System and method for additive manufacturing

Abstract

A method for forming a component includes providing a first layer of a mixture of first and second powders. The method includes determining the frequency of an alternating magnetic field to induce eddy currents sufficient to bulk heat only one of the first and second powders. The alternating magnetic field is applied at the determined frequency to a portion of the first layer of the mixture using a flux concentrator. Exposure to the magnetic field changes the phase of at least a portion of the first powder to liquid. The liquid portion couples to at least some of the second powder and subsequently solidifies to provide a composite component.

What is claimed is: 
     
         1 . A method for forming a component comprising:
 providing a first layer of a mixture of first and second powders;   determining a frequency of an alternating magnetic field to induce eddy currents sufficient to bulk heat only one of the first and second powders; and   applying the alternating magnetic field at the determined frequency to a portion of the first layer of the mixture using a flux concentrator, wherein exposure to the magnetic field changes the phase of at least a portion of the first powder to liquid.   
     
     
         2 . The method of  claim 1 , wherein two or more particles of the first powder combine to form a consolidated material after at least one of the particles changes to the liquid phase, the consolidated material having a size de-coupling the magnetic field from the consolidated material. 
     
     
         3 . The method of  claim 1 , wherein particles of the second powder remain in the solid phase throughout the method. 
     
     
         4 . The method of  claim 1 , wherein determining the frequency of the alternating magnetic field is based on a dimension of the particles within the first powder. 
     
     
         5 . The method according to  claim 4 , wherein the first powder has a first mean particle diameter and the second powder has a second mean particle diameter which is different from the first mean particle diameter. 
     
     
         6 . The method of  claim 1 , wherein determining the frequency of the alternating magnetic field is based on a resistivity of particles with the first powder. 
     
     
         7 . The method according to  claim 6 , wherein the first material has a first resistivity and the second material has a second resistivity different than the first resistivity. 
     
     
         8 . The method according to  claim 1 , wherein the first powder includes particles from a first material and the second powder includes particles from a different second material. 
     
     
         9 . The method according to  claim 8 , wherein the first material is carbon fiber and the second material is a metal. 
     
     
         10 . The method according to  claim 8 , wherein the first material is WC and the second material is cobalt. 
     
     
         11 . The method according to  claim 8 , wherein the first material is a metal and the second material is a ceramic. 
     
     
         12 . The method according to  claim 1 , further comprising applying a second layer of powder material over the first layer of powder material and applying the magnetic field to the second layer. 
     
     
         13 . The method according to  claim 1 , further comprising ceasing to apply the magnetic field to solidify the liquid portion and couple a portion of the first powder with portions of the second powder. 
     
     
         14 . A method for forming a composite material comprising:
 mixing a first powder material with a second powder material to form a powder mixture;   applying a concentrated magnetic field of at least one frequency between about 1 MHz and 2000 MHz to couple the alternating magnetic field with the first powder material to melt a portion of only the first powder material;   coupling the melted first powder material to the second powder material; and   de-coupling the concentrated magnetic field from the melted first powder material to allow solidification of the melted first material.   
     
     
         15 . The method of  claim 14 , wherein applying a concentrated magnetic field includes applying a concentrated magnetic field into a first layer of the powder mixture. 
     
     
         16 . The method according to  claim 14 , further comprising applying a second layer of a powder mixture over the first layer and applying the concentrated magnetic field to the second layer of a powder mixture. 
     
     
         17 . The method according to  claim 14 , wherein a magnitude of power absorbed by the first powder material is proportional to the resistivity and dimensions of a particle within the first powder material. 
     
     
         18 . The method according to  claim 14 , wherein applying a concentrated magnetic field includes applying a concentrated magnetic field at a plurality of frequencies between about 1 MHz and 2000 MHz. 
     
     
         19 . The method of  claim 14 , wherein the first powder material has a mean particle diameter between 1 μm and 400 μm. 
     
     
         20 . The method according to  claim 14 , wherein portions of the solidified and previously melted first material encapsulate portions of the second powder material and material properties of the second powder material remain unchanged after solidification of the first powder material. 
     
     
         21 . The method according to  claim 14 , further comprising applying a second concentrated magnetic field of at least one frequency between about 1 MHz and 2000 MHz to couple the alternating magnetic field with the second powder material to melt a portion of the second powder material. 
     
     
         22 . A method for forming a composite material comprising:
 forming a mixture of a first powder material and a second powder material;   applying an alternating concentrated magnetic field to a portion of the mixture so as to melt only the first powder material within the portion of the mixture; and   solidifying the first material to capture the second powder material within the composite material.   
     
     
         23 . The method of  claim 22 , wherein applying an alternating concentrated magnetic field includes applying an alternating concentrated magnetic field to a first layer of the mixture to melt a skin layer of particles forming the first powder material. 
     
     
         24 . The method of  claim 22 , wherein applying an alternating concentrated magnetic field includes applying an alternating concentrated magnetic field to a first layer of the mixture to bulk melt particles forming the first powder material. 
     
     
         25 . The method according to  claim 22 , further comprising applying a layer of the mixture over the solidified first material and applying the concentrated magnetic field to the layer of the mixture to couple a portion of the layer with the solidified first material. 
     
     
         26 . The method according to  claim 22 , wherein the frequency of the magnetic field is proportional to a first powder material resistivity. 
     
     
         27 . The method according to  claim 22 , wherein the frequency of the magnetic field is a function of a mean powder size of the first material. 
     
     
         28 . The method according to  claim 22 , wherein the first powder material has a resistivity of between 1 μOhm cm and 200 μOhm cm. 
     
     
         29 . The method according to  claim 22 , wherein the first powder material has a mean powder size of between 1 μm and 400 μm. 
     
     
         30 . The method according to  claim 22 , wherein the frequency of the magnetic field is between 1 MHz and 2000 MHz. 
     
     
         31 . The method according to  claim 22 , wherein portions of the solidified first material encapsulate portions of the second powder material and the material properties of the second powder material remain unchanged after forming a solidified first material. 
     
     
         32 . The method according to  claim 22 , wherein the first powder material includes particles having diameters within a first size distribution, the method further including varying the frequency of the alternating concentrated magnetic field over a frequency range to melt the first powder material particles having different diameters within the size distribution. 
     
     
         33 . The method according to  claim 32 , wherein the second powder material includes particles having diameters outside the size distribution of the first powder material, the method including maintaining the second powder material as a solid.