A component formed from a hybrid material

Abstract

Hybrid material components and methods of forming hybrid material components are provided. For example, a hybrid material component includes a plurality of metallic filaments and a plurality of non-metallic filaments. Each metallic filament of the plurality of metallic filaments is surrounded by a portion of the plurality of non-metallic filaments such that the plurality of metallic filaments is embedded within the plurality of non-metallic filaments. An exemplary hybrid material component is a containment assembly of a gas turbine engine. A method of forming such a component includes forming a hybrid material; laying up multiple layers of material to form a layup; and processing the layup such that the plurality of metallic filaments and the plurality of non-metallic filaments co-cure.

Description

Technical Field

[0001] This subject matter generally relates to components formed from composite materials. More specifically, this subject matter relates to housings formed from composite materials, such as fan housing systems for gas turbine engines. Background Technology

[0002] Aircraft gas turbine engines operate under various conditions, and foreign objects can be ingested into the engine. During engine operation, especially during the movement of an engine-powered aircraft, fan blades can be impacted and damaged by foreign objects, such as birds or debris kicked up from the runway. Impacts to fan blades can damage the blades and cause blade fragments or the entire blade to detach and fly radially outward at relatively high speeds.

[0003] To limit or minimize damage caused by detached blades or blade fragments, some known engines include a metal or composite casing or housing to help increase the engine's radial and axial stiffness and reduce stress near blade penetration. To provide blade containment, most of the kinetic energy from the released blade or blade fragment must be absorbed by the casing or housing material. For smaller diameter engines, sufficient containment can be achieved through a sufficiently thick metal "hard-walled" casing to resist blade fragment penetration. A layer of composite material, such as a graphite-epoxy polymer matrix composite, can be applied to the outer surface of the metal casing to enhance its containment capacity. Thus, the metal and composite elements of the casing are separate layers.

[0004] However, for larger diameter engines, a metal casing thick enough to resist penetration is very heavy. Therefore, composite hard-wall systems (using a composite casing instead of a metal casing) or composite “soft-wall” containment systems can be used for larger diameter engines. In soft-wall systems, lightweight, high-strength ballistic fabrics, such as those made of aramid fibers (e.g., ...), are used. The fabric formed can be wrapped in multiple layers around a relatively thin support structure. During operation, detached blades or blade fragments partially penetrate the support structure and impact the fabric. The fabric layers are designed to trap and contain the blades or blade fragments. Conventional support structures can be made of aluminum or fiber-reinforced composites based on weight considerations; for example, the support structure may include an aluminum honeycomb structure. Therefore, like typical hard-walled containment systems, typical soft-walled containment systems can utilize separate metals and composite materials to form the containment shell.

[0005] The layering of metallic and composite materials in containment systems in the manner typically used in hardwall and softwall containment systems can increase the weight and cost of engines using the containment systems. Further, all metallic containment systems or all composite (e.g., carbon) containment systems can also be relatively heavy and / or costly. Accordingly, an improved containment enclosure or casing for a gas turbine engine would be desirable. For example, it would be desirable to increase the strength and energy absorption of containment assemblies without unduly increasing the weight and / or cost of the containment systems. SUMMARY

[0006] Aspects and advantages of the application will be set forth in part in the following description, or can be obvious from the description, or can be learned through practice of the application.

[0007] In one example embodiment of the present subject matter, a containment assembly of a gas turbine engine is provided. The containment assembly includes a containment enclosure extending in an axial direction about a longitudinal centerline of the gas turbine engine. The containment enclosure is formed of a hybrid material. The hybrid material includes a plurality of metallic tows and a plurality of non-metallic tows. Each metallic tow of the plurality of metallic tows is surrounded by a non-metallic tow of the plurality of non-metallic tows such that the plurality of metallic tows is embedded within the plurality of non-metallic tows.

[0008] In another example embodiment of the present subject matter, a hybrid material component of a gas turbine engine is provided. The hybrid material component includes a plurality of metallic tows and a plurality of non-metallic tows. Each metallic tow of the plurality of metallic tows is surrounded by a portion of a non-metallic tow of the plurality of non-metallic tows such that the plurality of metallic tows is embedded within the plurality of non-metallic tows.

[0009] In a further example embodiment of the present subject matter, a method for forming a hybrid material component of a gas turbine engine is provided. The method includes forming a hybrid material from a plurality of metallic tows mixed with a plurality of non-metallic tows; laying up a plurality of layers of the hybrid material to form a hybrid material layup; and processing the hybrid material layup. Processing the hybrid material layup includes curing the hybrid material layup such that the plurality of metallic tows and the plurality of non-metallic tows are co-cured.

[0010] These and other features, aspects, and advantages of the present application will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the application and together with the description, serve to explain the principles of the application. BRIEF DESCRIPTION OF DRAWINGS

[0011] A complete and enabling disclosure of the application, directed to one of ordinary skill in the art, including the best mode, is set forth in the specification which follows, and is illustrated in the accompanying drawings, wherein:

[0012] Figure 1A schematic cross-sectional view of an exemplary gas turbine engine is provided in accordance with various embodiments of the present subject matter.

[0013] Figure 2 A schematic cross-sectional view of a fan containment housing assembly is provided in accordance with an exemplary embodiment of the present subject matter.

[0014] Figure 3A A perspective view of a portion of a three-dimensional braided hybrid material is provided in accordance with an exemplary embodiment of the present subject matter.

[0015] Figure 3B A schematic cross-sectional view of a portion of a hybrid material including a plurality of hybrid material layers is provided in accordance with an exemplary embodiment of the present subject matter.

[0016] Figure 4 A schematic side view of a portion of a hybrid material including a plurality of hybrid material layers with a metal sheet disposed therebetween is provided in accordance with an exemplary embodiment of the present subject matter.

[0017] Figure 5 A flowchart illustrating a method for forming a containment assembly for a gas turbine engine is provided. DETAILED DESCRIPTION

[0018] Reference will now be made in detail to the present embodiments of the application, one or more examples of which are illustrated in the drawings. The detailed description uses numerical and letter designations

[0019] As used herein, the terms "first," "second," and "third" can be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components.

[0020] The terms "forward" and "aft" refer to relative positions within a gas turbine engine or vehicle and refer to the normal operating attitude of the gas turbine engine or vehicle. For example, with respect to a gas turbine engine, forward refers to a position closer to the engine inlet and aft refers to a position closer to the engine nozzle or exhaust.

[0021] The terms "upstream" and "downstream" refer to the relative direction with respect to the fluid flow in a fluid pathway. For example, "upstream" refers to the direction from which the fluid flows, and "downstream" refers to the direction to which the fluid flows.

[0022] The terms "coupled," "fixed," "attached" and the like, mean either a direct coupling, fixation, or attachment, or an indirect coupling, fixation or attachment through one or more intermediate

[0023] The singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise.

[0024] Approximating language as used herein throughout the description and claims is applied to modify any quantitative representation that could permissibly vary without resulting in a change in the basic function to which it is directed. Accordingly, a value modified by a term or terms, such as "about" and "substantially," does not limit the exact value, and admits some variation as would be appreciated by one of ordinary skill in the art. In at least some instances, an approximation can correspond to the precision of an instrument for measuring the value, or the precision of the manner in which the value is constructed or manufactured. For example, an approximation can be within 1%, 2%, 4%, 10%, 15%, or 20% of a single value, a range of values, and / or an endpoint of a defined range of values.

[0025] Ranges are combined and interchanged, such ranges are identified and include all subranges therein unless the context or language clearly dictates otherwise. For example, all ranges disclosed herein include the endpoints, and the endpoints can be combined with one another to form further ranges.

[0026] Generally, the subject matter provides hybrid material components, and more particularly, components formed from a material that combines metal filaments with non-metal filaments. The metal filaments can be surrounded by the non-metal filaments, for example, by weaving or braiding the metal filaments and non-metal filaments together. Thus, the hybrid material used to form the components can include a non-metal material in equal or greater volume fraction than the metal material. The hybrid material can be used to form a ply or preform for forming a containment shell, such as a fan containment shell assembly. The ply or preform can initially be "dry" (e.g., the metal filaments and non-metal filaments are woven into a fabric or braided into a three-dimensional braid) or pre-impregnated with a matrix material. Further, the containment shell can be functionally graded, optimizing the ratio of metal filaments to non-metal filaments throughout the containment shell. Methods for forming the hybrid material components are also provided.

[0027] Reference will now be made to the drawings wherein like numerals refer to like components throughout the several figures, Figure 1 is a schematic cross-sectional view of a gas turbine engine in accordance with an example embodiment of the present disclosure. More particularly, for Figure 1 Embodiments of the present disclosure, the gas turbine engine is a high-bypass turbofan engine 10, referred to herein as "turbofan engine 10." As shown, Figure 1 The turbofan engine 10 defines an axial direction A (extending parallel to a longitudinal centerline 12 provided for reference) and a radial direction R. Generally, the turbofan 10 includes a fan section 14 and a core turbine engine 16 disposed downstream from the fan section 14.

[0028] The depicted exemplary core turbine engine 16 generally includes a substantially tubular outer casing 18 defining an annular inlet 20. The outer casing 18 encloses, in serial flow relationship: a compressor section, including a booster or low pressure (LP) compressor 22 and a high pressure (HP) compressor 24; a combustion section 26; a turbine section, including a high pressure (HP) turbine 28 and a low pressure (LP) turbine 30; and an ejection exhaust nozzle section 32. A high pressure (HP) shaft or spool 34 drivingly connects the HP turbine 28 to the HP compressor 24. A low pressure (LP) shaft or spool 36 drivingly connects the LP turbine 30 to the LP compressor 22.

[0029] For the depicted embodiment, the fan section 14 includes a fan 38 having a plurality of fan blades 40 coupled to a disk or hub 42 in a spaced apart manner. As depicted, the fan blades 40 generally extend outwardly from the disk 42 in a radial direction R. The fan blades 40 and disk 42 are rotatable together about the longitudinal centerline 12 by the LP shaft 36. In some embodiments, a power gearbox having a plurality of gears can be included for reducing the rotational speed of the LP shaft 36 to a more efficient fan rotational speed.

[0030] Still referring to Figure 1 the exemplary embodiment, the disk 42 is covered by a rotatable front nacelle 48 having an aerodynamic profile to facilitate airflow through the plurality of fan blades 40. Additionally, the exemplary fan section 14 includes an annular fan casing or outer nacelle 50 that circumferentially surrounds the fan 38 and / or at least a portion of the core turbine engine 16. It should be appreciated that the fan casing (nacelle) 50 can be structured to be supported relative to the core turbine engine 16 by a plurality of circumferentially spaced apart outlet guide vanes 52. Moreover, a downstream section 54 of the fan casing 50 can extend over an outer portion of the core turbine engine 16 so as to define a bypass airflow passage 56 therebetween.

[0031] During operation of the turbofan engine 10, a volume of air 58 enters the turbofan 10 through an associated inlet 60 of the fan casing and / or fan section 14. As the volume of air 58 passes through the fan blades 40, a first portion of the air 58 is directed or channeled into the bypass airflow passage 56 as indicated by arrows 62, and a second portion of the air 58 is directed or channeled into the LP compressor 22 as indicated by arrows 64. The ratio between the first portion of air 62 and the second portion of air 64 is generally referred to as the bypass ratio. The pressure of the second portion of air 64 is then increased as it is directed through the high pressure (HP) compressor 24 and into the combustion section 26 where it is mixed with fuel and combusted to provide combustion gases 66.

[0032] Combustion gases 66 are directed through the HP turbine 28, where sequential stages of HP turbine stator vanes 68 coupled to the outer casing 18 and HP turbine rotor blades 70 coupled to the HP shaft or spool 34 extract a portion of thermal and / or kinetic energy from the combustion gases 66, rotating the HP shaft or spool 34, thereby supporting operation of the HP compressor 24. The combustion gases 66 are then directed through the LP turbine 30, where sequential stages of LP turbine stator vanes 72 coupled to the outer casing 18 and LP turbine rotor blades 74 coupled to the LP shaft or spool 36 extract a second portion of thermal and kinetic energy from the combustion gases 66, rotating the LP shaft or spool 36, thereby supporting operation of the LP compressor 22 and / or rotation of the fan 38.

[0033] The combustion gases 66 are subsequently directed through the jet exhaust nozzle section 32 of the core turbine engine 16 to provide propulsive thrust. At the same time, the pressure of the first portion of air 62 is significantly increased as it is directed through the bypass airflow passage 56 before it is discharged from the fan nozzle exhaust section 76 of the turbofan 10, also providing propulsive thrust. The HP turbine 28, the LP turbine 30, and the jet exhaust nozzle section 32 at least partially define a hot gas path 78 for directing combustion gases 66 through the core turbine engine 16.

[0034] In some embodiments, components of the turbofan engine 10 can include composite materials, such as polymer matrix composite (PMC) materials or ceramic matrix composite (CMC) materials, which have high temperature capability. Composite materials generally include a fibrous reinforcement material, such as a polymer or ceramic matrix material, embedded in a matrix material. The reinforcement material serves as the load-bearing component of the composite material, while the matrix of the composite material serves to bond the fibers together and as a medium to transfer and distribute externally applied stresses to the fibers.

[0035] PMC materials are generally manufactured by impregnating a fabric or unidirectional tape with a resin (prepreg) and then curing. Prior to impregnation, the fabric can be referred to as a “dry” fabric and generally includes a stack of two or more fiber layers (plies). The fiber layers can be formed from a variety of materials, non-limiting examples of which include carbon (e.g., graphite), glass (e.g., fiberglass), polymers (e.g., aramid or polyimide), and ceramic (e.g., silicon carbide). The fabric can be formed from a single type of fiber or a combination of two or more types of fibers. The fabric can also include a combination of woven, knitted, and / or non-woven fibers. ) fiber and metal fibers. Fiber reinforcement materials can be used in the form of relatively short chopped fibers, typically less than 2 inches in length, more preferably less than 1 inch in length, or in the form of long continuous fibers, the latter typically used to produce woven fabrics or unidirectional tapes. PMC materials are produced by dispersing dry fibers into a mold and then flowing a matrix material around the reinforcing fibers, or by using prepreg. For example, multiple layers of prepreg can be stacked to the appropriate thickness and orientation of the part, and then the resin can be cured and solidified to provide a fiber-reinforced composite part. Resins used for PMC matrix materials can generally be classified as either thermoset or thermoplastic. Thermoplastic resins are generally classified as polymers that can be repeatedly softened and flowed upon heating and hardened upon sufficient cooling due to a physical change rather than a chemical change. A notable example class of thermoplastic resins includes nylons, thermoplastic polyesters, polyaryletherketones, and polycarbonate resins. Specific examples of high-performance thermoplastic resins that have been considered for aerospace applications include polyether ether ketone (PEEK), polyether ketone ketone (PEKK), polyetherimide (PEI), and polyphenylene sulfide (PPS). In contrast, thermoset resins do not significantly soften upon heating once fully cured into a hard solid, but rather thermally decompose upon sufficient heating. Notable examples of thermoset resins include epoxy, bismaleimide (BMI), and polyimide resins.

[0036] In some embodiments, a “dry” fabric (i.e., a fabric that is not impregnated with resin) can be used as one or more layers of a component of the turbofan engine 10. For example, the fabric can be formed of fibers of carbon, glass, polymer, and / or metal as described above. Without impregnating the fabric with resin, the fabric layer can be wrapped around other segments of the component, for example, imparting certain properties to the component due to the fibers used to form the fabric.

[0037] As described in greater detail herein, the fan section 14 of the engine 10 includes a fan containment enclosure assembly that includes a fan casing 50 and encloses and surrounds the fan 38 and fan blades 40 to retain any fan blades 40 or fan blade fragments that are shed from the engine fan 38. A “blade-off event” or fan blade off (FBO) event occurs when a fan blade or a portion thereof is accidentally released from a rotor of a high-bypass turbofan engine. When suddenly released in flight, a fan blade can impact the surrounding fan casing with considerable force, sometimes penetrating the fan casing and into the fan containment enclosure assembly.

[0038] Referring to Figure 2 , a fan containment enclosure assembly 100 according to example embodiments of the present subject matter is shown. The fan containment enclosure assembly 100 includes a fan casing 50 that extends along an axial direction A such that the fan casing 50 encloses and surrounds a longitudinal centerline 12 of the fan 38 and the fan blades 40. Figure 1) is provided, and can include a channel filler 51 inside the fan housing 50, for example, to mitigate the effects of blade friction. For example, the channel filler 51 can be joined to the fan housing 50 such that, within the assembly 100, the channel filler 51 is disposed radially inward of the fan housing 50, i.e., the channel filler 51 is disposed between the fan housing 50 and the plurality of fan blades 40 in the radial direction R. The fan housing 50 forms the radially outermost portion of the fan containment housing assembly 100, helping to contain objects traveling outward to prevent continued travel beyond the fan section 14. Thus, the fan housing 50 can also be referred to as a containment housing 50.

[0039] Referring to Figure 3A and 3B , the containment housing 50 is formed of a material 102, where metal and non-metal are combined to form the material. For example, the material 102 can include metal fibers and non-metal fibers that are used as reinforcing fibers in a composite material, such as a ceramic matrix composite or a polymer matrix composite. Thus, the material can be referred to as an integrated metal and composite material 102 or hybrid material 102. The fan housing or containment housing 50 formed of the integrated metal and composite material or hybrid material 102 can be referred to as a hybrid material fan or containment housing 50.

[0040] The hybrid material 102 includes a plurality of metal tows 104 and a plurality of non-metal tows 106. It will be understood that the term “tow” as used herein includes a bundle of continuous filaments or fibers that are not twisted. As Figure 3A and 3B shown in the example embodiment, the plurality of metal tows 104 are mixed with the plurality of non-metal tows 106. More specifically, each metal tow 104 of the plurality of metal tows 104 is surrounded by non-metal tows 106 such that the plurality of metal tows 104 are embedded within the plurality of non-metal tows 106. In other words, each metal tow 104 is surrounded by a portion of the plurality of non-metal tows 106 such that the plurality of metal tows 104 are embedded within the plurality of non-metal tows 106.

[0041] In the embodiment shown in Figure 3A , the hybrid material 102 is a three-dimensional (3D) woven material. In other embodiments, the hybrid material 102 is a woven material. That is, the plurality of metal tows 104 and the plurality of non-metal tows 106 can be woven into a textile (e.g., formed into a fabric) such that the metal tows 104 are embedded within or surrounded by the non-metal tows 106. In other embodiments, the metal tows 104 and the non-metal tows 106 can be processed into any common form to form the hybrid metal / non-metal fan housing 50 or hybrid material fan housing 50. For example, the tows 104, 106 can be stitched or processed into other three-dimensional weaves to form the hybrid material fan housing 50.

[0042] A variety of metals, including metal alloys, can be used for the metal filaments 104. In exemplary embodiments, the plurality of metal filaments 104 includes aluminum lithium (Al-Li) alloy filaments. In other exemplary embodiments, the plurality of metal filaments 104 includes steel filaments. In yet other exemplary embodiments, the plurality of metal filaments 104 includes titanium (Ti) filaments. In yet other exemplary embodiments, more than one metal can be used in the plurality of metal filaments 104. For example, the plurality of metal filaments 104 can include a first plurality of metal filaments 104 that includes aluminum lithium (Al-Li) alloy filaments and a second plurality of metal filaments 104 that includes steel filaments. In suitable embodiments, a combination of two or more different types of metal fibers can be used to form the metal filaments 104, i.e., two or more different types of metal fibers can be used to form a single filament 104. Other combinations of metals and metal fibers or metal filaments 104 can also be used.

[0043] Similarly, a variety of non-metallic materials can be used for the non-metallic filaments 106. In particular, reinforcing fibers commonly used in PMC materials can be selected for the non-metallic filaments 106. In exemplary embodiments, the plurality of non-metallic filaments 106 includes carbon filaments. In other exemplary embodiments, the plurality of non-metallic filaments 106 includes glass filaments or aramid filaments. In yet other exemplary embodiments, more than one non-metallic fiber can be used in the plurality of non-metallic filaments 106. For example, the plurality of non-metallic filaments 106 can include a first plurality of non-metallic filaments 106 that includes carbon filaments and a second plurality of non-metallic filaments 106 that includes glass filaments. In some embodiments, a combination of two or more different types of non-metallic reinforcing fibers can be used to form the non-metallic filaments 106, i.e., two or more different types of non-metallic reinforcing fibers can be used to form a single filament 106. Other combinations of metals and metal fibers or metal filaments 104 can also be used.

[0044] In some embodiments, the metal filaments 104 can each include a protective layer or coating 108. That is, a protective layer 108 can surround each filament 104. Such a layer or coating can inhibit corrosion of the metal material, among other things. For example, in embodiments in which the plurality of metal filaments 104 includes aluminum lithium (Al-Li) alloy filaments, the Al-Li filaments 104 can include a galvanic protective layer 108. Other protective layers or coatings can also be used, and the protective layer 108 or lack thereof can correspond to the metal used to form the filaments 104. For example, a first plurality of metal filaments 104 includes a first protective layer 108 and a second plurality of metal filaments 104 includes a second protective layer 108 (where the metal forming the first plurality of filaments 104 is different from the metal forming the second plurality of filaments 104 and the first protective layer 108 is different from the second protective layer 108), but a third plurality of metal filaments 104 does not include a protective layer 108.

[0045] In an exemplary embodiment, the plurality of metal wire bundles 104 comprise aluminum-lithium (Al-Li) alloy wire bundles coated with a current protection layer 108, and the plurality of non-metal wire bundles 106 comprise carbon wire bundles. However, other combinations of metal wire bundles 104 and non-metal wire bundles 106 can be used to form the hybrid material 102. For example, in some embodiments, the hybrid material 102 comprises steel metal wire bundles 104 and carbon non-metal wire bundles 106, and in other embodiments, the material 102 comprises titanium (Ti) metal wire bundles 104 and carbon non-metal wire bundles 106. Other metal wire bundles 104 and non-metal wire bundles 106 may also be used.

[0046] After multiple filament bundles 104, 106 are woven, braided, or otherwise processed into a composite material 102, the material 102 can form multiple layers 110. Layers 110 can be used to form a fan housing 50 or a fan emplacement housing 50. Each layer 110 includes multiple metal filament bundles 104 and multiple non-metal filament bundles 106. When laid, layers 110 can be “dry” (e.g., the metal filament bundles 104 and non-metal filament bundles 106 are woven into a fabric or braided into a three-dimensional braid as shown in Figure 3) or impregnated with a matrix material 112, such as resin or other PMC matrix, such as... Figure 3B As shown. As described herein, if dry, layer 110 is injected with matrix material 112 before curing.

[0047] Turning Figure 4 In some embodiments, metal sheet 114 is disposed between adjacent layers 110 of the composite material 102. The metal sheet 114 may be inserted between layers of a woven or braided structure, or between layers formed by other techniques, such as layers 110 of the composite material 102. Figure 4 As shown, in an exemplary embodiment, metal sheets 114 are disposed between the hybrid layers 110, such that there are two hybrid layers 110 between each metal sheet 114, that is, the ratio of layer 110 to metal sheet 114 is 2:1. Other ratios of layer 110 to metal sheet 114, such as 3:1, 4:1 or greater, may also be used.

[0048] Furthermore, the hybrid layer 110 can be thicker than the metal sheet 114; that is, the metal sheet 114 can have a layer thickness t less than or equal to that of each layer 110. layer sheet thickness t sheet (In other words, layer thickness t) layer Greater than or more than the sheet thickness t sheet , making t layer >t sheet). Thus, in embodiments where the ratio of layers 110 to metal sheets 114 is 2: 1, for each relatively thin metal sheet 114, the hybrid material 102 includes two relatively thick layers 110. Further, the metal sheets 114 can be of any suitable metallic material, such as the metals described with respect to the wire bundles 104, for example, aluminum lithium (Al-Li) alloys, steel, titanium (Ti), or any other suitable metallic material.

[0049] Referring again to Figure 3A and 3B Wire bundles 104, 106 of different thicknesses or diameters can be used to form the hybrid material 102. In some embodiments, each of the plurality of metallic wire bundles 104 has a first wire bundle thickness or diameter ti, each of the plurality of non-metallic wire bundles 106 has a second wire bundle thickness or diameter t2, and the first wire bundle thickness or diameter ti is different than the second wire bundle thickness or diameter t2. In some embodiments, the first wire bundle thickness ti is greater than the second wire bundle thickness t2, but in other embodiments, the second wire bundle thickness t2 is greater than the first wire bundle thickness ti. In yet other embodiments, the thickness or diameter of the metallic wire bundles 104 can vary among the plurality of metallic wire bundles 104, and the thickness or diameter of the non-metallic wire bundles 106 can vary among the plurality of non-metallic wire bundles 106. The first wire bundle thickness or diameter ti or the thickness / diameter of the metallic wire bundles 104 can be in a range of about 3 microns or 0.003 millimeters (0.003 mm) to about 0.400 millimeters, or in a range of about 5 microns or 0.005 millimeters to about 0.325 millimeters. The second wire bundle thickness or diameter t2 or the thickness / diameter of the non-metallic wire bundles 106 can be in a range of about 0.100 mm to about 0.500 mm, or in a range of about 0.200 mm to about 0.425 mm. Varying the thickness or diameter of the wire bundles 104, 106, whether between the metallic wire bundles 104 and the non-metallic wire bundles 106 and / or within the plurality of metallic wire bundles 104 and / or the plurality of non-metallic wire bundles 106, can vary the properties of the hybrid material 102.

[0050] The hybrid material 102 can include different amounts of the plurality of metallic filaments 104 and the plurality of non-metallic filaments 106. More specifically, the plurality of metallic filaments 104 is a metallic volume fraction of the hybrid material 102, and the remaining volume of the material 102 is a non-metallic portion of the material, i.e., the plurality of non-metallic filaments 106 and the matrix material 112, such as an epoxy resin. That is, the metallic volume fraction and the plurality of non-metallic filaments 106 and the matrix material 112 together form the total volume of the material 102. In exemplary embodiments, the metallic volume fraction is in a range of about 5% to about 50% of the total volume, and more specifically, the metallic volume fraction is in a range of about 10% to about 30% of the total volume. For example, in one embodiment, the metallic volume fraction is about 10%, while in another embodiment, the metallic volume fraction is about 25%. As a further example, in one embodiment, the metallic volume fraction is at least 5% or at least 10% but less than the combined volume fraction of the plurality of non-metallic filaments 106 and the matrix material 112, or the metallic volume fraction is at least 5% or at least 10% but less than the volume fraction of the plurality of non-metallic filaments 106.

[0051] Further, in some embodiments, the metallic volume fraction can vary throughout the fan containment housing assembly 100, e.g., the metallic volume fraction can vary circumferentially, axially, and / or radially. For example, the fan housing 50 or the hybrid material 102 can be referred to as a functionally graded material (FGM), where the composition and / or structure of the fan housing 50 or the material 102 gradually changes throughout its volume, resulting in a change in the properties of the respective fan housing 50 or material 102. As described herein, the hybrid material 102 can form a plurality of layers used to construct the hybrid fan housing 50. Thus, the ratio of the metallic filaments 104 to the non-metallic filaments 106 or the ratio of the metallic filaments 104 to the non-metallic filaments 106 and the matrix material 112 can be optimized, e.g., by using layers having different metallic volume fractions to form the material 102 and thereby construct the fan housing 50. Thus, a functionally graded fan containment housing assembly 100 can be produced that has increased strength at certain locations, e.g., at the leading edge impingement region or the root impingement region or at the inner surface of the fan housing 50. More specifically, the fan housing 50 can be segmented into circumferential regions, axial regions, and / or radial regions, and the volume fraction of the metallic filaments 104 (i.e., the metallic volume fraction) can be greater in one or more such regions than in other such regions. As one example, a plurality of regions circumferentially spaced apart from one another can be identified as having a greater likelihood of object impingement than the remainder of the fan housing 50 by testing, analyzing FBO events, etc. The volume fraction of the metallic filaments 104 (i.e., the metallic volume fraction) within the fan housing 50 at the plurality of circumferential regions is greater than the metallic volume fraction at least at circumferential locations between the plurality of circumferential regions. For example, the metallic volume fraction can be 25% or greater in the plurality of circumferential regions and 10% or less in the remainder of the fan housing 50.

[0052] As another example, the volume fraction of the wire bundle 104 can vary radially, for example, the metal volume fraction can taper from an inner portion of the fan casing 50 to an outer portion of the fan casing 50. In an example embodiment, the proportion of wire bundle 104 included by the fan casing 50 is greater at the inner surface 118 of the fan casing 50 than at locations within the fan casing 50 radially outward from the inner surface 118. For example, the proportion of wire bundle 104 within the fan casing 50 can decrease from the inner surface 118 of the fan casing 50 to the outer surface 120 of the fan casing 50. As yet another example, the volume fraction of the wire bundle 104 can vary axially, for example, the metal volume fraction can be greater at one or more axial locations of the fan casing 50 than along the remaining axial locations of the fan casing 50. Thus, the volume fraction of the wire bundle 104 can be varied through the fan casing 50 to optimize the characteristics of the fan casing 50 to resist damage, for example, by objects impacting the assembly 100 cutting, piercing, etc.

[0053] In some embodiments, the fan containment casing assembly 100 also includes the inlet 60 of the fan section 14. As previously described, the inlet 60 is upstream of the fan casing 50. Thus, the inlet 60 can be formed separately from the fan casing 50 and includes the hybrid material 102. By incorporating the material 102 into the inlet 60, the inlet 60 will also benefit from improved resistance to debris damage. Thus, by incorporating the hybrid material 102 into the containment casing (e.g., the fan casing 50) as well as the inlet 60, the resistance to damage of the entire fan section 14 can be improved.

[0054] Turning now to Figure 5, a flowchart is provided that illustrates an exemplary method 500 for forming a hybrid material component of a gas turbine engine, such as the fan containment outer casing 50 of the turbofan engine 10. As shown at 502, the exemplary method 500 includes forming a hybrid material 102 from a plurality of metal tows 104 mixed with a plurality of non-metallic tows 106 that combine metallic and composite materials. More specifically, each metal tow 104 can be surrounded by a plurality of non-metallic tows 106 such that the metallic material (i.e., the metal tow 104) is embedded within the non-metallic composite material (i.e., the non-metallic tow 106). As described herein, the metal tow 104 can be formed from any suitable metallic material, and the non-metallic tow 106 can be formed from any suitable composite fiber material. Further, forming the hybrid material 102 can include weaving the metal tow 104 and the non-metallic tow 106 together to form a hybrid fabric or cloth, or braiding the metal tow 104 and the non-metallic tow 106 together to form a three-dimensional (3D) braid. The woven or braided hybrid material 102 can be referred to as a preform, which can be cut into a plurality of plies or layers 110. Alternatively, the metal tow 104 and the non-metallic tow 106 can be impregnated with a matrix material 112 to form a tape that can be cut into a plurality of hybrid material plies or layers 110.

[0055] Referring to Figure 5 504, the method 500 further includes laying up a plurality of layers 110 of the hybrid material 102 to form a hybrid material layup. The layers 110 can be laid up to alternate the fiber direction of the plurality of fibers within the tows 104, 106, or the layers 110 can be laid up such that the fibers within the tows 104, 106 are substantially unidirectional. In some embodiments, the hybrid material layup defines the shape of the hybrid material component. For example, where the hybrid material component is the hybrid composite fan outer casing 50, the hybrid material layup can have a generally cylindrical shape. For “dry” layers 110, laying up the plurality of layers 110 further includes infusing the hybrid material layup with the matrix material 112, such as the epoxy resin described herein. For prepreg layers 110, the matrix material 112 is part of each layer 110, such that the layup does not need to be infused with the matrix material 112.

[0056] As shown at 506 in Figure 5 some embodiments, the method 500 includes inserting a layer or sheet 114 of metallic material between adjacent layers 110 of the hybrid material 102. As described herein, the metallic sheet 114 can be thinner than the hybrid material layers 110, for example the metallic sheet 114 can have a sheet thickness t layer that is less than the layer thickness t sheet of the hybrid material layers 110. Further, in some embodiments, for each metallic sheet 114, the hybrid material layup can include two hybrid material layers 110, such that the hybrid material layup has a ratio of layers 110 to layers 114 of 2: 1.

[0057] As in Figure 5 As shown in 508, exemplary method 500 further includes processing the hybrid material stack. At least in part, processing the hybrid material stack includes curing the stack such that a plurality of metal filament bundles 104 and a plurality of non-metal filament bundles 106 are co-cured. In some embodiments, the hybrid material stack may be resin transfer molding (RTM) or vacuum-assisted resin transfer molding (VARTM).

[0058] Therefore, forming a hybrid material component may include steps similar to those used to form a composite component (e.g., a component formed from a PMC material). As an example, metal wire bundles 104 and non-metal wire bundles 106 may be impregnated with a matrix material 112, and the resulting composition may be cut into layers or sheets 110 of the hybrid material 102. As another example, metal wire bundles 104 and non-metal wire bundles 106 may be woven or braided into a three-dimensional preform, which may be cut into layers or sheets 110 of the hybrid material 102. Forming a hybrid material component, such as a hybrid material fan housing housing 50, may then include laying multiple hybrid composite sheets 110 layer by layer to construct a sheet stack. It will be understood that the sheet stack can be formed by laying the hybrid sheets onto a tool, mandrel, or other support. The sheet stack may then undergo heat treatment and / or chemical treatment to form the component. For example, the hybrid material sheet stack may be compacted and consolidated, for example, in an autoclave at elevated temperatures and pressures before undergoing densification and final curing. Therefore, metallic and non-metallic (e.g., composite) materials are co-cured to produce hybrid material parts. In some embodiments, processing the hybrid material laminate stack may include a resin transfer molding process or a vacuum-assisted resin transfer molding process, such that the resulting hybrid material part may be referred to as resin transfer molding (RTM) or vacuum-assisted resin transfer molding (VARTM). The specific processing techniques and parameters for the heat treatment and / or chemical treatment of the laminate stack will depend on the specific composition of the materials used to form the laminates. As an example, other known methods or techniques for curing composite laminates may be used. Furthermore, as described herein, the metal filament bundle 104 may be set at one or more specific locations within the housing in a larger proportion or concentration than at other locations within the housing.

[0059] In embodiments where the hybrid material component is a hybrid composite fan housing 50, after the housing is formed, other components of the fan housing assembly 100 can be assembled to form the assembly 100. In particular, the groove filler 51 can be engaged, attached, or coupled to or otherwise abutted against the hybrid material fan housing 50 to form the fan housing assembly 100. The assembly 100 can then slide on the fan 38, or the fan 38 can be inserted into or assembled within the fan housing assembly 100.

[0060] Of course, the hybrid material component can be another or different component than the fan case. For example, it will be appreciated that an integrated metal / composite or hybrid material 102 can be formed as described herein and then used to manufacture or construct one or more gas turbine engine components in addition to or in lieu of the fan case 50.

[0061] Accordingly, the present subject matter relates to components and methods of forming components, including integrated metal and composite materials, also referred to as hybrid materials. As described herein, by integrating metal fibers with non-metal fibers within a woven or knit material, the strength and / or energy absorption of the component can be increased without an undue increase in the weight and / or cost of the component, for example, as compared to components formed from separate metal and composite sections, all-metal components, or all-composite components. A fan case or containment system can be formed from such hybrid materials, for example, to improve blade containment in fan blade out events. More specifically, the present subject matter provides fan containment case assemblies and methods for forming such assemblies that utilize integrated carbon and metal (e.g., Al-Li) tows for a woven or knit architecture to create a hybrid constructed fan containment case assembly. In some embodiments, the hybrid construction can include metal sheets inserted between layers of the woven / knit architecture. The hybrid construction including tows formed from carbon and metal can have high strength and can facilitate energy absorption in the event of a fan blade out (FBO), which can help contain the fan blade and / or fragments thereof in an FBO event. Further, the hybrid construction has reduced weight and cost as compared to, for example, all-carbon fan cases. Other benefits and advantages of the present subject matter can also be realized.

[0062] Further aspects of the present invention are provided by the subject matter of the following clauses:

[0063] 1. A containment assembly of a gas turbine engine, comprising: a containment case extending in an axial direction about a longitudinal centerline of the gas turbine engine, the containment case formed from a hybrid material, the hybrid material including a plurality of metal tows and a plurality of non-metal tows, wherein each metal tow of the plurality of metal tows is surrounded by a non-metal tow of the plurality of non-metal tows such that the plurality of metal tows are embedded within the plurality of non-metal tows.

[0064] 2. The containment assembly of any of the preceding clauses, wherein the hybrid material is a three-dimensional woven material.

[0065] 3. The containment assembly of any of the preceding clauses, wherein the hybrid material is a woven material.

[0066] 4. The containment assembly of any of the preceding clauses, wherein the plurality of metal tows includes aluminum lithium (Al-Li) alloy tows.

[0067] 5. The containment assembly of any of the preceding clauses, wherein the aluminum lithium (Al-Li) alloy wire bundle comprises a current protection layer.

[0068] 6. The containment assembly of any of the preceding clauses, wherein the plurality of non-metallic wire bundles comprises a carbon wire bundle.

[0069] 7. The containment assembly of any of the preceding clauses, wherein the plurality of metallic wire bundles comprises a steel wire bundle.

[0070] 8. The containment assembly of any of the preceding clauses, wherein the plurality of metallic wire bundles comprises a titanium (Ti) wire bundle.

[0071] 9. The containment assembly of any of the preceding clauses, wherein the plurality of non-metallic wire bundles comprises a carbon wire bundle.

[0072] 10. The containment assembly of any of the preceding clauses, wherein each metallic wire bundle of the plurality of metallic wire bundles has a first thickness and each non-metallic wire bundle of the plurality of non-metallic wire bundles has a second thickness, and wherein the first thickness is different than the second thickness.

[0073] 11. The containment assembly of any of the preceding clauses, wherein the hybrid material is formed as a plurality of layers, and wherein a metallic material sheet is disposed between adjacent layers of the hybrid material.

[0074] 12. The containment assembly of any of the preceding clauses, wherein the hybrid material comprises about 5% to about 50% metal by volume.

[0075] 13. The containment assembly of any of the preceding clauses, wherein the hybrid material comprises about 10% to about 30% metal by volume.

[0076] 14. The containment assembly of any of the preceding clauses, wherein the containment assembly surrounds a plurality of fan blades attached to a disc, each fan blade of the plurality of fan blades extending in a radial direction, and wherein the disc is rotatable about the longitudinal centerline.

[0077] 15. The containment assembly of any of the preceding clauses, further comprising:

[0078] a trench filler joined to the containment housing, the trench filler disposed radially inward of the containment housing such that the trench filler is disposed between the containment housing and the plurality of fan blades in the radial direction.

[0079] 16. The containment assembly of any of the preceding clauses, wherein a volume fraction of the wire bundle in the hybrid material varies radially, axially, or circumferentially.

[0080] 17. The containment assembly of any of the preceding clauses, wherein the volume fraction of the wire bundle decreases from a radially inner portion of the containment housing to a radially outer portion of the containment housing.

[0081] 18. The containment assembly of any of the preceding clauses, wherein the volume fraction of the wire bundle decreases from an inner surface of the containment housing to a location within the containment housing radially outward from the inner surface.

[0082] 19. The containment assembly of any of the preceding clauses, wherein the volume fraction of the wire bundle decreases from an inner surface of the containment housing to an outer surface of the containment housing.

[0083] 20. The containment assembly of any of the preceding clauses, wherein a volume fraction of the wire bundle at one axial location of the containment housing is greater than a volume fraction of the wire bundle at another axial location of the containment housing.

[0084] 21. The containment assembly of any of the preceding clauses, wherein a volume fraction of the wire bundle at a plurality of circumferentially spaced apart regions is greater than a volume fraction of the wire bundle at circumferential locations between the plurality of regions.

[0085] 22. The containment assembly of any of the preceding clauses, wherein a volume fraction of the wire bundle in the hybrid material is at least 5% of a total volume of the hybrid material but less than a combined volume fraction of the non-wire bundle and matrix material.

[0086] 23. The containment assembly of any of the preceding clauses, wherein a volume fraction of the wire bundle in the hybrid material is at least 10% of a total volume of the hybrid material but less than a combined volume fraction of the non-wire bundle and matrix material.

[0087] 24. The containment assembly of any of the preceding clauses, wherein a volume fraction of the wire bundle in the hybrid material is at least 5% of a total volume of the hybrid material but less than a volume fraction of the non-wire bundle.

[0088] 25. The containment assembly of any of the preceding clauses, wherein a volume fraction of the wire bundle in the hybrid material is at least 10% of a total volume of the hybrid material but less than a volume fraction of the non-wire bundle.

[0089] 26. A hybrid material component of a gas turbine engine, comprising:

[0090] a plurality of metal tows; and

[0091] a plurality of non-metallic tows,

[0092] wherein each of the plurality of metal tows is surrounded by a portion of the plurality of non-metallic tows such that the plurality of metal tows are embedded within the plurality of non-metallic tows.

[0093] 27. The containment assembly of any preceding clause, wherein the plurality of metal tows and the plurality of non-metallic tows are woven into a three-dimensional woven material, and wherein the plurality of metal tows comprise an aluminum lithium (Al-Li) alloy and the plurality of non-metallic tows comprise carbon.

[0094] 28. The containment assembly of any preceding clause, wherein the plurality of metal tows and the plurality of non-metallic tows are woven into a woven fabric material, and wherein the plurality of metal tows comprise an aluminum lithium (Al-Li) alloy and the plurality of non-metallic tows comprise carbon.

[0095] 29. The containment assembly of any preceding clause, wherein the plurality of metal tows and the plurality of non-metallic tows are formed into a plurality of layers, and wherein the plurality of layers form a fan containment outer casing of the gas turbine engine.

[0096] 30. A method of forming a hybrid material component of a gas turbine engine, comprising: forming a hybrid material from a plurality of metal tows mixed with a plurality of non-metallic tows; laying up a plurality of hybrid material layers to form a hybrid material layup; and processing the hybrid material layup, wherein processing the hybrid material layup comprises curing the hybrid material layup such that the plurality of metal tows and the plurality of non-metallic tows are co-cured.

[0097] 31. The method of any preceding clause, wherein each of the plurality of metal tows is surrounded by a metal tow of the plurality of non-metallic tows such that the metal tow is embedded within the non-metallic tow.

[0098] 32. The method of any preceding clause, wherein laying up a plurality of hybrid material layers comprises alternating a fiber direction of a plurality of metal fibers within the plurality of metal tows with a fiber direction of a plurality of non-metallic fibers within the plurality of non-metallic tows.

[0099] 33. The method of any preceding clause, wherein laying up a plurality of the hybrid material layers comprises laying up the plurality of layers such that fibers within each of the plurality of metal tows and the plurality of non-metallic tows are unidirectional.

[0100] 34. The method of any of the preceding clauses, wherein the stack of hybrid material has a generally cylindrical shape.

[0101] 35. The method of any of the preceding clauses, further comprising inserting a sheet of metallic material between adjacent layers of the hybrid material.

[0102] 36. The method of any of the preceding clauses, wherein the stack of hybrid material includes two layers of hybrid material for each sheet of metallic material.

[0103] 37. The method of any of the preceding clauses, wherein the stack of hybrid material is resin transfer molding (RTM) as part of processing the stack of hybrid material.

[0104] 38. The method of any of the preceding clauses, wherein the stack of hybrid material is vacuum assisted resin transfer molding (VARTM) as part of processing the stack of hybrid material.

[0105] This written description uses examples to disclose the application, including the best mode, and also to enable any person skilled in the art to practice the application, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the application is defined by the claims, and can include other examples that occur to those skilled in the art. Such other examples are intended to fall within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.

Claims

1. A containment assembly for a gas turbine engine, characterized by, comprising: a containment shell extending in an axial direction about a longitudinal centerline of the gas turbine engine, the containment shell formed of a hybrid material comprising a plurality of metallic tows and a plurality of non-metallic tows, wherein each metallic tow of the plurality of metallic tows is surrounded by a non-metallic tow of the plurality of non-metallic tows such that the plurality of metallic tows is embedded within the plurality of non-metallic tows.

2. The containment assembly of claim 1, wherein, wherein, the hybrid material is a three-dimensional woven material.

3. The containment assembly of claim 1, wherein, wherein, the hybrid material is a woven material.

4. The containment assembly of claim 1, wherein, wherein, the plurality of metallic tows comprises aluminum lithium (Al-Li) alloy tows.

5. The containment assembly of claim 4, wherein, wherein, the aluminum lithium (Al-Li) alloy tows comprise a galvanic protection layer.

6. The containment assembly of claim 5, wherein, wherein, the plurality of non-metallic tows comprises carbon tows.

7. The containment assembly of claim 1, wherein, wherein, the plurality of metallic tows comprises steel tows or titanium (Ti) tows.

8. The containment assembly of claim 1, wherein, wherein, the plurality of non-metallic tows comprises carbon tows.

9. The containment assembly of claim 1, wherein, wherein, each metallic tow of the plurality of metallic tows has a first thickness and each non-metallic tow of the plurality of non-metallic tows has a second thickness, and wherein the first thickness is different than the second thickness.

10. The containment assembly of claim 1, wherein, wherein, the hybrid material is formed in a plurality of layers, and wherein metallic material sheets are disposed between adjacent layers of the hybrid material.

11. The containment assembly of claim 1, wherein, wherein, the hybrid material comprises about 5% to about 50% metal by volume.

12. The containment assembly of claim 11, wherein, wherein, the hybrid material comprises about 10% to about 30% metal by volume.

13. The containment assembly of claim 1, wherein, wherein, the containment assembly surrounds a plurality of fan blades attached to a disk, each fan blade of the plurality of fan blades extending in a radial direction, and wherein the disk is rotatable about the longitudinal centerline.

14. The containment assembly of claim 13, wherein, further comprising: a trench filler joined to the containment shell, the trench filler disposed radially inward of the containment shell such that the trench filler is disposed between the containment shell and the plurality of fan blades in the radial direction.

15. The containment assembly of claim 13, wherein, wherein, a volume fraction of the metallic tows in the hybrid material varies radially, axially, or circumferentially.

16. A hybrid material component of a gas turbine engine, characterized by, comprising: a plurality of metallic tows; and a plurality of non-metallic tows, wherein each metallic tow of the plurality of metallic tows is surrounded by a portion of the plurality of non-metallic tows such that the plurality of metallic tows is embedded within the plurality of non-metallic tows.

17. The hybrid material component of claim 16, wherein, wherein, the plurality of metallic tows and the plurality of non-metallic tows are woven into a three-dimensional woven material, and wherein the plurality of metallic tows comprises aluminum lithium (Al-Li) alloy and the plurality of non-metallic tows comprises carbon.

18. The hybrid material component of claim 16, wherein, wherein, the plurality of metallic tows and the plurality of non-metallic tows are woven into a woven fabric material, and wherein the plurality of metallic tows comprises aluminum lithium (Al-Li) alloy and the plurality of non-metallic tows comprises carbon.

19. The hybrid material component of claim 16, wherein, wherein, the plurality of metallic tows and the plurality of non-metallic tows are formed in a plurality of layers, and wherein the plurality of layers form a fan containment shell of the gas turbine engine.

20. A method of forming a hybrid material component of a gas turbine engine, characterized by, comprising: forming a hybrid material from a plurality of metallic tows mixed with a plurality of non-metallic tows; laying up a plurality of layers of the hybrid material to form a hybrid material layup; and processing the hybrid material layup, wherein processing the mixed material stack includes curing the mixed material stack such that the plurality of metal tows and the plurality of non-metal tows are co-cured.

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