Binder compositions for additive manufacturing comprising low molecular weight polymers including acrylic acid repeat units

Patent metadata

Field	Value
Publication number	US-12023733-B2
Application number	US-202017075355-A
Country	US
Kind code	B2
Filing date	Oct 20, 2020
Priority date	Oct 21, 2019
Publication date	Jul 2, 2024
Grant date	Jul 2, 2024

Abstract

Methods of additive manufacturing, binder compositions for additive manufacturing, and articles produced by and/or associated with methods of additive manufacturing are generally described.

First claim

What is claimed is:

1. A method of additive manufacturing a metal-based composite structure by binder jet printing, the method comprising:
depositing a first layer of metal powder, the metal powder comprising steel;
depositing a binder composition on at least a portion of the first layer of metal powder, the binder composition comprising water and a low molecular weight polymer including an acrylic acid repeat unit, wherein the binder composition has a pH of greater than or equal to 7; and
drying and/or cross-linking at least the binder composition deposited on the first layer of the metal powder, thereby forming a metal-based composite structure.

2. The method of claim 1 , wherein the low molecular weight polymer has a weight average molecular weight of less than or equal to 40 kDa.

3. The method of claim 1 , wherein the metal-based composite structure has a flexural strength of greater than or equal to 2 MPa.

4. The method of claim 3 , wherein the flexural strength is that measured by a three-point bending test.

5. The method of claim 3 , wherein the flexural strength is that measured by a four-point bending test.

6. The method of claim 1 , wherein the binder composition has a viscosity of less than or equal to 20 cP at a printing temperature.

7. The method of claim 1 , wherein the wt % of the low molecular weight polymer in the binder composition is greater than or equal to 1 wt % and less than or equal to 40 wt %.

8. The method of claim 1 , wherein the depositing step comprises thermally depositing the binder composition, and wherein the viscosity of the binder composition is greater than or equal to 1 cP and less than or equal to 10 cP at a printing temperature.

9. The method of claim 1 , wherein the depositing step comprises piezoelectrically depositing the binder composition, and wherein the viscosity of the binder composition is greater than or equal to 3 cP and less than or equal to 30 cP at a printing temperature.

10. The method of claim 1 , comprising cross-linking the binder composition using heat, UV light, and/or microwave radiation.

11. The method of claim 1 , further comprising depositing a second layer of metal powder on the first layer of metal powder after the binder composition has been deposited thereon and prior to drying or cross-linking the binder composition deposited on the first layer of the metal powder.

12. The method of claim 11 , further comprising depositing the binder composition on at least a portion of the second layer of metal powder prior to drying or cross-linking the binder composition deposited on the first layer of the metal powder.

13. The method of claim 1 , further comprising depositing a second layer of metal powder on the first layer of metal powder after drying and/or cross-linking the binder composition deposited on the first layer of the metal powder.

14. The method of claim 13 , further comprising depositing the binder composition on at least a portion of the second layer of metal powder.

15. The method of claim 1 , further comprising heating the metal-based composite structure in an environment having a temperature of greater than or equal to 700° C. and less than or equal to 1400° C.

16. The method of claim 1 , wherein the steel comprises a ferrous alloy having a chromium content of greater than or equal to 2 wt %.

17. The method of claim 1 , wherein the steel comprises a ferrous alloy having a chromium content of less than or equal to 2 wt %.

18. A method of additive manufacturing a metal-based composite structure by binder jet printing, the method comprising:
depositing a first layer of metal powder, the metal powder comprising steel;
depositing a binder composition on at least a portion of the first layer of metal powder, the binder composition comprising water and a low molecular weight polymer including an acrylic acid repeat unit, wherein the binder composition has a pH of greater than or equal to 4; and
cross-linking at least the binder composition deposited on the first layer of the metal powder using heat, UV light, and/or microwave radiation, thereby forming a metal-based composite structure, wherein the acrylic acid repeat unit is esterified during the cross-linking.

19. The method of claim 18 , wherein the cross-linking is performed using heat.

20. The method of claim 18 , wherein the low molecular weight polymer has a weight average molecular weight of less than or equal to 40 kDa.

21. The method of claim 18 , wherein the binder composition has a viscosity of less than or equal to 20 cP at a printing temperature.

22. The method of claim 18 , wherein the wt % of the low molecular weight polymer in the binder composition is greater than or equal to 1 wt % and less than or equal to 40 wt %.

23. The method of claim 18 , wherein the depositing step comprises thermally depositing the binder composition, and wherein the viscosity of the binder composition is greater than or equal to 1 cP and less than or equal to 10 cP at a printing temperature.

24. The method of claim 18 , wherein the depositing step comprises piezoelectrically depositing the binder composition, and wherein the viscosity of the binder composition is greater than or equal to 3 cP and less than or equal to 30 cP at a printing temperature.

25. The method of claim 18 , further comprising heating the metal-based composite structure in an environment having a temperature of greater than or equal to 700° C. and less than or equal to 1400° C.

Assignees

• Desktop Metal Inc

Inventors

• Renner Christopher Benjamin
• Rushkin Ilya L
• Sachs Emanuel M

Classifications

• B22F1/10

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

• B33Y70/00 Primary

  Materials specially adapted for additive manufacturing · CPC title

• B29K2033/04

  Polymers of esters · CPC title

• B33Y80/00

  Products made by additive manufacturing · CPC title

• B29K2105/24

  crosslinked or vulcanised · CPC title