SOL-GEL DERIVED TIO2-SIO2 FIBERS

TiO2-SiO2 fibres with 0, 5, 10 and 20 volume % SiO2 have been prepared by drawing from a gel followed by sintering at different temperatures . Nearly one meter long fibres can be drawn easily in conditions of ab out 50% relative humidity. Addition of SiO2 inhibits the crystallisati on of TiO2 and also the anatase --> rutile transformation and improves the strength of the fibres. While the pure TiO2 fibres are brittle, t hose with 5, 10 and 20 volume % SiO2 are flexible and strong. Tensile strength values as high as 3 GPa have been achieved in the 10 volume % SiO2-TiO2 fibres. Fibres heated above 900 degrees C are brittle. The shape of the cross section of the fibres is found to depend on their d iameters.