Patent Publication Number: US-2022213583-A1

Title: Process for coating substrates with aperture(s)

Description:
This application is a Divisional application of U.S. patent application Ser. No. 16/849,418 filed Apr. 15, 2022, now U.S. Pat. No. ______, the entire contents of which are fully incorporated herein. 
    
    
     BACKGROUND 
     The disclosure relates generally to methods for coating substrates. In particular, the present disclosure is directed to coating methods for selectively coating a substrate that includes apertures, and a coated substrate that includes apertures formed by the coating methods. 
     When turbines are used on aircraft or for power generation, they are typically run at a temperature as high as possible, for increased operating efficiency. Since high temperatures can damage the alloys used for the components, a variety of approaches have been used to raise the operating temperature of metal components. One approach calls for the incorporation of internal cooling channels in the component, through which cool air is forced during engine operation. Apertures or cooling holes can be formed in the substrate by techniques such as water jet processing and/or electrical discharge machining (EDM). Cooling air (usually provided by the engine&#39;s compressor) is fed through the holes from the cooler side to the hot side of a component wall. As long as the holes remain clear, the rushing air will assist in lowering the temperature of the hot metal surface and preventing melting or other degradation of the component. 
     Another technique for protecting the metal parts and effectively raising the practical operating temperature involves the use of a coating, such as a bond coat, a thermal barrier coating (TBC) or environmental barrier coating (EBC). A TBC is usually ceramic-based. Coating systems frequently also include a bond coat which is placed between the ceramic coating and the substrate to improve adhesion. Use of TBCs in conjunction with cooling holes is sometimes an effective means for protecting an engine part. However, incorporation of both systems can be very difficult. For example, cooling holes sometimes cannot be formed in the engine part after a TBC has been applied, since lasers usually cannot effectively penetrate both ceramic material and metal to form the pattern of holes and may possibly crack a TBC. If cooling holes are formed prior to the application of a coating system, they may become covered and at least partially obstructed when a coating is applied. 
     BRIEF DESCRIPTION 
     A first aspect of the disclosure provides a coating method for a component with at least one aperture. The coating method includes providing a component having at least one aperture formed in a surface thereof; additively manufacturing a hollow member on a portion of the surface to define a space above each aperture, the portion of the surface being adjacent to the aperture, the hollow member having an inner peripheral geometry complementary to a peripheral geometry at least one of aperture; applying at least one coating over the surface of the component and around the hollow member to form an applied coating having an applied coating thickness; and removing at least a portion of the hollow member to make a top portion of the hollow member coplanar with the applied coating to expose the space through the applied coating; wherein a lower portion of the hollow member remains to define the space through the applied coating. 
     A second aspect of the disclosure provides a coated component. The component includes a surface; at least one aperture formed in the surface; a coating layer on the surface, the coating layer including: at least one hollow member additively manufactured on the surface extending from the surface to a top surface, each hollow member defining a space above a respective one of the at least one aperture, a perimeter of the hollow member being coincident with each at least one aperture and having an inner peripheral geometry complementary to a peripheral geometry the respective one of the at least one of the aperture; a coating material sprayed on the surface and around the hollow member, the coating material having a top surface coplanar with a portion of the hollow member after portions of at least one of the hollow member is removed. 
     All aspects, examples and features mentioned below can be combined in any technically possible way. 
     An aspect of the disclosure provides a coated component, with the component comprising a surface; at least one aperture formed in the surface; a coating layer on the surface, wherein the coating layer including at least one hollow member on the surface extending from the surface to an outer surface of the coating layer, each hollow member defining a space above a respective one of the at least one aperture, a perimeter of each hollow member being coincident with a perimeter of a respective one of the at least one aperture and having an inner peripheral geometry complementary to an inner peripheral geometry of the respective one of the at least one aperture; a coating material on the surface and around the at least one hollow member, the coating material having a top surface coplanar with a portion of the at least one hollow member. 
     Another aspect of the disclosure includes any of the preceding aspects, and the coating material includes at least one of a thermal barrier coating composition, an environmental barrier coating composition, or a bond coat composition. 
     Another aspect of the disclosure includes any of the preceding aspects, and the at least one hollow member includes at least one of a thermal barrier coating composition, an environmental barrier coating composition, or a bond coat composition. 
     Another aspect of the disclosure includes any of the preceding aspects, and the at least one hollow member is formed with the respective one of the at least one aperture. 
     Another aspect of the disclosure includes any of the preceding aspects, and the at least one hollow member is formed by additively manufacturing the at least one hollow member on the surface and extending from the surface to an outer surface of the at least one hollow member. 
     Another aspect of the disclosure includes any of the preceding aspects, and the at least one hollow member includes an inner periphery aligned with an outer perimeter of the respective one of the at least one aperture. 
     Another aspect of the disclosure includes any of the preceding aspects, and the at least one aperture defines an axis disposed at a non-perpendicular angle to the surface, and a respective at least one hollow member is coaxial with an axis of the at least one aperture. 
     Another aspect of the disclosure includes any of the preceding aspects, and the component is a turbomachine component. 
     Another aspect of the disclosure includes any of the preceding aspects, and the at least one hollow member includes a ceramic material selected from a group including at least one of aluminum-oxide, zirconium-oxide, hafnium-oxide, yttria-stabilized zirconium-oxide, metallic material, silicon based material, graphite, aluminum oxide, yttria-stabilized zirconia. 
     Another aspect of the disclosure includes any of the preceding aspects, and the coating material includes a ceramic material selected from a group including at least one of aluminum-oxide, zirconium-oxide, hafnium-oxide, yttria-stabilized zirconium-oxide, metallic material, silicon based materials, graphite, aluminum oxide, or yttria-stabilized zirconia. 
     Another aspect of the disclosure includes any of the preceding aspects, and an inner periphery of the at least one hollow member aligns with an outer perimeter of the at least one aperture to define a coplanar transitional surface. 
     Another aspect of the disclosure includes any of the preceding aspects, and the coating material is applied by spraying the coating material with a spray gun disposed at an angle to the at least one aperture. 
     Two or more aspects described in this disclosure, including those described in this summary section, may be combined to form implementations not specifically described herein. 
     The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features, objects and advantages will be apparent from the description and drawings, and from the claims. 
     The illustrative aspects of the present disclosure are designed to solve the problems herein described and/or other problems not discussed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features of this disclosure will be more readily understood from the following detailed description of the various aspects of the disclosure taken in conjunction with the accompanying drawings that depict various embodiments of the disclosure, in which: 
         FIG. 1  is a perspective view of a component of the present disclosure; 
         FIG. 2  is a flow chart of a process according to the present disclosure; 
         FIG. 3  is a sectional view of a component of  FIG. 1  including a plurality of apertures with hollow members formed thereon according to the present disclosure; 
         FIG. 4  is a sectional view of a component of  FIG. 1  including a plurality of apertures with hollow members and coating formed thereon according to the present disclosure; 
         FIG. 5  is a sectional view of a component of  FIG. 1  including a plurality of apertures with hollow members and coating formed thereon with portions of hollow members removed according to the present disclosure; 
         FIG. 6  is a sectional view of a component according to another aspect of the present disclosure including a plurality of apertures with hollow members formed thereon according to the present disclosure; 
         FIG. 7  is a sectional view of a component according to another aspect of the present disclosure including a plurality of apertures with hollow members and coating formed thereon according to the present disclosure; 
         FIG. 8  is a sectional view of a component according to another aspect of the present disclosure including a plurality of apertures with hollow members and coating formed thereon with portions of hollow members removed according to the present disclosure; and 
         FIG. 9  is an illustration of a spray apparatus with a component according to the present disclosure. 
     
    
    
     It is noted that the drawings of the disclosure are not to scale. The drawings are intended to depict only typical aspects of the disclosure, and therefore should not be considered as limiting the scope of the disclosure. In the drawings, like numbering represents like elements between the drawings. 
     DETAILED DESCRIPTION 
     As an initial matter, in order to clearly describe the current technology, it will become necessary to select certain terminology when referring to and describing relevant components within turbines. To the extent possible, common industry terminology will be used and employed in a manner consistent with its accepted meaning. Unless otherwise stated, such terminology should be given a broad interpretation consistent with the context of the present application and the scope of the appended claims. Those of ordinary skill in the art will appreciate that often a particular component may be referred to using several different or overlapping terms. What may be described herein as being a single part may include and be referenced in another context as consisting of multiple components. Alternatively, what may be described herein as including multiple components may be referred to elsewhere as a single part. 
     In addition, several descriptive terms may be used regularly herein, and it should prove helpful to define these terms at the onset of this section. These terms and their definitions, unless stated otherwise, are as follows. As used herein, “downstream” and “upstream” are terms that indicate a direction relative to the flow of a fluid, such as the working fluid through the turbine engine or, for example, the flow of air through the combustor or coolant through one of the turbine&#39;s component systems. The term “downstream” corresponds to the direction of flow of the fluid, and the term “upstream” refers to the direction opposite to the flow. The terms “forward” and “aft,” without any further specificity, refer to directions, with “forward” referring to the front or compressor end of the engine, and “aft” referring to the rearward or turbine end of the engine. 
     It is often required to describe parts that are disposed at differing radial positions with regard to a center axis. The term “radial” refers to movement or position perpendicular to an axis. For example, if a first component resides closer to the axis than a second component, it will be stated herein that the first component is “radially inward” or “inboard” of the second component. If, on the other hand, the first component resides further from the axis than the second component, it may be stated herein that the first component is “radially outward” or “outboard” of the second component. The term “axial” refers to movement or position parallel to an axis. Finally, the term “circumferential” refers to movement or position around an axis. It will be appreciated that such terms may be applied in relation to the center axis of the turbine. 
     In addition, several descriptive terms may be used regularly herein, as described below. 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 terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. “Optional” or “optionally” means that the subsequently described event or circumstance may or may not occur, and that the description includes instances where the event occurs and instances where it does not. 
     Where an element or layer is referred to as being “on,” “engaged to,” “connected to” or “coupled to” another element or layer, it may be directly on, engaged, connected, or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
     As indicated above, the disclosure provides methods for coating components. In particular, the present disclosure is directed to coating methods for selectively coating a component that includes apertures, and a coated component that includes apertures formed by coating methods. 
     Referring to  FIG. 1 , in one embodiment, a component  100  includes any suitable component having at least one aperture  109  formed therein. In another embodiment, component  100  includes any suitable component used in applications that undergo temperature changes, such as, but not limited to, power generation systems (e.g., gas turbines, jet turbines, and other turbine assemblies). Suitable illustrative components  100  include, but are not limited to: a nozzle, a blade, a vane, a shroud, a bucket, a transition piece, a liner, or a combination thereof. Aperture  109  includes any opening formed in an external surface  102  of component  100 , such as, but not limited to: a cooling hole (e.g., a trench cooling hole, a diffuser shape cooling hole, a straight cooling hole, an angled cooling hole), an opening to provide fuel flow, or a combination thereof, and other cooling hole configurations now known or hereinafter developed. 
     For example, as shown in  FIG. 1 , component  100  is illustratively shown as a turbine blade having an airfoil section  103 , a platform section  105 , and a dovetail section  107 . Airfoil section  103  has a plurality of apertures  109  functioning as cooling holes formed therein. 
     In one embodiment, component  100  is fabricated from a high temperature oxidation and corrosion resistant alloy with high temperature strength, such as a nickel-based, cobalt-based, or iron-based superalloy. In another embodiment, component  100  includes a coating  400  ( FIG. 4 ) applied over an external surface  102  of the component. Coating  400  can include any suitable coating covering at least a portion of external surface  102  and/or providing protection (e.g., increased heat tolerance, increased corrosion resistance) to external surface  102 , such as, but not limited to, a bond coat, a thermal barrier coating (TBC), an environmental barrier coating (EBC), or a combination thereof, or other coatings now known or hereinafter developed. Suitable examples of the bond coat include, but are not limited to: MCrAlX coatings, where M is cobalt, nickel, iron, or combinations thereof, X is an active element, such as yttrium (Y) and/or silicon (Si) and/or at least one rare earth element or hafnium (Hf). Suitable examples of the TBC include, but are not limited to, ceramic coatings such as zirconium oxide (ZrO 2 ), the crystalline structure of which may be partially or completely stabilized by adding yttrium oxide (Y 2 O 3 ), aluminum-oxide, zirconium-oxide, hafnium-oxide, yttria-stabilized zirconium-oxide, metallic material, silicon based materials, graphite, aluminum oxide, yttria-stabilized zirconia, and combinations thereof or other coatings now known or hereinafter developed. In general, an EBC system includes of two or more layers (for example, a bond coat and/or a thermal barrier coat) of coating materials often rare earth or yttrium silicates, in which each layer serves a specific purpose. Thus, this disclosure will focus on application of a layer, as an EBC may contain layers (so addressing a layer will address a plurality of layers in an EBC) t. 
     Referring to  FIGS. 2-5 , in one embodiment, a first coating method  200  includes providing component  100  (step  201 ) having aperture  109  formed in external surface  102  thereof, then additively manufacturing/printing at least one hollow member  300  (step  203 ) ( FIG. 3 ) on a portion of external surface  102  at aperture  109  to define a space  309  ( FIG. 4 ) above aperture  109 . After hollow member  300  is printed (step  203 ), at least one coating is applied (step  205 ) over external surface  102  of component  100  and around hollow member  300  to form a layer of coating  400  ( FIG. 4 ) having an applied coating thickness  403  ( FIG. 3 ). 
     Once coating  400  has been formed, a portion of hollow member  300  is removed (step  207 ) to expose space  309  through coating  400  to aperture  109 . Alternatively, if desired and to reduce the overall thickness of coating  400 , portion of coating  400  can be removed with removal of a portion of hollow member  300  (step  207 ), thus exposing space  309  through coating  400  to aperture  109  with the reduced coating thickness  410 . 
     In one embodiment, hollow member  300  includes a geometry complementary to aperture  109 . Suitable complementary geometries for aperture  109  and hollow member  300  include, but are not limited to, tubular, semi-spherical, square, rectangular, cylindrical, elliptical, hour-glass, chevron, any other complementary geometry capable of extending from external surface  102  at aperture  109  (e.g., in a planar or non-planar manner), or combinations thereof. For example, in one embodiment, the geometry of hollow member  300  is complementary to a diffuser-shaped cooling hole. 
     Hollow member  300  is printed on external surface  102  of component  100  with any suitable height for forming a space  309  coextensive with coating  400  after step  207 . Walls of space  309  are formed by the inner walls of hollow member  300 , which are essentially collinearly equal to walls of apertures  109 . 
     For example, hollow member  300  is printed on component  100  external surface  102  around an aperture  109  to extend away from external surface  102  of component  100  with a height greater than or equal to applied coating thickness  403  (see  FIG. 3  or  FIG. 5 ). Suitable coating thickness  403  heights include, but are not limited to, up to about 2.5 millimeters (0.1 inch). 
     In another aspect, inner perimeter  310  and geometry of hollow member  300  are aligned, equal to, and complementary to an outer perimeter  111  and geometry of aperture  109 . This configuration puts aperture  109  and hollow member  300  coaxial with each other. The configuration also permits a smooth linear transition from aperture  109  to hollow member  300 , essentially forming a coplanar transitional inner surface from aperture  109  to hollow member  300 . 
     Hollow member  300  is formed by any suitable 3-D printing process, printing process, or additive manufacturing processes (hereinafter collectively “additive manufacturing processes”), such as, but not limited to, a wide variety of processes of producing a component through the successive layering of material rather than the removal of material. As such, additive manufacturing can create complex geometries for hollow member  300  without the use of any sort of tools, molds, or fixtures, and with little or no waste material. Instead of machining hollow member  300  from solid billets of material, much of which is cut away and discarded, the only material used in additive manufacturing is what is required to print hollow member  300 . 
     Additive manufacturing techniques typically include taking a three-dimensional computer aided design (CAD) file of the component to be formed (here hollow member  300  on a build platform formed by external surface  102  of component  100 ), electronically slicing the component into layers, e.g., 18-102 micrometers thick, and creating a file with a two-dimensional image of each layer, including vectors, images, or coordinates. The file may then be loaded into a preparation software system that interprets the file such that hollow member  300  can be built by different types of additive manufacturing systems. In 3D printing, rapid prototyping (RP), and direct digital manufacturing (DDM) forms of additive manufacturing, material layers are selectively dispensed, sintered, formed, deposited, etc., to create the hollow member  300 . 
     In powder additive manufacturing techniques, such as direct metal laser melting (DMLM) (also referred to as selective laser melting (SLM)), powder layers are sequentially melted together to form the component. More specifically, fine powder layers are sequentially melted after being uniformly distributed using an applicator on a powder bed. Each applicator includes an applicator element in the form of a lip, brush, blade, or roller made of metal, plastic, ceramic, carbon fibers or rubber that spreads the powder evenly over the build platform. The powder bed can be moved in a vertical axis. The process takes place in a processing chamber having a precisely controlled atmosphere. Once each layer is created, each two-dimensional slice of the component geometry can be fused by selectively melting the powder. The melting may be performed by a high powered melting beam, such as but not limited to, a 100 Watt ytterbium laser, to fully weld (melt) the metal powder to form a solid. The melting beam moves in the X-Y direction using scanning mirrors and has an intensity sufficient to fully weld (melt) the powder to form a solid. The powder bed may be lowered for each subsequent two-dimensional layer, and the process repeats until the component is completely formed. 
     Referring again to  FIGS. 2-5 , after printing/additively manufacturing hollow member  300  (step  203 ), at least one coating  400  is applied (step  205 ) over external surface  102  of component  100  by any suitable application method for forming coating  400  with applied coating thickness  403 . Suitable application methods include, but are not limited to air plasma spray, high velocity oxygen fuel (HVOF) thermal spray, or electron beam physical vapor deposition or other application method now know or hereinafter developed. During the application (step  205 ) of the at least one coating, orientation and geometry of hollow member  300  with respect to the coating being applied (as described hereinafter) reduces or eliminates deposition of coating  400  material in any portion of hollow member  300  (e.g., aperture  109  and space  309  (see  FIG. 4 )). 
     Once coating(s)  400  has been applied (step  205 ), upper portion  301  of hollow member  300  may be removed (Step  207 ). Moreover, as noted herein, a portion of coating  400  can be optionally removed by any suitable removal method to provide the desired coating thickness  403 , if applied coating  400  (Step  205 ) is too thick. Thus, top surface  410  ( FIG. 5 ) of coating  400  will be coplanar with the remaining portions of hollow member  300 , after removal. Suitable removal methods include, but are not limited to machining, sanding, grit-blasting etching, polishing, or a combination thereof. For example, in one embodiment, the coating removal includes polishing coating  400  with a diamond pad. 
     In one aspect of the disclosure, upper portion  301  ( FIG. 4 ) of hollow member  300  includes an upper geometry that differs from a lower geometry of lower portion  303 . For example, hollow member  350  in  FIG. 4  includes a rectangular printed upper section, which is merely illustrative and not intended to limit the embodiments of the disclosure in any manner. This different upper geometry may be such that hollow member  300 , if open at the end remote from aperture  109  (see hollow member  320  in  FIG. 4  with open end  321 ) is configured to exclude coating  400  from entering hollow member  300 . With printing/additively manufacturing the hollow member  300 , upper portion  301  can be closed (see hollow member  330  in  FIG. 4 ), or open to a degree resisting entry of coating  400 , especially if coating  400  is sprayed. 
     Furthermore, as discussed herein, lower portion  303  geometry may conform to the geometry of aperture  109 , and upper geometry  301  may confirm to the geometry of aperture  109  or include any other configuration or shape extending from lower portion  303 . For example, and in no way intended to limit the disclosure, hollow member  300  at lower portion  303  may include a conforming geometry to a circular aperture  109  transitioning to an ellipsoid geometry in upper portion  301  extending away from external surface  102 . 
     When upper portion  301  is removed (step  207 ) parts of upper and lower portions  301 ,  303  remain to define space  309 , as shown in  FIG. 5 . In one embodiment, the geometry of the space  309  includes, but is not limited to: cylindrical, spherical, square, rectangular, domed, oblong, trapezoidal, curved, straight, skewed, irregular, any other shape permitting flow therethrough, or a combination thereof. 
     A further aspect of the disclosure includes printing/additively manufacturing angled hollow members  500  in conjunction with angled apertures  102  (including but not limited to those used for film cooling turbine components), as illustrated in  FIGS. 6-8 . Like reference characters are used for like elements. 
     In  FIGS. 6-8 , angled hollow members  500  are printed on a portion of external surface  102  at angled aperture  109  to define a space  509  above angled aperture  109 , usually oval or ellipsoid given the intersecting aperture  109  at surface  102 . As in the above embodiments, angled hollow member  500  includes a geometry complementary to aperture  109 . Also, inner perimeter  510  and geometry of angled hollow member  500  can be equal to and complementary to an outer perimeter  111  and geometry of angled aperture  109  at surface  102 . Accordingly, angled aperture  109  and angled hollow member  500  essentially form a coplanar transitional surface from angled aperture  109  to hollow member  500 , and hollow member  500  is essentially collinear with walls of angled apertures  109 . 
     Hollow member  500  is printed on external surface  102  of component  100  with any suitable height for forming a space  509  with the to-be-applied coating  400 . Walls of space  509  are formed by the inner walls of hollow member  500 , with walls of space  509  essentially collinear to walls of apertures  109 . 
     Hollow member  500  is printed (in any suitable printing or additive manufacturing process as described above) on component  100  external surface  102  around angled aperture  109  to extend away from external surface  102  of component  100  at an angle coincident with the angle of aperture  109 . This configuration puts aperture  109  and hollow member  500  coaxial with each other. As above, hollow member  500  has a height greater than or equal to the applied coating thickness  403 . 
     After printing/additively manufacturing hollow member  500 , at least one coating  400  is applied over external surface  102  of component  100  by any suitable application method for forming coating  400  with applied coating thickness  403 . During the application of coating(s)  400 , the orientation and geometry of hollow member  500  being angled with respect to an applicator/sprayer of coating material reduces or eliminates coating material on or in aperture  109  and space  509 . When upper portion  501  is removed as in  FIG. 8 , parts of upper and lower portions  501 ,  503  remain to define space  509 . Thus, top surface of coating  410  is coplanar with the remaining portions of hollow member  500 , after removal. Moreover, if needed to achieve a desired coating thickness  403 , removal of some portion of coating(s)  400  can occur with removal of hollow member  500 . 
     With respect to a process for applying coating  400 , as discussed above, coating(s)  400  is applied over external surface  102  of component  100  by any suitable applicator/sprayer and application method for forming coating  400  with applied coating thickness  403 . One suitable application method, as noted above, is by spraying coating(s)  400 . 
     With any of the embodiments herein, a spraying coating applicator/sprayer may include a spray gun with a spray head that can be disposed at an angle with respect to apertures  109  in component  100 . An angled spray head is effective to reduce spray entering aperture  109 , as angles of aperture  109  (including those essentially orthogonal to surface  102 ) and of hollow members  300 ,  500  and may not align with the spray, thus spray should not directly enter apertures  109 . Moreover, as apertures  109  are provided with printed hollow members  300 ,  500 , angled spray heads can provide enhanced coverage between apertures  109  and hollow members  300 ,  500 . With hollow members  300 ,  500  any spray and coating(s)  400  should be kept from entering apertures  109 , which enables more efficient and effective consumption of coating without wasted spray in apertures  109  needing to be removed and scrapped. 
       FIG. 9  illustrates this aspect of the embodiments with spray gun  550  having an angled spray head  555 . Moreover, angled spray head  555  can be an adjustable angled spray head  555  to move its orientation to surface  102  between 0 degrees (orthogonal to surface  102 ) to almost 90 degrees or almost parallel to surface  102 . As is illustrated, angled spray head  555  can have a direct line of spray in-between printed hollow members, as shown for a set  500 A of hollow members, or have an offset line of spray in-between printed hollow members, as shown for a set  500 B of hollow members. One desirable angle is about 20 degrees from orthogonal, however that angle is not intended to limit the embodiments in any manner. With hollow members  300 ,  500  spray and coating are kept from entering apertures  109 , which enables more efficient and effective consumption of coating without wasted spray in apertures  109  needing to be removed and scrapped. 
     One advantage of an embodiment of the present disclosure includes maintaining original shape and dimension of apertures or cooling holes in coated components. Another advantage of an embodiment is better control of airflow for coated components. Yet another advantage is faster processing of coated components. Another advantage of an embodiment is decreased time for cleaning of cooling holes after components are coated or recoated. Yet another advantage includes significant labor savings because no drilling is required to clear cooling holes after coating. 
     Components of the present disclosure can be used in any applications that undergo temperature changes, such as, but not limited to, power generation systems which include, but are not limited to gas turbines, steam turbines, jet turbines, and other turbine assemblies. Moreover, embodiments of the present disclosure, in comparison to coating methods not using one or more of the features disclosed herein, increase coating efficiency, provide apertures through a coating without post-coating clearing, increase control of airflow for coated components, decrease coating cost, decrease coating time, decreased time for cleaning apertures after coating components, or a combination thereof. 
     The foregoing drawings show some of the processing associated according to several embodiments of this disclosure. In this regard, each drawing or block within a flow diagram of the drawings represents a process associated with embodiments of the method described. It should also be noted that in some alternative implementations, the acts noted in the drawings or blocks may occur out of the order noted in the figure or, for example, may in fact be executed substantially concurrently or in the reverse order, depending upon the act involved. Also, one of ordinary skill in the art will recognize that additional blocks that describe the processing may be added. 
     Approximating language, as used herein throughout the specification and claims, may be 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. Here and throughout the specification and claims, range limitations may be combined and/or interchanged; such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise. “Approximately” as applied to a particular value of a range applies to both end values, and unless otherwise dependent on the precision of the instrument measuring the value, may indicate +/−10% of the stated value(s). 
     The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present disclosure has been presented for purposes of illustration and description but is not intended to be exhaustive or limited to the disclosure in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the disclosure. The embodiment was chosen and described in order to best explain the principles of the disclosure and the practical application, and to enable others of ordinary skill in the art to understand the disclosure for various embodiments with various modifications as are suited to the particular use contemplated.