FABRICATION OF POLYCRYSTALLINE ALUMINA/YAG COMPOSITE FIBERS BY SOL-GEL PROCESS USING α-ALUMINA FINE SEED PARTICLES

Abstract

Polycrystalline α-alumina matrix composite fiber dispersed with YAG (yttrium-aluminum garnet, Al₅Y₃O₁₂) particles have been prepared by sol-gel process using α-alumina fine seed particles. The α-alumina seed particles accelerated the crystallization of alumina matrix from θ to α phase resulting in composite fibers with dense and homogeneous microstructure. The YAG particles were evenly dispersed within the matrix grain as well as at grain boundaries. The effect of α-alumina seed particles and YAG on crystallization and microstructure of the composite fiber is discussed.