A high temperature gas turbine component for use in the gas flow path that
comprises a specular optical reflector coating system. A thin specular
optical reflector coating system is applied to the gas flow path of the
component, that is, the surface of the component that forms a boundary
for hot combustion gases. The component typically includes a thermal
barrier coating overlying the high temperature metallic component that
permits the component to operate at elevated temperatures. The thermal
barrier coating must be polished in order to provide a surface that can
suitably reflect the radiation into the gas flow path. The thin reflector
coating system comprises a thin high temperature and corrosion resistant
refractory stabilizing layer, which is applied over a thin reflective
metal layer, which is applied over a thin high temperature and corrosion
resistant refractory sealing layer. The coating system is applied over
the polished thermal barrier coating by a process that can adequately
adhere the reflector to the polished surface without increasing the
roughness of the surface. The coating system reflects radiation back into
the hot gas flow path or into the atmosphere. The reflected radiation is
not focused onto any other hardware component. The design of the
component is such that the radiation is returned to the gas flow path or
sent to the atmosphere rather than absorbed into a component that only
serves to increase the temperature of such a component.