Heat-exchanging forming tool and method of making

Abstract

A method of making a heat-exchanging forming tool for use in shaping articles of manufacture, said method comprising the steps of: forming a non-porous metallic shell of generally uniform thickness having an outer contoured shaping surface of predetermined configuration corresponding to the desired shape to be imparted to the article by the tool on the opposite backside surface inversely contoured to that of the shaping surface; supporting the shaping surface of the shell face down on an insulating support member such that the backside surface of the shell faces upwardly; arranging a container over the shell; introducing a plurality of discrete metallic elements into the container to provide a packed mass of such elements in contact with each other and with the backside surface of the shell and surrounding walls of the container, the elements being shaped such that when packed together the elements provide a network of interconnected open spaces throughout the packed mass of the elements; and heating the elements and shell sufficiently to metallurgically bond the packed metallic elements to one another and to the shell while preserving the network of interconnected open spaces between the elements thereby obtaining a one-piece structure comprised of the non-porous metallic shell backed by an integrated porous metallic support body through which a heat exchanging fluid may be passed to conduct heat to or from the shaping surface of the shell.

I claim:  
     
         1 . A method of making a heat-exchanging forming tool for use in shaping articles of manufacture, comprising: 
 providing a prefabricated non-porous metallic shell having an outer contoured shaping surface corresponding to the shape to be imparted to the article to be formed by the tool and an opposite backside surface;    providing a plurality of discrete metallic elements metallurgically bondable to each other and to the backside surface of the shell;    assembling the metallic elements against the backside surface of the shell and in contact with one another to provide a packed mass of such elements, the elements being shaped such that when packed together the elements provide a network of interconnected open spaces throughout the packed mass of the elements; and    metallurgically bonding the packed metallic elements to one another and to the shell while preserving the network of interconnected open spaces between the elements thereby obtaining a one-piece structure comprised of the non-porous metallic shell backed by an integrated porous metallic support body through which a heat exchanging fluid may be passed to conduct heat to or from the shaping surface of the shell.    
     
     
         2 . The method of  claim 1  wherein the metallic elements are packed and bonded within a container extending from the backside surface of the shell such that the structural support body assumes the shape of the interior of the container and the backside surface of the shell.  
     
     
         3 . The method of  claim 2  wherein the support body is releasable from the container.  
     
     
         4 . The method of  claim 2  wherein the container includes an insulating base having an upper support surface contoured inversely to that of the shaping surface and side walls extending upwardly of the support surface.  
     
     
         5 . The method of  claim 4  wherein the shaping surface of the shell is supported face down on the support surface of the base and the side walls of the container are extended upwardly from the backside surface of the shell.  
     
     
         6 . The method of  claim 5  wherein the side walls are lined with insulating material to prevent bonding of the support body to the side walls.  
     
     
         7 . The method of  claim 4  wherein the metallic elements metallurgically bond to the walls of the container such that the walls of the container become an integrated portion of the forming tool.  
     
     
         8 . The method of  claim 7  wherein the mass of metallic elements are encased by the container.  
     
     
         9 . The method of  claim 1  wherein the metallurgical bonding results from sintering the metallic elements and shell at an elevated sintering temperature.  
     
     
         10 . The method of  claim 1  wherein the metallic elements are coated with a low melting point metallurgical bonding metal and are heated to a temperature sufficient to fuse the coatings of contiguous metallic elements to one another and to the shell thereby producing the metallurgical bonding of the elements and shell.  
     
     
         11 . The method of  claim 10  wherein the bonding metal alloys with the metal of the metallic elements and shell.  
     
     
         12 . The method of  claim 1  wherein the metallic shell comprises a preformed cast member.  
     
     
         13 . The method of  claim 1  wherein the metallic shell comprises a preformed metal plate member.  
     
     
         14 . The method of  claim 1  wherein the metallic shell comprises a preformed thermal-spayed member.  
     
     
         15 . The method of  claim 1  wherein the preformed shell is a machined member.  
     
     
         16 . The method of  claim 1  wherein the preformed shell is fabricated from powder metal.  
     
     
         17 . The method of  claim 1  wherein the preformed shell is formed with a generally uniform thickness.  
     
     
         18 . The method of  claim 1  including supporting the shell shaping surface down on an insulating support member and arranging a five-sided metallic enclosure about the mass of metallic elements with an open end of the enclosure confronting the backside surface of the shell thereby providing a chamber housing the metallic elements, and heating the shell, elements and enclosure sufficiently to bond the elements to one another and to the shell and enclosure.  
     
     
         19 . A method of making a heat-exchanging forming tool for use in shaping articles of manufacture, said method comprising the steps of: 
 forming a non-porous metallic shell of generally uniform thickness having an outer contoured shaping surface of predetermined configuration corresponding to the desired shape to be imparted to the article by the tool on the opposite backside surface inversely contoured to that of the shaping surface;    supporting the shaping surface of the shell face down on an insulating support member such that the backside surface of the shell faces upwardly;    arranging a container over the shell;    introducing a plurality of discrete metallic elements into the container to provide a packed mass of such elements in contact with each other and with the backside surface of the shell and surrounding walls of the container, the elements being shaped such that when packed together the elements provide a network of interconnected open spaces throughout the packed mass of the elements; and    heating the elements and shell sufficiently to metallurgically bond the packed metallic elements to one another and to the shell while preserving the network of interconnected open spaces between the elements thereby obtaining a one-piece structure comprised of the non-porous metallic shell backed by an integrated porous metallic support body through which a heat exchanging fluid may be passed to conduct heat to or from the shaping surface of the shell.    
     
     
         20 . A heat-exchanging forming tool for use in shaping articles of manufacture comprising: 
 a non-porous preformed metallic shell having an outer shaping surface of predetermined contour corresponding in configuration to the desired shape to be imparted to the article by the tool; and    a porous heat-exchanging support body having a plurality of individual metallic elements packed together and against a backside surface of said shell and bonded metallurgically to one another and to said shell across contiguous points of contact while providing a network of interconnected open spaces throughout the support body defining a tortuous flow path through the support body through which a heat exchanging fluid may be passed to conduct heat to or from the shaping surface of the shell.