Login| Sign Up| Help| Contact|

Patent Searching and Data


Title:
PREFORM FOR METAL MATRIX CASTINGS
Document Type and Number:
WIPO Patent Application WO/2016/087867
Kind Code:
A1
Abstract:
A weave structure for use as a preform for a metal matrix casting. The weave structure comprises: a warp in the x direction, also called an x-tow, and a weft in the y direction, also called a y-tow. One of the x-tow or the y-tow comprises an alumina thread, and the alumina thread is 80 to 100 per cent aluminium oxide by weight. The other one of the x-tow or the y-tow comprises a second thread, and the second thread comprises regenerated cellulose fibre.

Inventors:
ANTICH CHRISTOPHER (GB)
Application Number:
PCT/GB2015/053706
Publication Date:
June 09, 2016
Filing Date:
December 03, 2015
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
ANTICH & SONS HUDDERSFIELD LTD (GB)
International Classes:
D03D1/00; B22D19/02; C22C47/06; C22C49/14; D03D15/02; D03D15/12; D03D25/00
Foreign References:
US20140161626A12014-06-12
EP0806285A21997-11-12
EP0402099A21990-12-12
JPS63135535A1988-06-07
JPH08120541A1996-05-14
EP0427873A11991-05-22
DE4300283A11994-07-14
Other References:
"Nextel(TM) Ceramic Textiles Technical Notebook", 30 November 2014 (2014-11-30), XP055252927, Retrieved from the Internet [retrieved on 20160224]
Attorney, Agent or Firm:
WITHERS & ROGERS LLP (London, Greater London SE1 2AU, GB)
Download PDF:
Claims:
Claims

1. A weave structure for use as a preform for a metal matrix casting, the weave structure comprising:

a warp in the x direction (an x-tow); and

a weft in the y direction (a y-tow);

wherein:

one of the x-tow or the y-tow comprises an alumina thread, and the alumina thread is 80 to 100 per cent aluminium oxide by weight; and

the other one of the x-tow or the y-tow comprises a second thread, and the second thread comprises regenerated cellulose fibre.

2. The weave structure of claim 1, wherein the one of the x-tow or the y- tow which comprises the alumina thread comprises one of the following: from 90 to 100 per cent alumina thread; from 95 to 100 per cent alumina thread; and substantially 100 per cent alumina thread.

3. The weave structure of claim 1 or claim 2, wherein the alumina thread is one of the following: from 80 to 100 per cent aluminium oxide by weight; from 85 to 100 per cent aluminium oxide by weight; from 90 to 100 per cent aluminium oxide by weight; from 95 to 100 per cent aluminium oxide by weight; from 97 to 100 per cent aluminium oxide by weight; 97 per cent aluminium oxide by weight; and 99 per cent aluminium oxide by weight.

4. The weave structure of any preceding claim, wherein the alumina thread includes silica.

5. The weave structure of claim 4, wherein the alumina thread includes one of the following: 20 per cent silica by weight or less; 15 per cent silica by weight or less; 10 per cent silica by weight or less; 5 per cent silica by weight or less; 3 per cent silica by weight or less; and 1 per cent silica or less.

6. The weave structure of any preceding claim, wherein the alumina thread is composite grade fibre designed for load bearing.

7. The weave structure of any preceding claim, wherein the alumina thread has substantially no glassy phases.

8. The weave structure of any preceding claim, wherein the alumina thread is fine-grained single-phase aluminium oxide thread.

9. The weave structure of any preceding claim, wherein the alumina thread is a long and narrow bundle of unspun fibre with a twist.

10. The weave structure of any preceding claim, wherein the alumina thread has a denier of one of the following: between 400 and 20,000 denier (444.44 and 22,222.22 decitex); 400 denier (444.44 decitex); 600 denier (666.66 decitex); 800 denier (888.88 decitex); 1000 denier (1111.11 decitex); 1100 denier (12222.22 decitex); 1300 denier (1444.44 decitex); 1500 denier (1666.66 decitex); 3000 denier (3333.33 decitex); 10000 denier (11, 11 1.1 1 decitex); 15000 denier (16,666.66 decitex); and 20000 denier (22,222.22 decitex).

11. The weave structure of any preceding claim, wherein the alumina thread has a filament count of one of the following: from 200 to 6000; 300; 400; 750; 2550; and 5100.

12. The weave structure of any preceding claim, wherein the alumina thread is roving and hence is unplied.

13. The weave structure of claim 12, wherein the roving has a twist.

14. The weave structure of any preceding claim, wherein the x-tow comprises the alumina thread.

15. The weave structure of any preceding claim, wherein the x-tow consists of the alumina thread.

16. The weave structure of any preceding claim, wherein the one of the x- tow or the y-tow which comprises the second thread comprises one of the following: from 90 to 100 per cent second thread; from 95 to 100 per cent second thread; and substantially 100 per cent second thread.

17. The weave structure of any preceding claim, wherein the second thread is one of the following: from 80 to 100 per cent regenerated cellulose fibre by weight; from 95 to 100 per cent regenerated cellulose fibre by weight; from 97 to 100 per cent regenerated cellulose fibre by weight; 97 per cent regenerated cellulose fibre by weight; and 99 per cent regenerated cellulose fibre by weight.

18. The weave structure of any preceding claim, wherein the second thread has a burning temperature of one of the following: from 200 to 700 degrees centigrade; from 250 to 550 degrees centigrade; from 300 to 500 degrees centigrade; from 350 to 450 degrees centigrade; from 400 to 425 degrees centigrade; and approximately 420 degrees centigrade.

19. The weave structure of any preceding claim, wherein the second thread comprises at least one of rayon and viscose.

20. The weave structure of any preceding claim, wherein the second thread is very fine.

21. The weave structure of any preceding claim, wherein the second thread is spun.

22. The weave structure of any preceding claim, wherein the second thread is one of the following: singles; a ply yarn; a two-ply yarn; a three-ply yarn; a four-ply yarn.

23. The weave structure of any preceding claim, wherein the second thread is one of the following: doubled, trebled, and quadrupled.

24. The weave structure of any preceding claim, wherein the second thread has a resultant decitex count of one of the following: 100 to 1000; 200 to 900; 300 to 800; 400 to 700; 500 to 700, 600 to 700; and 668.

25. The weave structure of any of claims 1 to 23, wherein the second thread has a resultant metric count (length in meters per 1 gram of mass) of one of the following: from Nm 20 to Nm 140; from Nm 30 to Nm 130; from Nm 40 to Nm 120; from Nm 50 to Nm 110; from Nm 60 to Nm 100; from Nm 70 to Nm 80.

26. The weave stmcture of any of claims 1 to 23, wherein the second thread has a metric count (length in meters per 1 gram of mass) of one of the following: Nm 40/2 to Nm 280/2; Nm 50/2 to Nm 180/2; from 80/2 to Nm 100/2; and 167/2.

27. The weave structure of any of claims 1 to 23, wherein the second thread has a metric count (length in meters per 1 gram of mass) in the range of one of the following: Nm 80/4 to Nm 400/4; Nm 100/4 to Nm 320/4; from 160/4 to Nm 240/4; and 334/4.

28. The weave structure of any preceding claim, wherein the y-tow comprises the second thread.

29. The weave structure of any preceding claim, wherein the y-tow consists of the second thread.

30. The weave structure of any preceding claim, wherein the weave structure comprises one of the following volume fraction percentages of alumina oxide, per cubed inch (or per cubed 25.4 mm), of the weave structure: 20 to 80 per cent; 30 to 70 per cent; 40 to 60 per cent; 45 to 55 per cent; and 42 per cent.

31. The weave structure of any preceding claim, wherein the weave structure comprises y-tow material having one of the following volume fraction percentages, per cubed inch (or per cubed 25.4 mm), of the weave structure: 2 and 15 percent; 3 and 10 percent; 4 and 7 percent and substantially 5 percent.

32. The weave structure of any preceding claim, wherein the weave structure has one of the following number of x-tows per inch (ends per inch, or epi): 30 to 100 epi (or ends per 25.4 mm); 40 to 90 epi (or ends per 25.4 mm); 50 to 80 epi (or ends per 25.4 mm); 60 to 70 epi (or ends per 25.4 mm); and 65 epi (or ends per 25.4 mm).

33. The weave structure of any preceding claim, wherein the weave structure has one of the following number of y-tows per inch (picks per inch, or ppi): 20 to 70 ppi (or picks per 25.4 mm); 30 to 60 ppi (or picks per 25.4 mm); 40 to 50 ppi (or picks per 25.4 mm); 42 to 48 ppi (or picks per 25.4 mm) and 45 ppi (or picks per 25.4 mm).

34. The weave structure of any preceding claim, wherein the weave structure is one of the following: at least 10 cm wide; at least 50 cm wide; at least 100 cm wide; from 100 cm to 200 cm wide; from 160 cm to 200 cm wide; 160 cm wide; and 200 cm wide.

35. The weave structure of any preceding claim, wherein the weave structure is a three-dimensional weave structure comprising a binder in the z direction (a z-tow).

36. The weave structure of claim 35, wherein the binder comprises one of the following: from 90 to 100 per cent alumina thread; from 95 to 100 per cent alumina thread; and substantially 100 per cent alumina thread.

37. The weave structure of any claim 35 or claim 36, wherein the weave structure is an interlaced three-dimensional weave structure.

38. The weave structure of any of claims 35 to 37, wherein the weave structure comprises one of the following: from 10 to 100 binders; 20 to 80 binders; 30 to 60 binders; and 40 binders.

39. The weave structure of any of claims 35 to 38, wherein the weave structure comprises one of the following number of stuffers in the x-direction (x- tows): from 80 to 160 stuffers; 100 to 140 stuffers; 110 to 120 stuffers; and 119 stuffers.

40. The weave structure of any of claims 35 to 39, wherein the weave structure is one of the following: at least 1 mm; at least 1.5 mm; at least 2.5 mm; substantially 2.5 mm thick; at least 5 mm thick; from 5 mm to 40 mm thick; from 5 mm to 30 mm thick; 5 to 10 mm thick; and substantially 25 mm thick.

41. The weave structure of any of claims 35 to 40, wherein the weave structure has one of the following cross-sectional shapes: T, U, I, bar, tube-like.

Description:
Preform for Metal Matrix Castings

FIELD OF THE INVENTION

[01] The invention relates to woven preforms for casting metal matrix materials, such as aluminium castings. In particular, but not exclusively, the invention relates to two- dimensional and three-dimensional woven preforms suitable for use in strengthening metal matrix composite castings. The invention relates especially, but not exclusively, to castings for the automotive industry.

BACKGROUND OF THE INVENTION

[02] There is an urgent need to provide components for industry which are lighter than before, yet which provide similar or improved strength characteristics. For example, in the automotive industry, there is an increased need to manufacture vehicles which are lighter in order to reduce the amount of energy required to move the vehicle. This in turn reduces the amount of carbon dioxide released into the environment during use of the vehicle.

[03] This approach of pursuing more lightweight materials is now being applied across many other industries, including the aerospace, rail, renewable energy and defence industries.

[04] Aluminium alloys and polymer composites are often the lightweight materials of choice. For example, the use of aluminium alloys in the automotive industry is widespread, with over 140 kg of aluminium used in the average European car. To put this in context, the European Union currently manufactures 15 million passenger cars per annum. For every kilogram of weight saved across the EU new car fleet, carbon dioxide emissions would reduce by approximately 10,000 tons each year.

[05] However, safety is an important consideration and lightweight components also need to perform mechanically. Simply using more lightweight materials is often not a solution unless those materials exhibit satisfactory mechanical performance, such as tensile strength or torsional stiffness. As a result, it is not always feasible to use aluminium or plastic composite materials and many highly loaded, discrete components are still made from heavier, but stiffer, ferrous materials. Changing material from cast iron or steel to aluminium can double the size of a given component, due to the inferior mechanical properties of aluminium. An alternative solution is required.

[06] Conventionally, aluminium composites have been manufactured from successive layers of alumina ceramic fibre, wound in directions corresponding to the stresses in the material, and then infiltrated with molten metal to produce a fused structure with a two- dimensional fibre arrangement. This technique produces a material with exceptional mechanical properties in the fibre direction. Under off-axis loading, the mechanical properties are reduced but are still superior to polymer composites, due to the presence of a metal rather than a plastic matrix, making the material more tolerant of unexpected load conditions. However the percentage of fibre in the final composite is high, increasing component cost. Additionally, aluminium composites produced by this technique suffer from failures which are catastrophic, in the sense that as soon as a breaking load is reached, a full failure of the component results.

[07] An aim of the invention is to provide preforms for reinforcing metal matrix composites, such as aluminium composites, which exhibit improved performance over prior art preforms. In particular, the invention aims to provide one or more of: improved mechanical properties of the composite, reduced manufacturing cost, and faster manufacturing processes.

SUMMARY OF THE INVENTION

[08] A first aspect of the invention provides a weave structure for use as a preform for a metal matrix casting. The weave structure comprises: a warp in the x direction, hereinafter called an x-tow, and a weft in the y direction, hereinafter called a y-tow. One of the x-tow or the y-tow comprises an alumina thread, and the alumina thread is 80 to 100 per cent aluminium oxide by weight. The other one of the x-tow or the y- tow comprises a second thread, and the second thread comprises regenerated cellulose fibre. In this way, the weave structure, or fibre preform, causes the metal matrix casting to have increased mechanical properties because the regenerated cellulose fibre in the y- tow burns off during casting to be replaced by the molten metal matrix material. Space and weight savings can therefore be obtained, and less carbon dioxide released into the environment. Also, material costs are reduced for equivalent stiffness properties of the metal matrix casting because the alumina thread can be more concentrated in the direction of required mechanical strength. Increasing the volume fraction percentage of alumina oxide in the weave structure improves the tensile strength of the metal matrix casting. For example, an alumina oxide volume fraction percentage of 7 per cent typically provides a tensile strength of 250 Mpa. Whereas an alumina oxide volume fraction percentage of 40 per cent typically provides a tensile strength of greater than 1200 MPa, and up to nearly 2000 MPa in some cases. Also, the woven structure provides protection against catastrophic failures.

[09] Alumina Thread

[10] Preferably, the one of the x-tow or the y-tow which comprises the alumina thread comprises one of the following: from 90 to 100 per cent alumina thread; from 95 to 100 per cent alumina thread; and substantially 100 per cent alumina thread. In this way, stiffness is further improved.

[11] Preferably, the alumina thread is one of the following: from 80 to 100 per cent aluminium oxide by weight; from 85 to 100 per cent aluminium oxide by weight; from 90 to 100 per cent aluminium oxide by weight; from 95 to 100 per cent aluminium oxide by weight; from 97 to 100 per cent aluminium oxide by weight; 97 per cent aluminium oxide by weight; and 99 per cent aluminium oxide by weight. In this way, stiffness is further improved.

[12] Preferably, the alumina thread includes silica. In this way, the thread is more pliable and flexible and is easier to weave. The alumina thread includes one of the following: 20 per cent silica by weight or less; 15 per cent silica by weight or less; 10 per cent silica by weight or less; 5 per cent silica by weight or less; 3 per cent silica by weight or less; and 1 per cent silica or less.

[13] Preferably, the alumina thread is composite grade fibre designed for load bearing.

[14] Preferably, the alumina thread has substantially no glassy phases. In this way, temperature is less likely to affect the mechanical properties of the finished casting.

[15] Preferably, the alumina thread is fine-grained single-phase aluminium oxide thread.

[16] Preferably, the alumina thread is a long and narrow bundle of unspun fibre with a twist.

[17] Preferably, the alumina thread has a denier of one of the following: between 400 and 20,000 denier (444.44 and 22,222.22 decitex); 400 denier (444.44 decitex); 600 denier (666.66 decitex); 800 denier (888.88 decitex); 1000 denier (1111.11 decitex); 1100 denier (1222.22 decitex); 1300 denier (1444.44 decitex); 1500 denier (1666.66 decitex); 3000 denier (3333.33 decitex); 10000 denier (11,111.11 decitex); 15000 denier (16,666.66 decitex) and 20000 denier (22,222.22 decitex). Increasing the denier of the alumina thread increases the weight and thickness of the thread, and allows a designer to suitably design a weave structure for a particular application. The inventor has found 10000 denier (11,111.11 decitex) to be particularly useful for an automotive component application but other deniers are also useful.

[18] Preferably, the alumina thread has a filament count of one of the following: from 200 to 6000; 300; 400; 750; 2550 and 5100. Similarly, increasing the filament count allows the designer to suitably design a weave structure for a particular application. The inventor has found 2550 filament count to be particularly advantageous for an automotive component application, but other filament counts are also useful.

[19] Preferably, the alumina thread is roving and hence is implied.

[20] Preferably, the roving has a twist.

[21] Preferably, the x-tow comprises the alumina thread.

[22] Preferably, the x-tow consists of the alumina thread. [23] Regenerated Cellulose Fibre

[24] Preferably, the one of the x-tow or the y-tow which comprises the second thread comprises one of the following: from 90 to 100 per cent second thread; from 95 to 100 per cent second thread; and substantially 100 per cent second thread. In this way, the regenerated cellulose fibre content in one direction of the weave is increased allowing more burn off of the second thread, to allow the metal matrix material to fill more of the fibre preform.

[25] Preferably, the second thread is one of the following: from 80 to 100 per cent regenerated cellulose fibre by weight; from 95 to 100 per cent regenerated cellulose fibre by weight; from 97 to 100 per cent regenerated cellulose fibre by weight; 97 per cent regenerated cellulose fibre by weight; and 99 per cent regenerated cellulose fibre by weight. Similarly, in this way, the regenerated cellulose fibre content is increased allowing more bum off of the second thread, to allow the metal matrix material to fill more of the fibre preform.

[26] Preferably, the second thread has a burning temperature of one of the following: from 200 to 700 degrees centigrade; from 250 to 550 degrees centigrade; from 300 to 500 degrees centigrade; from 350 to 450 degrees centigrade; from 400 to 425 degrees centigrade; and approximately 420 degrees centigrade. In this way, the second thread burns off cleanly during the casting process.

[27] Preferably, the second thread comprises at least one of rayon and viscose. [28] Preferably, the second thread is very fine. [29] Preferably, the second thread is spun.

[30] Preferably, the second thread is one of the following: singles; a ply yam; a two-ply yarn; a three-ply yarn; a four-ply yarn.

[31] Preferably, the second thread is one of the following: doubled, trebled, and quadrupled. [32] Preferably, the second thread has a resultant decitex count of one of the following: 100 to 1000; 200 to 900; 300 to 800; 400 to 700; 500 to 700, 600 to 700; and 668. In this way, the second thread is made just fine enough to hold the alumina thread, but does not take up more space and material than necessary in the weave structure.

[33] Preferably, the second thread has a resultant metric count (length in meters per 1 gram of mass) of one of the following: from Nm 20 to Nm 140; from Nm 30 to Nm 130; from Nm 40 to Nm 120; from Nm 50 to Nm 110; from Nm 60 to Nm 100; from Nm 70 to Nm 80. Similarly, in this way, the second thread is made just fine enough to hold the alumina thread, but does not take up more space and material than necessary in the weave structure.

[34] Preferably, the second thread has a metric count (length in meters per 1 gram of mass) of one of the following: Nm 40/2 to Nm 280/2; Nm 50/2 to Nm 180/2; from 80/2 to Nm 100/2; and 167/2. Similarly, in this way, the second thread is made just fine enough to hold the alumina thread, but does not take up more space and material than necessary in the weave structure.

[35] Preferably, the second thread has a metric count (length in meters per 1 gram of mass) in the range of one of the following: Nm 80/4 to Nm 400/4; Nm 100/4 to Nm 320/4; from 160/4 to Nm 240/4; and 334/4. Similarly, in this way, the second thread is made just fine enough to hold the alumina thread, but does not take up more space and material than necessary in the weave structure.

[36] Preferably, the y-tow comprises the second thread. This allows a weave structure to have the alumina thread in the x direction, and so it is easier, quicker and cheaper to weave elongate structures having increased tensile strength in the longitudinal direction.

[37] Preferably, the y-tow consists of the second thread.

[38] Weave Structure [39] Preferably, the weave structure comprises one of the following volume fraction percentages of alumina oxide, per cubed inch (or per cubed 25.4 mm), of the weave structure: 20 to 80 per cent; 30 to 70 per cent; 40 to 60 per cent; 45 to 55 per cent; and 42 per cent. In this way, additional mechanical strength is achieved in the metal matrix composite, and in particular, an efficient use of the alumina thread and regenerated cellulose fibre is achieved for the resultant mechanical strength improvement.

[40] Preferably, the weave structure comprises y-tow material having one of the following volume fraction percentages, per cubed inch (or per cubed 25.4 mm), of the weave structure: 2 and 15 percent; 3 and 10 percent; 4 and 7 percent; and substantially 5 percent. Similarly, in this way additional mechanical strength is achieved in the metal matrix composite, and in particular, an efficient use of the alumina thread and regenerated cellulose fibre is achieved for the resultant mechanical strength improvement.

[41] Preferably, the weave structure has one of the following number of x-tows per inch (ends per inch, or epi): 30 to 100 epi (or ends per 25.4 mm); 40 to 90 epi (or ends per 25.4 mm); 50 to 80 epi (or ends per 25.4 mm); 60 to 70 epi (or ends per 25.4 mm); and 65 epi (or ends per 25.4 mm).

[42] Preferably, the weave structure has one of the following number of y-tows per inch (picks per inch, or ppi): 20 to 70 ppi (or picks per 25.4 mm); 30 to 60 ppi (or picks per 25.4 mm); 40 to 50 ppi (or picks per 25.4 mm); 42 to 48 ppi (or picks per 25.4 mm) and 45 ppi (or picks per 25.4 mm).

[43] Preferably, the y-tow is one of the following: doubled, trebled or quadrupled.

[44] Preferably, the weave structure is one of the following: at least 10 cm wide; at least 50 cm wide; at least 100 cm wide; from 100 cm to 200 cm wide; from 160 cm to 200 cm wide; 160 cm wide; and 200 cm wide.

[45] 3D weave

[46] Preferably, the weave structure is a three-dimensional weave structure comprising a binder in the z direction (a z-tow). [47] Preferably, the binder comprises one of the following: from 90 to 100 per cent alumina thread; from 95 to 100 per cent alumina thread; and substantially 100 per cent alumina thread.

[48] Preferably, the weave structure is an interlaced three-dimensional weave structure.

[49] Preferably, the weave structure has three orthogonal interlaced tows.

[50] Preferably, the weave structure comprises one of the following: from 10 to 100 binders; 20 to 80 binders; 30 to 60 binders; and 40 binders.

[51] Preferably, the weave structure comprises one of the following number of stuffers in the x-direction (x-tows): from 80 to 160 stuffers; 100 to 140 stuffers; 110 to 120 stuffers; and 119 stuffers.

[52] Preferably, the weave structure is one of the following: at least 1 mm; at least 1.5 mm; at least 2.5 mm; substantially 2.5 mm thick; at least 5 mm thick; from 5 mm to 40 mm thick; from 5 mm to 30 mm thick; 5 to 10 mm thick; and substantially 25 mm thick.

[53] Preferably, the weave structure has one of the following cross-sectional shapes: T, U, I, bar, tube-like.

[54] There is also provided a metal matrix casting formed using a weave structure as defined above.

[55] Woven preforms are known to reinforce composite materials. For example, European patent EP-Bl-2391751 to Albany Engineered Composites of New Hampshire, USA, discloses a quasi-isotropic three-dimensional woven preform comprising a plurality of woven elements braided with each other to create a quasi-three dimensional weave. The aim of EP-Bl-2391751 is to produce components in configurations that are other than simple geometrical shapes such as plates, sheets, rectangular or square solids. In pursuit of a solution to this problem, the woven elements each comprise one or more integrally woven stiffeners or walls in a direction perpendicular to the plane of the woven element. The integrally woven stiffeners in the woven elements together form quasi-isotropic off axis or hexagonal stiffeners in the woven preform. A matrix material is then introduced to and into the preform, such as epoxy, polyester, vinyl-ester, ceramic, and carbon, so that typically the reinforcement preform becomes encased in the matrix material and the matrix material fills the interstitial areas between the constituent elements of the reinforcement preform. So combined, the reinforcement preform and the matrix material may then be cured and stabilized by thermosetting. As a result, stress on the finished component, particularly via its matrix material acting as an adhesive between fibres, may be effectively transferred to and borne by the constituent material of the reinforcement preform. However, it is not clear how this teaching can be used effectively and efficiently for forming metal composites.

BRIEF DESCRIPTION OF THE DRAWINGS

[56] Embodiments of the invention will now be described with reference to the accompanying drawings, in which:

[57] Figure 1 is a point paper drawing of an example embodiment of a two-dimensional plain weave structure.

[58] Figure 2 is a point paper drawing of an example embodiment of a two-dimensional twill weave structure.

[59] Figure 3 is a point paper drawing of an example embodiment of a three-dimensional weave structure.

DETAILED DESCRIPTION OF EMBODIMENT(S)

[60] 2D Plain Weave [61] Figure 1 is a point paper drawing of an example embodiment which serves to illustrate a weave design embodying the invention. Figure 1 is a technical drawing which is instructive to a weaver in the art and comprises a weave plan 110 and a weave draft 120 for the working dobby in a loom. Little more needs to be written about Figure 1, save for specifying some technical features of the weave plan 110 and draft 120 and hence resulting weave structure.

[62] The weave design illustrated in Figure 1 describes a two-dimensional weave structure having an x-tow and a y-tow. The weave structure shown is a plain weave. The weave plan illustrates a first x-tow 101 weaving one up, one down throughout the weave. A second x-tow 102 is illustrated weaving one down, one up throughout the weave. The weave draft 120 consists of two shafts working in relationship to the weave plan 110. The basic illustration of the weave structure is shown, and a skilled weaver, based on the weave plan 110 and draft 120, would be able to expand the weave plan 110 and draft 120 to a suitable size.

[63] Figure 1 shows the sleying at 2s (i.e. 2 per dent). Other suitable sleyings could be used.

[64] There are 34 x-tows per inch (34 x-tows per 25.4 mm) and 60 y-tows per inch (60 y- tows per 25.4 mm). The x-tow is alumina thread at 10k denier (11,111.11 decitex), and the y-tow is viscose thread at 668 decitex, in 2-ply yam doubled (i.e. (167 x 2, 167 x 2)). Other example threads, configurations, and specifications are given later in the specific description, after other embodiments are described.

[65] 2D Twill

[66] Figure 2 is another point paper drawing of an example embodiment which serves to illustrate a weave design embodying the invention, and comprises a weave plan 210 and a weave draft 220. [67] The weave design illustrated in Figure 2 describes a two-dimensional weave structure having an x-tow and a y-tow. The weave structure shown is a twill weave. The weave plan illustrates a first x-tow 201 weaving first and second up, third and fourth down; then a second x-tow 202 weaving second and third up, first and fourth down; then a third x-tow 203 weaving third and fourth up and first and second down; then a fourth x- tow 204 weaving first and fourth up, second and third down; with this repeating throughout the weave. The weave draft 220 consists of four shafts working in relationship to the weave plan 210. The basic illustration of the weave structure is shown, and a skilled weaver, based on the weave plan 210 and draft 220, would be able to expand the weave plan 210 and draft 220 to a suitable size.

[68] Figure 2 shows the sleying at 4s (i.e. 4 per dent). Other suitable sleyings could be used.

[69] There are 34 x-tows per inch and 60 y-tows per inch. The x-tow is alumina thread at 10k denier, and the y-tow is viscose thread at 668 decitex, in 2-ply yarn doubled (i.e. (167 x 2, 167 x 2). Other example threads, configurations, and specifications are given later in the specific description, after other embodiments are described.

[70] 3D Weave

[71] Figure 3 is a point paper drawing of an example embodiment which serves to illustrate a weave design embodying the invention. Figure 3 is a technical drawing which is instructive to a weaver in the art and includes a weaving plan 310 and a draft 320 for the working dobby in a loom. Little more needs to be written about Figure 3, save for specifying some technical features of the weave plan 310 and draft 320 and hence resulting weave structure.

[72] The weave design illustrated in Figure 3 describes a three-dimensional weave structure having x-tows (also referred to as stuffers), y-tows (also referred to as ys) and z- tows (also referred to as binders). All of the tows in each of the x, y and z directions are interlaced in some way. [73] The three-dimensional weave structure has 159 ends, comprising 119 stack ends (from the stuffers) and 40 binders. There are 45 picks per inch (ppi) (45 picks per 25.4 mm) in the y direction.

[74] The three-dimensional weave structure is formed on a suitably modified loom and the x-tows (stuffers) and z-tows (binders) are placed into eleven shafts 322 (shafts 1-11) as shown vertically in the weave draft 320 of Figure 3. Here, each "x" denotes a binder, and each "\" denotes a stuffer. Looking at the weave draft 320, there are four shafts given over to binders (shafts 1-4). There are seven shafts given over to stuffers (shafts 5-11).

[75] The section labelled 5T on the weave draft 320 of Figure 3 is drawn once but is repeated five times. So, it total, there are 4 + (5*(2+2+2)) + 2 + 4 = 40 binders, and 5* (7+7+7) + 7 + 7 = 119 stack ends, as mentioned before.

[76] Sleying is also illustrated in the weave draft 320 of Figure 3 by horizontal lines 20A/B. There are a total of 17 dents at 7 dents per inch (dpi). As can be seen, section 5T includes 3 dents (represented by sleying lines 20A), and so accounts for 15 dents. Two additional dents (represented by sleying lines 20B) are shown to the right of section 5T. The three-dimensional weave structure has a width of approximately 62 mm at this setting (17 dents at 7 dents per inch).

[77] The first dent comprises four binders from shafts 1 to 4, and then seven stuffers from shafts 5 to 11, and then two binders from shafts 1 and 2. The second dent comprises seven stuffers from shafts 5 to 11, and two binders from shafts 3 and 4. The third dent comprises seven stuffers from shafts 5 to 11, and two binders from shafts 3 and 4. The fourth dent comprises seven stuffers from shafts 5 to 11, and two binders from shafts 1 and 2. The fifth dent comprises seven stuffers from shafts 5 to 11, and two binders from shafts 3 and 4. The sixth dent comprises seven stuffers from shafts 5 to 11, and two binders from shafts 3 and 4. The fourth, fifth and sixth dents are repeated a further four times. The sixteenth dent comprises seven stuffers from shafts 5 to 11, and two binders from shafts 1 and 2. The seventeenth dent comprises seven stuffers from shafts 5 to 11, and four binders from shafts 1 to 4. [78] The binders on shafts 1 and 2 are full binders, in that they weave across the whole of the height of the three-dimensional stack, while the binders on shafts 3 and 4 are half binders, in that they weave through half of the height of the three-dimensional stack. Shaft 3 has half binders that weave from the bottom of the stack, and shaft 4 has half binders that weave from the top of the stack. This is illustrated in the weave plan 310 of Figure 3.

[79] The weave plan 310 of Figure 3 shows how each shaft of shafts 1 to 11 312 is positioned for each insertion of the y-tow. The shafts are indicated in columns from shaft 1 on the left to shaft 11 on the right. As already mentioned, shafts 1 and 2 have full binders, and shafts 3 and 4 have half binders. Shafts 5 to 11 have stuffers. The positions of each shaft is indicated for each y insertion, with an "x" indicating that the corresponding shaft is up, and a blank indicating that the corresponding shaft is down. Each insertion of the y-tow is represented by a row in the weave plan 310.

[80] The weave plan 310 of Figure 3 illustrates the full binders on shaft 1 weaving eight up, eight down throughout the weave, in relation to the y-tow insertions. The full binders on shaft 2 weave eight down, eight up throughout the weave, crossing with the full binders on the first shaft at the top and bottoms of the stack. The half binders on shaft 3 weave four up, twelve down throughout the weave, and weave from a mid-point of the stack to the bottom of the stack. The half binders on shaft 4 weave 7 down, five up, 4 down, and weave from a mid-point in the stack to the top of the stack.

[81] In the example embodiment of Figure 3, the stuffers are alumina thread having the following specifications: approximately 97 per cent aluminium oxide by weight; approximately 3 per cent silica by weight; approximately 10000 denier (11,111.11 decitex); a nominal filament count of approximately 2550; roving. The example x-tow is 3M(TM) Nextel(TM) Continuous Filament Ceramic Oxide Fiber 610 lOOOOd 324 Structural Roving. However, other suitable alumina threads may be used, not least those threads having specifications within the ranges given at the end of this description. [82] The example y-tow is viscose (i.e. regenerated cellulose fibre). In particular, the example y-tow has the following specifications: very fine; two-ply yam; doubled; 668 decitex (167 x 2) + (167 x 2). The y-tow has a burning temperature of approximately 420 degrees centigrade. However, other suitable regenerated cellulose threads may be used, not least those threads having specifications within the ranges given at the end of this description.

[83] The binders are the same material as the stuffers. However, other suitable alumina threads or non-alumina threads may be used, not least those threads having specifications within the ranges given and the end of this description.

[84] The example weave structure has a volume fraction percentage of stuffers and binders of approximately 42 per cent per cubed inch (or per cubed 25.4 mm) of weave structure. However, other volume fraction percentages are envisaged and other volume faction percentages of stuffers and binders would also be useful.

[85] The embodiment of Figure 3 is for illustrative purposes, and modifications may be made to the weave structure to suit different needs and applications. For example, the weave structure may be made wider, the weave structure may have another ratio of stack ends to binders, and the weave structure may have more or fewer picks per inch (ppi) (or picks per 25.4 mm).

[86] The y-tow is designed to burn off during the casting process, and is intended to hold together the weave structure, or fibre preform, only for as long as is necessary to place the fibre preform in place prior to casting in a metal matrix composite structure. By creating a fibre preform that uses as much aluminium oxide material in a single direction as possible (the x direction of the weave structure), the overall stiffness of the metal matrix composite component is increased.

[87] A suitable example casting process for the weave structure illustrated is shown in patent publication WO 2005/097377 A to Composite Metal Technology Ltd. [88] Although the invention has been described above with reference to one or more preferred embodiments, it will be appreciated that various changes or modifications may be made without departing from the scope of the invention as defined in the appended claims.

[89] The example embodiments use alumina oxide thread for the x-tow, and regenerated cellulose fibre for the y-tow. However, this configuration may be swapped.

[90] Alumina Thread

[91] Whilst the example embodiments described above use approximately 100 per cent alumina thread, it is envisaged that the alumina thread may comprise one of the following: from 80 to 100 per cent alumina thread; from 90 to 100 per cent alumina thread; from 95 to 100 per cent alumina thread; and substantially 100 per cent alumina thread, or any other suitable amount.

[92] Additionally, while the example embodiments use alumina thread having 97 per cent aluminium oxide by weight, the alumina thread may be one of the following: from 80 to 100 per cent aluminium oxide by weight; from 85 to 100 per cent aluminium oxide by weight; from 90 to 100 per cent aluminium oxide by weight; from 95 to 100 per cent aluminium oxide by weight; from 97 to 100 per cent aluminium oxide by weight; and 99 per cent aluminium oxide by weight, or any other suitable amount.

[93] In the example embodiments, the alumina thread includes silica at approximately 3 per cent silica by weight. However, the alumina thread may comprise one of the following: 20 per cent silica by weight or less; 15 per cent silica by weight or less; 10 per cent silica by weight or less; 5 per cent silica by weight or less; 3 per cent silica by weight or less; and 1 per cent silica or less; or any other suitable amount of silica. The silica is important for increasing the malleability and workability of the alumina thread. [94] The alumina thread is composite grade fibre designed for load bearing. The alumina thread has substantially no glassy phases. The alumina thread is fine-grained single-phase aluminium oxide thread. The alumina thread is a long and narrow bundle of unspun fibre with a twist.

[95] The alumina thread used in the example embodiments is 10000 denier. However, the alumina thread may have a denier of one of the following: between 400 and 20,000 denier (444.44 and 22,222.22 decitex); 400 denier (444.44 decitex); 600 denier (666.66 decitex); 800 denier (888.88 decitex); 1000 denier (1111.11 decitex); 1100 denier 1222.22 decitex); 1300 denier (1444.44 decitex); 1500 denier (1666.66 decitex); 3000 denier (3333.33 decitex); 15000 denier (16,666.66 decitex); 20000 denier (22,222.22 decitex); or any other suitable denier.

[96] The alumina thread used in the example embodiments has a filament count of 2550, but may also have a filament count of one of the following: from 200 to 6000; 300; 400; 750; 5100; or any other suitable filament count.

[97] The alumina thread is roving and hence is implied. The roving has a twist. However, other types of alumina thread may be used.

[98] Regenerated Cellulose Fibre

[99] Whilst the example embodiments use 100 per cent regenerated cellulose fibre for the y-tow y-tow may comprise one of the following: from 80 to 100 per cent regenerated cellulose fibre by weight; from 95 to 100 per cent regenerated cellulose fibre by weight; from 97 to 100 per cent regenerated cellulose fibre by weight; 97 per cent regenerated cellulose fibre by weight; and 99 per cent regenerated cellulose fibre by weight, or any other suitable amount.

[100] Whilst the example embodiments show regenerated cellulose fibre to have a buming temperature of approximately 420 degrees, the burning temperature may be one of the following: from 200 to 700 degrees centigrade; from 250 to 550 degrees centigrade; from 300 to 500 degrees centigrade; from 350 to 450 degrees centigrade; and from 400 to 425 degrees centigrade. [101] Indeed, using a significant amount of any type of fibre which has a bum off temperature such that a clean bum off is achieved during a metal casting process is envisaged. Using regenerated cellulose fibre is considered very useful.

[102] The y-tow may be one of rayon and viscose.

[103] The y-tow is very fine, but may be coarser depending on the application.

[104] The y-tow is spun, but may be unspun depending on the application.

[105] The y-tow in the example embodiments is two-ply yam, but may also usefully be one of the following: singles; a three-ply yam; a four-ply yam; or another suitable ply yam.

[106] The y-tow in the example embodiments is doubled, but may usefully be one of the following: trebled, quadrupled, or any other multiple depending on the application.

[107] The y-tow in the example embodiments has a resultant decitex count of 668, but may have a resultant decitex count of one of the following: 100 to 1000; 200 to 900; 300 to 800; 400 to 700; 500 to 700, 600 to 700; and any other suitable decitex count depending on the application.

[108] Additionally, the second thread may have a resultant metric count (length in meters per 1 gram of mass) of one of the following: from Nm 20 to Nm 140; from Nm 30 to Nm 130; from Nm 40 to Nm 120; from Nm 50 to Nm 110; from Nm 60 to Nm 100; from Nm 70 to Nm 80.

[109] Additionally, the second thread may have a metric count (length in meters per 1 gram of mass) of one of the following: Nm 40/2 to Nm 280/2; Nm 50/2 to Nm 180/2; from 80/2 to Nm 100/2; and 167/2.

[110] Additionally, the second thread may have a metric count (length in meters per 1 gram of mass) in the range of one of the following: Nm 80/4 to Nm 400/4; Nm 100/4 to Nm 320/4; from 160/4 to Nm 240/4; and 334/4. [111] Weave Structure

[112] In the example embodiments described, and in particular with reference to Figure 3, the weave structure has a volume fraction percentage of 42 per cent alumina oxide. However, the weave structure may comprise one of the following volume fraction percentages of alumina oxide, per cubed inch (or per cubed 25.4 mm), of the weave structure: 20 to 80 per cent; 30 to 70 per cent; 40 to 60 per cent; 45 to 55 per cent, depending on the application.

[113] Additionally, the weave structure comprises y-tow material having one of the following volume fraction percentages, per cubed inch (or per cubed 25.4 mm), of the weave structure: 2 and 15 percent; 3 and 10 percent; 4 and 7 percent; and substantially 5 percent.

[114] In the example embodiments described, and in particular with reference to Figure 3, the weave structure has 65 ends per inch (or ends per 25.4 mm). However, the weave structure may have one of the following number of x-tows per inch (ends per inch, or epi): 30 to 100 epi (or ends per 25.4 mm); 40 to 90 epi (or ends per 25.4 mm); 50 to 80 epi (or ends per 25.4 mm); 60 to 70 epi (or ends per 25.4 mm), depending on the application.

[115] In the example embodiments described, and in particular with reference to Figure 3, the weave structure has 45 picks per inch. However, the weave structure may have one of the following number of y-tows per inch (picks per inch, or ppi): 20 to 70 ppi; 30 to 60 ppi; 40 to 50 ppi; 42 to 48 ppi, depending on the application.

[116] The weave structure of the example embodiments may be one of the following: at least 10 cm wide; at least 50 cm wide; at least 100 cm wide; from 100 cm to 200 cm wide; from 160 cm to 200 cm wide; 160 cm wide; and 200 cm wide.

[117] 3D weave

[118] In the example embodiment described with reference to Figure 3, the binder comprises 100 per cent alumina thread, but may comprise one of the following: from 90 to 100 per cent alumina thread; from 95 to 100 per cent alumina thread; and substantially 100 per cent alumina thread. [119] In the example embodiment described with reference to Figure 3, the weave structure comprises 40 binders, but may comprise one of the following: from 10 to 100 binders; 20 to 80 binders; 30 to 60 binders, or any other suitable number depending on the application.

[120] In the example embodiment described with reference to Figure 3, the weave structure comprises 119 stuffers, but may comprise one of the following number of x-tows or stuffers: from 80 to 160 stuffers; 100 to 140 stuffers; 110 to 120 stuffers, or any other suitable number depending on the application.

[121] In the example embodiment described with reference to Figure 3, the weave structure is approximately 25 mm thick, but may be one of the following: at least 1 mm; at least 1.5 mm; at least 2.5 mm; substantially 2.5 mm thick; at least 5 mm thick; from 5 mm to 40 mm thick; from 5 mm to 30 mm thick; 5 to 10 mm thick; and substantially 25 mm thick.

[122] The weave structure may have one of the following cross-sectional shapes: T, U, I, bar, tube-like.

[123] The weave structures disclosed are particularly well suited to metal matrix castings for automotive applications, where the relationship between performance and cost is perhaps currently most challenging. Many cast or forged automotive components can use the weave structures for local reinforcement so as to be smaller, lighter and stiffer than the previous all aluminium component.

[124] Components using the disclosed weave structures are suitable and attractive for use in engine applications (such as block reinforcement, engine mounts, main bearing caps, connecting rods and piston pins), transmissions (gearbox casings, differential housings, transfer case housings), suspension components (uprights, radius arms, etc), brake calipers, seat frames, wheels, body structural components and sub-frames. Rotating or reciprocating components will in particular benefit from the disclosed weave structures, as the potential reduction in inertia will improve dynamic performance. [125] Applications for the disclosed technology are also found in the aerospace, heavy truck, rail, defence, power generation, and the renewable energy industries. Static systems may also benefit. There is considerable potential for application in wind turbine sub-systems, where weight saving in the turbine nacelle can provide secondary benefits in reducing tower, foundation, transportation and erection cost.