Metal injection molded article with a radiopaque dispersion and methods of making same

Abstract

The present invention includes a method of making a metal injection molded article and the metal injection molded article. The method includes mixing metal powders and a binder to form a mixture. The metal powders include a bulk material and at least one radiopaque material. The mixture is injected into a mold and processed into a green part. The green part is debound to form a brown part. The brown part is sintered to create a completed article. The completed article includes a metal alloy that includes the bulk material and a dispersion of the at least one radiopaque material substantially independent of the metal alloy.

1 . A metal injection molded article comprising: 
 a metal alloy; and    a dispersion of at least one radiopaque material substantially independent of the metal alloy.    
   
   
       2 . A metal injection molded article according to  claim 1 , wherein the article comprises a medical device.  
   
   
       3 . A metal injection molded article according to  claim 1 , wherein the metal alloy comprises one or more of commercially pure Titanium, Ti 6Al 4V, Ti 6Al 4V ELI, Nitinol, Cobalt Chrome Moly, 316L stainless steel, 304 stainless steel, and 17-4PH stainless steel.  
   
   
       4 . A metal injection molded article according to  claim 1 , wherein the at least one radiopaque material comprises at least one radiopaque element.  
   
   
       5 . A metal injection molded article according to  claim 4 , wherein the at least one radiopaque element is selected from the group consisting of iridium, platinum, gold, rhenium, tungsten, palladium, rhodium, tantalum, silver, ruthenium, and hafnium.  
   
   
       6 . A metal injection molded article according to  claim 1 , wherein the at least one radiopaque material comprises at least one radiopaque alloy.  
   
   
       7 . A metal injection molded article according to  claim 6 , wherein the at least one radiopaque alloy comprises one or more of the iridium, platinum, gold, rhenium, tungsten, palladium, rhodium, tantalum, silver, ruthenium, and hafnium.  
   
   
       8 . A metal injection molded article according to  claim 1 , wherein the article has a density of at least 95%.  
   
   
       9 . A metal injection molded article according to  claim 8 , wherein the article has a density of at least 97%.  
   
   
       10 . A method for making a metal injection molded article, the method comprising: 
 mixing metal powders and a binder to form a mixture, the metal powders comprising a bulk material and at least one radiopaque material;    injecting the mixture into a mold;    processing the mixture in the mold to form a green part;    debinding the green part to form a brown part; and    sintering the brown part to create a completed article.    
   
   
       11 . A method according to  claim 10 , wherein the binder comprises a polymer binder.  
   
   
       12 . A method according to  claim 11 , wherein the debinding step comprises heating the green part.  
   
   
       13 . A method according to  claim 11 , wherein the debinding step comprises dissolving the binder in at least one solvent or water.  
   
   
       14 . A method according to  claim 10 , wherein the completed article has a density of at least 95%.  
   
   
       15 . A method according to  claim 14 , wherein the completed article has a density of at least 97%.  
   
   
       16 . A method according to  claim 10 , wherein the radiopaque material is selected to have limited solubility in the matrix material during sintering.  
   
   
       17 . A method according to  claim 16 , wherein the completed article comprising a metal alloy comprising the bulk material and a dispersion of the at least one radiopaque material substantially independent of the metal alloy.  
   
   
       18 . A method according to  claim 10 , wherein the sintering step is performed at a temperature at or above the alloying temperature of the at least one radiopaque material.  
   
   
       19 . A method according to  claim 18 , wherein the completed article comprising a metal alloy comprising the bulk material alloyed with a dispersion of the at least one radiopaque material.  
   
   
       20 . A method according to  claim 10 , wherein the at least one radiopaque material comprises at least one radiopaque element.  
   
   
       21 . A method according to  claim 20 , wherein the at least one radiopaque element is selected from the group consisting of iridium, platinum, gold, rhenium, tungsten, palladium, rhodium, tantalum, silver, ruthenium, and hafnium.  
   
   
       22 . A method according to  claim 10 , wherein the at least one radiopaque material comprises at least one radiopaque alloy.  
   
   
       23 . A method according to  claim 22 , wherein the at least one radiopaque alloy comprises one or more of the iridium, platinum, gold, rhenium, tungsten, palladium, rhodium, tantalum, silver, ruthenium, and hafnium.  
   
   
       24 . A method according to  claim 10 , further comprising machining the completed article.  
   
   
       25 . A method according to  claim 10 , further comprising coating the completed article.  
   
   
       26 . A method according to  claim 10 , further comprising annealing the completed article.  
   
   
       27 . A method according to  claim 10 , where the article is a medical device.