Effect of Sol-Gel Precursors on Structure and high Temperature Oxidation Resistance of ZrO₂-Y₂O₃ Ceramic Coatings

Both metalorganic and inorganic salt precursors were used for preparation of GH220/NiCrAlYSiHf/ZrO₂-Y₂O₃ ceramic coatings. Effect on the structure of the Sol and the high temperature resistance of the resultant ceramic coatings were studied. It was found that although both process can be used for preparation of dense continuous ZrO₂-Y₂O₃ ceramic coatings,only the metalorganic process can give excellent high temperature resistance to the resultant ceramic coatings. Residue acid radicals presented in the Sol may be responsible for the bad performance of the coatings prepared from the inorganic salt process.