Process for heat treating metal powder and products made from the same

Abstract

A method of heat treating metal powder and/or metal oxide powder by microwave energy is described. Furthermore, products made by the various processes of the present invention are further described.

1 . A method for making powder selected from metal powder or metal oxide powder or both comprising heat treating said powder by microwave energy to form a heat-treated powder.  
   
   
       2 . The method of  claim 1 , wherein said powder is a valve metal powder.  
   
   
       3 . The method of  claim 1 , wherein said powder is a valve metal oxide powder.  
   
   
       4 . The method of  claim 1 , wherein said powder is a conductive niobium oxide powder.  
   
   
       5 . The method of  claim 1 , wherein said powder is NbO.  
   
   
       6 . The method of  claim 1 , wherein said powder is tantalum powder.  
   
   
       7 . The method of  claim 1 , wherein said powder is niobium powder.  
   
   
       8 . The method of  claim 1 , wherein said microwave energy is at a level of from about 0.5 to about 10 GHz.  
   
   
       9 . The method of  claim 1 , wherein said powder is pre-agglomerated prior to said heat treating.  
   
   
       10 . The method of  claim 1 , wherein said powder is un-agglomerated prior to said heat treating.  
   
   
       11 . The method of  claim 1 , further comprising reducing said heat-treated powder to a flowable powder.  
   
   
       12 . The method of  claim 1 , further comprising deoxidizing said heat-treated powder.  
   
   
       13 . The method of  claim 1 , further comprising deoxidizing said heat-treated metal powder to form a deoxidized metal powder, pressing said deoxidized powder into a compressed body, and sintering said compressed body to form a sintered body.  
   
   
       14 . The method of  claim 13 , wherein said sintering is achieved by subjecting said compressed body to microwave energy.  
   
   
       15 . The method of  claim 13 , further comprising anodizing and impregnating the sintered body with an electrolyte.  
   
   
       16 . The method of  claim 1 , wherein said powder is nitrided powder.  
   
   
       17 . The method of  claim 1 , further comprising nitriding said powder prior to, during, or after said heat treating.  
   
   
       18 . The method of  claim 1 , further comprising formed an oxide layer on said heat treated powder.  
   
   
       19 . A heat-treated powder formed by the process of  claim 1 .  
   
   
       20 . The heat-treated powder of  claim 19 , wherein said powder is a valve metal powder.  
   
   
       21 . The heat-treated powder of  claim 19 , wherein said powder is a valve metal oxide powder.  
   
   
       22 . The heat-treated powder of  claim 19 , wherein said powder is tantalum powder.  
   
   
       23 . The heat-treated powder of  claim 19 , wherein said powder is niobium powder.  
   
   
       24 . The heat-treated powder of  claim 19 , wherein said powder is a conductive niobium oxide.  
   
   
       25 . A method to increase capacitance capability of a metal powder or metal oxide powder comprising heat-treating said powder by microwave energy.