Novel route to alumina and aluminate interlayer coatings for SiC, carbon, and Kevlar(R) fiber-reinforced ceramic matrix composites using carboxylate-alumoxane nanoparticles

SIG, carbon, and Kevlar(R) fibers were coated with carboxylate-alumoxane nanoparticles and their calcium-, lanthanum-, and yttrium-doped analogs; firing to 1400 degrees C formed uniform aluminate coatings. Optimum processing sequences were determined. Both carboxylate-alumoxane- and ceramic-coated fibers were examined by field emission scanning electron microscopy, microprobe analysis, and optical microscopy. Coatings produced were stable to thermal cycling under air at 1400 degrees C. Fiber-reinforced ceramic matrix composites were prepared and results from 3-point bend tests for carbon/Kevlar(R)-fabric-reinforced ceramic matrix composites (CMCs) and carbon-fiber-reinforced CMCs were determined. Flexure strength for carbon-fiber- and carbon/Kevlar(R)-fiber-reinforced alumina CMCs was determined.