WO2019240785A1

WO2019240785A1 - Attachment arrangement for connecting components with different coefficient of thermal expansion

Info

Publication number: WO2019240785A1
Application number: PCT/US2018/037255
Authority: WO
Inventors: Zachary D. Dyer; Jan H. Marsh; Evan C. LANDRUM
Original assignee: Siemens Aktiengesellschaft
Priority date: 2018-06-13
Filing date: 2018-06-13
Publication date: 2019-12-19

Abstract

There is provided an arrangement (100) that includes a first component (102), a second component (104) having a greater coefficient of thermal expansion relative to the first component (102), and a pair of rails (126). Each rail (126) includes a channel (128) within a body (129) of the rail (126). An extent (124) of the first component (102) is retained within the channel (128). Each rail (126) is secured to the second component (104) to secure the first component (102) to the second component (104).

Description

ATTACHMENT ARRANGEMENT FOR CONNECTING COMPONENTS WITH DIFFERENT COEFFICIENT OF THERMAL EXPANSION

FIELD

The present disclosure relates to an attachment arrangement for connecting components with a thermal expansion differential, e.g., a metal component to a ceramic matrix composite (CMC) component. In certain embodiments, the components are portions of the same turbine structure, such as a blade or vane. In other embodiments, the attachment arrangement may be utilized for securement a discrete first component, e.g., a CMC component, to a discrete second, e.g., metallic, component.

BACKGROUND

Gas turbines comprise a casing or cylinder for housing a compressor section, a combustion section, and a turbine section. High efficiency of a gas turbine is achieved by heating the gas flowing through the combustion section to as high a temperature as is practical. The hot gas, however, may degrade the various metal turbine components, such as the combustor, transition ducts, vanes, ring segments, and turbine blades that it passes when flowing through the turbine.

For this reason, strategies have been developed to protect turbine components from extreme temperatures such as the development and selection of high temperature materials adapted to withstand these extreme temperatures and cooling strategies to keep the components adequately cooled during operation. State of the art superalloys with additional protective coatings are commonly used for hot gas path components of gas turbines. In view of the substantial and longstanding development in the area of superalloys, however, it figures to be extremely difficult to further increase the temperature capability of superalloys.

Accordingly, ceramic matrix composite (CMC) materials have thus been developed for gas turbine components (e.g., blades, vanes) with greater temperature resistance relative to superalloys. CMC materials may include a ceramic or a ceramic matrix material, either of which hosts a plurality of reinforcing fibers. Advantageously, CMC materials have a higher temperature capability than metallic alloys, thereby making them potentially very valuable for implementation into gas turbines. On the downside, the mechanical strength of CMC materials (even in the form of laminates) is notably less than that of corresponding high temperature superalloy materials, particularly its interlaminar strength. Superalloys are stronger and more ductile, making such metal materials better for supporting hardware, such as vane carriers, casings, bolting, and the like.

To combine the advantages of CMC and metal materials, at some point they must be attached to one another. However, attaching low thermal growth CMC materials to higher thermal growth metal materials is complex.

In dynamic environments, the CMC and metal need to be rigidly attached to prevent vibration, which may lead to wear and/or fatigue issues. In addition, upon being subjected to high temperatures, the metal and CMC will grow at different rates. If the materials are rigidly attached, the metal, being stiffer and stronger, will carry the CMC with it as it grows, thereby compromising the CMC material. If the connection is relatively loose by comparison, the CMC is by nature more brittle and less strain-tolerant than metal. As such, any movement between the materials will likely damage or even destroy the CMC material. An attachment arrangement for two or more components that better accounts for any thermal expansion differential therebetween is thus needed.

SUMMARY

In accordance with an aspect of the present invention, there is provided an attachment arrangement for connecting two components which have a thermal expansion differential therebetween, such as for connecting a metal component to a ceramic matrix composite (CMC) component. In certain embodiments, the two components are portions of the same turbine structure, such as a blade or vane. In other embodiments, the attachment arrangement may be utilized for securing a first component, e.g., a CMC component, to a discrete second component, e.g., a metal component. By way of example, in an embodiment, the attachment arrangement may comprise a CMC ring segment attached (secured) to a metal casing. The attachment arrangement securely retains the components together, and allows attachment of components having a thermal expansion differential relative to one another without placing undue stress on (over-constraining) the materials, particularly the lower thermal expansion material.

In a particular aspect, there is provided an attachment arrangement comprising a first component, a second component having a greater coefficient of thermal expansion relative to the first component, and a pair of rails. Each rail comprises a channel within a body of the rail. An extent of the first component is retained within the channel. In addition, each rail is secured to the second component to secure the first component to the second component.

In accordance with another aspect, there is provided an attachment method comprising securing an extent of a first component within a channel formed in a body of each member of a pair of rails; and securing the pair of rails to a second component to secure the first component to the second component, wherein the second component comprises a greater coefficient of thermal expansion relative to the first component.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a gas turbine having one or more components having an attachment arrangement in accordance with an aspect of the present invention.

FIG. 2 illustrates an attachment arrangement between a first, e.g., ceramic matrix composite (CMC), component and a second, e.g., metal component, in accordance with an aspect of the present invention. FIG. 3 illustrates the attachment of the first component to a plurality of rails in accordance with an aspect of the present invention.

FIG. 4 illustrates rails for attachment of the first, e.g., CMC, component to the second, e.g., metal, component in accordance with an aspect of the present invention.

FIG. 5 illustrates yet another view of an attachment arrangement between a first component and a second component in accordance with an aspect of the present invention.

FIG. 6 illustrates a cross-sectional view taken at line A-A of FIG. 5 in accordance with an aspect of the present invention.

FIG. 7 illustrates an axial length view of the embodiment shown in FIG. 5 in accordance with an aspect of the present invention.

FIG. 8 illustrates the delamination of edges of a CMC component in accordance with an aspect of the present invention.

FIG. 9 illustrates a clamp for preventing delamination of edges of the CMC component in accordance with an aspect of the present invention.

FIG. 10 illustrates end plies for preventing delamination of edges of the CMC component in accordance with an aspect of the present invention.

FIG. 11 illustrates an outer ply or overwrapping about a perimeter of the CMC component to prevent delamination of plies therein in accordance with an aspect of the present invention.

DETAILED DESCRIPTION

Now referring to the figures, FIG. 1 illustrates a gas turbine engine 2 having a compressor section 4, a combustor section 6, and a turbine section 8. In the turbine section 8, there are alternating rows of stationary airfoils 18 (commonly referred to as "vanes") and rotating airfoils 16 (commonly referred to as "blades"). Each row of blades 16 is formed by a circular array of airfoils connected to an attachment disc 14 disposed on a rotor 10 having a rotor axis 12. The blades 16 extend radially outward from the rotor 10 and terminate in blades tips. The vanes 18 extend radially inward from an inner surface of vane carriers 22, 24 which are attached to an outer casing 26 of the engine 2. Between the rows of vanes 18 a ring seal 20 is attached to the inner surface of the vane carrier 22. The ring seal 20 is a stationary component that acts as a hot gas path guide between the rows of vanes 18 at the locations of the rotating blades 16. The ring seal 20 is commonly formed by a plurality of ring segments 21 that are attached either directly to the vane carriers 22, 24 or indirectly such as by attachment to metal isolation rings (not shown) attached to the vane carriers 22, 24. During engine operation, high-temperature/high- velocity gases 28 flow primarily axially with respect to the rotor axis 12 through the rows of vanes 18 and blades 16 in the turbine section 8.

FIG. 2 illustrates an attachment arrangement 100 (hereinafter “arrangement 100”) in accordance with an aspect of the present invention comprising a first component 102, a second component 104, and at least one pair of rails 126 which retains the first component 102 therein and is securable to the second component 104. The rails 126 may removably or fixedly secure the first component 102 thereto. The second component 104 comprises a greater coefficient of thermal expansion relative to the first component 102. The first and second components 102, 104 may each comprise any suitable material that satisfies this condition of a thermal expansion differential between the materials. In particular embodiments, the first component 102 comprises a CMC material and the second component 104 comprises a metal material, e.g., a superalloy, having a greater coefficient of thermal expansion than the CMC material. It is understood, however, that the present invention is not so limited to such materials.

In accordance with another aspect, the first component 102 or second component 104 may comprise any other suitable material, such as a MAX phase material, a titanium material, and/or an aluminide material as are known in the art. In a particular embodiment, the first component 102 or the second component 104 comprises a MAX phase. MAX phases are layered, hexagonal carbides and nitrides have the general formula: M_n+iAX_n, (MAX) where n = 1 to 3, M is an early transition metal (e.g., Sc, Ti, V, Cr, Mn, Zr, Nb, Mo, Hf, and/or Ta); A is an A-group element (e.g., Al, Si, P, S, Ga, Ge, As,

Cd, In, Sn, Tl, Pb, and/or Bi); and X is either carbon and/or nitrogen. The layered structure consists of edge-sharing, distorted XM6 octahedra

interleaved by single planar layers of the A-group element.

Similarly, it is appreciated that the arrangement 100 may define any suitable component(s) or structure(s) having a first component 102 or second component 104 as described herein. In the embodiment shown in FIG. 2, the attachment arrangement 100 defines a vane 18 as was also illustrated in FIG. 1. In this instance, the vane 18 is a hybrid structure 101 which comprises a first component 102 and a second component 104. In an embodiment, the first component 102 comprises a CMC material and the second component 104 comprises a metal material. In the embodiment shown, the first component 102 comprises an airfoil 106 formed from the CMC material and the second component 104 comprises one or both of an inner platform 108 and an outer platform 110 formed from the metal material. In certain embodiments, the airfoil 106 also includes one or more metal spars 142 that extend between the inner and outer platforms 108, 110, and through the body of the airfoil 106 to provide for additional support (e.g., interlaminar support) for the CMC airfoil 106. In addition, in the illustrated embodiment, the first component 102 further includes a shroud portion 120 that transitions the airfoil 106 to a contour of a surface of the second component 102.

It is understood, however, that the present invention is not so limited to a vane 18 as shown herein. It is appreciated that the arrangement 100 may comprise any suitable structure(s) and that it is only necessary that one or more rails 126 as described below retain the first (e.g., CMC) component 102, and thereafter the rails 126 are secured to the second component 104. The second component 104 may be another portion/section of the same article of manufacture or a discrete structure from the first component 102. Thus, the arrangement 100 may comprise any other structure or structures comprising a first component 102 and a second component 104 as described herein and secured by the rails 126. In particular embodiments, the arrangement 100 may comprise a blade, wherein an airfoil 106 is secured to a platform 108, for example, as in known in the art. In other embodiments, the arrangement 100 may comprise a first component 102 and a second component 104, wherein the first component 102 comprises a ring segment 21 and the second component 104 comprises a component of the gas turbine engine 2 to which the ring segment is secured, such as a vane carrier 22, 24, isolation rings, or the like (FIG. 1 ).

In any embodiment described herein, the first component 102 may comprise a CMC material and the second component 104 may comprise a metal material.

In the embodiment shown in FIG. 2, the airfoil 106 includes a body 112 of a CMC material 114 defined between a leading edge 116 and a trailing edge 118 thereof. As shown in FIG. 3, the first component 102 also includes a (non-airfoil) shroud portion 120 for transitioning of the airfoil 106 to either or both of the platforms 108, 110. In addition, the shroud portion 120 provides an area of the first component 102 which can be retained by the rails 126 as will be described below so that the rails 126 can secure the first component 102 (including airfoil 106) to the second component 106 (e.g., one or both of platforms 108, 110). In certain embodiments and as shown in FIG. 3, the shroud portion 120 comprises two opposed lateral sides 122 and allows for smooth transition and attachment of the airfoil 106 of the CMC component 102 to the metal component 102 (shrouds 108 or 110).

Referring again to FIG. 3, there is illustrated a pair of rails 126 retaining the two opposed lateral sides 122 of the CMC component 102. Each rail 126 comprises a channel 128 formed within a body 129 of the rail 126 for retaining an extent 124 of the first component 102 within the channel 128. In the embodiment shown, the extent 124 of the first component 102 comprises a shroud portion 120 having at least opposed two lateral sides 122 which can be retained by the rails 102. In this way, each side 122 is retained within a respective channel 128. Further, in this way also, the first component 102, with its airfoil 106 and shroud portion 120, may be retained by the rails 126. The extent 124 (e.g., lateral sides 122) may be retained within a channel 128 of a respective rail 126 by any suitable structure or process. In certain embodiments, the first component 102 may be slid into the respective channel 128 and maintained in place by any suitable method or structure.

By way of example, an extent 124 of the first component 102 may be pushed into a respective channel 128 of the rails by a pressure load on the non-airfoil portion (shroud portion 120). Friction may act to hold the extent 124, e.g., shroud portion 120, in place within the channels 128. In addition, in certain embodiments, the rails 126 may comprise a suitable curvature such that the rails 126 prevent or reduce the ability of the first component 102 to slide within the rails 126. If the rails 126 are relatively straight and not curved, one could utilize use pins or other suitable fastening structure(s) in another plane of the first component 102. These pins (or the like) would prevent the first component 102 from sliding out of the rails 126 while the rails 126 constrain the first component 102 in all other directions. In some

embodiments, a gap is disposed between the first component 102 and the rails 126 and is sized to not over-constrain the first component 102.

The rails 126 may be formed from any suitable material having a strength sufficient to retain the first component 102 therein, as well as withstand the temperature(s) of the intended use of the arrangement 100. In an embodiment, the rails 126 are formed from a superalloy material as described herein for the second component 104. In a particular embodiment, since CMC materials have low thermal expansion, a low thermal expansion superalloy may be used for the rails 126, such as a commercially available material sold under the trade names IN-909 or Nilo®-k. In this way, the sliding contact wear between the CMC and the rails 126 can be minimized. Further, the rails 126 (and channels 128 therein) may comprise any suitable dimensions (length, width, height, etc.) and may be of any suitable shape and curvature (if present) for its intended use and to mate with the second component 104. In certainly, the rails 102 have a degree of curvature that matches a degree of curvature of a mating surface of the second component Once the extent 124 of the first component 102 is retained within the rail 126, each rail 126 is securable to the second component 104 by a suitable connection 130 such that the first component 102 is secured to the second component 104. The connection 130 may provide a removable/reversible connection or a fixed/permanent connection. In an embodiment and as shown in FIG. 4, the connection 130 comprises one or bolts 132 that extend from a surface 134 of a respective rail 126 and one or more corresponding nuts 140 to secure the bolts 132 in a fixed position. In an embodiment, the bolts 132 are configured to extend through corresponding openings 136 formed in the second component 102 to which the rails 126 are to be secured. In an embodiment, the second component 102 comprises an inner platform 108 or an outer platform 110 of a vane 18. In certain embodiments, the bolts 132 comprise a threaded portion 138 such that upon insertion of the bolts 132 through the openings 136, the bolts 132 are secured to the second

component 104 via the nut 140, which may be threaded onto a respective bolt 132. In this way, the rails 126 (which retain the first component therein) secure the first component 102 to the second component 104. Alternatively, the connection 130 may comprise any other structure other than nuts/bolts for securing the rails 126 to the second component 104, such as other mating male/female members, grooves, or the like.

FIG. 5-7 further illustrate views of a connection 130 comprising the bolts 132 and nuts 140 for connecting a first component 102 to a second component 104 (having a greater coefficient of thermal expansion than the first component 102) using rails 126 in accordance with an aspect of the present invention. FIG. 5 illustrates an arrangement 100 as including the first component 102 (airfoil 106 and shroud portion 120), second component 104 (which includes outer platform 110 and metal spar 142), and rails 126. FIG. 6 is a cross-sectional view taken at line A-A of FIG. 6. As shown, the rails 126 retain an extent 124 of the first component 102 therein and are secured to second component 104 by the connector 130, which in the embodiment shown, comprises bolts 132 that extend through a body 144 of the second component 104 and are secured on a top surface 146 thereof by nuts 140.

In certain embodiments and as is best shown in FIG. 6, the extent 124 retained within channels 128 of rails 126 may include a notched portion 150, jogged edge, or the like for facilitating retention in the channel 128. As will be appreciated, the channels 128 may have a mating shape for optimally retaining the extent 124. FIG. 7 provides a different (axial length) view of the connection 130 for the CMC component 102 and the metal component 104 with the same components as FIG. 6.

In certain embodiments and as shown in FIG. 7, the first component 102 optionally comprises a lip 148 extending from a face thereof at an end of the first component 102 that abuts a surface of a respective rail 126 and/or the second component 104. In an embodiment, the lip 148 is positioned so as to constrain axial growth of the first component 102 in one (axial) direction while allowing axial growth in an opposed direction (shown as arrow 149).

For example, in an embodiment, the lip 148 restrains growth of the first component 102 in the axial direction, e.g., at a leading edge 116, while allowing growth of the first component 102 at the trailing edge 118 upon subjecting the first component 102 to the operating temperatures of a gas turbine, for example. Meanwhile, in this embodiment, the connection 130 as described herein constrains the first component 102 (without damaging or weakening the material, e.g., CMC material thereof) in the radial direction.

In accordance with yet another aspect of the present invention, it is desirable for the extent 124 of the first component 102 that is inserted into the channels 128 of the rails 126 to substantially maintain its structural integrity within the channels upon exposure high temperatures, such as those provided in a hot gas path of a gas turbine engine. This is particularly the case when the first component 102 comprises a CMC material. Accordingly, in accordance with another aspect of the present invention, there are disclosed structures and processes for increasing interlaminar strength of at least the extent 124 of the first component 102 which is inserted into the channels 128 when the first component 102 comprises a CMC material 114. This may be achieved by one or more structures or processes as described herein.

To explain, in certain embodiments, the CMC material 114 comprises a plurality of plies laid up on one another, which are already pre-impregnated with or are later impregnated with a ceramic material. The impregnated plies are then fired to form a fiber-reinforced ceramic matrix. For ease of illustration, FIG. 8 illustrates a linear portion of a lateral side 122 of the first component 102 as being formed from a CMC material 114 comprising a plurality of plies 152. In normal operation, due to the limited thermal conductivity of the CMC material 114 and the relatively weak ceramic matrix thereof, a thermal gradient may be established across the CMC material 114 which causes uppermost plies to bend in the direction of arrow 153 while other plies 152 deform due to thermal expansion in the direction of arrow 155. This bending / deformation may cause structural failure of the CMC material 114 within the channels 128 described herein and eventual detachment of the first, e.g., CMC, component 102 from the rails 126, and thus also from the second, e.g., metal, component 104.

To help combat this bending/deformation issue, a reinforcement member 151 is applied over edges 156 of the plies 152, e.g., at least at locations which will be inserted into the channels 128 of the rails 126. In a first embodiment, FIG. 9 illustrates a CMC component 102 comprising a plurality of plies 152 and a reinforcement member 151 in the form of one or more clamps 154 that are positioned over edges 156 of the plies 152. Each clamp 154 is formed from any suitable material which will maintain its function and structural integrity during the intended operation of the component 100.

In an embodiment, one or more clamps 154 are formed from a suitable superalloy material. In addition, each clamp 154 comprises dimensions sufficient to encompass an amount of the CMC material 114 therebetween in order to prevent delamination of its plies 154 due to interlaminar shear stress or other forces which may occur upon heating. In certain embodiments, a plurality of clamps 154 are provided and are selectively disposed about the first component 102 as needed or desired. In certain embodiments, the clamps 154 are provided at the lateral sides 122 of the first component 102 as described herein. In an embodiment, the channels 128 of the rails 126 are dimensioned so as to receive the CMC material 114 with a clamp 154 thereon within the channels 128.

In accordance with another aspect and as shown in FIG. 10, instead of clamp 154, the reinforcement member 151 is in the form of one or more end plies 158 may be wrapped about edges 156 of the plies 152 - at least at locations of the CMC material 114 that will be inserted into the rails 126. In certain embodiments, the one or more end plies 158 are wrapped about the edges 156 and then fired together with the plies 152 to form the final CMC component 102 structure. In other embodiments, the one or more end plies 158 may be added about the edges 144 after initial firing of the plies 152 in order to reduce or prevent delamination of the plies 152. By attaching the one or more end plies 158 at the edges 156, delamination of plies 152 is substantially prevented from occurring.

In accordance with another aspect and as shown in FIG. 11 , instead of a clamp or plies at edges 156, the reinforcement member 151 comprises one or more outer plies (overwrapping) 160 that is wrapped about a majority (> 80 % surface area) of or an entirety of the CMC material 114 in order to prevent delamination of the (inner) plies 152 that makes up the majority of the CMC material 114 of the first component 102. As with end plies 158, the one or more outer plies 160 may be fired with plies 152 or may be positioned about the perimeter 162 thereof after initial firing of the plies 152 and then fired. As with the other solutions, by placing the one or more outer plies 160 about the CMC material 114, delamination of plies 152 is substantially prevented from occurring.

In any case, aspects of the present invention provide a structure about the CMC material 114 (having a plurality of plies 152) in an area which will be inserted into the rail 126. Doing so provides reinforcement to the CMC material 114 where needed to prevent delamination, and also reduces or eliminates weakening of the CMC material 1 14, as well as the connection between the first component 102 and the second component 104 upon exposure to high temperatures as expected in the operation of a gas turbine engine 2.

In the embodiments described herein, the CMC material 1 14 may comprise a fiber reinforced matrix material or metal reinforced matrix material as may be known or later developed in the art, such as one commercially available from the COI Ceramics Co. under the name AS-N720. If a fiber reinforced material is used, the fibers may comprise oxide ceramics, non- oxide ceramics, or a combination thereof. For example, the oxide ceramic fiber composition can include those commercially available from the

Minnesota Mining and Manufacturing Company under the trademark Nextel, including Nextel 720 (alumino-silicate), Nextel 610 (alumina), and Nextel 650 (alumina and zirconia). For another example, the non-oxide ceramic fiber composition can include those commercially available from the COI Ceramics Company under the trademark Sylramic (silicon carbide), and from the Nippon Carbon Corporation, Limited under the trademark Nicalon (silicon carbide).

The matrix material composition that surrounds the fibers may be made of an oxide or non-oxide material, such as alumina, mullite, aluminosilicate, ytrria alumina garnet, silicon carbide, silicon nitride, silicon carbonitride, and the like. In an embodiment, the CMC material 1 14 comprises an oxide-oxide material (oxide fibers and oxide matrix). The CMC material 1 14 may combine a matrix composition with a reinforcing phase of a different composition (such as mullite/silica) or may be of the same composition (alumina/alumina or silicon carbide/silicon carbide). The fibers may be continuous or long discontinuous fibers, and may be oriented in a direction generally parallel, perpendicular, or otherwise disposed relative to the major length of the CMC material 1 14. The matrix composition may further contain whiskers, platelets, particulates, or fugitives, or the like. In addition, the reinforcing fibers may be disposed in the matrix material in layers, with the plies of adjacent layers being directionally oriented to achieve a desired mechanical strength. Various techniques are known in the art for making a CMC material 1 14 and such techniques can be used in forming the CMC material 1 14. In addition, further exemplary CMC materials and methods for making the same are described in U.S. Patent Nos. 8,058, 191 , 7,745,022, 7, 153,096; 7,093,359; and 6,733,907, the entirety of each of which is hereby incorporated by reference.

The second component 104 may comprise any suitable material for the intended purpose. In certain embodiments, the second component 104 comprises a metal material. In particular embodiments, the second

component 104 comprises a superalloy material, such as a Ni-based or a Co- based superalloy material as are well known in the art. The term "superalloy" may be understood to refer to a highly corrosion-resistant and oxidation- resistant alloy that exhibits excellent mechanical strength and resistance to creep even at high temperatures. Exemplary superalloy materials are commercially available and are sold under the trademarks and brand names Hastelloy, Inconel alloys (e.g., IN 738, IN 792, IN 939), Rene alloys (e.g. Rene N5, Rene 41 , Rene 80, Rene 108, Rene 142, Rene 220), Haynes alloys, Mar M, CM 247, CM 247 LC, C263, 718, X-750, ECY 768, 262, X45, PWA 1483 and CMSX (e.g. CMSX-4) single crystal alloys, GTD 1 1 1 , GTD 222, MGA 1400, MGA 2400, PSM 1 16, CMSX-8, CMSX-10, PWA 1484, IN 713C, Mar- M-200, PWA 1480, IN 100, IN 700, Udimet 600, Udimet 500 and titanium aluminide, for example.

It is appreciated that the present invention is not so limited to the vane 18 shown or the components therein, and that the attachment arrangement 100 for securing a first component 102 to a second component 104

(comprising a material having a greater coefficient of thermal expansion relative to the first component 102) may be employed on any other

components, including blades, ring segments, or the like, that employ both CMC and metal materials, for example, and require a connection for the same.

In accordance with another aspect of the present invention, there is provided a process for securely attaching a first component 102, e.g., a CMC component, to a second component 104, e.g., a metal component. In a particular aspect, the process comprises securing an extent 124 of a first component 102 within a channel 128 formed in a body of each of a pair of rails 126. Thereafter, the process includes securing the pair of rails 126 to a second component 104 to secure the first component 102 to the second component 104. As mentioned, the second component 104 comprises a greater coefficient of thermal expansion relative to the first component 102. In an embodiment, the first component 102 comprises a CMC material and the second component 104 comprises a metal material.

To explain an embodiment of the assembly process, first, lateral sides 122 of the first component 102 are inserted into the rails 126 so as to be secured within the rails 126 (FIG. 3). In an embodiment, the first component 102 comprises an airfoil 106 and a shroud portion 120, which includes an extent 124 retained by the rails 126. Thereafter, as is illustrated in FIGS. 4-5, the rails 126 are secured to the second component 104 by any suitable method. It is noted that FIG. 4 eliminates the first component 102 retained within the rails 126 for ease of illustration. In the embodiment shown, the rails 126 are secured to the second component 104 by inserting bolts 132 through corresponding openings 106 in the second component 104. The bolts 132 are then secured by nuts 140 over the second component 104. In an embodiment, the second component 104 comprises an upper platform of a vane 18 as is known in the art.

As will be appreciated by reference to FIG. 5, the arrangement and process described herein renders the assembly of a vane 18 or the like simple - even in the case where the second component 104 comprises a metal spar 142 that extends from the second component 104. In such a case, the metal spar 142 can be easily arranged through a body of an airfoil when the first component 102 comprises an airfoil 106 (e.g., CMC airfoil). It is appreciated that the first component 102 may also be secured to an inner platform 108 in a similar manner. Further, it is appreciated that the above process may be modified or altered for the connection of a first component 102 to a second component 104 as described herein, wherein the first component 102 and second component are of a different size, shape, or the like from the components shown in FIGS. 2-7, for example.

While various embodiments of the present invention have been shown and described herein, it will be obvious that such embodiments are provided by way of example only. Numerous variations, changes and substitutions may be made without departing from the invention herein. Accordingly, it is intended that the invention be limited only by the spirit and scope of the appended claims.

Claims

What we claim is:

1 . An arrangement (100) comprising:

a first component (102);

a second component (104) having a greater coefficient of thermal expansion relative to the first component (102); and

a pair of rails (126), wherein each rail (126) comprises a channel (128) within a body (129) of the rail (126), and wherein an extent (124) of the first component (102) is retained within the channel (128);

wherein each rail (126) is secured to the second component (104) to secure the first component (102) to the second component (104).

2. The arrangement (100) of claim 1 , wherein each channel (128) retains an opposed lateral side (122) of the first component (102).

3. The arrangement (100) of claim 1 , wherein each rail (126) comprises a plurality of bolts (132) extending from a surface (134) thereof, wherein the bolts (132) extend through a body (144) of the second component (104), and further comprising a nut (140) securing the bolts (132) over a surface (146) of the second component (104).

4. The arrangement (100) of claim 1 , wherein the first component (102) comprises an airfoil (106) having a shroud portion (120), and wherein the shroud portion (120) is retained within the channels (120) of the rails (126), and wherein the second component (104) comprises a platform (108,

1 10) to which the shroud portion (120) is secured.

5. The arrangement (100) of claim 1 , wherein the arrangement (100) comprises a gas turbine component selected from the group consisting of a vane (18), a blade (16), and a ring segment (21 ).

6. The arrangement (100) of claim 1 , wherein the first component (102) comprises a ceramic matrix composite material (114) including plurality of plies (152), and wherein the first component (102) comprises a

reinforcement member (151 ) disposed over edges (156) of the plies (152) to prevent delamination of the plies (152).

7. The arrangement (100) of claim 6, wherein the reinforcement member (151 ) comprises a clamp (154) disposed over edges (156) of the plies (152).

8. The arrangement (100) of claim 6, wherein the reinforcement member (151 ) comprises one or more plies (152) disposed over edges (156) of the plies (152).

9. The arrangement of claim 8, wherein the reinforcement member

(151 ) comprises an overwrapping (151 ) about a perimeter (162) of the plies

(152).

10. The arrangement (100) of claim 1 , wherein the first component (102) comprises an axial length and a lip (148) extending from an end of the axial length, the lip (148) abutting a face of one or both of the second component (104) and a respective rail (126)

11. The arrangement (100) of claims 1 to 10, wherein the first component (102) comprises a ceramic matrix composite material (114) and the second component (104) comprises a metal material.

12. An attachment method comprising:

securing an extent (124) of a first component (102) within a channel (128) formed in a body (128) of each member of a pair of rails (126); and securing the pair of rails (126) to a second component (104) to secure the first component (102) to the second component (104), wherein the second component (104) comprises a greater coefficient of thermal expansion relative to the first component (102).

13. The method of claim 12, wherein each rail (126) comprises a plurality of bolts (132) extending from a surface (134) of the rail (126), wherein the bolts (132) extend through a body (144) of the second component (104), and further comprising securing the bolts (132) over a surface of the second component (104).

14. The method of claim 12, wherein the first component (102) comprises an airfoil (106) having a shroud portion (120), and wherein the shroud portion (120) is retained within the channels (128) of the rails (126), and wherein the second component (104) comprises a platform (108, 1 10) to which the shroud portion (120) is secured.

15. The method of claim 12, wherein the arrangement (100) comprises a gas turbine component selected from the group consisting of a vane (18), a blade (16), and a ring segment (21 ).

16. The method of claim 12, wherein the first component (100) comprises a ceramic matrix composite material (1 14) including plurality of plies (152), and further comprising disposing a reinforcement member (151 ) over edges (156) of the plies (152) to prevent delamination of the plies (152).

17. The method of claim 16, wherein the reinforcement member (151 ) comprises a clamp (154) disposed over edges (156) of the plies (152).

18. The method of claim 16, wherein the reinforcement member (151 ) comprises one or more plies (152) disposed over edges (156) of the plies (152).

19. The method of claim 16, wherein the reinforcement member

(151 ) comprises an overwrapping (151 ) about a perimeter (162) of the plies

(152).

20. The method of claims 12 to 19, wherein the first component (102) comprises a ceramic matrix composite material (114) and the second component (104) comprises a metal material.