PREPARATION OF CONTINUOUS ZRO2-Y2O3 FIBERS BY PRECURSOR METHOD USING POLYZIRCONOXANE

The acid catalyzed hydrolysis of bis (ethyl acetoacetato) zirconium diisopropoxide [(etac)2Zr(OPr(i))2; EZP] in methanol followed by concentration of the reaction mixture gave a polyzirconoxane (PZO) solution which showed excellent spinnability and very remarkable stability to self-condensation as not to gel for more than one year. A 3.0 mol% Y2O3-Containing solution (Y-PZO) was prepared by addition of tris (acethyl acetonato) yttrium [Y(acac)3] to PZO solution without changing spinnability and stability. Dry spinning of the Y-PZO solution provided continuous pale yellow precursor fibers of 10-30 mum diameter with circular or ellipsoidal cross sections. Continuous ZrO2-Y2O3 fibers of 10-13 mum diameter with a tensile strength of about 1 GPa were obtained by sintering precursor fibers at 1200-degrees-C (2-degrees-C/min) for 1 h after steam treatment.