CONTROL OF METALLIC ELECTROHYDRODYNAMIC THREE-DIMENSIONAL PRINTING USING FEEDBACK OF SURFACE CHARACTERISTICS

• US 20170056967A1
• Filed: 08/24/2016
• Published: 03/02/2017
• Est. Priority Date: 08/24/2015
• Status: Abandoned Application

• Current Assignee: Desktop Metal, Inc.
• Original Assignee: Desktop Metal, Inc.
• Inventors: Fulop, Ric, Myerberg, Jonah Samuel, Chin, Ricardo, Ming-Chiang, Yet
• Application Number:
  US15/245,784
• Publication Number:
  US 20170056967A1
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B22D 11/01 without moulds, e.g. on molten surfaces
• CPC Class Codes: B22D 11/18 for pouring B22D11/20 takes precedence
• CPC Class Codes: B22D 23/003 Moulding by spraying metal on a surface
• CPC Class Codes: B22D 37/00 Controlling or regulating the pouring of molten metal from a casting melt-holding vessel B22D11/18, B22D39/00, B22D41/00 take precedence
• CPC Class Codes: B22D 39/00 Equipment for supplying molten metal in rations
• CPC Class Codes: B22F 10/12 by photopolymerisation, e.g. stereolithography [SLA] or digital light processing [DLP]
• CPC Class Codes: B22F 10/18 by mixing binder with metal in filament form, e.g. fused filament fabrication [FFF]
• CPC Class Codes: B22F 10/22 Direct deposition of molten metal
• CPC Class Codes: B22F 10/28 Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM]
• CPC Class Codes: B22F 10/43 characterised by material
• CPC Class Codes: B22F 12/55 Two or more means for feeding material
• CPC Class Codes: B22F 12/90 Means for process control, e.g. cameras or sensors
• 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: 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: B33Y 70/00 Materials specially adapted for additive manufacturing
• CPC Class Codes: Y02P 10/25 Process efficiency

Abstract

A metallic electrohydrodynamic (EHD) three-dimensional printer fabricates an object while surface characteristics of the object are monitored. Sensors acquire data on surface characteristics, and feedback related to these surface characteristics is used to adjust the fabrication process, e.g., where the surface characteristics deviate from a target surface shape.

Claims

1. A method for additive manufacturing comprising:

fabricating an object based on a three-dimensional model with a printer, wherein the printer is a three-dimensional metallic printer configured to additively manufacture the object with a number of droplets of liquefied metal as a build material using a metallic liquid expeller;

acquiring surface data from the object with one or more sensors during fabrication, the surface data characterizing a location on a layer of a build material of the object deposited by the printer;

estimating a target surface shape for the build material at the location based on the three-dimensional model;

comparing the surface data to the target surface shape at the location; and

adjusting a fabrication process when a discrepancy is identified between the surface data and the target surface shape.

2. The method of claim 1, wherein the metallic liquid expeller is configured to drive the droplets of liquefied metal by applying an electrostatic field to a meniscus of the liquefied metal extending from an outlet of the metallic liquid expeller of the printer.

3. The method of claim 1, wherein the surface data is acquired for each one of the droplets of liquefied metal.

4. The method of claim 1, wherein the surface data is acquired for a surface region about the location.

5. The method of claim 1, wherein the surface data is acquired for a voxel about the location.

6. The method of claim 1, further comprising capturing process data characterizing the droplets of liquefied metal.

7. The method of claim 6, wherein the process data includes at least one of a volume of one of the droplets of liquefied metal and an average volume of the droplets of liquefied metal.

8. The method of claim 6, wherein the process data includes at least one of a dimension of one of the droplets of liquefied metal and an average dimension of the droplets of liquefied metal.

9. The method of claim 6, wherein the process data includes at least one of a velocity of one of the droplets of liquefied metal and an average velocity of the droplets of liquefied metal.

10. The method of claim 6, wherein the process data includes at least one of a temperature of one of the droplets of liquefied metal and an average temperature of the droplets of liquefied metal.

11. The method of claim 6, wherein the process data includes at least one of a distance between an expeller of the printer and the layer of the build material, a temperature of a build chamber of the printer, and a temperature of a print bed of the printer.

12. The method of claim 1, wherein the one or more sensors include at least one of a contact profilometer and a non-contact profilometer.

13. The method of claim 12, wherein the one or more sensors include an optical profilometer.

14. The method of claim 1, wherein the discrepancy includes a depression at a position in the layer of the build material, and wherein adjusting the fabrication process includes repeating a deposition of droplets of liquefied metal at the position.

15. The method of claim 1, wherein the discrepancy includes a protrusion at a position in the surface of the layer of the object, and wherein adjusting the fabrication process includes omitting a deposition of droplets of liquefied metal at the position while fabricating a second layer of the object on the layer containing the protrusion.

16. The method of claim 1, further comprising refinishing the location on the layer of the object when the discrepancy between the surface data and the target surface shape exceeds a predetermined threshold.

17. The method of claim 1, further comprising sending a notification to a user of the printer when the discrepancy between the surface data and the target surface shape exceeds a predetermined threshold.

18. The method of claim 1, further comprising acquiring parameter data related to at least one parameter or condition of the printer present during fabrication of the layer of the build material.

19. A computer program product comprising computer executable code embodied in a non-transitory computer-readable medium that, when executing on one or more computing devices in electronic communication with a three-dimensional metallic printer configured to additively manufacture an object based on a three-dimensional model with a number of droplets of liquefied metal as a build material using a metallic liquid expeller, performs the steps of:

acquiring surface data from the object with one or more sensors during fabrication, the surface data characterizing a location on a layer of a build material of the object deposited by the three-dimensional metallic printer;

estimating a target surface shape for the build material at the location based on the three-dimensional model;

comparing the surface data to the target surface shape at the location; and

adjusting a fabrication process of the three-dimensional metallic printer when a discrepancy is identified between the surface data and the target surface shape.

20. An additive manufacturing system including:

a three-dimensional metallic printer configured to additively manufacture an object based on a three-dimensional model with a number of droplets of liquefied metal as a build material using a metallic liquid expeller; and

a controller in electronic communication with the three-dimensional metallic printer over a data network, the controller including a processor and a memory, the memory bearing computer executable code configured to perform the steps of acquiring surface data from the object with one or more sensors during fabrication, the surface data characterizing a location on a layer of a build material of the object deposited by the three-dimensional metallic printer, estimating a target surface shape for the build material at the location based on the three-dimensional model, comparing the surface data to the target surface shape at the location, and adjusting a fabrication process of the three-dimensional metallic printer when a discrepancy is identified between the surface data and the target surface shape.