Process for Producing Articles From Ceramic or Metal by Electrophoretic Free Forming

Abstract

The invention relates to an electrophoretic free forming process, by which both metallic and ceramic formed parts can be produced. In this process, a slip (suspension of water and metal powder or ceramic powder) is fed via a hollow needle ( 6 ) to the substrate ( 3 ) to be produced. By applying a voltage between the slip ( 7 ) and the substrate ( 3 ) a material deposit is produced. To build up a three-dimensional form scanned into a computer, the substrate is moved past the tip of the hollow needle ( 6 ) in a controlled manner. The control is performed on the basis of known CAD/CAM methods. With this process it is possible in particular to produce all formed parts known in dental technology on one machine. It is suitable in particular for producing reinforcing structures and for coating reinforcing structures with dentine or incisal material. Equally possible is the production of non-dental formed parts of dimensions comparable to those of dental formed parts.

1 . Process for the electrophoretic production of ceramic and metallic articles, the process comprising the steps of providing a slip comprising a suspension of ceramic or metal powder in a liquid suspending medium, feeding the slip through a pointed feed element ( 6 ) onto a substrate ( 3 ) to effect a material deposition on the substrate, and applying a voltage between the slip ( 7 ) and the substrate ( 3 ), wherein the substrate ( 3 ) is moved past a tip of the feed element ( 6 ) in a controlled manner to construct a scanned three-dimensional form. 
   
   
       2 . Process pursuant to  claim 1 , wherein the pointed feed element ( 6 ) comprises a hollow needle. 
   
   
       3 . Process pursuant to  claim 1 , wherein the slip comprises a metallic slip. 
   
   
       4 . Process pursuant to  claim 1 , wherein the slip comprises a ceramic slip. 
   
   
       5 . Process pursuant to  claim 1 , wherein the substrate ( 3 ) is moved under control on the tip of the feed element ( 6 ). 
   
   
       6 . Process pursuant to  claim 1 , wherein the process further comprises the production of frames. 
   
   
       7 . Process pursuant to  claim 1 , wherein a computer program in a computer ( 1 ) is provided and adapted to compensate for sintering shrinkage. 
   
   
       8 . Process pursuant to  claim 7 , wherein the slip comprises a zirconium oxide slip. 
   
   
       9 . Process pursuant to  claim 1 , wherein dentine and/or incisal material is applied to the material deposition. 
   
   
       10 . Process pursuant to  claim 2 , wherein the slip is fed to the tip of the feed element ( 6 ) under pressure. 
   
   
       11 . Process pursuant to  claim 1 , wherein the feed element ( 6 ) comprises a pointed feed element that has lengthwise profiling on the outside thereof. 
   
   
       12 . Process pursuant to  claim 1 , wherein the feed element ( 6 ) rotates during the application of the slip.