Rapid non-contact energy transfer for additive manufacturing driven high intensity electromagnetic fields

• US 10,124,531 B2
• Filed: 12/30/2013
• Issued: 11/13/2018
• Est. Priority Date: 12/30/2013
• Status: Active Grant

• Current Assignee: UT-Battelle LLC
• Original Assignee: UT-Battelle LLC
• Inventors: Duty, Chad E., Kunc, Vlastimil, Love, Lonnie J., Peter, William H., Rios, Orlando
• Primary Examiner(s): Daniels, Matthew J
• Application Number:
  US14/143,971
• Publication Number:
  US 20150183138A1
• Time in Patent Office: 1,779 Days
• CPC Class Codes: B29B 13/022 Melting the material to be shaped
• CPC Class Codes: B29B 13/08 by using wave energy or particle radiation
• CPC Class Codes: B29C 2035/0811 using induction
• CPC Class Codes: B29C 2948/92571 Position, e.g. linear or angular
• CPC Class Codes: B29C 2948/92857 Extrusion unit
• CPC Class Codes: B29C 48/02 Small extruding apparatus, e.g. handheld, toy or laboratory extruders
• CPC Class Codes: B29C 48/05 Filamentary, e.g. strands
• CPC Class Codes: B29C 48/266 Means for allowing relative movements between the apparatus parts, e.g. for twisting the extruded article or for moving the die along a surface to be coated
• CPC Class Codes: B29C 48/865 Heating
• 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: B29C 64/209 Heads; Nozzles
• CPC Class Codes: B29C 64/25 Housings, e.g. machine housings
• CPC Class Codes: B29K 2055/02 ABS polymers, i.e. acrylonitrile-butadiene-styrene polymers
• 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

Abstract

A method and apparatus for additive manufacturing that includes a nozzle and/or barrel for extruding a plastic material and a supply of polymeric working material provided to the nozzle, wherein the polymeric working material is magnetically susceptible and/or electrically conductive. A magneto-dynamic heater is provided for producing a time varying, high flux, frequency sweeping, alternating magnetic field in the vicinity of the nozzle to penetrate into and couple the working material to heat the material through at least one of an induced transient magnetic domain and an induced, annular current.

Claims

1. A method of additive manufacturing comprising the steps of:

a. providing an apparatus for additive manufacturing, the apparatus including a nozzle for extruding a material, the nozzle including a barrel through which a polymeric working material is provided, and a plate extending around the barrel at an end of the barrel adjacent a tip, wherein the barrel is not electromagnetically susceptible and the plate is electromagnetically susceptible;

b. operably contacting the nozzle with a polymeric working material that has at least one of the properties;

i. magnetically susceptible, and

ii. electrically conductive;

c. producing a time varying, frequency sweeping, alternating magnetic field by an induction heating coil wrapped around the barrel of the nozzle so that at least one of the following processes occurs;

i. the time varying magnetic field penetrates into and is coupled by the magnetically susceptible working material to induce transient magnetic domains resulting in heating of the magnetically active components to form a flowable deposition material; and

ii. the transient magnetic field penetrates into and is coupled by the electrically conductive working material to generate an induced, annular current that causes direct electrical resistive heating of the material to form a flowable deposition material;

wherein the magnetic field further induces heating of the electromagnetically susceptible plate.

2. The method of claim 1, further comprising:

compounding the working material with magnetically active microscale and nano particles to adjust a heating efficiency of the magnetic field.

3. The method of claim 1 wherein the polymeric working material is both magnetically susceptible and electrically conductive.

4. The method of claim 1 wherein the polymeric working material comprises at least one of a thermoplastic selected from nylon or ABS, or a thermosetting polymer comprising an epoxy.

5. The method of claim 1 wherein the polymeric working material comprises a thermoplastic or thermosetting polymer doped with a doping agent including at least one of iron oxide, manganese borate, and nano particles.

6. The method of claim 5 wherein the nano particles comprise at least one of Ho_0.06Fe_2.94O₄ and Gd_0.06Fe_2.94O₄.

7. The method of claim 5 wherein the polymeric working material comprises 90-99% thermoplastic or thermosetting polymer and 1-10% doping agent.

8. The method of claim 1 wherein the polymeric working material comprises an thermoplastic or thermosetting polymer doped with a doping agent including at least one of iron, Ni, Co, iron oxide, Nickel oxide, Cobalt Oxide, manganese borate, ferromagnetic nano particles and ferrimagnetic nano particles.

9. The method of claim 8 wherein the polymeric working material comprises 95-99% themioplastic or thermosetting polymer and 1-5% doping agent.

10. The method of claim 1, further comprising:

compounding the working material with magnetically active microscale and nano particles to adjust a heating efficiency of the magnetic field.

11. The method of claim 1 wherein the apparatus comprises a magneto-dynamic heater in combination with the nozzle for producing the time varying, frequency sweeping, alternating magnetic field in the vicinity of the nozzle to penetrate into and couple the working material to heat the material through at least one of the induced transient magnetic domain or the induced, annular current, wherein the polymeric working material is both magnetically susceptible and electrically conductive.

12. The method of claim 1 wherein the polymeric working material is not flowable before heating.

13. The method of claim 1 wherein the apparatus includes a frame or gantry for containing a build without a further heating oven.

14. The method of claim 13, wherein the frame or gantry comprises a deposition arm including the nozzle and moveable through an x, y and z-axis.

15. The method of claim 1 wherein the plate extends perpendicular to the longitudinal direction of the barrel between the induction heating coil and the tip.

16. The method of claim 1 wherein the plate is displaced from a bottom winding of the coil.

17. The method of claim 16, wherein a wrap is disposed between the barrel and the coil and the plate is disposed between the wrap and the tip.

18. The method of claim 1 further comprising maintaining the coil at a lower temperature than the barrel by cooling the coil with a heat exchanger.

19. The method of claim 1 further comprising maintaining the plate at a temperature of 240°

C. to 280°

C. via the magnetic field.