Method of manufacturing gas turbine part using porous metal

Abstract

A method of manufacturing a gas turbine part including a member having fluid transmission paths therein utilized as a cooling/heat insulating structure, includes the steps of: melting a metal under pressurization of an atmospheric gas; dissolving a gas in the molten metal; and solidifying the metal to thereby manufacture the member including a porous metal having thus created pores. The pores of the porous metal are arranged as a plurality of through pores and/or closed pores, each of which is formed in an substantially linear shape by controlling an angle of a solid-liquid interface in solidification with respect to a plane perpendicular to a traveling direction of the solid-liquid interface which is a determination factor of a pore growing direction.

What is claimed is:  
     
         1 . A method of manufacturing a gas turbine part including a member having a plurality of fluid transmission paths therein utilized as a cooling/heat insulating structure, comprising the steps of: 
 melting a metal as a raw material of the member under pressurization of an atmospheric gas;    dissolving a gas in the metal in a molten state; and    solidifying the metal to thereby manufacture the member including a porous metal having thus created pores, wherein the pores of the porous metal are arranged as a plurality of through pores and/or closed pores, each of which is formed in an substantially linear shape and acts as a fluid path and/or as a void exhibiting a heat insulting effect, by controlling an angle of a solid-liquid interface in solidification with respect to a plane perpendicular to a traveling direction of the solid-liquid interface, which is a determination factor of a pore growing direction.    
     
     
         2 . The method of manufacturing a gas turbine part according to  claim 1 , wherein the pores of the porous metal are generated so as to extend obliquely with respect to a surface of the porous metal by controlling the angle of the solid-liquid interface with respect to the plane perpendicular to the traveling direction of the solid-liquid interface, so that the solid-liquid interface is oblique with respect to the plane perpendicular to the traveling direction.  
     
     
         3 . The method of manufacturing a gas turbine part according to  claim 2 , wherein the metal to be melted is a sheet metal; 
 wherein the sheet metal is locally heated to generate a partial molten region in the sheet metal and cooled to solidify the partial molten region while the partial molten region is moved; and    wherein the angle of the solid-liquid interface with respect to the plane perpendicular to the traveling direction of the solid-liquid interface is controlled by cooling both sides of the sheet metal in a different degree of cooling, respectively, so that the solid- liquid interface is oblique with respect to the plane perpendicular to the traveling direction.    
     
     
         4 . The method of manufacturing a gas turbine part according to  claim 3 , wherein the sheet metal is heated by at least one of a heater and a high frequency coil to generate the partial molten region and cooled by a blower or the like to solidify the partial molten region.  
     
     
         5 . The method of manufacturing a gas turbine part according to  claim 3 , wherein the sheet metal is cooled at a different position on the sides of the sheet, respectively, or in a different degree of cooling on the sides of the sheet, respectively.  
     
     
         6 . The method of manufacturing a gas turbine part according to  claim 2 , wherein the metal to be melt is a sheet metal; 
 wherein the sheet metal is locally heated by at least one of heater and a high frequency coil to generate a partial molten region in the sheet metal and cooled to solidify the partial molten region while the partial molten region is moved; and    wherein the angle of the solid-liquid interface with respect to the plane perpendicular to the traveling direction of the solid-liquid interface is controlled by obliquely drawing out the sheet member with respect to the heater and/or the high frequency coil, so that the solid-liquid interface is oblique with respect to the plane perpendicular to the traveling direction.    
     
     
         7 . The method of manufacturing a gas turbine part according to  claim 6 , wherein the sheet metal is cooled by a blower or the like to solidify the partial molten region.  
     
     
         8 . The method of manufacturing a gas turbine part according to  claim 2 , wherein the porous metal is formed using an inside cooled casting mold capable of obtaining a sheet cast member; and 
 wherein the angle of the solid-liquid interface with respect to the plane perpendicular to the traveling direction of the solid-liquid interface is controlled by cooling both sides of the sheet cast member in a different degree of cooling, respectively, so that the solid-liquid interface is oblique with respect to the plane perpendicular to the traveling direction.    
     
     
         9 . The method of manufacturing a gas turbine part according to  claim 8 , wherein the both sides of the sheet cast member are cooled in a different degree of cooling, respectively, by controlling a flow rate of a coolant or by a cooling mechanism.  
     
     
         10 . The method of manufacturing a gas turbine part according to  claim 1 , wherein a desired cooling performance and a desired heat insulating performance of the member of the gas turbine part are realized by controlling a pore diameter and/or a porosity by controlling at least one of a pressure of the atmospheric gas and a speed of solidifying of the metal.  
     
     
         11 . The method of manufacturing a gas turbine part according to  claim 1 , wherein the metal to be melted is a sheet metal; 
 wherein the sheet metal is locally heated to generate a partial molten region in the sheet metal and cooled to solidify the partial molten region while the partial molten region is moved.    
     
     
         12 . The method of manufacturing a gas turbine part according to  claim 11 , wherein the sheet metal is heated by at least one of a heater and a high frequency coil to generate the partial molten region and cooled by a blower or the like to-solidify the partial molten region.