Method and apparatus for fabrication of articles by molten and semi-molten deposition

Abstract

A method and apparatus for depositing metals and metal-like substances in two and three dimensional form without a substrate in a safe, rapid and economical fashion using gas shielded arc welding equipment and programmable robotic motion. The method and apparatus includes the use and application of robotic controls, temperature and position feedback, single and multiple material feeds, and semi liquid deposition thereby creating near net shape parts particularly well suited to rapid prototyping and lower volume production.

I claim: 
     
         1 . A method of fabricating an object formed from a metal and metal-like material on a platen, the method comprising:
 depositing a plurality of spots of material on the substrate wherein each of the plurality of spots is separated from an adjacent one of the plurality of spots of material;   depositing a bead of material between each of the adjacent ones of the plurality of spots of material to connect adjacent spots with the deposited bead of material;   depositing a continuous bead of material on top of the plurality of spots of material and the beads of material between adjacent ones of the plurality of spots; and   successively depositing a continuous bead of material on a previously deposited continuous bead of material to complete the fabrication of the object.   
     
     
         2 . The method of  claim 1  wherein the depositing the plurality of spots of material further comprises:
 depositing the spots of material at a first power setting sufficient to fix each of the plurality of spots to the platen. 
 
     
     
         3 . The method of  claim 2  wherein the depositing the bead of material between each of the adjacent ones of the plurality of spots comprises depositing the bead of material at a second power setting less than the first power setting, the second power setting being sufficient to adhere the bead of material to the spots, but insufficient to adhere the bead of material to the platen. 
     
     
         4 . The method of  claim 3  wherein the successively depositing the continuous bead of material on the previously deposited continuous bead of material comprises successively depositing the continuous bead of material at one of the second power setting and another power setting less than the first power setting. 
     
     
         5 . The method of  claim 4  further comprising cooling the previously deposited continuous beads of material during the depositing of a continuous bead of material on a previously deposited continuous bead of material. 
     
     
         6 . The method of  claim 5  wherein the cooling the previously deposited continuous beads of material further comprising cooling the previously deposited continuous beads of material with a submersive cooling bath. 
     
     
         7 . The method of  claim 6  wherein the cooling the previously deposited continuous beads of material further comprises lowering the previously deposited continuous beads of material in the submersive cooling bath at a submersive rate of speed.