Subsurface inclusions of objects for increasing interlaminar shear strength of a ceramic matrix composite structure

• US 8,293,356 B2
• Filed: 05/12/2009
• Issued: 10/23/2012
• Est. Priority Date: 05/12/2009
• Status: Expired due to Fees

• Current Assignee: Siemens Energy Incorporated (Siemens AG)
• Original Assignee: Siemens Energy Incorporated (Siemens AG)
• Inventors: Merrill, Gary B., Morrison, Jay A.
• Primary Examiner(s): Simone, Catherine A
• Application Number:
  US12/464,512
• Publication Number:
  US 20100291349A1
• Time in Patent Office: 1,260 Days
• Field of Search: 428/111, 428/113, 428/114, 428/156, 428/172, 428/210, 428/293.4, 428/323, 428/328, 428/330, 428/161, 428/162, 428/166
• US Class Current: 428/166
• CPC Class Codes: B32B 18/00 Layered products essentially comprising ceramics, e.g. refractory products
• CPC Class Codes: C04B 2235/5268 Orientation of the fibers
• CPC Class Codes: C04B 2235/528 Spheres
• CPC Class Codes: C04B 2235/5427 millimeter or submillimeter sized, i.e. larger than 0,1 mm
• CPC Class Codes: C04B 2235/945 Products containing grooves, cuts, recesses or protusions
• CPC Class Codes: C04B 2237/38 Fiber or whisker reinforced
• CPC Class Codes: C04B 2237/64 Forming laminates or joined articles comprising grooves or cuts
• CPC Class Codes: C04B 35/00 Shaped ceramic products characterised by their composition porous ceramic products C04B38/00; ceramic articles characterised by particular shape, see the relevant classes, e.g. linings for casting ladles, tundishes, cups or the like B22D41/02; ceramic substrates for microelectronic semi-conductors H01L23/15; Ceramics compositions containing free metal bonded to carbides, diamond, oxides, borides, nitrides, silicides, e.g. cermets, or other metal compounds, e.g. oxynitrides or sulfides other than as macroscopic reinforcing agents C22C; shaping of ceramics B28B; Processing powders of inorganic compounds preparatory to the manufacturing of ceramic products chemical preparation of powders of inorganic compounds C01; infiltration of sintered ceramic preforms with molten metal C04B41/51
• CPC Class Codes: C04B 35/565 based on silicon carbide
• CPC Class Codes: C04B 35/80 Fibres, filaments, whiskers, platelets, or the like
• CPC Class Codes: Y10T 428/24479 including variation in thickness
• CPC Class Codes: Y10T 428/24562 Interlaminar spaces
• CPC Class Codes: Y10T 428/24612 Composite web or sheet
• CPC Class Codes: Y10T 428/249928 Fiber embedded in a ceramic, glass, or carbon matrix

Abstract

A ceramic matrix composite (CMC) structure 12 includes a plurality of layers (e.g., 16, 18, 20) of ceramic fibers. The CMC structure 12 further includes a plurality of spaced apart objects 22 on at least some of the plurality of layers along a thickness of the composite structure. The inclusion of the objects introduces an out-of-plane fiber displacement arranged to increase an interlaminar shear strength of the structure.

Claims

1. A ceramic matrix composite structure comprising:

a plurality of layers of ceramic fibers; and

a plurality of spaced apart objects on at least some of the plurality of layers along a thickness of the composite structure, wherein the inclusion of said objects introduces an out-of-plane fiber displacement arranged to increase an interlaminar shear strength of the structure, wherein at least some of the objects comprise spheroid objects.

2. The structure of claim 1, wherein the spheroid objects are distributed over said at least some layers with a geometric arrangement configured to produce a sinusoidal out-of-plane fiber displacement.

3. The structure of claim 1, wherein the spheroid objects are selected from the group consisting of a sphere, an ellipsoid, and an object free of corners.

4. The structure of claim 1, wherein the objects further comprise at least some objects having a sufficient length dimension to penetrate into adjoining layers to provide a degree of interlocking therebetween.

5. The structure of claim 1, wherein every layer of the composite structure includes the out-of-plane displacement.

6. The structure of claim 1, wherein said at least some layers comprise just layers located in a thickness range that extends from beneath a middle section of the composite structure to above the middle section of the composite structure while excluding top and bottom layers.

7. The structure of claim 6, wherein said range comprises 75 percent of an entire thickness of the composite structure.

8. The structure of claim 6, wherein said range comprises 50 percent of an entire thickness of the composite structure.

9. The structure of claim 6, wherein said range comprises 33 percent of an entire thickness of the composite structure.

10. The structure of claim 1, wherein said at least some layers comprise a distribution along the thickness of the composite selected to at least in part counteract an expected interlaminar shear load distribution along the thickness of the composite.

11. The structure of claim 10, wherein at least some of the objects comprise objects distributed over said at least some layers in an arrangement selected to further counteract the expected level of interlaminar shear load distribution.

12. A ceramic matrix composite structure comprising:

a plurality of layers of ceramic fibers; and

a plurality of spaced apart objects on at least some of the plurality of layers along a thickness of the composite structure, wherein the inclusion of said objects introduces an out-of-plane fiber displacement arranged to increase an interlaminar shear strength of the structure, wherein said at least some layers comprise a random layer distribution along the thickness of the composite structure.

13. A ceramic matrix composite structure comprising:

a plurality of layers of ceramic fibers; and

a plurality of spaced apart objects on at least some of the plurality of layers along a thickness of the composite structure, wherein the inclusion of said objects introduces an out-of-plane fiber displacement arranged to increase an interlaminar shear strength of the structure, wherein the objects further comprise at least some objects having a sufficient length dimension to penetrate into adjoining layers to provide a degree of interlocking therebetween, wherein the objects having the sufficient length dimension include angulated ends to provide the interlocking.

14. A ceramic matrix composite structure comprising:

a plurality of layers of ceramic fibers; and

a plurality of spaced apart objects on at least some of the plurality of layers along a thickness of the composite structure, wherein the inclusion of said objects introduces an out-of-plane fiber displacement arranged to increase an interlaminar shear strength of the structure, wherein a first group of the objects comprise spheroid objects distributed over said at least some layers to produce a sinusoidal out-of-plane fiber displacement, and further wherein a second group of the objects has a sufficient length dimension to penetrate into adjoining layers and include angulated ends to provide a degree of interlocking therebetween.