Gas turbine component, method for its production and casting mold for use of this method

Abstract

A method is provided for casting a gas turbine component having at least a first section and a second section. As per the method, a liquid metal is cast into a casting mold and solidification of the metal is induced by means of controlled cooling. The cooling of the liquid metal in the first section is controlled in such a way that the metal solidifies in a directionally solidified crystal structure or a single-crystal structure. In the second section the cooling is carried out in such a way that it solidifies in a multidirectional crystal structure.

1 . A method for casting a gas turbine component having at least a first section and a second section, the method comprising:
 casting a liquid metal into a casting mold, and   inducing solidification of the metal by means of controlled cooling,   wherein the cooling of the liquid metal in the first section is controlled in such a way that the metal solidifies in a directionally solidified crystal structure or a single-crystal structure, and   wherein in the second section the cooling is carried out in such a way that it solidifies in a multidirectional crystal structure.   
     
     
         2 . The method as claimed in  claim 1 , wherein the second section of the gas turbine component comprises a low-mass region and a high-mass region, wherein the method further comprises supplying additional liquid metal to the high-mass region at least when the directionally solidified or single-crystal structure is being formed. 
     
     
         3 . The method as claimed in  claim 2 , comprising storing the additional liquid metal in the form of a reservoir of liquid metal which adjoins the wide region. 
     
     
         4 . The method as claimed in  claim 3 , wherein the additional liquid metal is kept liquid by thermal insulation of the reservoir. 
     
     
         5 . The method as claimed in  claim 3 , wherein the additional liquid metal is kept liquid by adding an exothermic material to the free surface of the additional liquid metal in the reservoir. 
     
     
         6 . The method as claimed in  claim 1 , wherein the gas turbine component is a rotor blade or guide vane, and the first section is the main blade of the rotor blade or guide vane. 
     
     
         7 . The method as claimed in  claim 6 , wherein
 the gas turbine component is a rotor blade,   the second section includes the blade root and the blade platform,   the high-mass region and the low-mass region are both part of the blade root, and   the low-mass region lies between the high-mass region and the platform.   
     
     
         8 . The method as claimed in  claim 7 , wherein the high-mass region comprises side surfaces, and the additional liquid metal is supplied to the side surfaces of the high-mass region. 
     
     
         9 . The method as claimed in  claim 7 , wherein the high-mass region comprises an end surface which constitutes the end of the rotor blade facing away from the main blade, and wherein the additional liquid metal is supplied to the end surface. 
     
     
         10 . A gas turbine component, comprising:
 a first section, and   a second section, which is formed integrally with the first section,   wherein the first section has a directionally solidified crystal structure or a single-crystal structure and the second section has a multidirectionally solidified crystal structure.   
     
     
         11 . The gas turbine component as claimed in  claim 10 , wherein the gas turbine component is formed as a rotor blade or guide vane, wherein the first section is formed by the main blade. 
     
     
         12 . A casting mold for casting a gas turbine component by means of the method as claimed in one of  claims 1  to  9 , the casting mold comprising:
 at least a first casting mold section for molding the first section of the gas turbine component, 
 a second casting mold section for molding the second section of the gas turbine component, and 
 a supply channel which communicates with the second casting mold section in order to permit supply of additional liquid metal into the second casting mold section. 
 
     
     
         13 . The casting mold as claimed in  claim 12 , wherein the supply channel comprises a volume for receiving a reservoir of liquid metal. 
     
     
         14 . The casting mold as claimed in  claim 12 , wherein the casting mold has a thermal insulation where the supply channel is located. 
     
     
         15 . The casting mold as claimed in  claim 12 , wherein the second casting mold section comprises a casting mold region with a narrow intermediate space for molding the low-mass region of the gas turbine component and a casting mold region with a wide intermediate space for molding the high-mass region of the gas turbine component, and wherein the supply channel leads to the casting mold region with the wide intermediate space. 
     
     
         16 . The casting mold as claimed in  claim 12 , wherein
 the gas turbine component is a rotor blade or guide vane, and   the first casting mold section has a contour for molding the main blade.   
     
     
         17 . The casting mold as claimed in claim, wherein
 the gas turbine component is a rotor blade,   the second casting mold section includes a blade root casting mold section for molding the blade root and a platform casting mold section for molding the blade platform,   the casting mold region with the narrow intermediate space and the casting mold region with the wide intermediate space are both part of the blade root casting mold section, and   the casting mold region with the narrow intermediate space lies between the casting mold region with the wide intermediate space and the platform casting mold section.   
     
     
         18 . The casting mold as claimed in  claim 17 , wherein the casting mold region with the wide intermediate space comprises casting mold side surfaces, and wherein supply channels lead to the casting mold side surfaces of the casting mold region with the wide intermediate space. 
     
     
         19 . The casting mold as claimed in  claim 17 , wherein the casting mold region with the wide intermediate space comprises a casting mold end surface for defining the end surface of the blade root facing away from the main blade, and the at least one supply channel leads to the casting mold end surface.