Methods of additively manufacturing a structure and related structures

Patent metadata

Field	Value
Publication number	US-2020251233-A1
Application number	US-202016801011-A
Country	US
Kind code	A1
Filing date	Feb 25, 2020
Priority date	Jul 19, 2016
Publication date	Aug 6, 2020
Grant date	—

Abstract

A method of forming one or more structures by additive manufacturing comprises introducing a first layer of a powder mixture comprising graphite and a fuel on a surface of a substrate. The first layer is at least partially compacted and then exposed to laser radiation to form a first layer of material comprising the fuel dispersed within a graphite matrix material. At least a second layer of the powder mixture is provided over the first layer of material and exposed to laser radiation to form inter-granular bonds between the second layer and the first layer. Related structures and methods of forming one or more structures are also disclosed.

First claim

1 . A method of additively manufacturing a structure, the method comprising:
disposing a first layer of a powder onto a surface of a substrate; compacting the first layer of the powder on the surface of the substrate; exposing the first layer of the powder to defocused laser radiation to form a first layer of a structure comprising inter-granular bonds between particles of the powder; disposing a second layer of another powder on the first layer of the structure; and exposing the second layer of the another powder to defocused laser radiation to form a second layer of the structure.

2 . The method of claim 1 , further comprising selecting the powder and the another powder to comprise a different material.

3 . The method of claim 2 , further comprising selecting the powder to comprise one of a metal and a ceramic material and selecting the another powder to comprise the other of the metal and the ceramic material.

4 . The method of claim 1 , further comprising selecting the powder and the another powder to comprise graphite.

5 . The method of claim 1 , further comprising selecting the powder and the another powder to comprise a uranium-containing material.

6 . The method of claim 1 , further comprising selecting the powder to comprise a matrix material and the another powder to comprise a fuel material.

7 . The method of claim 1 , wherein exposing the first layer of the powder to defocused laser radiation comprises exposing the first layer of the powder to defocused laser radiation having a spot size between about 1 mm and about 10 mm.

8 . The method of claim 1 , further comprising forming a third layer of a powder over the second layer of the structure, the third layer of the powder having a same composition as the first layer of the powder.

9 . A structure including a fissile fuel material, comprising:
at least a first layer comprising a fuel material dispersed in a graphite matrix material, wherein particles of the fuel material are directly bonded to adjacent particles of the graphite matrix material, the structure exhibiting a graphite to total carbon ratio equal to about 1.0:1.0; and at least a second layer of another material bonded to the first layer.

10 . The structure of claim 9 , wherein the fuel material comprises at least one of uranium dioxide, uranium silicide, or uranium carbide.

11 . The structure of claim 9 , wherein the fuel material comprises at least a portion of a fuel block or at least a portion of a fuel rod.

12 . The structure of claim 9 , wherein the fuel material exhibits a porosity between about 0.01 and about 0.05.

13 . The structure of claim 9 , wherein the fuel material comprises a carbon to uranium ratio between about 700:1 and about 10,000:1

14 . The structure of claim 9 , wherein the graphite matrix material constitutes between about 97.0 weight percent and about 99.9 weight percent of the structure.

15 . The structure of claim 9 , wherein the at least a first layer and the at least a second layer comprise the same material.

16 . A method of additively manufacturing a structure, the method comprising:
introducing a first layer of a powder mixture over a surface; exposing the first layer of the powder mixture to defocused laser radiation to form a first layer of a structure having the same composition as the first layer of the powder mixture; forming a second layer of the structure over the first layer of the structure.

17 . The method of claim 16 , wherein exposing the first layer of the powder mixture to defocused laser radiation comprises exposing the first layer of the powder mixture to laser radiation having a power between about 5 W and about 60 W.

18 . The method of claim 16 , wherein exposing the first layer of the powder mixture to defocused laser radiation comprises exposing the first layer of the powder mixture to defocused laser radiation to heat the first layer of the powder mixture to a temperature less than about 1,000° C.

19 . The method of claim 16 , wherein exposing the first layer of the powder mixture to defocused laser radiation comprises exposing the first layer of the powder mixture to laser radiation having a spot size between about 0.5 mm and about 10.0 mm.

20 . The method of claim 16 , wherein exposing the first layer of the powder mixture to defocused laser radiation comprises exposing the first layer of the powder mixture to laser radiation having a spot size between about 1.0 mm and about 5.0 mm.

21 . The method of claim 16 , wherein exposing the first layer of the powder mixture to defocused laser radiation comprises exposing the first layer of the powder mixture to defocused laser radiation having a beam divergence between about 5 milliradians and about 100 milliradians.

22 . The method of claim 16 , wherein introducing a first layer of a powder mixture over a surface comprises introducing a first layer of a powder mixture comprising a uranium-containing material over a surface.

23 . The method of claim 22 , wherein introducing a first layer of a powder mixture comprising a uranium-containing material over a surface comprises introducing a first layer of a powder mixture comprising a composite material comprising a graphite matrix material and the uranium-containing material dispersed win the graphite matrix material.

24 . The method of claim 16 , wherein introducing a first layer of a powder mixture over a surface comprises introducing a first layer of a powder mixture comprising particles of a fuel material coated with another material over the surface.

Assignees

• Battelle Energy Alliance Llc

Inventors

• Van Rooyen Isabella J
• Morrell Sean R

Classifications

• B22F10/28

  Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM] · CPC title

• B22F12/53

  Nozzles · CPC title

• B22F10/66

  by mechanical means · CPC title

• B22F10/38

  to achieve specific product aspects, e.g. surface smoothness, density, porosity or hollow structures · CPC title

• B22F10/36

  of energy beam parameters · CPC title