Additive manufacturing techniques and applications thereof

Abstract

In one aspect, a method of making a sintered article comprises providing a composite article comprising a porous exterior printed from a powder composition via one or more additive manufacturing techniques, the porous exterior defining an interior volume and providing a loose powder component in the interior volume. The porous exterior and loose powder component are simultaneously sintered to provide the sintered article comprising a sintered interior and sintered exterior.

1 . A method of making a sintered article comprising:
 providing a composite article including a porous exterior printed from a powder composition via one or more additive manufacturing techniques, the porous exterior defining an interior volume;   providing a loose powder component in the interior volume; and   simultaneously sintering the porous exterior and loose powder component to provide the sintered article comprising a sintered interior and sintered exterior.   
     
     
         2 . The method of  claim 1 , wherein the porous exterior forms less than 60 volume percent of the composite article. 
     
     
         3 . The method of  claim 1 , wherein the porous exterior forms 5-30 volume percent of the composite article. 
     
     
         4 . The method of  claim 1 , wherein average density of the sintered article is at least 97 percent theoretical density. 
     
     
         5 . The method of  claim 1 , wherein average density of the sintered article is at least 98 percent theoretical density. 
     
     
         6 . The method of  claim 1  comprising a density gradient between the sintered interior and sintered exterior. 
     
     
         7 . The method of  claim 6 , wherein the sintered interior is greater than 99 percent theoretical density. 
     
     
         8 . The method of  claim 7 , wherein the sintered exterior is 92-95 percent theoretical density. 
     
     
         9 . The method of  claim 1 , wherein the sintered interior has less than 2 volume percent porosity. 
     
     
         10 . The method of  claim 1 , wherein the composite article is at least 50 percent tap density of the loose powder component. 
     
     
         11 . The method of  claim 1 , wherein the composite article is at least 55 percent tap density of the loose powder component. 
     
     
         12 . The method of  claim 1 , wherein the powder composition of the porous exterior and the loose powder component have the same composition. 
     
     
         13 . The method of  claim 1 , wherein the powder composition of the porous exterior and the loose powder component are of differing compositions. 
     
     
         14 . The method of  claim 1 , wherein the powder composition of the porous exterior and the loose powder component are independently selected from the group consisting of powder metal and powder alloy. 
     
     
         15 . The method of  claim 14 , wherein the powder alloy comprises cobalt-based alloy, nickel-based alloy, iron based alloy or combinations thereof. 
     
     
         16 . The method of  claim 1 , wherein the powder composition of the porous exterior and the loose powder component comprise sintered cemented carbide particles. 
     
     
         17 . The method of  claim 16 , wherein the sintered cemented carbide particles have apparent density of at least 6 g/cm 3 . 
     
     
         18 . The method of  claim 1 , wherein the porous exterior has thickness less than or equal to 0.5 mm. 
     
     
         19 . The method of  claim 1 , wherein the porous exterior is formed around the loose powder component. 
     
     
         20 . The method of  claim 1 , wherein the loose powder component is added to the interior volume. 
     
     
         21 . The method of  claim 1 , wherein the sintered interior and sintered exterior are continuous with one another. 
     
     
         22 . The method of  claim 1  further comprising vibrating the loose powder component. 
     
     
         23 . The method of  claim 1  further comprising printing one or more lattice structures in the interior volume. 
     
     
         24 . The method of  claim 23 , wherein the lattice structures span the interior volume, contacting sections of the porous exterior. 
     
     
         25 . The method of  claim 23 , wherein the loose powder component surrounds the lattice structures. 
     
     
         26 . The method of  claim 1 , wherein the additive manufacturing technique is binder jetting. 
     
     
         27 . The method of  claim 1  further comprising removing at least a portion of the sintered exterior.