting in predictable, consistent specimens. Mechanical characterization was made by means of three point flexural testing with acoustic emission monitoring. Both continuous aligned fiber reinforcement and whisker reinforcement show improvement in strength and stiffness over monolithic specimens. The hybrid system displayed significant improvement in transverse properties when compared with the continuous fiber composite. The stress associated with the onset of microcracking in the matrix was increased for the hybrid ceramic matrix composite.