Feedstock for an additive manufacturing method, additive manufacturing method using the same, and article obtained therefrom

Patent metadata

Field	Value
Publication number	US-11633786-B2
Application number	US-201716461193-A
Country	US
Kind code	B2
Filing date	Nov 15, 2017
Priority date	Nov 15, 2016
Publication date	Apr 25, 2023
Grant date	Apr 25, 2023

Abstract

A feedstock for a 3D manufacturing process, in particular a Fused Filament Fabrication process. The feedstock includes (P) sinterable particles made of a metal, metal alloy, glass, ceramic material, or a mixture thereof; and (B) a binder composition including (b1) 5-15% by weight, relative to the total weight of the binder composition, of a polymeric compatibilizer, and (b2) 85-95% by weight, relative to the total weight of the binder composition, of a polymeric binder component, the polymeric binder component being selected from the group consisting of (b2-1) a polymer mixture or polymer alloy, the mixture or alloy including at least a first and a second polymer; (b2-2) one, two or more block copolymers, including at least a first polymer block and second polymer block; and (b2-3) mixtures of (b2-1) and (b2-2), wherein the amount of sinterable particles P is 40 Vol % or more of the composition.

First claim

The invention claimed is:

1. A feedstock comprising:
sinterable particles P made of a metal, metal alloy, glass, ceramic material, or a mixture thereof; and
a binder composition B comprising:

5-15% by weight, relative to the total weight of the binder composition, of a polymeric compatibilizer b1; and
85-95% by weight, relative to the total weight of the binder composition, of a polymeric binder component b2,
the polymeric binder component b2 being selected from the group consisting of:
a polymer mixture or polymer alloy b2-1, the mixture or alloy comprising at least a first and a second polymer, the Tg of the first polymer being −20° C. or lower and the Tg of the second polymer being 60° C. or higher;
at least one block copolymer b2-2, comprising at least a first polymer block and second polymer block, the first polymer block having a Tg in the range of −20° C. or lower and the second polymer block having a Tg of 60° C. or higher; and
mixtures b2-3 of b2-1 and b2-2,

wherein the amount of sinterable particles P is 40 Vol.-% or more of the feedstock.

2. The feedstock according to claim 1 , wherein the first polymer and the second polymer in b2-1 are both selected from b2-1-1 homopolymers obtained from a (meth)acrylate or (meth)acrylic acid, are both selected from b2-1-2 random copolymers obtained from two or more monomers selected from (meth)acrylic acid and (meth)acrylates, or form a mixture of such homopolymers and copolymers, and/or
wherein the at least one block copolymer b2-2 is a block copolymer wherein all polymer blocks are obtained from monomers selected from the group consisting of (meth)acrylic acid and (meth)acrylates.

3. The feedstock according to claim 1 , wherein the at least one block copolymer b2-2 is selected from diblock copolymers and triblock copolymers.

4. The feedstock according to claim 3 , wherein the at least one block copolymer b2-2 is a triblock copolymer of the structure B-A-B, wherein the polymer block A is the first polymer block having a Tg of −20° C. or lower and the polymer block B is the second polymer block having a Tg of 60° C. or higher.

5. The feedstock according to claim 1 , wherein said first polymer or said first polymer block having a Tg in the range of −20° C. or lower is obtained from n-butyl acrylate, and said second polymer or said second polymer block having a Tg of 60° C. or higher is obtained from methyl methacrylate.

6. The feedstock according to claim 1 , wherein in b2-1 the content of said first polymer having a Tg of −20° C. or lower is in the range from 65 to 95% by weight, and the content of the second polymer having a Tg of 60° C. or higher is in the range of 5 to 35% by weight, based on the total weight of the polymers forming the component b2-1; or
wherein in the at least one block copolymer b2-2, the content of the first polymer block having a Tg of −20° C. or lower is in the range of 65-95% by weight, and the content of the second polymer block having a Tg in the range of 60° C. or higher is in the range of 5 to 35% by weight, based on the total weight of the block copolymer; or
wherein when two or more block copolymers b2-2 are used, the content of the first polymer block having a Tg of −20° C. or lower is in the range of 65-95% by weight, and the content of the second polymer block having a Tg in the range of 60° C. or higher is in the range of 5 to 35% by weight, based on the total weight of all block copolymers.

7. The feedstock according to claim 1 , wherein the polymeric binder component consists of the at least one block copolymer b2-2 the block copolymer having a structure B-A-B, wherein A is the first polymer block having a Tg of −20° C. or lower and is obtained from n-butyl acrylate and B is the second polymer block having a Tg in the range of 60° C. or higher and is obtained from methyl methacrylate, wherein the content of the first polymer block is in the range of 65-95% by weight, and the content of the second polymer block is in the range of 5-35% by weight, based on the total weight of each block copolymer.

8. The feedstock according to claim 1 , wherein the polymeric compatibilizer b-1 is a polymer having in a side chain or in the main chain of the polymer one or more groups selected from a hydroxyl group, an ether group, an oxo group, an ester group, a carboxylic acid group, a carboxylic acid anhydride group, a thiol group, an primary, secondary or tertiary amine group, and an amide group.

9. The feedstock according to claim 8 , wherein the polymeric compatibilizer b-1 is a polymer having in a side chain one or more groups selected from a hydroxyl group, a carboxylic acid group, and a carboxylic acid anhydride group.

10. The feedstock according to claim 1 , wherein the polymeric compatibilizer b-1 is a carboxylic acid or carboxylic acid anhydride modified polyolefin.

11. The feedstock according to claim 1 , wherein the binder composition B consists of the polymeric compatibilizer b-1 and the at least one block copolymer b-2-2 as a binder component, the polymeric compatibilizer b-1 being a carboxylic acid modified polyethylene, a carboxylic acid anhydride modified polyethylene, a carboxylic acid modified polypropylene or a carboxylic acid anhydride modified polypropylene.

12. The feedstock according to claim 1 , the feedstock being in the form of a filament or pellet.

13. The feedstock according to claim 1 , wherein the sinterable particles P are selected from the group consisting of a metal or metal alloy, and ceramic materials.

14. The feedstock according to claim 1 , wherein 95% by weight or more of the sinterable particles P have a diameter of 100 μm or less.

15. An additive manufacturing method comprising the use of the feedstock according to claim 1 .

16. An additive manufacturing method, the additive manufacturing method comprising the steps:
A. forming a first layer of a feedstock as defined in claim 1 on a support;
B. forming at least one further layer on top of the first layer to form a green body;
C. preforming a debinding treatment, in order to form a brown body from the green body obtained in step B; and
D. simultaneously or subsequently to step C, performing a sintering treatment to sinter the sinterable particles P.

17. The method according to claim 16 , wherein the thermal debinding treatment in step C comprises a heating treatment that is performed for 2 hours or more, according to a temperature profile that comprises one or more temperature increasing segments and optionally at least one temperature holding segment defining an end temperature, the highest temperature of the heating treatment being in the range of 300-450° C., wherein the average heating rate between 200° C. and the highest temperature is 5° C./minute or less.

18. The method according to claim 16 , wherein the thermal debinding step C and/or the sintering step D are performed vacuum, in an inert atmosphere, a reducing atmosphere or air.

Assignees

• Hoeganaes Ab Publ

Inventors

• Lundin Eva
• Darnis Magalie
• Nilsson Sofia
• Flodin Anders

Classifications

• B22F1/103

  containing an organic binding agent comprising a mixture of, or obtained by reaction of, two or more components other than a solvent or a lubricating agent · CPC title

• B33Y70/00

  Materials specially adapted for additive manufacturing · CPC title

• B22F3/1021 Primary

  Removal of binder or filler (removal of binder from ceramics C04B35/638) · CPC title

• B33Y10/00

  Processes of additive manufacturing · CPC title

• B33Y30/00

  Apparatus for additive manufacturing; Details thereof or accessories therefor · CPC title