Device and method for additive casting of metallic parts

Abstract

A method and an apparatus for additive casting of parts is disclosed. The method may include: depositing, on a build table, a first portion of a mold, such that, the depositing may be performed layer by layer; pouring liquid substance into the first portion of the mold to form a first casted layer; solidifying at least a portion of the first casted layer; depositing a second portion of the mold, on top of the first portion of the mold; pouring the liquid substance into the second portion of the mold to form a second casted layer, on top of at least a portion of the first casted layer; and solidifying at least a portion of the second casted layer. The method may further include joining the first and second casted layers prior to the pouring of a third casted layer.

1 .- 20 . (canceled) 
     
     
         21 . A system for casting an object by additively producing layers of the object using a build table, the system comprising:
 a mold system for constructing multiple mold layers over the build table, the multiple mold layers delineating multiple object layers;   a positionable object material dispenser, moveable about an area of the build table, for depositing object material into an object layer defined by a mold layer, the object material dispenser comprising:
 a molten metal system; and 
 a holder for holding the molten metal system; and 
 one or more heating units moveable about the area of the build table; 
   wherein, the positionable object material dispenser moves while depositing a current object layer over a previous object layer, of molten metal, and the one or more heating units configured for at least one of: a) a pre-heating process including heating at least a portion of a previous object layer prior to the deposition of the object material of the current object layer, and b) a post heating process including heating at least a portion of the current object layer, and wherein a consecutive mold layer is constructed after the deposition of the current object layer is complete.   
     
     
         22 . The system of  claim 21 , wherein the positionable object material dispenser comprises a holder heater in communication with the holder, for heating the molten metal in the holder. 
     
     
         23 . The system of  claim 21 , additionally comprising: a controller for controlling the moveable heater for the pre-heating and the post heating processes. 
     
     
         24 . The system of  claim 23 , wherein the controller controls the one or more heating units during the pre-heating process to heat the at least a portion of the previous object layer to a temperature where a temperature gradient with the current object layer upon its being deposited over the previous object layer is reduced. 
     
     
         25 . The system of  claim 23 , wherein the controller controls the one or more heating units in the one or both of preheating and post heating processes to affect solidification parameters of a melt pool constituted by the preheating process on at least a portion of the previous object layer prior to the deposition of the current object layer, and the post heating process including heating at least a portion of the current object layer. 
     
     
         26 . The system of  claim 23 , wherein the controller controls the one or more heating units during the post heating process such that heating at least a portion of the current object layer is at a temperature sufficient to join the at least the heated portion of the current object layer to a corresponding portion of the previous object layer. 
     
     
         27 . The system of  claim 21 , additionally comprising: a three dimensional (3D) system for providing relative movement between the build table and the positionable object material dispenser in a direction perpendicular to a build plane defined by the build table, and wherein the relative movement between the build table and the positionable object material dispenser is provided after the deposition of the current object layer is complete and before constructing consecutive mold layer. 
     
     
         28 . The system of  claim 21 , additionally comprising: a controller for controlling the positionable object material dispenser during depositing of the previous and current object layers. 
     
     
         29 . The system of  claim 21 , wherein the one or more heating units include a preheating unit and a joining unit. 
     
     
         30 . The system of  claim 21 , wherein the mold system and the positionable object material dispenser operate by following at least one build plan. 
     
     
         31 . The system of  claim 21  wherein the mold system is to use mold material made of ceramic powder mixed with binders and metal powder in a paste form and wherein the mold layers receiving the object material is at a state selected from a group consisting of a green state, a fully cured state and a partially sintered state. 
     
     
         32 . A method for casting an object by additively producing layers of the object using a build table, the method comprising, for a plurality of layers:
 constructing multiple mold layers on the build table, the mold layers delineating multiple object layers;   moving a positionable object material dispenser including molten metal, about an area of the build table, for depositing the molten metal into the object layers defined by a mold structure; and   depositing, by the object material dispenser, of molten metal, into the object layer, and performing at least one of a) a preheating process including heating at least a portion of a previous object layer prior to the deposition of a current object layer, and b) a post heating process including heating at least a portion of the current object layer,   wherein a consecutive mold layer is constructed after the deposition of the current object layer is complete.   
     
     
         33 . The method of  claim 32 , wherein the preheating process additionally comprises: heating the at least a portion of the previous object layer to a temperature where a temperature gradient with the current layer upon its being deposited over the previous object layer is reduced. 
     
     
         34 . The method of  claim 32 , additionally comprising: providing one or more positionable heating units during the at least preheating and post heating processes to affect solidification parameters of a melt pool constituted by the preheating process on at least a portion of the previous object layer prior to the deposition of the current object layer, and the post heating process including heating at least a portion of the current object layer. 
     
     
         35 . The method of  claim 32 , wherein the post heating process includes heating at least a portion of the current layer is at a temperature sufficient to join the at least the heated portion of the current object layer to a corresponding portion of the previous object layer. 
     
     
         36 . The method of  claim 32 , wherein the mold structure and the object layers are made in accordance with at least one build plan. 
     
     
         37 . The method of  claim 32 , additionally comprising: adding nucleating agents to the molten metal, prior to the depositing of the molten metal into the object layers to control a microstructure of the deposited object layer. 
     
     
         38 . The method of  claim 32  wherein the constructing of multiple mold layers uses mold material made of ceramic powder mixed with binders and metal powder in a paste form and wherein the mold layers receiving the object material is at a state selected from a group consisting of a green state, a fully cured state and a partially sintered state. 
     
     
         39 . The method of  claim 32  wherein the one or more mold layers are hardened by heating the one or more mold layers. 
     
     
         40 . The method of  claim 32  further comprising providing relative movement between the build table and the positionable object material dispenser in a direction perpendicular to a build plane defined by the build table, wherein the relative movement between the build table and the positionable object material dispenser is provided after the deposition of the current object layer is complete and before the construction of the consecutive mold layer.