Additively manufactured build assemblies having reduced distortion and residual stress
A build assembly and a method of manufacturing the same are provided. The build assembly includes a first component, a second component, and a support structure coupling the two components together to fix their relative position. The support structure may be a “ghost” structure that is not connected with or does not contact the components, but is positioned such that the components are restrained to prevent distortion. The support structure may also be connected to the components and may define channels for removing additive powder from within or around the components.
1. An additively manufactured build assembly for a part, the additively manufactured build assembly comprising:
a first component of the part;
a second component of the part spaced apart from the first component; and
a support structure, the support structure coupled between the first component and the second component such that the support structure fixes the relative position of the first component and the second component, wherein:
the support structure defines one or more channels;
the first component and the second component each define a plurality of internal passages, wherein the one or more channels of the support structure are fluidly coupled to the internal passages; and
the support structure is configured to be removed after the manufacturing process is complete.
2. The additively manufactured build assembly of claim 1 , wherein:
the support structure comprises a frangible connector, wherein:
the frangible connector defines a portion of the support with a reduced strength as compared to a remainder of the support structure; and
the frangible connector defines a relatively low density as compared to the remainder of the support structure, is configured to fracture or break more easily as compared to the remainder of the support structure, defines a necked portion that is thinner than the remainder of the support structure, includes an increased porosity as compared to the remainder of the support structure, defines a series of voids along a fracture line of the support structure, defines a plurality of holes, includes a lattice structure, or any combination thereof such that the frangible connector defines the reduced strength as compared to the remainder of the support structure.
3. The additively manufactured build assembly of claim 1 , wherein the support structure is connected to the first component and the second component.
4. The additively manufactured build assembly of claim 3 , wherein the support structure is connected to the first component and the second component by a frangible connector.
5. The additively manufactured build assembly of claim 1 , wherein the first component and the second component are substantially identical and the build assembly is substantially symmetric about a midplane.
6. The additively manufactured build assembly of claim 1 , further comprising a third component and second and third support structures, the first, second, and third components each being joined to the other two of the first, second, or third components by two of the support structure, the second support structure, or the third support structure such that the build assembly forms a polygon.
7. The additively manufactured build assembly of claim 1 , wherein at least one of the first component and the second component defines a dimensional ratio equal to a length divided by a depth of the first component or the second component, wherein the dimensional ratio is less than 10.
8. The additively manufactured build assembly of claim 1 , wherein the build assembly is post-processed prior to removing the support structure.
9. The additively manufactured build assembly of claim 1 , wherein the first component, the second component, and the support structure are manufactured using at least one of selective laser sintering, selective laser melting, electron beam melting, or binder jetting.
10. The additively manufactured build assembly of claim 1 , wherein the first component, the second component, and the support structure are additively manufactured as a single monolithic component.
11. The additively manufactured build assembly of claim 1 , wherein the build assembly comprises a plurality of layers formed by:
depositing a layer of additive material on a bed of an additive manufacturing machine; and
selectively directing energy from an energy source onto the layer of additive material to fuse a portion of the additive material.
12. A method of manufacturing a build assembly of a part, the method comprising:
depositing a layer of additive material on a bed of an additive manufacturing machine;
selectively directing energy from an energy source onto the layer of additive material to fuse a portion of the additive material and form the build assembly, the build assembly comprising:
a first component of the part;
a second component of the part spaced apart from the first component; and
a support structure, the support structure coupled between the first component and the second component such that the support structure fixes the relative position of the first component and the second component, wherein;
the support structure defines one or more channels; and
the first component and the second component each define a plurality of internal passages, wherein the one or more channels of the support structure are fluidly coupled to the internal passages; and
removing the support structure.
13. The method of claim 12 , wherein:
the support structure comprises a frangible connector, wherein:
the frangible connector defines a portion of the support with a reduced strength as compared to a remainder of the support structure; and
the frangible connector defines a relatively low density as compared to the remainder of the support structure, is configured to fracture or break more easily as compared to the remainder of the support structure, defines a necked portion that is thinner than the remainder of the support structure, includes an increased porosity as compared to the remainder of the support structure, defines a series of voids along a fracture line of the support structure, defines a plurality of holes, includes a lattice structure, or any combination thereof such that the frangible connector defines the reduced strength as compared to the remainder of the support structure.
14. The method of claim 12 , further comprising:
removing additive powder through the one or more channels after the build assembly is completed.
15. The method of claim 12 , further comprising:
measuring an airflow through the internal passages of the first component and the second component by coupling an airflow measurement device to the one or more channels;
post-processing the build assembly; and
removing the support structure.
16. The method of claim 12 , wherein the first component, the second component, and the support structure are additively manufactured as a single monolithic component.