Supports for sintering additively manufactured parts
According to one aspect, embodiments herein provide a method of reducing distortion in an additively manufactured part comprising forming a shrinking platform from a composite including metal particles embedded in a first matrix, forming shrinking supports from the composite, forming a part from the composite upon the shrinking platform and shrinking supports, forming an interior structure in at least one of the shrinking platform, the shrinking supports, and the part having a plurality of chambers with interconnections therebetween, forming from the shrinking platform, the sintering supports, and the part a portable assembly, and debinding the first matrix in the portable assembly to form a portable assembly in a brown state, wherein debinding the first matrix includes penetrating a fluid debinder into the interior structure of the at least one of the shrinking platform, the shrinking supports, and the part to debind the first matrix from within the interior structure.
1. A method of reducing distortion in an additively manufactured part, comprising:
depositing successive layers of a composite to form a shrinking platform, wherein the composite includes metal particles embedded in a first matrix;
depositing successive layers of the composite to form shrinking supports upon the shrinking platform;
depositing successive layers of the composite to from a part upon the shrinking platform and shrinking supports;
forming an interior structure in at least one of the shrinking platform, the shrinking supports, and the part, wherein the interior structure is comprised of a plurality of chambers having interconnections therebetween;
forming, from the shrinking platform, the sintering supports, and the part, a portable assembly in a green state, wherein the shrinking supports are configured to prevent the part from distorting due to gravitational force during a sintering process; and
debinding, in a debinding chamber, the first matrix in the portable assembly to form a portable assembly in a brown state, wherein debinding the first matrix includes penetrating a fluid debinder into the interior structure of the at least one of the shrinking platform, the shrinking supports, and the part to debind the first matrix from within the interior structure.
2. The method according to claim 1 , further comprising:
interconnecting the composite of the shrinking platform to the composite of the shrinking supports to permit mass diffusion between metal particles of the shrinking platform and adjacent metal particles of the shrinking supports to unitarily densify the shrinking platform and shrinking supports during the sintering process.
3. The method according to claim 1 , wherein forming the shrinking platform comprises:
forming the shrinking platform to form a foundation for the shrinking supports and the part, and wherein the shrinking platform interconnects the shrinking supports with one another; and
forming the shrinking platform to hold the part and the shrinking supports in relative position during the sintering process to prevent distortion to the part.
4. The method according to claim 1 , further comprising:
maintaining, with the first matrix, a shape of the portable assembly during deposition;
transporting the portable assembly in the brown state to a sintering chamber for sintering;
sintering, during the sintering process, the portable assembly in the brown state to shrink at a uniform rate throughout; and
maintaining, with the first matrix, a shape of the portable assembly during at least part of the sintering process.
5. The method according to claim 4 , further comprising:
forming parting lines in the shrinking supports, wherein the parting lines are configured to divide the shrinking supports into fragments that are separable along the parting lines.
6. The method according to claim 5 , further comprising:
detaching, after the sintering process, the shrinking supports from the portable assembly by separating the fragments of the shrinking supports from one another along the parting lines.
7. The method according to claim 1 , wherein forming the interior structure includes forming a honeycomb structure in at least one of the shrinking platform, the shrinking supports, and the part.
8. The method according to claim 1 , wherein depositing successive layers to form the shrinking supports further comprises forming from the composite a lateral support shell to follow a lateral contour of the part.
9. The method according to claim 8 , further comprising:
connecting the lateral support shell to the lateral contour of the part by forming separable attachment protrusions of the composite between the lateral support shell and the part.
10. The method according to claim 1 , further comprising:
forming the shrinking platform, the shrinking supports, and the part to substantially align a centroid of the combined shrinking platform and shrinking supports with a centroid of the part.
11. A method of reducing distortion in an additively manufactured part, comprising:
forming a shrinking platform through depositing successive layers of a composite, wherein the composite includes metal particles embedded in a first matrix;
forming shrinking supports through depositing successive layers of the composite upon the shrinking platform;
forming a part through depositing successive layers of the composite upon the shrinking platform and shrinking supports;
forming an interior structure in at least one of the shrinking platform, the shrinking supports, and the part, wherein the interior structure is comprised of a plurality of fluidly connected chambers having interconnections therebetween;
forming from the shrinking platform, the shrinking supports, and the part, a portable assembly in a green state, wherein the shrinking supports are configured to prevent the part from distorting due to gravitational force during a heating process;
debinding the first matrix in the portable assembly to form a portable assembly in a brown state, wherein debinding the first matrix includes:
penetrating a fluid debinder into the interior structure of the at least one of the shrinking platform, the shrinking supports, and the part; and
flowing the debinding fluid throughout the plurality of fluidly connected chambers via the interconnections to debind the first matrix from within the interior structure; and
heating, during the heating process, the portable assembly in the brown state to a temperature sufficient to densify all of the shrinking platform, the shrinking supports, and the part at a uniform rate.
12. The method according to claim 11 , further comprising:
interconnecting the composite of the shrinking platform to the composite of the shrinking supports to permit mass diffusion between metal particles of the shrinking platform and adjacent metal particles of the shrinking supports to unitarily densify the shrinking platform and shrinking supports during the heating process.
13. The method according to claim 11 , wherein forming the shrinking platform comprises: forming the shrinking platform to form a foundation for the shrinking supports and the part, and wherein the shrinking platform interconnects the shrinking supports with one another; and forming the shrinking platform to hold the part and the shrinking supports in relative position during the heating process to prevent distortion to the part.
14. The method according to claim 11 , further comprising:
maintaining, with the first matrix, a shape of the portable assembly during deposition; and
maintaining, with the first matrix, a shape of the portable assembly during at least part of the heating process.
15. The method according to claim 11 , wherein forming the interior structure includes forming a honeycomb structure in at least one of the shrinking platform, the shrinking supports, and the part.
16. The method according to claim 11 , wherein depositing successive layers to form the shrinking supports further comprises forming from the composite a lateral support shell to follow a lateral contour of the part.
17. The method according to claim 16 , further comprising:
connecting the lateral support shell to the lateral contour of the part by forming separable attachment protrusions of the composite between the lateral support shell and the part.
18. The method according to claim 11 , further comprising:
forming the shrinking platform, the shrinking supports, and the part to substantially align a centroid of the combined shrinking platform and shrinking supports with a centroid of the part.
19. The method according to claim 11 , further comprising:
forming parting lines in the shrinking supports, wherein the parting lines are configured to divide the shrinking supports into fragments that are separable along the parting lines.
20. The method according to claim 19 , further comprising:
detaching, after the heating process, the shrinking supports from the portable assembly by separating the fragments of the shrinking supports from one another along the parting lines.