Patent Publication Number: US-2023147009-A1

Title: Composite components and methods of redefining openings in composite components

Description:
FIELD 
     The present subject matter relates generally to composite components. More particularly, the present subject matter relates to methods of redefining openings in composite components. 
     BACKGROUND 
     Reinforced ceramic matrix composites (“CMCs”) comprising fibers dispersed in continuous ceramic matrices of the same or a different composition are well suited for structural applications because of their toughness, thermal resistance, high-temperature strength, and chemical stability. Such composites typically have high strength-to-weight ratio that renders them attractive in applications in which weight is a concern, such as in aeronautic applications. Their stability at high temperatures renders CMCs very suitable in applications in which components are in contact with a high-temperature gas, such as in a gas turbine engine. 
     CMCs can have additional surface coatings to protect the composite when used in high temperature, corrosive, and/or other harsh environments. Further, one or more holes or openings may be defined in a CMC, which can present a challenge for repairing a surface coating and/or the underlying CMC. For example, the holes or openings may be kept open during the repair or may be plugged and re-opened after the repair, either of which can be difficult. For example, the exact original location of holes or openings that are plugged during the repair must be found to re-open the holes or openings after the repair. Similar repair challenges can exist for other composites. Accordingly, improved methods for repairing CMCs and other composites would be desirable. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       A full and enabling disclosure, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures, in which: 
         FIG.  1    provides a schematic cross-section view of a gas turbine engine. 
         FIG.  2 A  provides a schematic cross-section view of a portion of a composite component having a coating disposed on a surface and having a plurality of openings defined therein perpendicular to the surface. 
         FIG.  2 B  provides a schematic cross-section view of a portion of a composite component having a coating disposed on a surface, a plurality of openings defined therein perpendicular to the surface, and a plurality of openings defined therein at a non-zero, non-orthogonal angle to the surface. 
         FIG.  2 C  provides a schematic cross-section view of a portion of a composite component having a coating disposed on a surface, a plurality of openings defined therein having a larger cross-sectional area at one end than at an opposite end, and an opening defined therein having a non-round cross-section and not extending through the composite component. 
         FIG.  2 D  provides a schematic illustration of the composition of the composite component. 
         FIG.  3    provides a schematic cross-section view of the portion of the composite component of  FIG.  2 A  having the coating removed from the surface. 
         FIG.  4    provides a schematic cross-section view of the portion of the composite component of  FIG.  3    having the plurality of openings filled in with a filling material. 
         FIG.  4 A  provides a schematic illustration of an injection tool injecting the filling material into the plurality of openings. 
         FIG.  4 B  provides a schematic illustration of an application tool applying the filling material to the composite component. 
         FIG.  4 C  provides a schematic illustration of the composite component with the filling material applied thereto disposed in a pressurizable chamber. 
         FIG.  4 D  provides a schematic illustration of the composite component with the filling material applied thereto disposed in a vacuum bag within a vacuum chamber. 
         FIG.  5    provides a schematic cross-section view of the portion of the composite component of  FIG.  4    having a new coating applied to the surface. 
         FIG.  6    provides a schematic cross-section view of the portion of the composite component of  FIG.  5    having the plurality of openings redefined in the composite component. 
         FIG.  7    provides a flow diagram illustrating a method of redefining openings in a composite component. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to present embodiments of the disclosure, one or more examples of which are illustrated in the accompanying drawings. The detailed description uses numerical and letter designations to refer to features in the drawings. Like or similar designations in the drawings and description have been used to refer to like or similar parts of the disclosed embodiments. 
     As used herein, the terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components. 
     The terms “forward” and “aft” refer to relative positions within a gas turbine engine or vehicle and refer to the normal operational attitude of the gas turbine engine or vehicle. For example, with regard to a gas turbine engine, forward refers to a position closer to an engine inlet and aft refers to a position closer to an engine nozzle or exhaust. 
     The terms “upstream” and “downstream” refer to the relative direction with respect to 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. 
     The terms “coupled,” “fixed,” “attached to,” and the like refer to both direct coupling, fixing, or attaching, as well as indirect coupling, fixing, or attaching through one or more intermediate components or features, unless otherwise specified herein. 
     The singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise. 
     The terms “redefine,” “redefining,” and the like refer to removing material from a component to define a hole, aperture, or other opening in the component, such as through machining (e.g., drilling, electric discharge machining, etc.) or other means for material removal. 
     Approximating language, as used herein throughout the specification 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 related. Accordingly, a value modified by a term or terms, such as “about,” “approximately,” and “substantially,” are not to be limited to the precise value specified. In at least some instances, the approximating language may correspond to the precision of an instrument for measuring the value, or the precision of the methods or machines for constructing or manufacturing the components and/or systems. The approximating language may refer to being within a +/−1, 2, 4, 10, 15, or 20 percent margin in either individual values, range(s) of values, and/or endpoints defining range(s) of values. 
     Here and throughout the specification and claims, range limitations are combined and interchanged, such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise. For example, all ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other. 
     Generally, the present subject matter provides methods for redefining openings in composite components. For instance, the present subject matter provides a method of redefining openings in a composite component where openings in the composite component are filled with a material, such as a matrix material, after a surface coating is removed. The composite component is re-coated with a new surface coating, and the openings are redefined in the composite component. The opening filler or matrix material is well-matched to one or more properties of the material of the composite component such that the openings redefined in the composite component do not have to be defined in the exact same location as the original openings. For example, the redefined openings can be defined within a range of distances relative to the respective locations of the original openings. Additionally, or alternatively, the redefined openings can have a different size, shape, and/or pattern relative to the original openings. 
     Referring now to the drawings, wherein identical numerals indicate the same elements throughout the figures,  FIG.  1    is a schematic cross-sectional view of a gas turbine engine in accordance with an embodiment of the present disclosure. More particularly, for the embodiment of  FIG.  1   , the gas turbine engine is a high-bypass turbofan jet engine  10 , referred to herein as “turbofan engine  10 .” As shown in  FIG.  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. In general, the turbofan engine  10  includes a fan section  14  and a core turbine engine  16  disposed downstream from the fan section  14 . 
     The core turbine engine  16  depicted generally includes a substantially tubular outer casing  18  that defines an annular inlet  20 . The outer casing  18  encases, 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 a jet 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 . 
     For the depicted embodiment, fan section  14  includes a fan  38  having a plurality of fan blades  40  coupled to a disk  42  in a spaced apart manner. As depicted, fan blades  40  extend outward from disk  42  generally along the radial direction R. The fan blades  40  and disk  42  are together rotatable about the longitudinal centerline  12  by LP shaft  36 . In some embodiments, a power gear box having a plurality of gears may be included for stepping down the rotational speed of the LP shaft  36  to a more efficient rotational fan speed. 
     Referring still to the embodiment of  FIG.  1   , disk  42  is covered by a rotatable front nacelle  48  aerodynamically contoured to promote an airflow through the plurality of fan blades  40 . Additionally, the 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 nacelle  50  may be configured to be supported relative to the core turbine engine  16  by a plurality of circumferentially-spaced outlet guide vanes  52 . Moreover, a downstream section  54  of the nacelle  50  may extend over an outer portion of the core turbine engine  16  so as to define a bypass airflow passage  56  therebetween. 
     During operation of the turbofan engine  10 , a volume of air  58  enters turbofan engine  10  through an associated inlet  60  of the nacelle  50  and/or fan section  14 . As the volume of air  58  passes across fan blades  40 , a first portion of the air  58  as indicated by arrows  62  is directed or routed into the bypass airflow passage  56  and a second portion of the air  58  as indicated by arrows  64  is directed or routed into the LP compressor  22 . The ratio between the first portion of air  62  and the second portion of air  64  is commonly known as a bypass ratio. The pressure of the second portion of air  64  is then increased as it is routed through the high pressure (HP) compressor  24  and into the combustion section  26 , where it is mixed with fuel and burned to provide combustion gases  66 . 
     The combustion gases  66  are routed through the HP turbine  28  where a portion of thermal and/or kinetic energy from the combustion gases  66  is extracted via sequential stages of HP turbine stator vanes  68  that are coupled to the outer casing  18  and HP turbine rotor blades  70  that are coupled to the HP shaft or spool  34 , thus causing the HP shaft or spool  34  to rotate, thereby supporting operation of the HP compressor  24 . The combustion gases  66  are then routed through the LP turbine  30  where a second portion of thermal and kinetic energy is extracted from the combustion gases  66  via sequential stages of LP turbine stator vanes  72  that are coupled to the outer casing  18  and LP turbine rotor blades  74  that are coupled to the LP shaft or spool  36 , thus causing the LP shaft or spool  36  to rotate, thereby supporting operation of the LP compressor  22  and/or rotation of the fan  38 . 
     The combustion gases  66  are subsequently routed through the jet exhaust nozzle section  32  of the core turbine engine  16  to provide propulsive thrust. Simultaneously, the pressure of the first portion of air  62  is substantially increased as the first portion of air  62  is routed through the bypass airflow passage  56  before it is exhausted from a fan nozzle exhaust section  76  of the turbofan engine  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 routing the combustion gases  66  through the core turbine engine  16 . 
     In some embodiments, components of the turbofan engine  10  may comprise a composite material, such as a ceramic matrix composite (CMC) material, which has high temperature capability. Composite materials generally comprise a fibrous reinforcement material embedded in matrix material, e.g., a ceramic matrix material. The reinforcement material serves as a load-bearing constituent of the composite material, while the matrix of a composite material serves to bind the fibers together and act as the medium by which an externally applied stress is transmitted and distributed to the fibers. 
     Exemplary CMC materials may include silicon carbide (SiC), silicon, silica, carbon, or alumina matrix materials and combinations thereof. Ceramic fibers may be embedded within the matrix, such as oxidation stable reinforcing fibers including monofilaments like sapphire and silicon carbide (e.g., Textron&#39;s SCS-6), as well as rovings and yarn including silicon carbide (e.g., Nippon Carbon&#39;s NICALON®, Ube Industries&#39; TYRANNO®, and Dow Corning&#39;s SYLRAIVIIC®), alumina silicates (e.g., 3M&#39;s Nextel 440 and 480), and chopped whiskers and fibers (e.g., 3M&#39;s Nextel 440 and SAFFIL®), and optionally ceramic particles (e.g., oxides of Si, Al, Zr, Y, and combinations thereof) and inorganic fillers (e.g., pyrophyllite, wollastonite, mica, talc, kyanite, and montmorillonite). For example, in certain embodiments, bundles of the fibers, which may include a ceramic refractory material coating, are formed as a reinforced tape, such as a unidirectional reinforced tape. A plurality of the tapes may be laid up together (e.g., as plies) to form a preform component. The bundles of fibers may be impregnated with a slurry composition prior to forming the preform (e.g., prepreg plies) or after formation of the preform. The preform may then undergo thermal processing, such as a cure or burn-out to yield a high char residue in the preform, and subsequent chemical processing, such as melt-infiltration with silicon, to arrive at a component formed of a CMC material having a desired chemical composition. In other embodiments, the CMC material may be formed as, e.g., a carbon fiber cloth rather than as a tape. 
     Turning to  FIG.  2 A , a composite component  100  of a gas turbine engine, such as turbofan engine  10 , will be described according to an embodiment of the present subject matter. As schematically illustrated in  FIG.  2 A , the composite component  100  may be a composite airfoil such as a turbine stator nozzle airfoil. In other embodiments, the composite component  100  may be another composite airfoil, such as an inlet guide vane (IGV), an outlet guide vane (OGV)  52 , a rotor blade, etc. or other composite component such as a combustor liner, a fan case, a shroud, a turbine nozzle inner band or outer band, a frame (e.g., a turbine center frame or the like), etc. 
     The composite component  100  shown in  FIG.  2 A  includes a body  102  defining a surface  104 , with an existing coating  106  disposed on the surface  104 . A plurality of apertures, holes, or openings  108  are defined through the existing coating  106  into the body  102 . The plurality of openings  108  may be cooling holes, openings for instrumentation such as one or more sensors, openings for attachment features, channels, cavities, or the like or combinations thereof. For example, the plurality of openings  108  may be defined in the composite component  100  as cooling holes that allow a cooling fluid to flow from a cavity  105  defined within the composite component  100 , through the body  102  and the existing coating  106  to cool the composite component  100 , e.g., as the cooling fluid flows through the composite component  100  and/or as the cooling fluid flows over a surface  110  defined by the existing coating  106 . However, it will be appreciated that one or more of the openings  108  need not go all the way through the composite component  100 , e.g., from the surface  110  to the cavity  105 ; that is, one or more openings  108  of the plurality of openings  108  may or may not be defined through the composite component  100  to the cavity  105 . 
     As shown in  FIG.  2 A , each opening  108  has an opening length l. The opening length l may be the same for each opening  108  or may vary among the plurality of openings  108 , e.g., one opening  108  may define a shorter path between the cavity  105  and the surface  110  than another opening  108 . As further illustrated in  FIG.  2 A , one or more openings  108  of the plurality of openings  108  may be defined at a substantially orthogonal angle with respect to the body surface  104 , i.e., the opening length l may extend at a substantially orthogonal angle with respect to surface  104 . Additionally, or alternatively, one or more of the openings  108  may have an opening length l extending at one or more non-zero and non-orthogonal angles, respectively, to the body surface  104 . For example, as shown in  FIG.  2 B , a portion of the plurality of openings  108  have an opening length l extending at a non-zero and non-orthogonal angle α with respect to the surface  104 , while the remainder of the openings  108  have an opening length l extending substantially orthogonal or perpendicular to the surface  104 . 
     Additionally, or alternatively, one or more of the openings  108  may have a non-constant cross-sectional area and/or one or more of the openings  108  may have a non-round cross-sectional shape. For example, referring to  FIG.  2 C , the openings  108  depicted that are defined from the surface  110  to the cavity  105  taper from a larger cross-sectional area at the surface  110  to a smaller cross-sectional area at the cavity  105 , e.g., the openings  108  defined through the composite component  100  to the cavity  105  have a larger width w o  at the surface  110  than at the cavity  105 . Further, the two openings  108  defined approximately in the middle of the illustrated portion of the composite component  100  are non-line of sight openings  108 , which comprise a change in direction from an end  108   b  at the cavity  105  to an end  108   a  at the surface  110  such that the end  108   b  of the opening  108  at the cavity  105  is not along a line of sight to the end  108   a  of the opening  108  at the surface  110 . Moreover,  FIG.  2 C  depicts an opening  108  on the right that has a non-round cross-section and that does not extend through the composite component  100  to the cavity  105 , e.g., the rightmost opening  108  may be an opening for an attachment feature or the like. 
     Over time, e.g., after a certain period of use or after an event in which the turbofan engine  10  and/or the composite component  100  is damaged, the existing coating  106  may need to be replaced. For instance, the existing coating  106  may sustain chipping, cracking, abrasion, erosion, recession, or other degradation, illustrated as degraded areas  112  in  FIG.  2 A , that could hinder the performance or usefulness of the existing coating  106 . 
     In at least some embodiments, the existing coating  106  may be an environmental barrier coating (EBC), which can help protect the composite component body  102  from the harsh environment of, e.g., high temperature engine sections. For example, EBCs can provide a seal against the corrosive gases in the hot combustion environment, which can oxidize silicon-containing CMCs and monolithic ceramics, and EBCs can help prevent dimensional changes in the CMC component due to oxidation and volatilization of silicon oxide in high temperature steam, where silicon oxide can be converted to volatile (gaseous) silicon hydroxide species. Thus, when the EBC sustains chipping, cracking, abrasion, erosion, recession, etc., the EBC may need to be removed and reapplied to continue realizing the benefits of the EBC. 
     Referring now to  FIGS.  3  through  7   , various methods of repairing a composite component  100 , e.g., by replacing the existing coating  106  with a new coating, are described. For example,  FIGS.  3  through  6    provide schematic illustrations of various points in a method  700  of repairing a composite component  100 .  FIG.  7    provides a flow diagram of the method  700 . 
     As shown in  FIG.  7   , the method  700  includes ( 702 ) removing an existing coating  106  from a surface  104  of the composite component  100 . As previously described, the existing coating  106  may become degraded such that the performance or benefits of the coating are diminished or non-existent, and to restore the benefits provided by the coating, it is removed and replaced. In some embodiments, the existing coating  106  may be stripped from the composite component  100  by any suitable chemical or physical process, such as milling or the like. Referring to  FIG.  3   , removing the existing coating  106  from the composite component  100  exposes the surface  104  of the composite component  100  defined by the body  102 . 
     After the existing coating  106  is removed, the method  700  includes ( 704 ) filling the plurality of openings  108  with a filling material  114 , as shown in  FIG.  4   . For example, the composite component  100  may be a CMC component comprising a ceramic reinforcement material  116 , such as fibers or particles, disposed in a component matrix material  118  as schematically shown in  FIG.  2 D . The filling material  114  may be a ceramic matrix material comprising a liquid carrier, a filler dispersed within the carrier, and a polymeric binder disposed in the carrier. The liquid carrier may be selected such that it partially or fully dissolves one or more organic components of the formulation, such as the binder. The filler may be fibers and/or a powder and may comprise at least one of silicon, silicon carbide, and carbon. The polymeric binder may be used to alter the flow properties of the filling material  114 , such as by thickening the filling material  114  to allow it to remain in place when applied to the composite component  100  as described herein. Optionally, the filling material  114  further comprises other ingredients disposed in the carrier, such as a shrinkage control agent, which provides a measure of rigidity to the formulation as it is processed. For example, the mass loss associated with volatilizing the liquid carrier and converting the binder to char creates a driving force to shrink the size of the remaining material, and excessive shrinkage can lead to undesirable cracking within the product material. Including a shrinkage control agent such as short fibers can provide mechanical support to mitigate the tendency to shrink. 
     The filling material  114  (e.g., the liquid carrier, the ceramic filler, and/or the polymeric binder forming the filling material  114 ) may be selected to have substantially similar thermodynamic, physical, and/or chemical properties to the component matrix material  118 , e.g., such that the thermodynamic, physical, and/or chemical properties of the filling material  114  are well-matched to the thermodynamic, physical, and/or chemical properties of the component matrix material  118 . For instance, the filling material  114  and the component matrix material  118  may have a substantially similar coefficient of thermal expansion, elastic modulus, thermal conductivity, oxidation resistance, material compatibility, and/or chemical composition. As one example, the filling material  114  and the component matrix material  118  may have a material compatibility that helps prevent an unfavorable or undesirable reaction between the filling material  114  and the component matrix material  118 . Because the thermodynamic, physical, and/or chemical properties are substantially similar or well-matched, the composite component  100  at the plurality of openings  108  is similar to the remainder of the composite component  100 , the openings  108  need not be defined at precisely their original location when the openings  108  are redefined in the composite component  100  after recoating the composite component  100  as described below. 
     Comparing  FIGS.  3  and  4   ,  FIG.  4    illustrates the filling material  114  disposed over the composite component surface  104  and within the plurality of openings  108 . The filling material  114  may be a paste, slurry, or other consistency for dispersing within the plurality of openings  108 . For instance, a filling material  114  slurry may be formed by mixing a liquid carrier with a ceramic filler and a polymeric binder and, optionally, other ingredients such as, e.g., a shrinkage control agent, etc. It will be appreciated that the filling material  114  need not completely fill each opening  108 , i.e., one or more of the openings  108  may be partially filled with the filling material  114  along the length l of the opening  108 . For example, when the filling material  114  is received in the one or more openings  108 , a small depression may be left near the composite component surface  104 , e.g., to help locate the openings  108  when redefining the openings  108  as described herein. As another example, one or more openings  108  may not be filled near the end of the respective opening  108  opposite the composite component surface  104 , e.g., at or near end  108   b  illustrated in  FIG.  2 C . 
     In some embodiments, filling the plurality of openings  108  with the filling material  114  comprises injecting the filling material  114  into the plurality of openings  108 . As schematically shown in  FIG.  4 A , the filling material  114  may be injected manually, e.g., by a human operator  120  manipulating an injection tool  122  by hand or otherwise to inject the filling material  114  into the openings  108  ( FIG.  3   ), or the filling material  114  may be injected automatically, e.g., by a robot or other automated machine  124  using an injection tool  122  to inject the filling material  114  into the openings  108 . It will be appreciated that the filling material  114  may be injected into each opening  108  individually or simultaneously into a plurality of openings  108 . 
     In other embodiments, filling the plurality of openings  108  with the filling material  114  comprises applying the filling material  114  to the surface  104  and over the plurality of openings  108 . For example, referring to  FIG.  4 B , an application tool  126 , such as a putty knife or other straight-edge or similar tool, may be used by a human operator  120  to manually apply the filling material  114  over the surface  104 , including over the plurality of openings  108  ( FIG.  3   ). As another example, a robot or other automated machine  124  may automatically apply the filling material  114  over the surface  104 , including over the plurality of openings  108 , using the application tool  126 , e.g., a putty knife or other straight-edge or similar tool. In yet other embodiments, rather than or in addition to applying the filling material to the outer surface  104  and over the openings  108 , the filling material  114  may be applied to an inner surface, such as the inner surface of the composite component  100  defining the cavity  105 , and over the plurality of openings  108 . 
     In still further embodiments, filling the plurality of openings  108  with the filling material  114  comprises applying the filling material  114  to the surface  104 , and/or to an inner surface of the composite component  100 , and subjecting the composite component  100  to an elevated pressure. For instance, referring to  FIG.  4 C , after the filling material  114  is applied over the surface  104 , including over one or more of the openings  108  ( FIG.  3   ), using the application tool  126  or another suitable tool, the composite component  100  is disposed in an autoclave or other chamber  128 . Then, the pressure within the chamber  128  is raised above ambient pressure to force the filling material  114  on the surface  104  into the plurality of openings  108 . 
     In yet other embodiments, filling the plurality of openings  108  with the filling material  114  comprises applying the filling material  114  to the surface  104  (and/or to an inner surface of the composite component  100 ), placing the composite component  100  within an enclosure, and creating a pressure differential between an interior of the enclosure and an exterior of the enclosure. For example, referring to  FIG.  4 D , after the filling material  114  is applied over the surface  104 , including over one or more of the openings  108 , using the application tool  126  or another suitable tool (e.g., as described with respect to  FIGS.  4 A and  4 B ), the composite component  100  is disposed in a bag  130  and sealed within the bag  130 . As such, the composite component  100  with the filling material  114  is placed within an enclosure, i.e., the bag  130 . In some embodiments, a vacuum line is connected to the bag  130  such that a vacuum may be drawn on the bag  130  with the composite component  100  therein, which lowers the pressure in the bag  130  relative to atmospheric pressure outside the bag  130 . The pressure differential between an interior  132  of the bag  130  and an exterior  133  of the bag  130  causes the bag  130  to push against the composite component  100  and force the filling material  114  into the openings  108 . In further embodiments, the composite component  100 , disposed in the bag  130 , may be placed in a chamber  128 , such as an autoclave or other pressure vessel, and the pressure raised above atmospheric pressure within the chamber  128  to force the filling material  114  on the surface  104  (and/or the inner surface of the composite component  100 ) into the plurality of openings  108 . The bagged composite component  100  may be subjected to the elevated pressure within the chamber  128  with or without a vacuum being pulled on the bag  130 . It will be appreciated that, if a vacuum is pulled on the bag  130 , thereby lowering the pressure in the interior  132  of the bag  130  below atmospheric pressure, and the bag  130  is disposed in the chamber  128  and the pressure within the chamber  128  raised above atmospheric pressure, the pressure differential between the interior  132  of the bag  130  and the exterior  133  of the bag  130  will be greater than only pulling a vacuum on the bagged composite component  100 . In at least some embodiments, the greater compaction pressure provided by the larger pressure differential can help force the filling material  114  into the openings  108  compared to vacuum bagging alone. 
     As shown in  FIG.  7   , the method  700  further may include ( 706 ) repairing the body  102  of the composite component  100 . As previously discussed with reference to  FIG.  2 B , the composite component  100  may sustain damage, which can produce degraded areas  112  in the existing coating  106  and can also damage the body  102  of the composite component  100 . Accordingly, the body  102  may be repaired, e.g., by scarfing or otherwise cleaning out the damaged area(s) and replacing the damaged composite material with new layers of ceramic reinforcement material  116  (e.g., new fibers, etc.), new component matrix material  118 , new composite plies, etc., along with replacing the damaged existing coating  106 . It will be appreciated that repairing the body  102  need not occur after filling the one or more openings  108  with the filling material  114  as shown in  FIG.  7    but, instead, may occur at any appropriate point in the method  700 . For instance, in some embodiments, repairing the body  102  may occur after removing the existing coating  106  but prior to filling the one or more openings  108  with the filling material  114 . 
     Keeping with  FIG.  7   , after the one or more openings  108  are filled with the filling material  114 , the method  700  includes ( 708 ) processing the composite component  100  having the filled openings  108 . For instance, the composite component  100  may undergo burnout (or firing) and densification, e.g., the composite component  100  may be heated (fired) in a vacuum or inert atmosphere to decompose any binders and remove any solvents in the filling material  114  and convert the filling material  114  to the desired ceramic matrix material. Due to decomposition of the binders during burnout, the filling material  114  is porous, and the body  102  of the composite component  100 , particularly any areas that may have received new ceramic reinforcement material  116  and/or ceramic matrix material  118 , also may have pores or voids therein. Accordingly, the composite component  100  may undergo densification, e.g., melt infiltration (MI), chemical vapor infiltration (CVI), or polymer infiltration and pyrolysis (PIP), to fill the porosity and yield a densified CMC component  100 . Specific processing techniques and parameters for the above process will depend on the particular composition of the materials. For example, silicon carbide CMC components may be infiltrated with molten silicon, e.g., through a silicon MI process or a reactive MI process. Other densification techniques include, but are not limited to, PIP processes (e.g., where silicon carbide reinforcement material components are infiltrated with a preceramic polymer, such as polysilazane and then heat treated to form a SiC matrix), oxide/oxide processes (e.g., for aluminum or alumino-silicate reinforcement material components), and CVI processes (e.g., for carbon fiber reinforced silicon carbide matrix (C/SiC) CMCs, for SiC/SiC CMCs, etc.). 
     As further shown in  FIG.  7   , the method  700  includes ( 710 ) applying a new coating  134  to the surface  104 . As shown in  FIG.  5   , the new coating  134  is applied over the surface  104  and the openings  108  filled with the filling material  114 . The new coating  134  may be, e.g., a new EBC or other surface coating, and may be applied using any suitable application method. For instance, the new coating  134  may be applied as a thermal spray, such as an air plasma spray, or a slurry coating, e.g., using a dip and spin application technique. 
     Referring still to  FIG.  7   , the method  700  includes ( 712 ) redefining at least one opening  108  of the plurality of openings  108  such that a new, redefined opening  108 ′ extends through the new coating  134  and into the body  102  of the composite component  100 , as shown in  FIG.  6   . The opening(s)  108  may be redefined as new opening(s)  108 ′, e.g., by drilling, electric discharge machining (EDM), laser drilling, or any suitable means for defining a hole, aperture, or other opening in the composite component  100 . 
     It will be appreciated that the redefined opening(s)  108 ′ may be referred to as new opening(s)  108 ′ because the original plurality of openings  108  were filled with the filling material  114  such that the new opening(s)  108 ′ need not be redefined in precisely the same location, orientation, size, shape, number, and/or pattern as the original openings  108 . For example, referring back to  FIG.  2 A , each existing or original opening  108  of the plurality of openings  108  has an original width w o  and is defined at an original location  136  in the body  102  of the composite component  100 , prior to filling the existing or original opening  108  with the filling material  114  as described herein. The original width w o  may be within a range of about 6 mils to about 160 mils, such as within a range of about 40 mils to about 120 mils and such as within a range of about 60 mils to about 100 mils. For example, the low end of the range of original width w o  may be about the thickness of a single CMC ply. As described herein, e.g., with respect to  FIG.  2 C , the original width w o  of each opening  108  may vary along the length l of the original opening  108 , or the cross-sectional area of the original opening  108  may vary along its length l. 
     In at least some embodiments, redefining the opening  108  in the body  102  comprises redefining the opening  108  (as a new opening  108 ′) at a new location  138  that may be, e.g., within one-half the original width w o  (½ w o ) of the original location  136 . For instance, in  FIG.  6   , an original opening  108  is shown in phantom or dashed lines, with a new opening  108 ′ shown in solid lines. As indicated, the difference in location between the new opening  108 ′ and the original opening  108  is up to one-half the original width w o . For example, for an original opening  108  having an original width w o  of 100 mils and defined at an original location  136 , the redefined or new opening  108 ′ is defined at a new location  138  within 50 mils of the original location  136 . In at least some embodiments, the new opening(s)  108 ′ are defined at the respective original location  136  of each opening  108 . 
     Further, a new opening  108 ′ may be defined in the same orientation as the respective original opening  108 , e.g., the new opening  108 ′ may be defined at the same angle to the surface  104  as the respective original opening  108 . Additionally, or alternatively, one or more new openings  108 ′ may be defined at different orientations than the respective original opening  108 , e.g., one or more new openings  108 ′ may be defined at a different angle to the surface  104  than the respective original opening  108 . As further examples, one or more new openings  108 ′ may be defined with a different width or cross-sectional area as the respective original opening  108  and/or the new openings  108 ′ may be defined in a different pattern in the composite component  100  compared to the original openings  108 . Further, the width or cross-sectional area of each new opening  108 ′ may vary in the same manner or in a different manner as a respective original opening  108 . 
     Accordingly, as described herein, the present subject matter provides methods of redefining one or more openings in composite components and composite components having one or more redefined openings therein. For instance, the present subject matter provides for filling in openings of a composite component with a matrix material to provide a relatively pristine surface for re-coating the composite component in a repair process. That is, the matrix material fills openings defined in the composite component to restore a surface of the composite component to an uninterrupted state to accept a coating on the surface and then the openings are redefined in the composite component. The matrix material may have one or more properties that are substantially similar to the properties of the composite component material such that when the openings are redefined in the composite component, the alignment of the openings does not have to exactly match the original positions of the openings. Other advantages of the subject matter described herein also may be realized by those of ordinary skill in the art. 
     Further aspects of the disclosure are provided by the subject matter of the following clauses: 
     A method comprising filling an opening with a filling material, the opening defined in a body of a composite component and opening onto a surface defined by the composite component; and redefining the opening such that the opening extends into the body, wherein the composite component is a ceramic matrix composite component comprising ceramic reinforcement material disposed in a component matrix material. 
     The method of any preceding clause, further comprising applying a coating to the surface after filling the opening with the filling material. 
     The method of any preceding clause, further comprising removing an existing coating from the surface of the composite component prior to filling the opening with the filling material. 
     The method of any preceding clause, further comprising adding ceramic reinforcement material, component matrix material, or both in the body of the composite component. 
     The method of any preceding clause, wherein the opening is defined at an original location in the body prior to filling the opening with the filling material, and wherein redefining the opening comprises redefining the opening at a new location. 
     The method of any preceding clause, wherein the opening has an original width, and wherein the new location is within one-half the original width of the original location. 
     The method of any preceding clause, wherein filling the opening with the filling material comprises injecting the filling material into the opening. 
     The method of any preceding clause, wherein filling the opening with the filling material comprises applying the filling material to the surface and over the opening. 
     The method of any preceding clause, wherein filling the opening with the filling material comprises applying the filling material to the surface, placing the composite component with the filling material applied thereto within an enclosure, and creating a pressure differential between an interior of the enclosure and an exterior of the enclosure. 
     The method of any preceding clause, wherein the enclosure is a bag. 
     The method of any preceding clause, wherein the enclosure is a bag, and wherein creating the pressure differential between the interior of the enclosure and the exterior of the enclosure comprises drawing a vacuum on the bag. 
     The method of any preceding clause, wherein the enclosure is a bag, and further comprising disposing within a chamber the composite component with the filling material applied thereto that is placed within the bag. 
     The method of any preceding clause, wherein creating the pressure differential between the interior of the enclosure and the exterior of the enclosure comprises raising the pressure within the chamber. 
     The method of any preceding clause, wherein the filling material has substantially similar thermodynamic, physical, and chemical properties to the component matrix material, and wherein the substantially similar thermodynamic, physical, and chemical properties are at least one of coefficient of thermal expansion, elastic modulus, thermal conductivity, oxidation resistance, material compatibility, and chemical composition. 
     The method of any preceding clause, wherein the opening has a length extending substantially orthogonal to the surface. 
     The method of any preceding clause, wherein the opening has a length extending at a non-zero and non-orthogonal angle to the surface. 
     The method of any preceding clause, wherein the opening has a width within a range of about 6 mils to about 160 mils. 
     The method of any preceding clause, wherein the opening has a width within a range of about 40 mils to about 120 mils. 
     The method of any preceding clause, wherein the opening has a width within a range of about 60 mils to about 100 mils. 
     The method of any preceding clause, wherein the composite component is an airfoil, shroud, combustor liner, turbine nozzle band, or frame and the opening is a cooling hole. 
     The method of any preceding clause, wherein the existing coating is an environmental barrier coating. 
     The method of any preceding clause, wherein the opening filled with the filling material is an original opening and the redefined opening is a new opening, and wherein the new opening is defined at a different location than the original opening. 
     The method of any preceding clause, wherein the original opening is a plurality of original openings and the new opening is a plurality of new openings, and wherein the plurality of new openings are defined in a different pattern than the plurality of original openings. 
     The method of any preceding clause, wherein the original opening is a plurality of original openings and the new opening is a plurality of new openings, and wherein at least one new opening of the plurality of new openings has different dimensions from an original opening of the plurality of original openings. 
     The method of any preceding clause, wherein the original opening is a plurality of original openings and the new opening is a plurality of new openings, and wherein at least one new opening of the plurality of new openings has a different cross-sectional shape from an original opening of the plurality of original openings. 
     The method of any preceding clause, wherein the original opening is a plurality of original openings and the new opening is a plurality of new openings, and wherein the plurality of new openings is different in number from the plurality of original openings. 
     A method comprising removing an existing coating from a surface of a ceramic matrix composite component; filling an opening with a filling material, the opening defined in a body of the ceramic matrix composite component and opening onto the surface; applying a new coating to the surface; and redefining the opening such that the opening extends through the new coating and into the body. 
     The method of any preceding clause, wherein the filling material comprises a liquid carrier, a filler dispersed within the liquid carrier, and a polymeric binder disposed in the liquid carrier. 
     The method of any preceding clause, wherein the filler comprises at least one of silicon, silicon carbide, and carbon. 
     The method of any preceding clause, wherein the opening has a width within a range of about 6 mils to about 160 mils. 
     The method of any preceding clause, wherein the opening has a width within a range of about 40 mils to about 120 mils. 
     The method of any preceding clause, wherein the opening has a width within a range of about 60 mils to about 100 mils. 
     The method of any preceding clause, wherein the opening is defined at an original location in the body prior to filling the opening with the filling material, and wherein redefining the opening comprises redefining the opening within one-half the width of the original location. 
     A composite component comprising a ceramic matrix composite body having a surface; a coating on the surface; an original opening defined through the body, the original opening filled with a filling material; and a new opening defined through the coating into the body, wherein the original opening is defined at an original location in the body, and wherein the new opening is defined at a new location. 
     The composite component of any preceding clause, wherein the original opening has an original width, and wherein the new location is within one-half the original width of the original location. 
     This written description uses examples to disclose embodiments of the disclosure, including the best mode, and also to enable any person skilled in the art to practice the disclosure, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the disclosure is defined by the claims and may include other examples that occur to those skilled in the art. Such other examples are intended to be 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 language of the claims.