Fused filament fabrication

• US 10,232,443 B2
• Filed: 06/29/2018
• Issued: 03/19/2019
• Est. Priority Date: 12/16/2015
• Status: Active Grant

• Current Assignee: Desktop Metal, Inc.
• Original Assignee: Desktop Metal, Inc.
• Inventors: Myerberg, Jonah Samuel, Fulop, Ricardo, Gibson, Michael Andrew, Hart, Anastasios John, Fontana, Richard Remo, Schuh, Christopher Allan, Chiang, Yet-Ming, Verminski, Matthew David, Sachs, Emanuel Michael, Chin, Ricardo
• Primary Examiner(s): Sanders, James
• Application Number:
  US16/023,957
• Publication Number:
  US 20180318932A1
• Time in Patent Office: 263 Days
• CPC Class Codes: B22F 10/18 by mixing binder with metal in filament form, e.g. fused filament fabrication [FFF]
• CPC Class Codes: B22F 10/30 Process control
• CPC Class Codes: B22F 10/43 characterised by material
• CPC Class Codes: B22F 12/10 Auxiliary heating means
• CPC Class Codes: B22F 12/53 Nozzles
• CPC Class Codes: B22F 12/55 Two or more means for feeding material
• CPC Class Codes: B22F 12/57 Metering means
• CPC Class Codes: B22F 12/90 Means for process control, e.g. cameras or sensors
• CPC Class Codes: B22F 2003/247 Removing material: carving, cleaning, grinding, hobbing, honing, lapping, polishing, milling, shaving, skiving, turning the surface
• CPC Class Codes: B22F 2202/01 Use of vibrations
• CPC Class Codes: B22F 2203/11 temperature, temperature profile
• CPC Class Codes: B22F 2999/00 Aspects linked to processes or compositions used in powder metallurgy
• CPC Class Codes: B22F 3/115 by spraying molten metal, i.e. spray sintering, spray casting
• CPC Class Codes: B22F 3/20 by extruding
• CPC Class Codes: B22F 3/227 by organic binder assisted extrusion
• CPC Class Codes: B22F 3/24 After-treatment of workpieces or articles B22F3/1146 takes precedence
• CPC Class Codes: B22F 9/007 Transformation of amorphous into microcrystalline state
• 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 64/40 Structures for supporting 3D objects during manufacture and intended to be sacrificed after completion thereof
• CPC Class Codes: B29K 2101/12 Thermoplastic materials
• CPC Class Codes: B29K 2105/16 : Fillers
• CPC Class Codes: B29K 2505/00 : Use of metals, their alloys or their compounds, as filler
• CPC Class Codes: B29K 2509/08 : Glass
• CPC Class Codes: B33Y 10/00 : Processes of additive manufacturing
• CPC Class Codes: B33Y 30/00 : Apparatus for additive manufacturing; Details thereof or accessories therefor
• CPC Class Codes: B33Y 50/02 : for controlling or regulating additive manufacturing processes
• CPC Class Codes: C22C 2200/02 : Amorphous
• CPC Class Codes: G05B 19/4099 : Surface or curve machining, making 3D objects, e.g. desktop manufacturing
• CPC Class Codes: G05B 2219/49007 : Making, forming 3-D object, model, surface
• CPC Class Codes: Y02P 10/25 : Process efficiency

Abstract

A printer fabricates an object from a computerized model using a fused filament fabrication process. The shape of an extrusion nozzle may be varied during extrusion to control, e.g., an amount of build material deposited, a shape of extrudate exiting the nozzle, a feature resolution, and the like.

Claims

1. A method comprising:

heating a wire form of a build material from a first temperature to a second temperature as the wire form of the build material moves, in a direction toward a first nozzle, along a feed path extending from a source of the wire form of the build material to the first nozzle, the build material including a metal powder dispersed in a binder system;

at a working temperature greater than the second temperature, extruding the build material through the first nozzle and in a direction toward a build plate, the build material extruded through the first nozzle forming a three-dimensional object on the build plate; and

through a second nozzle, extruding a support material including the metal powder through the second nozzle toward the build plate, the support material forming supports supporting at least a portion of the three-dimensional object on the build plate as the three-dimensional object is formed, wherein a volumetric concentration of the metal powder in the build material is greater than a volumetric concentration of the metal powder in the support material.

2. The method of claim 1, wherein the support material is different from the build material.

3. The method of claim 1, wherein a concentration of the metal powder in the build material is greater than 50 percent by volume.

4. The method of claim 1, wherein the support material includes a polymer thermally compatible with the binder system.

5. The method of claim 1, wherein the support material includes an oxygen getter.

6. The method of claim 1, wherein the support material includes a zirconium powder.

7. The method of claim 1, wherein the support material is formed of a thermoplastic material.

8. The method of claim 1, wherein the wire form of the build material is in a brittle state at the first temperature and the wire form of the build material is in a plastic state at the second temperature.

9. The method of claim 8, wherein the wire form of the build material in the brittle state is in a spool.

10. The method of claim 9, wherein the wire form of the build material is unspooled as the wire form of the build material is heated from the first temperature to the second temperature.

11. The method of claim 1, wherein heating the wire form of the build material from the first temperature to the second temperature includes resistively heating the filament of the build material through contact pads disposed along the feed path.

12. The method of claim 1, wherein heating the wire form of the build material from the first temperature to the second temperature includes inductively heating the filament of the build material via one or more electromagnets disposed along the feed path.

13. The method of claim 1, wherein heating the wire form of the build material from the first temperature to the second temperature includes directing heat into the wire form of the build material via at least one portion of a drive train in contact with the wire form of the build material moving along the feed path.

14. The method of claim 1, wherein, at the working temperature, the build material is a paste having non-Newtonian fluid properties.

15. The method of claim 1, wherein extruding the build material through the first nozzle and in the direction toward the build plate includes moving the first nozzle along an extrusion path relative to the build plate.

16. The method of claim 1, further comprising debinding the binder system from the three-dimensional object to form a brown part.

17. The method of claim 16, wherein the binder system includes a bulk binder and a backbone binder and debinding the binder system from the three-dimensional object includes removing the bulk binder and the backbone binder separately from the three-dimensional object.

18. The method of claim 16, further comprising densifying the metal powder in the brown part to form a final part.

19. The method of claim 18, wherein densifying the metal powder in the brown part includes sintering the metal powder in the brown part.

20. The method of claim 1, further comprising heating the nozzle to maintain the working temperature of the build material during extrusion of the build material through the nozzle.

21. The method of claim 1, further comprising extruding an interface material through the second nozzle toward the build plate, at least a portion of the extrusion of the interface material disposed between the build material and the support material.

22. The method of claim 21, wherein the interface material resists sintering.

23. The method of claim 21, further comprising sintering the three-dimensional object, the support material, and the interface material, wherein sintering the interface material forms a brittle interface between at least a portion of the three-dimensional object and the support material.

24. The method of claim 1, further comprising extruding an interface material through a third nozzle toward the build plate, at least a portion of the extrusion of the interface material disposed between the build material and the support material.