Preparation of polycrystalline YAG/alumina composite fibers and YAG fiber by sol-gel method

Polycrystalline yttrium-aluminum garnet, Y3Al5O12 (YAG) fiber and alpha -al umina and YAG matrix composite fiber were prepared by the sol-gel method. a -Alumina and YAG matrix composite fiber with fine and homogeneous microstru cture could be successfully fabricated by interpenetrating YAG in alumina m atrix and adding a-alumina of seed particles to fibers. Effect of a-alumina seed particles and YAG on crystallization and microstructure of composite fiber were discussed. The size of alumina matrix of the composite fibers he ated at 1600 degreesC for 4 h was below 2 mum The tensile of strength alumi na fiber heat-treated at 1500 degreesC was 0.2 GPa, while that of the compo site fiber was 1.1 GPa. (C) 2001 Elsevier Science Ltd. All rights reserved.