HIGH PURITY CERAMIC ABRADABLE COATINGS

摘要

The invention is directed to a material and method for obtaining a ceramic abradable system for high temperature applications. High purity partially stabilized zirconia and/or hafnia base material has higher sintering resistance compared to conventional 6-9 weight percent yttria stabilized zirconia systems. The benefits of these systems are higher service lifetime and low thermal conductivity to achieve high operating temperatures. System includes a superalloy substrate, oxidation resistant bond coat and a thick ceramic abradable top coat. Total coating thickness is about 0.5-5 mm. In some applications an intermediate layer of high purity partially stabilized zirconia or a partially stabilized YSZ/MCrAlY cermet is applied over the oxidation resistant bond coat. In other applications an abradable system is applied on top of a grid. Additional benefits should be reduced blade wear at high operating conditions.