Methods and compositions for the preparation of powders for binder-based three-dimensional additive metal manufacturing

Patent metadata

Field	Value
Publication number	US-2021260652-A1
Application number	US-201917254805-A
Country	US
Kind code	A1
Filing date	Jun 20, 2019
Priority date	Jun 20, 2018
Publication date	Aug 26, 2021
Grant date	—

Abstract

Devices, systems, and methods are directed to coated powder for three dimensional additive manufacturing. The powder may include a first material coated with a second material, with the coating advantageously resisting segregation of the first material and the second material during handling processes associated with fabrication. The reduced segregation of the first material and the second material may facilitate forming finished three-dimensional parts with improved homogeneity of microstructures and, thus, improved physicochemical properties. More generally, the reduced segregation of the first material and the second material achievable through coating the first material with the second material may facilitate binder jet fabrication using a wider array of combinations of first material and second material as compared to binder jet fabrication using mixtures of constituent powders of the first material and the second material.

First claim

What is claimed is:

1 . A dispersible power for three-dimensional additive metal manufacturing, comprising:
a plurality of granules, each granule including a dispersion of first metallic particles agglomerated in an organic binder matrix.

2 . The dispersible powder of claim 1 wherein the granules are flowable relative to one another.

3 . The dispersible powder of claim 2 wherein the granules are substantially spherical.

4 . The dispersible powder of claim 3 wherein the granules have an average particle size of between 20 microns and 100 microns.

5 . The dispersible powder of claim 4 wherein the first metallic particles have an average particle size of between 1 micron and 5 microns.

6 . The dispersible powder of claim 4 wherein the first metallic particles have an average particle size of between 1 nanometer and 100 nanometers.

7 . The dispersible powder of claim 4 wherein the first metallic particles are selected to be one or more of tungsten, copper, nickel, cobalt, iron, tin, silver and aluminum, as well as ceramics, alloys, mixtures, carbides and composites thereof.

8 . The dispersible powder of claim 7 wherein the first metallic particles include a mixture of tungsten carbide and cobalt.

9 . The dispersible powder of claim 4 wherein the first metallic particles are sintered to one another.

10 . The dispersible powder of claim 4 wherein the organic binder matrix is soluble in a solvent.

11 . The dispersible powder of claim 10 wherein the solvent is selected from the group consisting of water, hexane, heptane, acetone, perchloroethylene (PERC), alcohol and limonene.

12 . The dispersible powder of claim 4 wherein the melt temperature of the organic binder matrix is less than the melt temperature of the first metallic particles.

13 . The dispersible powder of claim 10 wherein the organic binder matrix is formed from a polymer selected from the group consisting of polyethylene glycol, polyethylene, polylactic acid, polyacrylic acid, polypropylene and combinations thereof.

14 . The dispersible powder of claim 4 wherein a plurality of second metallic particles are mixed with the granules in a flowable mixture.

15 . The dispersible powder of claim 14 wherein the organic binder matrix is effective to bind the first metallic particles and the second metallic particles.

16 . The dispersible powder of claim 14 wherein the granules and the second metallic particles form a bimodal powder distribution.

17 . The dispersible powder of claim 14 wherein a composition of the second metallic particles differs from the composition of the first metallic particles.

18 . The dispersible powder of claim 17 wherein the hardness of the second metallic particles differs from the composition of the first metallic particles.

19 . The dispersible powder of claim 17 wherein first metallic particles do not alloy with the second metallic particles.

20 . The dispersible powder of claim 19 wherein the first metallic particles are copper or a copper-base alloy and the second metallic particles are selected from the group consisting of tungsten, molybdenum, alloys thereof and mixtures thereof.

21 . A binder jetting system for three-dimensional additive metal manufacturing, comprising:
a powder supply configured to receive a dispersible power for three-dimensional additive metal manufacturing, the powder containing a plurality of granules where each granule includes a dispersion of first metallic particles agglomerated in an organic binder matrix; a powder bed; a spreader configured to transfer the powder from the powder supply to the powder bed; and a printhead moveable relative to the powder bed.

22 . The binder jetting system of 21 wherein the binder matrix is soluble in a solvent.

23 . The binder jetting system of claim 22 wherein the solvent is selected from the group consisting of water, hexane, heptane, PERC, alcohol and limonene.

24 . The binder jetting system of claim 23 wherein the organic binder matrix is formed from a polymer selected from the group consisting of polyethylene glycol, polyethylene, polylactic acid, polyacrylic acid, polypropylene and combinations thereof.

25 . The binder jetting system of claim 22 wherein a plurality of second metallic particles are mixed with the granules in a flowable mixture.

26 . The binder jetting system of claim 25 wherein the binder matrix is effective to bind the first metallic particles and the second metallic particles.

27 . The binder jetting system of claim 22 wherein the printhead is configured to deliver one or more liquids to the powder bed.

28 . The binder jetting system of claim 27 wherein the one or more liquids include one or more of an organic binder matrix solvent and a second binder.

29 . The binder jetting system of claim 28 wherein the printhead is configured to move in a predetermined two dimensional pattern along an x-axis and a y-axis.

30 . The binder jetting system of claim 29 wherein the powder bed is configured to move towards and away from the printhead along a z-axis.

31 . The binder jetting system of claim 28 wherein approximately equal volumes of binder are provided to the powder bed by the organic binder matrix and the second binder.

32 . The binder jetting system of claim 28 wherein the second binder is effective to cause cross-linking a reflowed organic binder matrix.

33 . The binder jetting system of claim 28 wherein the second binder melts at a different temperature than the organic binder matrix.

34 . The binder jetting system of claim 21 wherein the printhead is configured to deliver energy effective to reflow the organic binder matrix to the powder bed.

35 . The binder jetting system of claim 34 wherein the printhead includes an energy source selected from the group consisting of an electron beam, a laser and directed infrared.

36 . The binder jetting system of claim 34 wherein the energy source is configured to heat the binder matrix to a temperature below the organic binder matrix burn-off temperature.

37 . A dispersible power for three-dimensional additive metal manufacturing, comprising:
a plurality of granules, each granule including a core of a first material overlaid with a coating of a second material wherein the first material is different from the second material.

38 . The dispersible powder of claim 37 wherein the core is selected from the group consisting of tungsten, molybdenum, tungsten carbide, iron, diamond, aluminum, glass and ceramic and alloys and mixtures thereof and the coating is selected from the group consisting of copper, silver, nickel, cobalt and iron and alloys and mixtures thereof.

39 . The dispersible powder of claim 38 wherein the coating has a melting temperature less than the melting temperature of the core.

40 . The dispersible powder of claim 39 wherein the core is tungsten or a tungsten alloy and the coating is copper or a copper alloy.

41 . The dispersible powder of claim 37 wherein the coating has a melting temperature greater than the melting temperature of the core.

42

Assignees

• Desktop Metal Inc

Inventors

• Bose Animesh

Classifications

• B22F1/18

  Non-metallic particles coated with metal · CPC title

• B22F1/148

  Agglomerating · CPC title

• B22F10/16

  by embedding the binder within the powder bed · CPC title

• B22F1/17

  Metallic particles coated with metal · CPC title

• B22F1/065

  Spherical particles · CPC title