PROTECTIVE LAYER FOR PROTECTING PARTS AGAINST CORROSION, OXIDATION AND EXCESSIVE THERMAL STRESSES, AS WELL AS PROCESS FOR PRODUCING THE SAME

摘要

A protective coating for protecting a component from corrosion and oxidation at a high temperature and from excessive thermal stress, has a heat insulation layer including a ceramic material and an adhesion-promoting layer including a rhenium containing metal alloy. The metal alloy belongs to the alloys covered by the general term MCrAlY, where M represents cobalt and/or nickel and Y represents yttrium and/or at least one equivalent metal from the group including scandium and the rare earth elements. The protective coating is distinguished by high oxidation resistance and corrosion resistance of the alloy, by outstanding thermal fatigue properties and an effective and permanent bond between the alloy and the ceramic heat insulation layer. As a result of the heat insulation, the temperature at the outer surface of the protective coating can be considerably higher than with purely metallic protective coatings, without an increased thermal load being exerted on the component. The protective coating is therefore particularly suitable for a gas turbine component exposed to a hot combustion gas, for example a guide vane, a rotor blade or a heat shield.