Thermal Stability and Chemical Corrosion Resistance of Newly Developed Continuous Si-Zr-C-O Tyranno Fiber

A new continuous inorganic fiber, Si-Zr-C-O fiber, containing zirconium instead of titanium (Si-Ti-C-O fiber), has been successfully developed. This new Si-Zr-C-O fiber exhibits improved thermal stability and chemical corrosion resistance and has a decreased oxygen content. This reduction in oxygen content of Si-Zr-C-O fiber can be achieved by changing additives, from titanium alkoxide to a zirconium complex during the polymerization process of the precursor polymer. Continuous Si-Zr-C-O fiber "ZM" and "improved ZM" produced by oxidation curing had oxygen contents of 10 and 7.6 wt%, respectively. The oxygen content of "ZE" produced by electron beam curing was reduced to 1.7 wt%. The thermal stability and oxidation resistance of both ZM fiber and improved ZM fiber were superior to those of Si-Ti-C-O fiber (LoxE) produced by electron beam curing which has an oxygen content of only 5wt%. The crystalline grain growth of ZM fiber up to 1773 K for 1 hour in argon gas and the level of decomposition of ZM fiber during heat treatment in CO gas at 1773K for 3 hours were very low in comparison with those of LoxM fiber (Si-Ti-C-O) by oxidation curing and LoxE fiber. Furthermore, concerning chemical corrosion resistance, when ZM and LoxM fibers were immersed in salt(NaCl) water and then heat treated at 1273K in air for 2 hours, LoxM fiber containing titanium was considerably damaged, but ZM fiber exhibited minimal damage.