Additive fabrication with infiltratable structures

Patent metadata

Field	Value
Publication number	US-2018305266-A1
Application number	US-201815961638-A
Country	US
Kind code	A1
Filing date	Apr 24, 2018
Priority date	Apr 24, 2017
Publication date	Oct 25, 2018
Grant date	—

Abstract

An infiltratable material forms a net shape containing a porous network that can be infiltrated with a supplemental material, commonly referred to as an infiltrant, e.g., by heating the infiltrant so that it melts and wicks into the porous network of the net shape. By using additive fabrication technologies to spatially dispose an infiltrant about an infiltratable structure, a composite structure can be created that advantageously controls the amount of infiltrant applied to the infiltratable structure and the spatial distribution of the infiltrant about and/or within the infiltratable structure prior to infiltration.

First claim

1 . A method for fabricating a self-infiltrating structure comprising:
providing a build material including a sinterable powder containing particles of a first material in a binder system selected to retain a shape of the build material during processing; providing an infiltrant having a melt temperature substantially lower than a melting point of the build material and a low wetting angle to the sinterable powder; determining an amount of the infiltrant sufficient to replace a volume of a porous network formed in a net shape of an object fabricated from the build material when the net shape is thermally processed to create an infiltratable structure; fabricating the object with the net shape from the build material; and fabricating one or more infiltration structures for the object, the one or more infiltration structures containing the amount of the infiltrant and positioned for the infiltrant to flow into the object during an infiltration process.

2 . The method of claim 1 wherein the volume of the porous network is substantially equal to a second volume of the binder system in the net shape before the object is thermally processed to create the infiltratable structure.

3 . The method of claim 1 further comprising thermally processing the object to couple particles of the first material into a skeleton of the first material substantially retaining the net shape to the infiltratable structure containing the porous network.

4 . The method of claim 3 wherein thermally processing the object includes thermally processing the object to provide a pore size in the porous network of between about one micron and thirty microns.

5 . The method of claim 3 further comprising debinding the object to remove the binder system from the object.

6 . The method of claim 5 further comprising heating the object to a temperature above the melt temperature of the infiltrant and below the melting point of the build material for a time sufficient for the infiltrant to infiltrate the porous network.

7 . The method of claim 6 wherein heating the object includes microwaving the object.

8 . The method of claim 1 wherein the melt temperature of the infiltrant is at least one hundred degrees lower than the melting point of the build material.

9 . The method of claim 1 wherein the one or more infiltration structures enclose a majority of an exterior surface of the object.

10 . The method of claim 1 wherein the one or more infiltration structures include at least one structure disposed in an interior of the object.

11 . The method of claim 1 wherein fabricating one or more infiltration structures includes fabricating the net shape with alternating layers of the infiltrant and the build material.

12 . The method of claim 1 further comprising determining a shape of the one or more infiltration structures to optimize an infiltration rate based on predetermined wicking patterns for the infiltrant into the porous network in the first material.

13 . The method of claim 1 further comprising determining one or more slowest heating regions of the net shape during the infiltration process and positioning the one or more infiltration structures for proximity to the one or more slowest heating regions.

14 . The method of claim 1 wherein the infiltrant is selected to alloy with the first material during the infiltration process.

15 . The method of claim 1 wherein the one or more infiltration structures include a second binder system to retain a second net shape of the one or more infiltration structures at least until a beginning of the infiltration process.

16 . The method of claim 1 further comprising fabricating an interface layer between the object and a support structure for the object that resists wicking of the infiltrant into the support structure.

17 . The method of claim 1 further comprising fabricating an interface layer between the object and a support structure that resists bonding of the object to the support structure during processing of the object into a final part.

18 . The method of claim 1 further comprising fabricating one or more supplemental structures to retain the infiltrant in contact with the object when heated to a molten state above the melt temperature.

19 . The method of claim 1 wherein fabricating the object includes fabricating the object with a binder jetting process.

20 . The method of claim 1 wherein fabricating the object includes fabricating the object with a fused filament fabrication process.

21 - 32 . (canceled)

Assignees

• Desktop Metal Inc

Inventors

• Gibson Michael Andrew
• Kernan Brian Daniel
• Tuncer Nihan
• Fontana Richard Remo

Classifications

• B22F10/32

  of the atmosphere, e.g. composition or pressure in a building chamber · CPC title

• B22F12/90

  Means for process control, e.g. cameras or sensors · CPC title

• B22F10/64

  by thermal means (control of energy beam parameters for post heating B22F10/364) · CPC title

• B22F10/34

  of powder characteristics, e.g. density, oxidation or flowability · CPC title

• B22F10/66

  by mechanical means · CPC title