Curved high temperature alloy sandwich panel with a truss core and fabrication method

Patent metadata

Field	Value
Publication number	US-9731471-B2
Application number	US-201514970521-A
Country	US
Kind code	B2
Filing date	Dec 15, 2015
Priority date	Dec 16, 2014
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

A lightweight sandwich panel structure with a complex shape and curvature, and a method to fabricate such a panel out of high temperature alloys. Embodiments of a micro-truss core structure that offer high specific strength and stiffness while allowing for curvature, and methods for depositing multiple layers of metals that can be interdiffused into complex alloys, are provided. A core of a panel may be fabricated from a polymer template, which may be shaped, e.g., curved, and coated with metal layers, which may then be heat treated to cause the layers of metal to interdiffuse, to form an alloy.

First claim

What is claimed is:

1. An article, comprising:
a core; and
two facesheets secured to the core;
the core comprising:
a plurality of hollow first truss members extending in a first direction; and
a plurality of hollow second truss members extending in a second direction;
the truss members of the plurality of first truss members and the plurality of second truss members interpenetrating at a plurality of hollow nodes,

each of the hollow nodes being immediately adjacent to, and secured to, one of the two facesheets,
each of the truss members of the plurality of first truss members and the plurality of second truss members having:
an outside diameter between 0.1 mm and 5 mm,
a length between 3 mm and 50 mm, and
a wall thickness between 1 micron and 1000 microns,

wherein a hollow node is truncated, so that a saddle point of the hollow node is spaced from the facesheet to which it is immediately adjacent by a distance of less than one half of an outside diameter of a hollow truss member extending from the hollow node.

2. The article of claim 1 , wherein the two facesheets are attached to the core with an adhesive configured to transfer a load directly from a portion of a hollow node including a saddle point of the hollow node to the facesheet to which the hollow node is immediately adjacent.

3. The article of claim 1 , further comprising a hollow fourth truss member perpendicular to the two facesheets and interpenetrating one of the truss members of the plurality of first truss members and the plurality of second truss members at one of the plurality of hollow nodes.

4. The article of claim 1 , wherein the core comprises two interlaced tetrahedral structures.

5. The article of claim 1 , wherein a truss member of the truss members of the plurality of first truss members and the plurality of second truss members comprises:
a first coating layer comprising, as a major component, a substance selected from the group consisting of nickel, cobalt, iron, and combinations thereof;
a second coating layer comprising chromium or NiCr, the second coating layer having a Cr thickness of 10-40% of the thickness of the first coating layer,
a third coating layer of aluminum or NiAl, the third coating layer having a Al thickness of 10-40% of the thickness of the first coating layer.

6. The article of claim 5 , wherein the truss member further comprises a fourth coating layer having a thickness between 1% and 15% of a thickness of the first coating layer, the fourth coating layer comprising, as a major component, a substance selected from the group consisting of Mo, W, Ta, Ti, and Re, and combinations thereof.

7. The article of claim 6 , wherein the truss member further comprises a fifth coating layer having a thickness less than 2% of the thickness of the first coating layer, the fifth coating layer comprising, as a major component, a substance selected from the group consisting of Si, C, B, Zr, Hf, and Y, and combinations thereof.

8. The article of claim 1 , wherein a facesheet of the two facesheets has a radius of curvature between 5 cm and 10 m.

9. The article of claim 1 , wherein a facesheet of the two facesheets has a radius of curvature greater than 10 m.

10. The article of claim 1 , wherein a facesheet of the two facesheets has a first radius of curvature at a first point on the facesheet and a second radius of curvature at a second point on the facesheet, and the second radius of curvature differs by at least 30% from the first radius of curvature.

11. The article of claim 1 , wherein a first facesheet of the two facesheets has a first normal at a first point, and a second facesheet of the two facesheets has a second normal at a second point opposite the first point, wherein the angle between the first normal and the second normal is less than 175 degrees.

12. The article of claim 1 , wherein a feature selected from the group consisting of fasteners, bushings, inserts, and combinations thereof, is embedded in the core and in a facesheet of the two facesheets.

13. The article of claim 1 , wherein a density of the core in a first region within the article is greater by 10% than a density of the core in a second region within the article.

14. The article of claim 1 , wherein a truss member of the truss members of the plurality of first truss members and the plurality of second truss members has a cross-sectional shape selected from the group consisting of ovals, rectangles, and irregular shapes.

15. The article of claim 1 , further comprising:
three standoffs secured to a first facesheet of the two facesheets, each of the three standoffs having a length between 1 cm and 10 cm, and
a thermally insulating material adjacent to the first facesheet.

16. The article of claim 15 , further comprising a radiation barrier within the core.

17. The article of claim 15 , further comprising a thermally insulating material within the core.

18. The article of claim 1 , wherein:
the two facesheets comprise a first curved facesheet and a second curved facesheet;
the article has a shape of an airfoil, a flight control surface, or a leading edge;
each of the truss members of the plurality of first truss members and the plurality of second truss members has a wall thickness between 30 microns and 500 microns;
the wall thickness is between 0.01 and 0.1 times the outside diameter.

19. The article of claim 18 , wherein each of the hollow nodes is immediately adjacent to, and secured to, a facesheet of the two facesheets.

20. The article of claim 18 , further comprising an internal sheet in the core, wherein each of the hollow nodes is immediately adjacent to, and secured to:
a facesheet of the two facesheets, or
the internal sheet.

21. The article of claim 1 , wherein the core further comprises a plurality of hollow third truss members extending in a third direction,
the truss members of the plurality of first truss members, the plurality of second truss members, and the plurality of third truss members interpenetrating at the plurality of hollow nodes.

22. The article of claim 1 , wherein the truss members of the plurality of first truss members and the plurality of second truss members comprise, as a major component, an element selected from the group consisting of Ni, Co, Fe, Cu, Cr, Zn, Sn, and combinations thereof.

Assignees

• Hrl Lab Llc

Inventors

• Schaedler Tobias A
• Hundley Jacob M
• Martin John H
• Roper Christopher S
• Clough Eric C

Classifications

• C23F1/00

  Etching metallic material by chemical means (manufacture of printing surfaces B41C; manufacture of printed circuits H05K) · CPC title

• B32B15/20

  comprising aluminium or copper {(B32B15/016 and B32B15/017 take precedence)} · CPC title

• B29C2045/0079

  applying a coating or covering · CPC title

• B32B2607/00

  Walls, panels · CPC title

• B29C67/0066

  Operations & Transport · mapped topic