Method for treating a thermally loaded component

Abstract

A method for treating a thermally loaded component having a metallic substrate and at least partially coated on an outer side with a protective coating, is provided. The method includes the step of predamaging the protective coating before removing the protective coating from the substrate using dry ice blasting. The predamaging is performed so as to lead to an increase of efficiency of the removal process.

1 . A method for treating a thermally loaded component having a metallic substrate and at least partially coated on an outer side with a protective coating, the method comprising:
 predamaging the protective coating; and   removing the protective coating from the substrate using dry ice blasting, wherein the predamaging is performed so as to lead to an increase of efficiency of the removal process.   
     
     
         2 . The method as recited in  claim 1 , wherein the predamaging includes creating cracks in the protective coating. 
     
     
         3 . The method as recited in  claim 1 , further comprising heating the component at least locally to a raised temperature substantially greater than room temperature. 
     
     
         4 . The method as recited in  claim 3 , wherein the heating is performed using at least one of a burner, a plasma jet and a laser jet. 
     
     
         5 . The method as recited in  claim 3 , wherein the substrate includes at least one of an Ni-based and a Co-based alloy, and wherein the raised temperature is less than or equal to 600° C. 
     
     
         6 . The method as recited in  claim 2 , wherein the predamaging includes shot-peening the protective coating so as to create the cracks. 
     
     
         7 . The method as recited in  claim 6 , wherein the shot-peening is performed using steel balls having a diameter between 0.5 and 5 mm. 
     
     
         8 . The method as recited in  claim 7 , wherein the shot-peening includes introducing the steel balls into a high-speed flow of a gas for blast formation. 
     
     
         9 . The method as recited in  claim 8 , wherein the gas includes compressed air. 
     
     
         10 . The method as recited in  claim 1 , wherein the dry ice blasting is performed using dry ice grains including carbon dioxide having a temperature of about −78° C. 
     
     
         11 . The method as recited in  claim 10 , wherein the dry ice grains include compressed carbon dioxide snow and have a diameter of between 1 and 3.5 mm and a length of between 2 and 10 mm. 
     
     
         12 . The method as recited in  claim 11 , wherein the dry ice blasting includes accelerating the dry ice grains in a compressed air flow to speeds of about 300 m/s before striking the predamaged protective coating. 
     
     
         13 . The method as recited in  claim 1 , wherein the component has a thermally grown oxide coating directly beneath the protective coating, and wherein the removing includes removing the thermally grown oxide coating together with the protective coating. 
     
     
         14 . The method as recited in  claim 1 , wherein the component has a bonding layer disposed between the substrate and the protective coating, and wherein the removing includes removing the protective coating down to the bonding layer. 
     
     
         15 . The method as recited in  claim 1 , wherein the includes at least one of a Ni-based and a Co-based alloy, and the protective coating is a ceramic thermal barrier coating. 
     
     
         16 . The method as recited in  claim 15 , wherein the thermal barrier coating includes yttrium-stabilized zirconium oxide. 
     
     
         17 . The method as recited in  claim 1 , wherein the component is at least one of a stator blade and a rotor blade of a gas turbine. 
     
     
         18 . The method as recited in  claim 1 , wherein the component is a burner component. 
     
     
         19 . The method as recited in  claim 18 , wherein the burner component includes a protective segment of a combustion chamber of an internal combustion engine.