Compositions comprising a binder and a powder, and associated methods

Patent metadata

Field	Value
Publication number	US-2021394265-A1
Application number	US-201917285650-A
Country	US
Kind code	A1
Filing date	Oct 16, 2019
Priority date	Oct 16, 2018
Publication date	Dec 23, 2021
Grant date	—

Abstract

The present invention generally relates to compositions comprising a binder and a metal powder, and associated methods. Some compositions provided include a polymer and a metal powder. Some compositions provided include a binder formulation and a metal powder. The binder formulation generally includes a first liquid and a polymer. The binder formulation may be a solution. The polymer may include a nitrogen-containing repeat unit. The metal powder may include a noble metal. Some methods provided include combining a metal powder with a binder formulation. Methods provided include but are not limited to additive manufacturing processes and injection molding processes.

First claim

What is claimed is:

1 . A method of fabricating a metal part through additive manufacturing, the method comprising:
depositing a binder formulation onto a powder layer comprising a plurality of metal particles to form a composite layer; curing the composite layer; and heating the cured composite layer such that at least a portion of the binder formulation is removed from the cured composite layer, wherein the binder formulation comprises a polymer comprising a nitrogen-containing repeat unit.

2 . A method as in claim 1 , wherein the depositing step comprises producing a droplet of the binder formulation having a droplet size of between or equal to 0.5 pL and 20 pL, or between or equal to 2 pL and 20 pL, or between or equal to 0.5 pL and 2 pL.

3 . A method as in any preceding claim, wherein the binder formulation is deposited at a velocity of between or equal to 4 m/sec and 12 m/sec.

4 . A method as in any preceding claim, wherein depositing the binder formulation does not substantially form satellite droplets with the main droplet.

5 . A method as in any preceding claim, wherein the depositing step comprises producing a droplet of the binder formulation using a piezoelectric print head component.

6 . A method as in any preceding claim, wherein the depositing step comprises producing a droplet of the binder formulation using a thermal print head component.

7 . A method as in any preceding claim, wherein the step of depositing the binder formulation results in the formation of a two-dimensional image layer of a three-dimensional structure.

8 . A method as in any preceding claim, wherein the thickness of the composite layer is between or equal to 10 microns and 200 microns, or between or equal to 25 microns and 100 microns.

9 . A method as in any preceding claim, further comprising depositing a second powder layer on the deposited binder formulation to form the composite layer.

10 . A method as in any preceding claim, wherein the curing step comprises heating an environment in which the composite layer is positioned to a temperature of between or equal to 120° C. and 220° C.

11 . A method as in claim 10 , wherein the composite layer is heated for between or equal to 0.5 hours and 100 hours.

12 . A method as in any preceding claim, wherein the step of heating the cured composite layer comprises heating an environment in which the cured composite layer is positioned to a temperature of between or equal to 220° C. and 1200° C.

13 . A method as in any preceding claim, wherein the step of heating the cured composite layer comprises heating an environment in which the cured composite layer is positioned to a temperature of greater than or equal to 220° C. and less than or equal to 300° C. in an oxidative environment.

14 . A method as in any one of claims 12 - 13 , wherein the step of heating is performed for between or equal to 4 hours and 10 hours.

15 . A method as in any preceding claim, wherein the step of heating an environment in which the composite layer is positioned is performed in air or in inert gas.

16 . A method as in any preceding claim, wherein the step of heating an environment in which the composite layer is positioned is performed in a gaseous environment having an oxygen content of at most 10 ppm.

17 . A method as in any preceding claim, further comprising sintering the cured composite layer to form the three-dimensional structure.

18 . A method as in any preceding claim, wherein the heating step and the sintering step are performed in an environment comprising at least 2 wt % hydrogen.

19 . A method as in any one of claims 17 - 18 , wherein sintering is performed at a temperature of greater than or equal to 750° C. and less than or equal to 1700° C.

20 . A method as in any one of claims 17 - 19 , wherein sintering is performed at a temperature of at most 850° C.

21 . A method as in any one of claims 17 - 20 , wherein the heating step is performed at a temperature at least 50° C. lower than a temperature at which the sintering step is performed.

22 . A method as in claim 17 , wherein the three-dimensional structure has a relative density of at least 94%.

23 . A binder formulation for use in additive manufacturing, the binder formulation comprising:
polymer comprising a nitrogen-containing repeat unit in an amount of between or equal to 5 wt % and 50 wt %; and water, wherein the binder formulation is configured, in the presence of heat, to form a composition with a metal powder.

24 . A composition formed in an additive manufacturing system, the composition comprising:
a plurality of metal particles embedded in a polymer comprising a nitrogen-containing repeat unit; wherein the plurality of metal particles are present in the composition in an amount of greater than or equal to 40 wt % and less than or equal to 99.7 wt %, and wherein the composition has a transverse rupture strength of greater than or equal to 2 MPa and less than or equal to 100 MPa.

25 . A method of fabricating a metal part through additive manufacturing, the method comprising:
depositing a binder formulation onto a powder layer comprising a plurality of metal particles, wherein the binder formulation comprises:
a polymer present in the binder formulation in an amount of greater than or equal to 5 wt % and less than or equal to 50 wt %, wherein the polymer comprises a nitrogen-containing repeat unit; and
water.

26 . A composition comprising:
a polymer; and a metal powder; wherein the polymer comprises a nitrogen-containing repeat unit.

27 . The composition of claim 26 , wherein the nitrogen-containing repeat unit is a repeat unit of a polypeptide, a protein, a polyacrylamide, or a glycosaminoglycan.

28 . The composition of claim 26 , wherein the polymer is a biologically-derived polymer.

29 . The composition of claim 28 , wherein the biologically-derived polymer is chitosan, chitosan oligosaccharide, collagen, gelatin, collagen hydrolysate, or hyaluronic acid (HA).

30 . The composition of claim 26 , wherein the polymer is a synthetic polymer.

31 . The composition of claim 30 , wherein the synthetic polymer is polyvinylpyrrolidone, poly(2-(diethylamino)ethyl methacrylate), polyacrylamide, poly(N-isopropylacrylamide), or N-(2-hydroxypropyl) methacrylamide (HPMA).

32 . The composition of claim 26 , wherein the polymer has a weight-average molecular weight of between or equal to 1 kDa and 40 kDa.

33 . The composition of claim 32 , wherein the polymer has a weight-average molecular weight of between or equal to 2 kDa and 20 kDa.

34 . The composition of claim 32 , wherein the polymer has a weight-average molecular weight of between or equal to 1 kDa and 15 kDa.

35 . The composition of claim 26 , further comprising a first liquid that forms a binder formulation with the polymer.

36 . The composition of claim 35 , wherein the first liquid comprises water.

37 . The composition of claim 35 , wherein the binder formulation has a weight percent of polymer of between or equal to 5 wt % and 50 wt %, relative to the total weight of the binder formulation.

38 . The composition of claim 35 , wherein the binder formulation

Assignees

• Desktop Metal Inc

Inventors

• Rushkin Ilya L
• Bai Yun
• Lee Shannon

Classifications

• B22F1/107

  containing organic material comprising solvents, e.g. for slip casting · CPC title

• B29C64/165 Primary

  using a combination of solid and fluid materials, e.g. a powder selectively bound by a liquid binder, catalyst, inhibitor or energy absorber · CPC title

• B22F1/052

  characterised by a mixture of particles of different sizes or by the particle size distribution · CPC title

• B22F1/10

  Metallic powder containing lubricating or binding agents; Metallic powder containing organic material · CPC title

• B22F2998/10

  Processes characterised by the sequence of their steps · CPC title