COMPONENT HAVING THERMAL BARRIER COATING PROVIDED WITH PROTECTIVE TOP COATING, GAS TURBINE ENGINE COMPONENT AND METHOD FOR PREVENTING BREAKAGE OF COATING

摘要

PURPOSE: Provided is a component having a thermal barrier coating, which further comprises a protective top coating to maintain its performance when exposed to high temperature under an extreme thermal environment surrounding a gas turbine engine. CONSTITUTION: The component having a thermal barrier coating(62) on the surface thereof comprises an outer protective top coating(64) overlapped with the thermal barrier coating. The outer protective top coating(64) comprises alumina particles in a silica-containing matrix. The alumina particles comprise about 5-85 wt% of the outer protective top coating. The silica-containing matrix essentially comprises at least one of silica, silicate and mullite and comprises about 1-45 wt% of the outer protective top coating. The thermal barrier coating has a thickness determined by the function depending on the temperature where the thermal barrier coating is used.