FERRITE COMPOSITIONS

Abstract

Ferrite compositions, particularly ferrite coated substrates and more particularly fibre plys coated with ferrites in fibre reinforced polymer composites (FRPC), and composites with a plurality of functionalised fibre layers, include a magnetic ferrite composition for coating a substrate, said composition comprising a resin, and dispersed therein ferrite particulates, wherein said ferrite particulates have an average longest dimension of less than 500 nm. The composition may be used to provide a ferrite composite structure comprising at least one fibre ply, with at least one layer of a magnetic ferrite composition disposed thereon, wherein said ply is substantially encapsulated in a binder matrix to form a fibre reinforced polymer composite.

Claims

1. A ferrite composite structure comprising at least one glass fibre ply, with at least 40% v/v of a magnetic ferrite powder embedded therein, wherein particles of the magnetic ferrite powder have an average longest dimension of less than 500 nm, wherein the at least one glass fibre ply is substantially encapsulated in a binder matrix to form a fibre reinforced polymer composite.

2. The ferrite composite structure of claim 1, wherein the average longest dimension of the magnetic ferrite powder particles is in the range of from 50 to 150 nm.

3. The ferrite composite structure of claim 1, wherein the magnetic ferrite powder is one of manganese-zinc and nickel-zinc.

4. The ferrite composite structure of claim 1, wherein the magnetic ferrite powder is a nickel ferrite and further includes one or more of cobalt, copper, and magnesium.

5. The ferrite composite structure of claim 1, further comprising a plurality of glass fibre plys interspersed between untreated fibre plys, the untreated fibre plys not including ferrite particles.

6. The ferrite composite structure of claim 1, wherein the binder matrix includes particulate fillers, the particulate fillers being conductive particulate fillers.

7. The ferrite composite structure of claim 1, wherein the binder matrix comprises a resin, and dispersed therein are ferrite particulates, the ferrite particulates having an average longest dimension of less than 500 nm.

8. The ferrite composite structure of claim 1, wherein the binder matrix comprises a resin, and dispersed therein are ferrite particulates, the ferrite particulates being present in the range of from 20 to 90% v/v.

9. The ferrite composite structure of claim 1, wherein the binder matrix comprises a resin, and dispersed therein are ferrite particulates, the ferrite particulates being present in the range of from 50 to 80% v/v.

10. The ferrite composite structure of claim 1, wherein the binder matrix includes a ceramic binder.

11. The ferrite composite structure of claim 1, wherein the ferrite composite structure is a non-planar structure, the non-planar structure being one of a curved or tubular structure.

12. The ferrite composite structure of claim 1, further comprising at least one metallic fibre ply substantially encapsulated in the binder matrix with the at least one glass fibre ply.

13. The ferrite composite structure of claim 12, wherein the at least one metallic fibre ply includes a fibre ply with at least one layer of non-ferrite metallic material.

14. The ferrite composite structure of claim 1, wherein the binder matrix comprises a resin, and dispersed therein are ferrite particulates, the ferrite particulates in the binder matrix being the same as the particles of the magnetic ferrite powder.

15. The ferrite composite structure of claim 1, wherein the binder matrix comprises a resin, and dispersed therein are ferrite particulates, the ferrite particulates in the binder matrix being different from the particles of the magnetic ferrite powder.

16. A vehicle comprising the ferrite composite structure of claim 1.

17. A method of manufacturing a ferrite composite structure comprising at least one glass fibre, the method comprising: causing heating of the at least one glass fibre ply to a softening point; embedding a magnetic ferrite powder in the at least one glass fibre ply, wherein particles of the magnetic ferrite powder have an average longest dimension of less than 500 nm; causing the at least one glass fibre ply to cool; encapsulating the at least one glass fibre ply in a binder matrix; and causing a cure of the binder matrix thereby forming a fibre reinforced polymer composite.

18. The method of claim 17, wherein the magnetic ferrite powder is embedded in the at least one glass fibre ply by spraying the magnetic ferrite powder.

19. The method of claim 17, further comprising shaping the fibre reinforced polymer composite to form a structural panel.

20. The method of claim 17, wherein at least 40% v/v of the magnetic ferrite powder is embedded in the at least one glass fibre ply.

Description

[0032] Exemplary embodiments of the device in accordance with the invention will now be described with reference to the accompanying drawings in which:

[0033] FIGS. 1a and 1b show a composite structure, and ferrite composition

[0034] FIG. 2 shows a patch antenna pattern disposed on the surface of a substrate.

[0035] FIG. 1a shows an example of a composite structure depicted generally at 10, comprising a nickel ferrite fibre ply 11, optionally a standard fibre ply 14, optionally a metallic coated fibre ply (non ferrite) 15. The fibre plys (11, 14, 15) are encapsulated in a binder matrix 12 to form the composite structure 10. The binder matrix 12 may also contain filler particulates 16, which may also be nickel ferrite particulates.

[0036] The enlarged cut portion shows the nickel ferrite fibre ply 11, which is formed from a standard fibre ply 14a, which is impregnated with a ferrite composition 17 and optionally a surface coating 17a of a ferrite composition. FIG. 1b shows a ferrite composition 17 comprising a resin 18 loaded with ferrite particulates 19.

[0037] The resin 18 and binder matrix 12, may be independently selected resins or may be selected from the same resin systems. In a preferred arrangement, the ferrite composition 17 may also be selected as the preferred binder matrix material 12, such that the binder matrix 12 comprises ferrite particulates which are not disposed on the fibre ply.

[0038] The layers are not necessarily planar. Non-planar configurations may be employed, for example, to provide a curved or even a generally tubular device structure, or to provide devices which can be shaped to any currently existing shaped panel. The structures of the invention are well suited for such configurations.

[0039] FIG. 2 shows a top view of a patch antenna 21, which is formed from a substrate 23, which may be a fibre ply, with a disposed ferrite composition 22 in the form of an array pattern 24.