Tungsten-containing articles and methods for forming the same

Abstract

Articles formed from powders containing tungsten and at least one binder. In some embodiments, the article contains at least one metallic binder. In some embodiments, the binder includes tin and/or a tin-containing alloy, such as bronze. In some embodiments, the article contains at least one non-metallic binder, such as a polymeric binder. In some embodiments, the article contains both a metallic binder and a non-metallic binder. In some embodiments the article is a firearms projectile, such as a bullet or shot, which may be ferromagnetic or non-ferromagnetic, which may be frangible or infrangible, and which may be jacketed or unjacketed. In some embodiments, the article is a radiation shield, and in other embodiments, the article is a weight or foundry article. In some embodiments, the article has a density in the range of approximately 8 g/cc and approximately 15 g/cc.

1 . A sintered, non-frangible shot shell, comprising: 
 a casing;    a primer;    a propellant; and    a plurality of sintered, infrangible projectiles having a density of at least 10.5 g/cc and comprising tungsten, bronze and iron.    
     
     
         2 . The shell of  claim 1 , wherein the projectiles are formed by compacting a powdered mixture comprising tungsten powder, bronze powder and iron powder.  
     
     
         3 . The shell of claim l,wherein the projectiles comprise at least 50 wt % tungsten.  
     
     
         4 . The shell of  claim 1 , wherein the projectiles have a density of at least 12 g/cc.  
     
     
         5 . The shell of  claim 1 , wherein the projectiles comprise at least 10 wt % bronze.  
     
     
         6 . The shell of  claim 1 , wherein the projectiles further include a coating.  
     
     
         7 . The shell of  claim 6 , wherein the coating is a metallic coating.  
     
     
         8 . The shell of  claim 6 , wherein the coating is a non-metallic coating.  
     
     
         9 . The shell of  claim 1 , wherein the projectiles further include a polymeric binder.  
     
     
         10 . The shell of  claim 1 , wherein the projectiles are formed by compressing a powder-form composition of matter that includes tungsten powder, bronze powder and iron powder.  
     
     
         11 . A method for manufacturing a firearm projectile comprising tungsten and bronze, the method comprising: 
 mixing at least a tungsten-containing powder and a bronze powder to form a powder-form composition of matter;    placing the powder-form composition of matter into a die; and    compressing the powder-form composition of matter to produce a firearm projectile having a density of at least 10.5 g/cc.    
     
     
         12 . The method of  claim 11 , wherein the projectile has a density of at least 12 g/cc.  
     
     
         13 . The method of  claim 11 , wherein the composition of matter further includes a non-metallic binder component.  
     
     
         14 . The method of  claim 13 , wherein the non-metallic binder component is a heat-actuated polymeric component.  
     
     
         15 . The method of  claim 11 , wherein the compressing step includes compressing the composition of matter to at least 60 ksi.  
     
     
         16 . The method of  claim 15 , wherein the compressing step includes compressing the composition of matter to at least 75 ksi.  
     
     
         17 . The method of  claim 11 , wherein the method further includes placing the composition of matter into a jacket.  
     
     
         18 . The method of  claim 11 , wherein the method includes coating the composition of matter after the compressing step.  
     
     
         19 . The method of  claim 11 , further including heating the composition of matter without sintering the composition of matter.  
     
     
         20 . The method of  claim 11 , further including sintering the composition of matter.  
     
     
         21 . The method of  claim 20 , wherein the projectile is an infrangible projectile.  
     
     
         22 . A method for forming a firearm projectile comprising tungsten and bronze, the method comprising: 
 forming a composition of matter comprising tungsten, iron and bronze;    extruding firearms projectiles from the composition of matter via an injection molding process; and    sintering the firearms projectiles.    
     
     
         23 . The method of  claim 22 , wherein the method further includes mixing a lubricant with the composition of matter.  
     
     
         24 . The method of  claim 22 , wherein the method further includes applying a coating to the projectiles.  
     
     
         25 . The method of  claim 24 , wherein the coating is a metallic coating.  
     
     
         26 . The method of  claim 24 , wherein the coating is a non-metallic coating.  
     
     
         27 . The method of  claim 22 , wherein the projectiles comprise at least 50 wt % tungsten.  
     
     
         28 . The method of  claim 22 , wherein the projectiles have a density of at least 11 g/cc.