System and method for additively manufacturing porous parts via salt micro-spheres

Abstract

A system and method of additively manufacturing a part via salt micro-spheres. The method includes mixing salt micro-spheres with an additive manufacturing material to form an additive manufacturing material mixture. The additive manufacturing material mixture is deposited on a build platform layer by layer and cured so as to create a structure having pores formed by the salt micro-spheres. The salt micro-spheres may then be dissolved and flushed from the pores.

1 . An additive manufacturing system for forming a part via additive manufacturing, the additive manufacturing system comprising:
 a build platform configured to support an additive manufacturing material mixture deposited thereon, the additive manufacturing material mixture including additive manufacturing material and salt micro-spheres;   a material deposition device configured to deposit the additive manufacturing material mixture onto the build platform; and   a cure device configured to cure the additive manufacturing material so as to create a structure having pores formed by the salt micro-spheres.   
     
     
         2 . The additive manufacturing system of  claim 1 , further comprising a mixing device configured to mix the salt micro-spheres and the additive manufacturing material together. 
     
     
         3 . The additive manufacturing system of  claim 2 , wherein the mixing device is selected from the group consisting of a planetary mixer and a resonance acoustic mixer. 
     
     
         4 . The additive manufacturing system of  claim 1 , further comprising a warm water system configured to remove the salt micro-spheres from the pores of the structure. 
     
     
         5 . The additive manufacturing system of  claim 1 , wherein the additive manufacturing material is silicone. 
     
     
         6 . The additive manufacturing system of  claim 1 , wherein the additive manufacturing material is selected from the group consisting of HVM/LVM rubber gum and direct-write ink. 
     
     
         7 . The additive manufacturing system of  claim 1 , wherein the salt micro-spheres are hollow. 
     
     
         8 . The additive manufacturing system of  claim 1 , wherein the salt micro-spheres and hence the pores have a diameter of between 20 and 102 microns. 
     
     
         9 . The additive manufacturing system of  claim 1 , further comprising a sieve configured to filter salt micro-spheres so that the salt micro-spheres mixed with the additive manufacturing material have a diameter within a pre-determined range. 
     
     
         10 . The additive manufacturing system of  claim 1 , wherein the pores account for at least fifty percent of an effective volume of the structure. 
     
     
         11 . A method of forming a part via additive manufacturing, the method comprising the steps of:
 mixing salt micro-spheres with an additive manufacturing material to form an additive manufacturing material mixture;   depositing the additive manufacturing material mixture onto a build platform; and   curing the additive manufacturing material mixture so as to create a structure having pores formed by the salt micro-spheres.   
     
     
         12 . The method of  claim 11 , further comprising the step of removing the salt micro-spheres from the pores of the structure. 
     
     
         13 . The method of  claim 12 , wherein the step of removing the salt micro-spheres from the pores of the structure includes subjecting the salt micro-spheres to warm water. 
     
     
         14 . The method of  claim 11 , further comprising the step of filtering the salt micro-spheres through a sieve so that the salt micro-spheres mixed with the additive manufacturing material have a diameter within a pre-determined range. 
     
     
         15 . The method of  claim 11 , wherein the step of mixing the salt micro-spheres with the additive manufacturing material is performed via a mixing device selected from the group consisting of a planetary mixer and a resonance acoustic mixer. 
     
     
         16 . The method of  claim 11 , wherein the step of depositing the additive manufacturing material mixture includes direct ink writing (DIW). 
     
     
         17 . The method of  claim 11 , wherein the step of mixing the salt micro-spheres with the additive manufacturing material includes mixing relative amounts of salt micro-spheres and additive manufacturing material so that the pores account for at least fifty percent of an effective volume of the structure. 
     
     
         18 . The method of  claim 11 , wherein the step of mixing the salt micro-spheres with the additive manufacturing material includes at least one of planetary mixing and resonance acoustic mixing. 
     
     
         19 . The method of  claim 11 , wherein the additive manufacturing material is cured at above 270 degrees Fahrenheit. 
     
     
         20 . A method of forming a part via additive manufacturing, the method comprising the steps of:
 filtering salt micro-spheres through a sieve so that the filtered salt micro-spheres have a diameter within a pre-determined range;   mixing the filtered salt micro-spheres with an additive manufacturing material to form an additive manufacturing material mixture;   depositing the additive manufacturing material mixture onto a build platform;   curing the additive manufacturing material mixture above at least 270 degrees Fahrenheit via a curing device so as to create a structure having pores formed by the filtered salt micro-spheres; and   flushing the filtered salt micro-spheres from the pores via warm water.