Powder extrusion of shaped sections

Abstract

The present invention provides a continuous powder extrusion method for making an article having a profile including an outer shape and optionally including one or more inner hollows. One or more bulk material powders and one or more binders are provided, and the bulk material powders and the binders are mixed to form a mixture. A die is provided, the die optionally including a mandrel having one or more shapes. The mixture is extruded through the die and the optional mandrel to produce a green form. The green form is debound to produce a brown form and the brown form is sintered to produce a densified form. The densified form is optionally processed using thermal, mechanical, and/or thermomechanical processing to produce a wrought form. The densified or wrought form is optionally cut to a length and/or finished using traditional metal finishing processes.

1 . A method for making a powder extruded non-molded article, the method comprising:
 providing one or more bulk material powders;   providing one or more binders;   mixing the one or more bulk material powders and the one or more binders to make a mixture;   providing a die having a shape;   extruding the mixture through the die to produce a green form;   debinding the green form to produce a brown form;   sintering the brown form to produce a densified form; and   processing the densified form to produce an article.   
     
     
         2 . The method of  claim 1 , wherein the extruding step comprises receiving the green form onto a setter tray, wherein the debinding step comprises supporting the green form on the setter tray, and wherein the sintering step comprises supporting the brown form on the setter tray. 
     
     
         3 . The method of  claim 2 , wherein the setter tray has a recess for receiving the green form. 
     
     
         4 . The method of  claim 3 , wherein the sintering step further comprises tilting the setter tray to enable the brown form to shrink during the sintering step without fracturing. 
     
     
         5 . The method of  claim 2 , wherein the green form is received as a coil onto a setter tray to enable the brown form to shrink during the sintering step without fracturing. 
     
     
         6 . The method of  claim 5 , wherein the setter tray is a conical setter tray. 
     
     
         7 . The method of  claim 1 , wherein the extruding step comprises:
 heating the mixture and forcing the heated mixture through the die to produce a green form having a net or near-net outer profile corresponding to the shape of the die.   
     
     
         8 . The method of  claim 7 , wherein the die has a generally circular shape and wherein the processing step comprises forming external threads onto the densified form. 
     
     
         9 . The method of  claim 1 , wherein the die includes a mandrel having one or more shapes and wherein the extruding step comprises:
 heating the mixture and forcing the heated mixture through the combination of the die and the mandrel to produce a green form, the green form having an outer profile corresponding to the shape of the die, the green form further having one or more inner hollows respectively corresponding to the one or more shapes of the mandrel.   
     
     
         10 . The method of  claim 9 , wherein the die has a generally circular shape and the mandrel has a generally hexagonal shape. 
     
     
         11 . The method of  claim 1 , wherein the processing step comprises cutting the densified form to a length. 
     
     
         12 . The method of  claim 1 , wherein the processing step comprises subjecting the densified form to mechanical then thermal processing, and/or to thermomechanical processing, or some combination thereof. 
     
     
         13 . The method of  claim 1 , wherein the bulk material powders comprise one or more metallic materials. 
     
     
         14 . The method of  claim 13 , wherein the metallic material comprises one or more of austenitic, ferritic, martensitic and precipitation hardenable stainless steels per ASTM F899, 316L stainless steel per ASTM F138, commercially pure Titanium per ASTM F67, Ti 6Al 4V per ASTM F1472, Ti 6Al 4V ELI per ASTM F136, Ti 6Al 7Nb per ASTM F1295, Nitinol per ASTM F2063, Cobalt Chromium Molybdenum (CoCrMo) per ASTM F75 or ASTM F1537, Cobalt Chromium Tungsten per ASTM F90, and Cobalt Nickel Chromium per ASTM F562. 
     
     
         15 . The method of  claim 1 , wherein the bulk material powders comprise a ceramic material. 
     
     
         16 . The method in  claim 1  wherein the bulk material powders comprise a combination of metallic and ceramic materials. 
     
     
         17 . The method of  claim 1 , wherein the bulk material powders have a diameter of less than 50 microns. 
     
     
         18 . The method of  claim 17 , wherein the bulk material powders have a diameter of less than 25 microns. 
     
     
         19 . The method of  claim 1 , wherein the bulk material powders have a diameter of less than 80 microns. 
     
     
         20 . The method of  claim 19 , wherein the bulk material powders have a diameter of less than 40 microns. 
     
     
         21 . The method of  claim 1 , wherein the debinding step comprises heating the green form. 
     
     
         22 . The method of  claim 1 , wherein the debinding step comprises dissolving the binder in at least one solvent, supercritical fluid, or water. 
     
     
         23 . The method of  claim 1 , wherein the binder comprises a polymer binder. 
     
     
         24 . The method of  claim 23 , wherein the debinding step comprises decomposing the polymer using a reactive chemical debinding agent. 
     
     
         25 . The method of  claim 1 , wherein the binder comprises an inorganic binder. 
     
     
         26 . A non-molded article having a net or near-net profile, the article being produced by the method comprising:
 providing one or more bulk material powders;   providing one or more binders;   mixing the one or more bulk material powders and the one or more binders to make a mixture;   providing a die having a shape;   extruding the mixture through the die to produce a green form;   debinding the green form to produce a brown form;   sintering the brown form to produce a densified form; and   cutting the densified form to a length to produce an article;   the profile of the article comprising an outer shape corresponding to the shape of the die.   
     
     
         27 . The article of  claim 26 , wherein the die includes a mandrel having one or more shapes and the profile of the article further comprises one or more internal lumens respectively corresponding to the one or more mandrel shapes. 
     
     
         28 . The article of  claim 27 , wherein the die has a generally round shape and the mandrel has a generally hexagonal shape for forming an article having a generally round outer shape and a generally hexagonal internal lumen. 
     
     
         29 . The article of  claim 27 , wherein the die has a generally round shape and the mandrel has a generally octagonal shape for forming an article having a generally round outer shape and a generally octagonal internal lumen. 
     
     
         30 . The article of  claim 26 , wherein the die has a generally circular shape and wherein external threads are formed onto the article. 
     
     
         31 . The article of  claim 26 , wherein the bulk material powders comprise one or more of austenitic, ferritic, martensitic and precipitation hardenable stainless steels per ASTM F899, 316L stainless steel per ASTM F138, commercially pure Titanium per ASTM F67, Ti 6Al 4V per ASTM F1472, Ti 6Al 4V ELI per ASTM F136, Ti 6Al 7Nb per ASTM F1295, Nitinol per ASTM F2063, Cobalt Chromium Molybdenum (CoCrMo) per ASTM F75 or ASTM F1537, Cobalt Chromium Tungsten per ASTM F90, and Cobalt Nickel Chromium per ASTM F562. 
     
     
         32 . The article of  claim 31 , wherein the bulk material powders have a diameter of less than 50 microns and the article has a net or near net shape. 
     
     
         33 . The article of  claim 31 , wherein the bulk material powders have a diameter of less than 80 microns and the article is further formed by thermal processing, mechanical processing, thermomechanical processing, or some combination thereof. 
     
     
         34 . The article of  claim 26 , wherein the bulk material powders comprise a ceramic material. 
     
     
         35 . A method for making a powder extruded non-molded article, the method comprising:
 providing one or more bulk material powders;   providing one or more binders;   mixing the one or more bulk material powders and the one or more binders to make a mixture;   providing a die having a shape;   heating the mixture;   extruding the mixture through the die to produce a green form having a net or near-net outer profile corresponding to the shape of the die;   receiving the green form onto a setter tray;   debinding the green form to produce a brown form;   sintering the brown form to produce a densified form, the setter tray enabling the brown form to shrink without fracturing; and   processing the densified form to produce an article.   
     
     
         36 . The method of  claim 35 , wherein the die includes a mandrel having one or more shapes and wherein when the mixture is extruded through the die, the mandrel produces one or more inner hollows in the green form respectively corresponding to the one or more shapes of the mandrel. 
     
     
         37 . The method of  claim 35 , wherein the processing step comprises cutting the densified form to a length. 
     
     
         38 . The method of  claim 35 , wherein the processing step comprises subjecting the densified form to mechanical then thermal processing and/or to thermomechanical processing, or some combination thereof, to produce a wrought form.