Method for manufacturing a fuel nozzle blank with a metallic cladding

Abstract

A method for manufacturing a metallic body having a core and metallic cladding by Hot Isostatic Pressing includes the step of providing a hollow body that has a bottom wall, a core and a lateral wall, wherein the hollow body is filled with cladding material. The bottom wall and the top wall of the hollow body, prior to the step of HIP, are provided with at least one centering means for centering a final body obtained in the step HIP in a metal machining apparatus.

1 . A method for manufacturing a metallic body having a core and metallic cladding, comprising the steps of:
 providing at least one a hollow body that a bottom wall, a core that extends from the bottom wall and a lateral wall that extends from said bottom wall and encloses the core so that an inner space is formed around the core;   filling the inner space with a metallic cladding material;   closing the inner space by arranging a top wall on the lateral wall;   positioning the filled hollow body in a capsule, evacuating air from the capsule and sealing the capsule;   subjecting the capsule to Hot Isostatic Pressing (HIP) at a predetermined temperature, a predetermined pressure and for a predetermined time so that the cladding material bonds to the hollow body and a solid body is formed.   machining the solid body in a metal machining apparatus wherein at least a portion of the lateral wall is removed and the exposed cladding material is machined to a cladding of a predetermined thickness; and   the bottom wall and the top wall of the hollow body, prior to the step of Hot Isostatic Pressing, each are provided with at least one centering means for centering the final body obtained from Hot Isostatic Pressing in the metal machining apparatus.   
     
     
         2 . The method according to  claim 1 , wherein the final body is centered in the metal machining apparatus by engagement between the centering means in the final body and corresponding centers in the metal machining apparatus. 
     
     
         3 . The method according to  claim 1 , wherein the centering means is a male centering means or a female centering means. 
     
     
         4 . The method according to  claim 3 , wherein the male centering means is a cone or a truncated cone. 
     
     
         5 . The method according to  claim 3 , wherein the female centering means is a recess having the shape of a cone or a recess having the shape of a truncated cone. 
     
     
         6 . The method according to  claim 1 , wherein the centering means, prior to Hot Isostatic Pressing, are provided in a center of the bottom wall and a center of the top wall of the hollow body and are aligned along a perpendicular axis which extends through the center of the core of the hollow body and both centering means. 
     
     
         7 . The method according to  claim 1 , further comprising the step of arranging at least a first cover piece in the capsule, wherein the cover piece includes a protrusion arranged to be fully received in a female centering means or wherein the cover piece includes a recess arranged to fully receive a male centering means. 
     
     
         8 . The method according to  claim 1 , wherein the hollow body is formed by a metal machining operation in which metal is removed from a solid blank. 
     
     
         9 . The method according to  claim 1 , wherein the hollow body is manufactured by attaching a tube section to a pre-body a having the bottom wall from which the core extends such that the tube section forms the lateral wall around the core. 
     
     
         10 . The method according to  claim 1 , further comprising the step of manufacturing a plurality of hollow bodies and placing the hollow bodies on top of each other in the capsule. 
     
     
         11 . The method according to  claim 10 , wherein the bottom wall of each hollow body includes a female centering means and wherein the top wall of each hollow body includes a male centering means, wherein the female and male centering means are arranged such that a male centering means can be fully received in a female centering means. 
     
     
         12 . The method according to  claim 11 , wherein the bottom wall and/or the top wall of the plurality of hollow bodies are provided with a coating that prevents bonding of adjacent hollow bodies. 
     
     
         13 . The method according to  claim 11 , further comprising the step of placing a first cover piece in the capsule and then positioning the hollow bodies on top of each other in the capsule, wherein the cover element has a first surface which is directed towards the bottom of the capsule and a second surface which includes a protrusion which is arranged to be fully received in a female centering means. 
     
     
         14 . The method according to  claim 1 , wherein the metal machining apparatus is a lathe.