Fabrication of customized, composite, and alloy-variant components using closed-loop direct metal deposition

Abstract

A laser-assisted, direct metal deposition (DMD™), preferably in a closed-loop arrangement, is used to fabricate designed articles and tools such as molds and tools with improved properties. According to the method of the invention, a substrate is provided having a surface, onto which a layer of a material is deposited having the desired characteristic using the laser-assisted DMD process. In different embodiments, the substrate/layer combination may be tailored for improved wear resistance, thermal conductivity, density/hardness, corrosion and/or resistance to corrosion, oxidation or other undesirable effects. Alternatively, the layer of material may be tailored to have a phase which is different from that of the substrate. In particular, the layer material itself may be chosen to promote a phase which is different from that of the substrate. In the preferred embodiment, a closed-loop, laser-assisted DMD process is deployed to build the substrate on an incremental basis. To enhance throughput, the substrate and/or outer layer(s) of material may be fabricated using a robotic closed-loop DMD arrangement. In concert with the improvements made possible through the tailored outer layer(s), the method may further include the step of incorporating one or more conformal cooling channels within the component or the formation of one or more conductive heat sinks or thermal barriers during the DMD fabrication of the component itself.

1 . A method of fabricating a component having improved properties, z comprising the steps of: 
 a) providing a substrate having a surface;    b) providing a description of the component to be fabricated;    c) heating a region of the component with a laser sufficient to form a localized meltpool;    d) feeding material into the meltpool to deposit a layer having a physical dimension;    e) monitoring the physical dimension using only radiation generated by the meltpool;    f) automatically controlling the physical dimension in accordance with the description of the article to be fabricated based upon feedback derived through the optical monitoring; and    wherein, compared to the substrate, the layer of material exhibits: 
 improved resistance to wear, corrosion, or oxidation,  
 improved thermal conduction,  
 greater density, or  
 a different phase.  
   
     
     
         2 . The method of  claim 1 , wherein the material of the layer is specifically chosen to promote a phase which is different from that of the substrate.  
     
     
         3 . The method of  claim 1 , further including the step of using non-equilibrium synthesis to dissolve a low-solubility material into the layer of material to increase its hardness.  
     
     
         4 . The method of  claim 1 , wherein the step of providing a substrate having a surface includes the step of using direct metal deposition to build the substrate on an incremental basis.  
     
     
         5 . The method of  claim 1 , wherein the substrate and layer comprise a die, mold or other tool.  
     
     
         6 . The method of  claim 1 , further including the step of applying the layer of material using a robotic, closed-loop process involving steps c) through f).  
     
     
         7 . A method of fabricating a component having improved properties, comprising the steps of: 
 a) providing a computer-aided design (CAD) description of a component having an outer surface to be fabricated;    b) feeding material into a laser-heated meltpool to deposit material increments with physical dimensions until the component is fabricated according to the description;    c) optically monitoring the physical dimensions using only radiation generated by the meltpool;    d) automatically controlling the physical dimensions in accordance with the optical monitoring to match the CAD description more accurately; and    e) depositing one or more additional layers of different material having a desired characteristic onto at least a portion of the outer surface of the fabricated component, using steps b) through d), above, to deposit the different material.    
     
     
         8 . The method of  claim 7 , wherein the of different material exhibits improved wear resistance relative to the component.  
     
     
         9 . The method of  claim 7 , wherein the of different material is more thermally conductive than the component itself.  
     
     
         10 . The method of  claim 7 , wherein the layer of material is more thermally conductive than the component itself.  
     
     
         11 . The method of  claim 7 , wherein the different material has a density greater than that of the component itself.  
     
     
         12 . The method of  claim 7 , wherein the different material is more resistant to corrosion than the component itself.  
     
     
         13 . The method of  claim 7 , wherein the different material is more resistant to oxidation than the component itself.  
     
     
         14 . The method of  claim 7 , wherein the different material has a phase which is different from that of the component itself.  
     
     
         15 . The method of  claim 14 , further including the step of choosing the different material to promote a phase which is different from that of the substrate.  
     
     
         16 . The method of  claim 7 , further including the step of using non-equilibrium synthesis to dissolve low a solubility material into the layer of material to increase hardness.  
     
     
         17 . The method of  claim 7 , wherein the component is a die, mold or other tool.  
     
     
         18 . The method of  claim 7 , further including the step of applying the layer of material using a robotic, closed-loop process involving steps b) through e).  
     
     
         19 . The method of  claim 7 , further including the step of incorporating one or more conformal cooling channels within the component during its fabrication.  
     
     
         20 . The method of  claim 7 , further including the step of incorporating one or more conductive heat sinks or thermal barriers in the component during the fabrication thereof.