SYSTEM AND METHOD FOR BUILDING THREE-DIMENSIONAL OBJECTS WITH METAL-BASED ALLOYS

• US 20090314391A1
• Filed: 06/24/2008
• Published: 12/24/2009
• Est. Priority Date: 06/24/2008
• Status: Active Grant

• Current Assignee: Stratasys Incorporated
• Original Assignee: Stratasys Incorporated
• Inventors: Crump, S. Scott, Batchelder, J. Samuel, Barnett, John, Zinniel, Robert L., Sampson, Timothy
• Granted Patent: US 7,942,987 B2
• Time in Patent Office: Days
• US Class Current: 148/523
• CPC Class Codes: B21C 31/00 Control devices, e.g. for regulating the pressing speed or temperature of metal B21C25/08 takes precedence; Measuring devices, e.g. for temperature of metal, combined with or specially adapted for use in connection with extrusion presses
• CPC Class Codes: B21C 33/02 the metal being in liquid form
• CPC Class Codes: B22F 10/25 Direct deposition of metal particles, e.g. direct metal deposition [DMD] or laser engineered net shaping [LENS]
• CPC Class Codes: B22F 10/32 of the atmosphere, e.g. composition or pressure in a building chamber
• CPC Class Codes: B22F 12/13 to preheat the material
• CPC Class Codes: B22F 12/20 Cooling means
• CPC Class Codes: B22F 2998/00 Supplementary information concerning processes or compositions relating to powder metallurgy
• CPC Class Codes: B22F 3/003 Apparatus, e.g. furnaces in general F27B
• CPC Class Codes: B29C 64/106 using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material
• CPC Class Codes: B29C 64/118 using filamentary material being melted, e.g. fused deposition modelling [FDM]
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 40/00 Auxiliary operations or equipment, e.g. for material handling
• CPC Class Codes: B33Y 40/20 Post-treatment, e.g. curing, coating or polishing
• CPC Class Codes: B33Y 70/00 Materials specially adapted for additive manufacturing
• CPC Class Codes: Y02P 10/25 Process efficiency
• CPC Class Codes: Y10S 164/90 Rheo-casting

Abstract

A digital manufacturing system comprises a build chamber, a build platform disposed within the build chamber, at least one extrusion line configured to heat a metal-based alloy up to a temperature between solidus and liquidus temperatures of the metal-based alloy, a deposition head disposed within the build chamber and configured to deposit the heated metal-based alloy onto the build platform in a predetermined pattern, an umbilical having a first end located outside of the build chamber and a second end connected to the deposition head, and at least one gantry assembly configured to cause relative motion between the build platform and the deposition head within the build chamber, where the at least one gantry assembly comprises a motor disposed outside of the build chamber.

Claims

1. A digital manufacturing system for building a three-dimensional object with a metal-based alloy, the system comprising:

a build chamber configured to be maintained at one or more temperatures of at least about 200°

C.;

a build platform disposed within the build chamber;

at least one extrusion line configured to heat the metal-based alloy up to a temperature between a solidus temperature of the metal-based alloy and a liquidus temperature of the metal-based alloy;

a deposition head disposed within the build chamber, and configured to deposit the heated metal-based alloy onto the build platform in a predetermined pattern;

an umbilical having a first end located outside of the build chamber and a second end connected to the deposition head; and

at least one gantry assembly configured to cause relative motion between the build platform and the deposition head within the build chamber, wherein the at least one gantry assembly comprises a motor disposed outside of the build chamber.

2. The digital manufacturing system of claim 1, wherein the one or more temperatures at which the build chamber is configured to be maintained range from about 400°

C. to about 700°

C.

3. The digital manufacturing system of claim 1, wherein the extrusion line comprises:

a drive mechanism configured to receive and drive a feedstock of the metal-based alloy;

a liquefier assembly configured to receive the driven feedstock from the drive mechanism, and further configured to heat the metal-based alloy of the feedstock to the temperature between the solidus temperature of the metal-based alloy and the liquidus temperature of the metal-based alloy; and

an extrusion tip configured to receive the heated metal-based alloy.

4. The digital manufacturing system of claim 1, wherein the metal-based alloy comprises aluminum and silicon, the aluminum constituting about 90% by weight to about 95% by weight of the metal-based alloy, and the silicon constituting about 5% by weight to about 10% by weight of the metal-based alloy.

5. The digital manufacturing system of claim 1, wherein the at least one extrusion line is disposed outside of the build chamber and is configured to drive the heated metal-based alloy to the deposition head through the umbilical.

6. The digital manufacturing system of claim 1, wherein the deposition head comprises:

a freeze valve assembly disposed within the build chamber; and

at least one coolant solenoid disposed outside of the build chamber and configured to relay coolant gas to the freeze valve assembly.

7. The digital manufacturing system of claim 1, wherein the at least one gantry assembly comprises:

at least one threaded screw that is threadedly engaged with the build platform for transferring rotational motion of the threaded screw to linear motion of the build platform along at least one axis; and

a belt mechanism operably engaged with the motor and the at least one threaded screw for transferring rotational power of the motor to the rotational motion of the threaded screw.

8. The digital manufacturing system of claim 1, wherein the at least one gantry assembly comprises:

at least one first-axis guide rail extending along a first axis;

at least one bearing sleeve slidably retained on the at least one first-axis guide rail;

at least one second-axis guide rail extending along a second axis that is orthogonal to the first axis, wherein the at least one second-axis guide rail is retained by the at least one bearing sleeve, and wherein the deposition head is slidably retained on the at least one second-axis guide rail;

a first belt mechanism operably engaged with the motor and the at least one bearing sleeve, the first belt mechanism being configured to transfer rotational power of the motor to linear motion of the bearing sleeve along the first axis; and

a second belt mechanism operably engaged with a second motor disposed outside of the build chamber and with the deposition head, the second belt mechanism being configured to transfer rotational power of the second motor to linear motion of the deposition head along the second axis.

9. The digital manufacturing system of claim 1, wherein the umbilical comprises a first baffle configured to curl along a first axis and a second baffle configured to curl along a second axis that is substantially orthogonal to the first axis.

10. A method for building a three-dimensional object in a layer-by-layer manner with a digital manufacturing system, the method comprising:

heating a build chamber of the digital manufacturing system to one or more temperatures of at least about 200°

C.;

heating a metal-based alloy in an extrusion line of the digital manufacturing system, wherein the metal-based alloy is heated up to a temperature between a solidus temperature of the metal-based alloy and a liquidus temperature of the metal-based alloy;

depositing the heated metal-based alloy from a deposition head of the digital manufacturing system onto a build platform of the digital manufacturing system in a predetermined pattern; and

solidifying the heated metal-based alloy to provide a re-solidified alloy that is substantially free of dendrites.

11. The method of claim 10, further comprising substantially removing oxygen-containing gases from the build chamber.

12. The method of claim 10, wherein the one or more temperatures to which the build chamber is heated range from about 400°

C. to about 700°

C.

13. The method of claim 10, wherein the deposition head comprises a freeze valve assembly, and wherein the method further comprises relaying a coolant gas to the freeze valve assembly from a coolant solenoid disposed outside of the build chamber.

14. The method of claim 10, wherein the extrusion line is disposed outside of the build chamber and the deposition head is disposed within the build chamber, and wherein the method further comprises driving the heated metal-based alloy from the extrusion line to the deposition head through a thermally-isolating umbilical.

15. A method for building a three-dimensional object in a layer-by-layer manner with a digital manufacturing system, the method comprising:

substantially removing oxygen-containing gases from a build chamber of the digital manufacturing system;

heating the build chamber to one or more temperatures of at least about 200°

C.;

providing an alloy that comprises aluminum and silicon, the aluminum constituting about 90% by weight to about 95% by weight of the alloy, and the silicon constituting about 5% by weight to about 10% by weight of the alloy;

heating the alloy to a temperature that is above a solidus temperature of the alloy and that is below a liquidus temperature of the alloy;

depositing the heated alloy onto a build platform of the digital manufacturing system in a predetermined pattern; and

solidifying the deposited alloy.

16. The method of claim 15, wherein the one or more temperatures to which the build chamber is heated range from about 400°

C. to about 700°

C.

17. The method of claim 15, wherein the one or more temperatures to which the build chamber is heated range from about 500°

C. to about 650°

C.

18. The method of claim 15, wherein the heated alloy is deposited from a deposition head disposed in the build chamber, and wherein the method further comprises moving the deposition head along at least one axis within the build chamber with the use of a motor disposed outside of the build chamber.

19. The method of claim 15, further comprising relaying the heated alloy from a location outside of the build chamber to a deposition head disposed within the build chamber.

20. The method of claim 15, further comprising quenching the solidified alloy.