Sol-Gel derived SrTiO3 and SrZrO3 coatings on SiC and C-fibers

Sols in the systems Sr-Ti-O and Sr-Zr-O have been prepared by an alkoxide sol/gel-process using Strontium acetate, Titanium-isopropoxide and Zirconium-n-propoxide. SiC- and C-fibers were coated with the SrTiO3 and SrZrO3 sols. Annealing in N2-atmosphere at temperatures of 900 and 1100°C resulted in the formation of crack free coatings of monophase SrTiO3 and SrZrO3, respectively. The thickness of the coatings ranged from 350 to 500 nm. The SrTiO3 and SrZrO3 reaction products were characterized by differential thermal analysis (DTA), thermal gravimetry (TG), X-ray diffraction (XRD) and scanning electron microscopy (SEM).