Methods for shaping green bodies and articles made by such methods

Abstract

A method of shaping a green body provides a shaped green body comprised of a plurality of sinterable particles and an organic binder. Such a method includes: ( 1 ) molding a mixture of sinterable particles and organic binder into the shape of an initial green body or intermediate, wherein the sinterable particles include at least one of metal particles or ceramic particles; and ( 2 ) shaping the green body intermediate with at least one of a stream of energy or a stream of matter, wherein the shaping yields a green body having a desired shape. The shaped green body can be sintered in order to provide a hardened body having substantially the shape of the shaped green body.

1 . A method of manufacturing a shaped green body, comprising: 
 forming an initial green body by molding a mixture of sinterable particles and organic binder into a desired shape of the initial green body, wherein the sinterable particles include at least one of metal particles or ceramic particles; and    shaping the initial green body by removing a portion of the sinterable particles from the initial green body using at least one of a stream of energy or a stream of matter to yield the shaped green body.    
   
   
       2 . A method as in  claim 1 , wherein forming the initial green body further comprises: 
 introducing the sinterable particles into a mold; and    introducing the organic binder into the mold in an, amount and distribution sufficient to hold the particles together after being released from the mold as the initial green body, wherein the initial green body is sufficiently a form-stable so as to resist cracking or breaking during shaping.    
   
   
       3 . A method as in  claim 2 , wherein the sinterable particles and organic binder are injected into the mold substantially simultaneously.  
   
   
       4 . A method as in  claim 3 , further comprising: 
 introducing the sinterable particles into a mixer;    introducing the organic binder into the mixer; and    mixing the particles and binder so as form a mixture.    
   
   
       5 . A method as in  claim 3 , wherein at least a portion of the sinterable particles are at least partially coated with the organic binder before being introduced into the mold.  
   
   
       6 . A method as in  claim 1 , wherein the shaping is performed using a laser beam.  
   
   
       7 . A method as in  claim 1 , wherein the shaping is performed using a stream of energy that comprises at least one of an electron beam, an electrical discharge, or an ion beam.  
   
   
       8 . A method as in  claim 1 , wherein the shaping is performed using a stream of matter that comprises at least one of a water-jet, a stream for sandblasting, a chemical-jet, or a fluid jet.  
   
   
       9 . A method as in  claim 8 , wherein the water-jet further comprises abrasive particles.  
   
   
       10 . A method as in  claim 1 , further comprising: 
 melting, on the stream-cut surface, at least one of a portion of the metal particles or a portion of the organic binder with a thermal beam.    
   
   
       11 . A shaped green body formed according to  claim 1 , the shaped green body comprising: 
 a plurality of sinterable particles;    the organic binder sufficiently holding the plurality of sinterable particles together in order to be form-stable during the shaping; and    at least one stream-cut surface on the shaped green body.    
   
   
       12 . A shaped green body as in  claim 11 , wherein the shaped green body consists essentially of metal particles and has a laser-cut surface thereon, the laser-cut surface being characterized as including at least one of melted metal particles or melted organic binder.  
   
   
       13 . A shaped green body as in  claim 11 , wherein the shaped green body has a volume about 10% to about 30% larger than a sintered body obtained by sintering the shaped green body.  
   
   
       14 . A method of manufacturing a shaped sintered article, comprising: 
 manufacturing a shaped green according to  claim 1;  and    sintering the shaped green body to yield the shaped sintered article.    
   
   
       15 . A method as in  claim 14 , wherein the sintering causes the shaped sintered article to have a volume that is about 10% to about 30% less than the volume of the shaped green body.  
   
   
       16 . A method as in  claim 14 , wherein the shaping is performed using a laser before the sintering to provide a laser-cut surface on the article that is substantially devoid of charring after sintering.  
   
   
       17 . A method as in  claim 14 , further comprising smoothing the stream-cut surface during sintering.  
   
   
       18 . A shaped sintered article formed according to  claim 14 , comprising: 
 a hardened sintered body, the sintered body including at least one of a metal material or a ceramic material; and    a stream-cut surface on the sintered body, the stream-cut surface being characterized by having a smoother topology after sintering compared to before sintering.    
   
   
       19 . A shaped hardened body as in  claim 18 , wherein the sintered body consists essentially of sintered metal.  
   
   
       20 . A shaped hardened body as in  claim 18 , wherein the sintered body consists essentially of ceramic.  
   
   
       21 . A shaped green body comprising: 
 a plurality of sinterable particles;    an organic binder in an amount and distribution so as to hold the plurality of sinterable particles together so that the shaped green body is form-stable when shaped with at least one of a stream of energy or a stream of matter; and    at least one stream-cut surface on the shaped green body formed by at least one of a stream of energy or a stream of matter.    
   
   
       22 . A shaped green body as in  claim 21 , wherein the plurality of sinterable particles consists essentially of ceramic particles.  
   
   
       23 . A shaped green body as in  claim 21 , wherein the plurality of sinterable particles consists essentially of sinterable metal particles.  
   
   
       24 . A shaped green body as in  claim 21 , wherein the organic binder includes at least one member selected from the group consisting of polypropylene, polyethylene, acrylic polymers, polystyrene, polyethylene-vinyl acetate, polyethylene vinyl alcohol, polyethylene acetate, chlorinated polyethylene, polyisoprene, polybutadiene, styrenebutadiene di-and tri-block polymers, polychloroprenes, polyethylene-propylene copolymers, chlorosulfonated polyethylenes, polyurethanes, styrene-isoprene copolymers, styrene ethylbutylene copolymers, styrene-butadiene rubber latex, polychloroprene latex, polymethylmethacrylate, polyethylmethacrylate, and polydimethylsiloxanes.  
   
   
       25 . A green body for use in preparing a stream-shaped green body, the green body comprising: 
 a plurality of sinterable particles including at least one of a metal material or a ceramic material; and    an organic binder matrix comprised of an organic binder that binds the sinterable particles together, wherein the organic binder at least partially coats a portion of each sinterable particle within the plurality of sinterable particles, the organic binder being characterized as: 
 being sufficiently adhesive to hold the plurality of sinterable particles together; and  
 forming a form-stable green body that is capable of being shaped with at least one of a stream of energy or a stream of matter without cracking or breaking the green body.  
   
   
   
       26 . A green body as in  claim 25 , wherein the sinterable particles consist essentially of ceramic particles.  
   
   
       27 . A green body as in  claim 25 , wherein the sinterable particles consist essentially of sinterable metal particles  
   
   
       28 . A shaped green body as in  claim 25 , wherein the organic binder includes at least one member selected from the group consisting of polypropylene, polyethylene, acrylic polymers, polystyrene, polyethylene-vinyl acetate, polyethylene vinyl alcohol, polyethylene acetate, chlorinated polyethylene, polyisoprene, polybutadiene, styrenebutadiene di-and tri-block polymers, polychloroprenes, polyethylene-propylene copolymers, chlorosulfonated polyethylenes, polyurethanes, styrene-isoprene copolymers, styrene ethylbutylene copolymers, styrene-butadiene rubber latex, polychloroprene latex, polymethylmethacrylate, polyethylmethacrylate, and polydimethylsiloxanes.