Polymer-synthesizing binder compositions for additive fabrication and related methods and compositions
Techniques are described for fabricating sinterable metallic parts by coating a metal powder with a first material, and by depositing a binder composition onto the metal powder that contains a second material, then causing the first and second materials to react to form a polymer. The first and second materials may be selected so that they combine to produce a desired polymer. The binder composition may be deposited using conventional binder jetting techniques.
1. A method of additive manufacturing comprising:
forming ones or more parts by performing, a plurality of times:
depositing a layer of metal powder, wherein particles of the metal powder are coated with a first material; and
depositing a binder composition on at least a portion of the layer of metal powder, the binder composition comprising a second material; and
curing the metal powder and binder composition, wherein said curing causes the first material to react with the second material and thereby form a polymer, wherein the first material comprises dimethyl terephthalate diester.
2. The method of claim 1 , wherein curing the metal powder and binder composition comprises heating the metal powder and binder composition.
3. The method of claim 1 , wherein curing the metal powder and binder composition comprises heating the metal powder and binder composition to above 180° C.
4. The method of claim 1 , wherein the first material comprises a monomer.
5. The method of claim 1 , wherein the first material comprises an aliphatic diester or an aromatic diester.
6. The method of claim 1 , wherein the second material is a dial or a polyol.
7. The method of claim 1 , wherein the second material is polyethylene glycol.
8. The method of claim 1 , wherein the second material is monoethylene glycol.
9. The method of claim 1 , wherein the binder composition comprises the second material in an amount greater than 90% w/w.
10. The method of claim 1 , wherein the polymer is polyethyleterphthalate (PET).
11. The method of claim 1 , wherein the polymer is a polyester.
12. The method of claim 1 , wherein the binder composition does not comprise a polymer.
13. The method of claim 1 , wherein the binder composition comprises water and ethylene glycol.
14. A method of additive manufacturing comprising:
forming ones or more parts by performing, a plurality of times:
depositing a layer of metal powder, wherein particles of the metal powder are coated with a first material; and
depositing a binder composition on at least a portion of the layer of metal powder, the binder composition comprising a second material; and
curing the metal powder and binder composition, wherein said curing causes the first material to react with the second material and thereby form a polymer,
wherein the polymer is a polyester.
15. A method of additive manufacturing comprising:
forming ones or more parts by performing, a plurality of times:
depositing a layer of metal powder, wherein particles of the metal powder are coated with a first material; and
depositing a binder composition on at least a portion of the layer of metal powder, the binder composition comprising a second material; and
curing the metal powder and binder composition, wherein said curing causes the first material to react with the second material and thereby form a polymer,
wherein the binder composition does not comprise a polymer.