Selective powder processing during powder bed additive manufacturing
The present disclosure generally relates to methods and apparatuses for secondary material deposition and insert deposition during additive manufacturing (AM) processes. Such methods and apparatuses can be used to embed chemical signatures into manufactured objects, and such embedded chemical signatures may find use in anti-counterfeiting operations and in manufacture of objects with multiple materials.
1. A method of fabricating an object, comprising:
(a) providing a given layer of a first build material:
(b) fusing at least a portion of the given layer of the first build material to form at least one fused region;
(c) providing a subsequent layer of the first build material;
(d) fusing at least a portion of the subsequent layer of the first build material: and
(e) repeating steps (c) and (d) until the object is formed,
(d) wherein, between steps (c) and (d) or between steps (c) and (d) during at least one repetition set forth in step (e):
removing a portion of the subsequent layer of the first build material to expose an exposed portion of a fused region through the subsequent layer of build material,
depositing a second build material or insert consisting of a pre fused portion of the second build material; and
moving a recoater arm after depositing the second build material or insert, and
wherein the providing the subsequent layer of the first build material comprises moving the recoater arm to move the first build material onto a build platform from a reservoir on a lateral side of the build platform, and
wherein the depositing the second build material or the insert comprises dispensing the second build material or the insert from a dispenser vertically above the build platform.
2. The method of claim 1 , wherein the removing is done by vacuum.
3. The method of claim 1 , wherein the second build material or insert is deposited over at least a portion of the exposed portion of the fused region.
4. The method of claim 1 , wherein the fusing comprises irradiating with a laser beam or with an electron beam.
5. The method of claim 1 , wherein the fusing comprises binder jetting.
6. The method of claim 1 , wherein the second build material or insert has different electromagnetic absorption or reflection characteristics from the first build material.
7. The method of claim 6 , wherein the absorption or reflection characteristics are measured using x-rays, ultraviolet, infrared, or computed tomography methods.
8. A method of fabricating an object on a build platform, comprising:
(a) providing a given layer of a first build material;
(b) fusing at least a portion of the given layer of a first build material, to form a fused region;
(c) providing a subsequent layer of the first build material by moving a recoater arm laterally to move the first build material onto the build platform from a reservoir on a lateral side of the build platform;
(d) fusing at least a portion of the subsequent later of the first build material; and
(e) repeating steps (c) and (d) until the object is formed,
wherein, between steps (c) and (d) during at least one repetition set forth in step (e), selectively depositing, via a dispenser vertically above the build platform, a second build material or insert consisting of a pre-fused portion of the second build material over at least a portion of the subsequent layer of the first build material, to form a bilayer of the first build material and the second build material, wherein the first build material differs from the second build material in one or more physicochemical properties, and
wherein the bilayer of the first build material and the second build material are fused to form a fused region of the fused first build material and the fused second build material.
9. The method of claim 8 , wherein the second build material or insert has different electromagnetic absorption or reflection characteristics from the first build material.
10. The method of claim 9 , where the absorption or reflection characteristics are measured using x-rays, ultraviolet, infrared, or computed tomography methods.