Three-dimensional metal printing

Abstract

One or more metal printing techniques are described for generating a three-dimensional metal structure, such as a one-dimensional or two-dimensional anti-scatter grid. The techniques comprise applying a thin layer of powdered metal onto a printing area and using a binder (which is printed onto the printing area according to a specified pattern) to bind the powdered metal particles together. The acts of applying powdered metal and a binder may be repeated a plurality of times until a three-dimensional metal structure having a specified height is created. Moreover, in one embodiment, once the layering is complete, another binder is applied to the one or more layers to provide strength and/or support. While heat may be used in some embodiments to activate one or more of the applied binders the three-dimensional metal structure is generally not heated to a melting point of the powdered metal.

1 . A method for three-dimensional metal printing, comprising:
 printing a first pattern onto a printing area by applying a first binder to the printing area;   applying a first layer of powdered metal onto the printing area before or during or after the first binder is applied, the first binder configured to bind particles of the first layer of powdered metal;   printing a second pattern on the printing area by applying a second binder to the printing area;   applying a second layer of powdered metal onto the printing area before or during or after the second binder is applied, the second layer imposed adjacent the first layer of powdered metal, the second binder configured to bind particles of the second layer of powdered metal; and   infiltrating the first and second layers of powdered metal using a third binder to yield a three-dimensional metal structure.   
     
     
         2 . The method of  claim 1 , comprising generating the first and second patterns by decomposing a three-dimensional model of the metal structure to identify at least two slices, where a first slice corresponds to the first pattern and a second slice corresponds to the second pattern. 
     
     
         3 . The method of  claim 2 , wherein respective slices have a thickness of between about 20 microns to about 100 microns. 
     
     
         4 . The method of  claim 1 , wherein the first layer of powdered metal and the second layer of powdered metal comprise a metal configured to attenuate radiation. 
     
     
         5 . The method of  claim 1 , wherein the first layer of powdered metal and the second layer of powdered metal comprise at least one of tungsten powder and molybdenum powder. 
     
     
         6 . The method of  claim 1 , comprising, before infiltrating the first and second layers of powdered metal using the third binder:
 displacing powdered metal of the first layer that is not bound by the first binder; and   displacing powdered metal of the second layer that is not bound by the second binder.   
     
     
         7 . The method of  claim 6 , comprising:
 activating the third binder by heating the third binder to a temperature below a melting point of the powdered metal of the first layer and below a melting point of the powdered metal of the second layer.   
     
     
         8 . The method of  claim 1 , comprising binding the powdered metal of the first and second layers to the third binder without melting the metal powder of the first layer and without melting the metal powder of the second layer. 
     
     
         9 . The method of  claim 1 , wherein the three-dimensional metal structure is an anti-scatter device configured to attenuate radiation. 
     
     
         10 . The method of  claim 9 , wherein the anti-scatter device is an anti-scatter grid positioned between an object under examination and a detector array configured to detect radiation. 
     
     
         11 . An anti-scatter apparatus manufactured from a metal printing process, the apparatus comprising:
 two or more layers of radiation attenuating powdered metal, adjacent layers of the radiation attenuating powdered metal in direct physical contact with one another; and   a binding agent configured to infiltrate at least two adjacent layers of radiation attenuating powdered metal.   
     
     
         12 . The anti-scatter apparatus of  claim 11 , wherein the radiation attenuating powdered metal comprises at least one of tungsten, lead and molybdenum. 
     
     
         13 . The anti-scatter apparatus of  claim 11 , wherein adjacent layers of radiation attenuating powdered metal are in direct physical contact with one another substantially throughout. 
     
     
         14 . The anti-scatter apparatus of  claim 11 , wherein the binding agent is configured to infiltrate the at least two layers of radiation attenuating powdered metal to form a composite structure such that an interface between a first layer of the radiation attenuating powdered metal and a second layer of the radiation attenuating powdered metal is substantially indiscernible. 
     
     
         15 . The anti-scatter apparatus of  claim 14 , wherein adjacent layers of the radiation attenuating powdered metal are in direct physical contact with one another throughout. 
     
     
         16 . A method for generating a three-dimensional anti-scatter apparatus of a radiographic examination apparatus, comprising:
 creating a first layer of the three-dimensional anti-scatter apparatus using a radiation attenuating, powdered metal;   creating a second layer of the three-dimensional anti-scatter apparatus using the radiation attenuating, powdered metal;   applying a first binder configured to bind the first layer of the three-dimensional anti-scatter apparatus to the second layer of the three-dimensional anti-scatter apparatus to generate the three-dimensional anti-scatter apparatus.   
     
     
         17 . The method of  claim 16 ,
 wherein creating the first layer of the three-dimensional anti-scatter apparatus comprises:
 applying a first layer of the radiation attenuating, powdered metal to a printing area, and 
 printing a second binder according to a specified print pattern for the first layer to bind the powdered metal comprised in the first layer; and 
   wherein creating the second layer of the three-dimensional anti-scatter apparatus comprises:
 applying a second layer of the radiation attenuating, powdered metal on the printing area, the second layer applied adjacent to the first layer, and 
 printing a third binder according to a specified print pattern for the second layer to bind the powdered metal comprised in the second layer. 
   
     
     
         18 . The method of  claim 16 , comprising activating the first binder to bind the first layer of the three-dimensional anti-scatter device to the second layer of the three-dimensional anti-scatter device. 
     
     
         19 . The method of  claim 18 , wherein activating the first binder comprises heating the first binder to a temperature below a melting point of the radiation attenuating, powdered metal. 
     
     
         20 . The method of  claim 16 , wherein the three-dimensional anti-scatter device is a two-dimensional anti-scatter grid positioned between an object under examination and a detector array configured to detect radiation.