Abstract
Technique of dip-coating (solution, sol-gel, precursor) is simple and inexpensive compared with others, such as CVD, PVD, plasma sputtering. In a sol-gel coating process, ceramic coatings are generally formed on fibers, which have proven to be advantages for protecting the fiber from high temperature oxidation, degradation and chemical interaction between the fiber and matrix. Therefore, in this work, the layers of ZrO2-Al2O3 were coated on the surface of SiC fibers (Tyranno SA fiber) by dip-coating. The citric acid-ethylene glycol solution containing Al and Zr ions was polymerized at 130oC to obtain a polymerized complex precursor. 2D-woven SiC fibers were dipped into this precursor few times. Heat treatment for coated fiber was conducted at 500-1000oC for 1 h in nitrogen atmosphere. Coated fibers were characterized by infrared (IR) spectroscopy, scanning electron microscopy (SEM) and X-ray diffractometry (XRD). Mechanical properties of the composites using these fibers will be presented.
