Binder composition for additive manufacturing
Methods of additive manufacturing, binder compositions for additive manufacturing, and articles produced by and/or associated with methods of additive manufacturing are generally described.
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;
depositing a binder composition on at least a portion of the first layer of metal powder, the binder composition comprising:
water,
an adhesion promoter that is a small molecule, the adhesion promoter comprising a thiol group, 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
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 thiol group is a first functional group, and wherein the adhesion promoter further comprises a second functional group.
4. The method of claim 3 , wherein the second functional group is a nucleophilic functional group or an electrophilic group.
5. The method of claim 3 , wherein the adhesion promoter further comprises a third functional group.
6. The method of claim 5 , wherein the third functional group is a nucleophilic group or an electrophilic group.
7. The method of claim 1 , wherein the metal powder comprises gold metal and/or a gold alloy.
8. The method of claim 1 , wherein the adhesion promoter has a molecular weight of less than 1000 Da.
9. The method of claim 8 , wherein the low molecular weight polymer has a weight average molecular weight of less than or equal to 40 kDa.
10. The method of claim 1 , wherein the adhesion promoter has a molecular weight of less than 500 Da.
11. The method of claim 1 , wherein the adhesion promoter has a molecular weight of less than 300 Da.
12. The method of claim 1 , wherein the adhesion promoter forms a covalent bond with the low molecular weight polymer.
13. The method of claim 12 , wherein the adhesion promoter forms a covalent bond with the metal powder.
14. A method of additive manufacturing a metal-based composite structure by binder jet printing, the method comprising:
depositing a first layer of metal powder;
depositing a binder composition on at least a portion of the first layer of metal powder, the binder composition comprising:
water,
an adhesion promoter that is a small molecule, wherein the adhesion promoter is or comprises cysteine, cystine, methionine, homocysteine, an amine thiol, dithiothreitol, mercaptoethanol, a thiocarboxylic acid, and/or a thiocarboxylate, 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
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.
15. The method of claim 14 , wherein the adhesion promoter is cysteine, cystine, methionine, homocysteine, dithiothreitol, or mercaptoethanol.
16. The method of claim 14 , wherein the adhesion promoter is cysteine.
17. The method of claim 14 , wherein the metal powder comprises gold metal and/or a gold alloy.