Masking system and method of masking component

Abstract

The invention provides a masking system and a method of masking a component, the masking system for selectively masking a component, the masking system comprising a housing made of a high temperature material. The housing has a first housing and a second housing. The first housing has a first receiving area and a first window extending through the first housing. The masking system has a liner comprising an elastomeric material. The liner has a rear side configured to fit within the first receiving area and a front side having a retention feature configured to receive and retain the component. The first window corresponds to at least a contactable portion of the component when the liner is disposed within the first receiving area and the component is received by the retention feature.

Description

Technical Field

[0001] The present disclosure relates generally to the field of masking systems. More specifically, the present disclosure relates to masking systems for masking components that undergo high temperature processes. Background Art

[0002] The following presents an overview of the present invention in order to provide a basic understanding of some aspects of the present invention. This overview is not a broad overview of the present invention. It is not intended to identify key elements of the present invention or to describe the scope of the present invention. Its only purpose is to present some concepts of the present invention in a simplified form, as a preface to the more detailed description presented elsewhere herein. Summary of the invention

[0003] In one aspect of the present disclosure, a masking system for selectively masking a component includes a housing made of a high temperature material. The housing has a first shell and a second shell. The first shell has a first receiving area and a first window extending through the first shell. The masking system has a liner including an elastomeric material. The liner has a rear side configured to fit within the first receiving area and a front side having a retaining feature configured to receive and retain the component. When the liner is disposed within the first receiving area and the component is received by the retaining feature, the first window corresponds to at least a portion of the component that is accessible.

[0004] In one aspect, according to any of the preceding aspects, the second housing comprises a second receiving area and a second window extending through the second housing.

[0005] In one aspect, according to any of the preceding aspects, the liner has a first portion and a second portion spaced apart from the first portion.

[0006] In one aspect, according to any of the preceding aspects, the housing is additively manufactured.

[0007] In one aspect, according to any of the preceding aspects, the liner is additively manufactured.

[0008] In one aspect, according to any of the preceding aspects, the first housing is configured to be retained together with the second housing.

[0009] In one aspect, according to any of the preceding aspects, the first housing has a groove configured to fit within a channel of the second housing to retain the first housing to the second housing.

[0010] In one aspect, according to any of the preceding aspects, the masking system is configured for a component that is to be a gas turbine component.

[0011] In one aspect, according to any of the preceding aspects, the gas turbine component is at least one of a blade and a bucket.

[0012] In one aspect, according to any of the preceding aspects, the masking system is configured to enable a gas turbine component to be subjected to a high temperature process.

[0013] In one aspect, according to any of the preceding aspects, the high temperature process comprises HVOF coating.

[0014] In one aspect, according to any of the preceding aspects, the first window is not obstructed by the liner.

[0015] In one aspect, according to any of the preceding aspects, the retaining feature comprises a groove configured to correspond to a dovetail of the blade.

[0016] In an aspect, according to any of the preceding aspects, the first receiving area is substantially V-shaped.

[0017] In one aspect of the present disclosure, a method of masking a component includes additively manufacturing a closable housing having a first outer shell and a second outer shell using a rigid high temperature material. The first outer shell has a first receiving area and a first window. The method includes additively manufacturing a liner including an elastomeric material. The liner has a rear side configured to fit within the first receiving area and a front side having a retaining feature configured to receive the component. The method includes arranging the liner within the first receiving area and receiving the component with the retaining feature. The method includes closing the housing so that the component is secured within the housing and the first window corresponds to at least a portion of the component that is accessible.

[0018] In one aspect, according to any of the preceding aspects, the second housing has a second receiving area and a second window.

[0019] In one aspect, according to any of the preceding aspects, the method comprises HVOF coating at least a portion of the component through the first window.

[0020] In one aspect, according to any of the preceding aspects, the first housing has a frusto-cylindrical portion and a rectangular portion.

[0021] In an aspect of the present disclosure, a masking system for selectively masking a component during a high temperature process includes a closable housing made of a high temperature material and having a window. The masking system has an elastomeric liner disposed within the housing and configured to receive the component such that when the housing is closed, there is no relative movement between the housing and the component, and the window corresponds to at least a portion of the component that will be subjected to the high temperature process.

[0022] In one aspect, according to any of the preceding aspects, each of the closable shell and the resilient liner is additively manufactured.

[0023] In one aspect, according to any of the preceding aspects, the component is a gas turbine blade. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Illustrative embodiments of the present disclosure are described in detail below with reference to the accompanying drawings, and in which:

[0025] Figure 1 is a perspective view of a turbine blade.

[0026] Figure 2 yes Figure 1 An enlarged view of a portion of the serrations on the root of a turbine blade.

[0027] Figure 3 is a top view of a portion of a mask made from an elastomeric material.

[0028] Figure 4 is a top view of a portion of a shelter made from a high temperature, low elongation material.

[0029] Figure 5A is a perspective view of a masking system according to some aspects of the present disclosure.

[0030] Figure 5B yes Figure 5A Exploded view of the masking system.

[0031] Fig. 6A and Figure 6B yes Figure 5A A perspective view of the housing of the masking system.

[0032] Fig. 7A yes Figure 5A A front view of a first housing of a housing of the masking system.

[0033] Figure 7B yes Figure 5A A rear view of a first housing of a housing of the masking system.

[0034] Figure 7C yes Figure 5A A perspective view of a first housing of a housing of a masking system.

[0035] Fig. 8A yes Figure 5A A front view of a second housing of a housing of the masking system.

[0036] Figure 8B yes Figure 5A A rear view of the second housing of the housing of the masking system.

[0037] Figure 8C yes Figure 5A A perspective view of a second housing of a housing of the masking system.

[0038] Fig.9A yes Figure 5A Front view of a first portion of an inner liner of a masking system.

[0039] Fig. 9B yes Figure 5A Rear view of the first section of the inner liner of the masking system.

[0040] Fig. 9C and Fig.9D Each is a perspective view of a first shell of a housing with a first portion of a liner arranged therein.

[0041] Fig. 10A yes Figure 5A Front view of a second portion of the inner liner of the masking system.

[0042] Fig. 10B yes Figure 5A Rear view of the second section of the inner liner of the masking system.

[0043] Fig. 10C and Fig. 10D Each is a perspective view of a second outer shell of the housing, with a second part of the liner arranged therein.

[0044] Fig.11 It shows that during the high temperature process Figure 5A Schematic representation of the blades within the housing of the masking system.

[0045] Fig.12 is a flow chart illustrating a method of making and using a masking system according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0046] A gas turbine engine typically includes a multi-stage compressor coupled to a multi-stage turbine via an axial shaft. Air enters the gas turbine engine through the compressor, and its temperature and pressure increase as the air passes through the rear stage of the compressor. The compressed air is then directed to one or more combustors, where it is mixed with a fuel source to produce a combustible mixture. The mixture is ignited in the combustor to produce a stream of hot combustion gases. These gases are directed into the turbine, causing the turbine to rotate, thereby driving the compressor. The output of the gas turbine engine can be mechanical thrust via exhaust from the turbine or shaft power from the rotation of the axial shaft, where the axial shaft can drive a generator to produce electricity.

[0047] The compressor and turbine each include a plurality of rotating blades and fixed vanes with airfoils extending into the compressed air flow or hot combustion gas flow. Each blade or vane has a specific set of design criteria that must be met to provide the necessary work for the flow through the compressor and turbine. However, due to the harsh nature of the operating environment, especially in turbines, it is often necessary to cool these blades and vanes. The blades and vanes typically utilize complex internal cooling passages in order to maximize the efficiency of the cooling fluid passing therethrough.

[0048] Figure 1 A gas turbine component, such as a gas turbine blade 10, is shown. The turbine blade 10 generally includes an airfoil 12 extending from a top or gas path side surface 14 of a platform 16 and a root fixing portion or "dovetail" 18 depending from a lower surface 20 of the platform 16. The dovetail 18 may include one or more serrated protrusions or tongues 22 extending laterally from one side 23A of the dovetail 18 to an opposite side 23B of the dovetail 18. The dovetail 18 may terminate at an end or bottom wall 25 that may span between the dovetail sides 23A, 23B. The dovetail 18 (including the tongue 22 and its bottom wall 25) may be adapted for interlocking engagement in a corresponding groove defined in an outer edge of a hub of a turbine rotor. The bottom wall 25 may be part of a metering plate 35 that is brazed or otherwise secured to the dovetail 18.

[0049] The airfoil 12 may have a pressure side 26, a suction side 27 opposite to the pressure side 26, a tip 28, a leading edge 29, and a trailing edge 31. The tip 28 may include or may be configured to interact with a shroud. The shroud may be provided at the tip 28 of each blade 10 or may be a stationary ring comprising one or more circumferentially extending sections, each of which is connected to the gas turbine casing. The shroud may be configured to seal the gap between the tip 28 of the blade 10 and a fixed component (e.g., a stator) of the turbine, and thereby reduce the leakage flow between the rotating component and the fixed component. The airfoil 12, such as its pressure side 26, may be in contact with combustion gases at extremely high temperatures. The airfoil 12 or a portion thereof may therefore be coated with heat-resistant, wear-resistant, and / or other coatings. During operation, the tip 28 may rub against the tip shroud, so the tip 28 may be additionally or alternatively coated with a wear-resistant coating. In a similar manner, one or more other portions of the blade 10 may be coated with different materials, depending on the environment in which those portions are located and the stresses encountered thereby.

[0050] The bottom wall 25 of the dovetail 18 may include one or more air inlet apertures 30. In addition, one or more portions of the blade 10 may include cooling holes 32 for cooling the blade 10 during operation. The cooling holes 32 may be disposed on one or more surfaces of the airfoil 12, such as the pressure side 26, the suction side 27, the tip 28, the leading edge 29, the trailing edge 31, or a combination thereof. The cooling holes 32 may be circular cooling holes, diffused (e.g., angled) cooling holes, cooling slots, or one or more other regular or irregular shapes. The cooling gas may pass through an internal cooling passage (not shown for ease of description) in the blade 10 and out of the cooling holes 32 to form a thin film coating on the outer surface of the airfoil 12, thereby preventing direct contact of the hot gas with the surface of the blade 10. For example, the illustrated blade 10 has an air inlet aperture 30 in the bottom wall 25 of the dovetail 18 and a cooling hole 32 on the pressure side 26 of the airfoil 12. The blade 10 (including its airfoil 12) may include a hollow internal passage for cooling air to pass through, such as, but not limited to, a hollow internal passage from the air inlet aperture 30 to the cooling hole 32. Thus, cooling air may be exhausted from the compressor and directed into the air inlet aperture 30. The air may exit the cooling hole 32 to cool one or more portions of the blade 10 during operation. Those skilled in the art will appreciate that different blades may have different cooling schemes, and Figure 1 The inlet apertures 30 and cooling holes 32 in FIG. 3 are exemplary only and are not intended to be independently limiting.

[0051] Gas turbine blades, such as blade 10, may be manufactured using investment casting, also known in the art as lost wax machining. The investment casting process may involve making an accurate negative mold of the blade shape, which is filled with wax to form the blade shape. If a blade, such as blade 10, is hollow and has internal cooling passages, a ceramic core in the shape of the cooling passage may be inserted in the middle. The wax blade may be coated with a heat resistant material to make a shell, which may then be filled with the blade alloy.

[0052] Once cast, the blade 10 may undergo one or more finishing processes to prepare the blade 10 for operation. The finishing process may ensure that the blade 10 has a desired aerodynamic profile, as this may affect engine efficiency and fuel consumption. The finishing process may also make the blade 10 more fatigue-resistant and thereby increase the life of the blade 10. Some finishing processes may reduce maintenance requirements associated with the blade 10.

[0053] In some cases, one or more portions of the blade 10 may be coated using a thermal spraying technique such as air plasma spray (APS), vacuum plasma spray (VPS), low pressure plasma spray (LPPS), high velocity oxygen fuel spray (HVOF), etc. For example, HVOF may be used to coat all or part of a serration of a blade, vane, or other component. In order to spray a component using HVOF, a mixture of fluid fuel and oxygen may be fed into a combustion chamber and ignited. The resulting gas may have an extremely high temperature and pressure, which may be ejected at supersonic speeds through a nozzle. Powder may be injected into a high velocity gas stream, and the gas stream may cause partial melting of the powder. The hot gas stream and powder may be directed toward the surface to be coated. The resulting coating may be dense, have low porosity and high bond strength, and may provide corrosion resistance and other benefits.

[0054] Figure 2 Shows Figure 1 1 is an enlarged view of the serrations 22 of the dovetail 18 of the blade 10. In the example shown, each of the portion 40A of the serrations 22 on the pressure side of the dovetail 18 and the portion 40B of the serrations 22 on the suction side of the dovetail 18 will undergo a high temperature process (the portion 40B may be opposite the portion 40A and Figure 2 40B). For example, portions 40A, 40B may need to be coated using a thermal spray technique, such as HVOF or another coating technique now known or hereinafter developed. The coating on portions 40A, 40B of serrations 22 may cause portions 40A, 40B to protrude slightly relative to adjacent areas of serrations 22. Thus, the coating on portions 40A, 40B may provide material for the turbine disk to cut into, and thereby may improve retention of dovetail 18 within the turbine disk during operation of the gas turbine. The coated area of ​​blade 10 (i.e., portions 40A, 40B in the illustrated example) may each be small, for example, in some non-limiting examples, the area of ​​each of portions 40A, 40B may be less than about 0.08 m 2 . For example, each of portions 40A, 40B may be approximately 250 mm wide and approximately 300 mm high. In some examples, portions 40A, 40B may be identical, while in other examples, portion 40A may be larger or smaller than portion 40B. In some examples, only one of portions 40A, 40B may undergo a high temperature process (e.g., only one of portions 40A, 40B may be HVOF coated). The size of one or more portions of a component requiring HVOF or other coatings may vary from one component to the next.

[0055] HVOF is typically performed at extremely high temperatures. For example, the temperature of the gas during HVOF coating may reach approximately 2700° C., and the temperature of each of the coated portions 40A, 40B may reach between approximately 230° C. and approximately 370° C. Care may be taken to ensure that the thermal coating (e.g., HVOF coating) does not impact the dovetail 18 or areas of the blade 10 other than the portions 40A, 40B, since the inclusion of coatings on other areas of the blade 10 may impact the operation of the gas turbine. To ensure that the HVOF coating is limited to the portions 40A, 40B of the serrations 22, the remainder of the blade 10, or at least areas of the blade 10 adjacent to and / or near the portions 40A, 40B and any other areas that have the potential to be inadvertently coated during the HVOF coating process, may be shielded or “masked.” In the prior art, prior to HVOF coating of the portions 40A, 40B, resistant heat strips may be used to mask other areas of the blade 10 that may come in contact with the coating. The portions 40A, 40B may be coated after these areas of the blade 10 have been covered with heat resistant tape so that the portions 40A, 40B are exposed.

[0056] Although heat-resistant tape can be used to increase the likelihood that the HVOF coating is confined to portions 40A, 40B of the serrations 22, this technique is not without challenges. The tape must typically be applied manually by an operator, and given that portions 40A, 40B to be coated may be small, applying the tape to the blade 10 may take up to an hour or more, leaving only portions 40A, 40B exposed. In addition, since the tape adjacent portions 40A, 40B is removed after these portions have been coated, the tape may pull some of the coating with the tape, and thus require re-coating of portions 40A and / or portions 40B. In addition, the tape may be a consumable item (i.e., may not be used again), and the cost of the tape may be large, particularly in the case of a large number of blades being coated. It is not uncommon for manufacturers of turbine components to spend hundreds of thousands of dollars each year on high temperature shielding tape alone.

[0057] One possible alternative to using high temperature masking tape to mask the blade 10 while coating the portions 40A, 40B of the serrations 22 may be to use an elastomeric mask to selectively mask the blade 10 such that the portions 40A, 40B remain exposed. Figure 3A portion of a mask 50 manufactured using a molding process is shown. In the illustrated example, the mask 50 is made of an elastomeric material and has an opening 52. The opening 52 may be intended to correspond to the portion 40A of the blade 10, such that the portion may be coated through the opening 52 while the mask 50 covers one or more other areas of the blade 10. Using an elastomeric material to manufacture the mask 50 may ensure that the mask 50 is flexible and conforms to the surface of the blade 10 protected by the mask 50. Advantageously, due to its elastomeric construction, the mask 50 may be stretched and pulled onto the blade 10 without damaging the blade 10.

[0058] In the illustrated example, the mask 50 is made of RTV silicone (room temperature vulcanized silicone). Because the portion 40A is small (eg, having a thickness of about 0.08 m 2 About 0.04m 2 The area between the portions 40A and 40B is small, so the opening 52 corresponding to the portion 40A is also small. Figure 3 As shown, the opening 52 is not symmetrical and has a flash 54 and an irregularity 56. The flash 54 may be generated during molding when the injected material (i.e., silicone in this example) overflows outside the mold and accidentally fills a portion of the opening 52. The flash 54 and the irregularity 56 are unintended results of using conventional molding techniques to manufacture an elastomeric mask having small features (i.e., the opening 52 corresponding to the portion 40A in this example). Such irregularities and flash are typically associated with using elastomeric materials to mold parts having fine features (such as a mask 50 having a small opening 52, etc.). Due to the distortion of the shape of the opening 52, the elastomeric mask 50 is ineffective in covering the blade 10, so that only the portion 40A (or portion 40B) is exposed.

[0059] Another problem with the elastomeric mask 50 may be that elastomers (e.g., silicone) cannot withstand high temperatures for extended durations. As described above, the surface temperature of a portion coated using an HVOF process may exceed 200°C, for example, the temperature of the portion may reach between about 230°C and about 370°C. However, RTV silicone may not be able to withstand temperatures above 230°C. Therefore, even if the elastomeric mask 50 can be manufactured using conventional methods (such as molding, etc.) to include small symmetrical openings 52 that appropriately correspond to the portion 40A and / or the portion 40B, the elastomeric mask 50 may still not be used to protect those areas of the blade 10 that are not subjected to high temperature processes. The high temperatures encountered during HVOF coating may cause the mask 50 to deform and / or crack, and the coating may inadvertently contact areas of the blade 10 that are not desired to be coated.

[0060] Figure 4 A portion of the mask 60 is shown, instead of Figure 3The mask 60 comprises a silicone or other elastomeric material in the mask 50 of FIG. 5 , which comprises a high temperature, low elongation material. The mask 60 is intended to cover the blade 10 so that its portion 40A is exposed for HVOF coating. The mask 60 may be manufactured using conventional techniques (eg, molding) or may be additively manufactured.

[0061] The mask 60 has a configuration corresponding to the portion 40A ( Figure 2 ) of the opening 62, and another opening ( Figure 4 4A and 4B). The openings 62 are generally symmetrical and, unlike the openings 52 of the mask 50, appropriately correspond to the portion 40A of the blade 10 to allow coating of the portion 40A. Thus, unlike using an elastomer to manufacture the mask 50, using a high temperature, low elongation material to manufacture the mask 60 may allow for incorporation of small openings 62 in the mask 60 that precisely correspond to the portion 40A and / or the portion 40B. Furthermore, unlike the elastomeric mask 50, the high temperature, low elongation material of the mask 60 may withstand the excessive temperatures encountered during high temperature applications such as HVOF coating.

[0062] However, due to the rigidity of the low elongation material in the mask 60, the mask 60 may not be ideally suited for coating the portion 40A (or portion 40B) via HVOF coating. The blades 10, particularly in applications involving repairing blades, may not be identical to other blades 10 in the same group. For example, one blade 10 may have a different wear pattern than another blade 10 in the same group (e.g., the airfoil of one blade 10 may wear at the tip, while the airfoil of another blade 10 in the same group may additionally or alternatively wear at the leading edge). In view of even minor differences between blades 10 in the same group, the mask 60 may not allow the same portion 40A of each blade 10 to be accessed for high temperature processes due to its rigid construction. For example, a mask 60 adapted to one blade 10 to expose the portion 40A may not correspond appropriately to other blades 10 in the same group (e.g., the opening 62 of the mask 60 may not correspond to the same location on each of the different blades 10). This may be undesirable. Having a mask that is resistant to high temperatures may be beneficial, but the mask may also be used to coat the same portions 40A, 40B of blades 10 in a group, despite slight differences between the blades 10 .

[0063] Figure 5A A multi-component masking system 100 for high temperature processes according to some aspects of the present disclosure is shown. The multi-component masking system 100 may also be referred to herein as a masking system, a mask, a high temperature mask, a cover, or a jacket (hereinafter, "masking system 100"). Figure 5B An exploded view of the masking system 100 is shown.

[0064] In some aspects, the masking system 100 can have a housing 102 and a liner 162 ( Figure 5B ). The component to be coated (e.g., blade 10 or another component) may be located within masking system 100. Liner 162 may be made of a flexible material (e.g., an elastomer) and may ensure that each blade in the same group (despite minor differences between blades as discussed above) is properly secured within masking system 100 and does not move relative to masking system 100 during high temperature processes. Housing 102 may have windows (described below) through which portions of a component (e.g., portions 40A, 40B of blade 10) may be coated without affecting the remainder of the component.

[0065] Fig. 6A and Figure 6B The housing 102 is shown in more detail. In some non-limiting examples, the housing 102 may include a first shell or portion 104 and a second shell or portion 132 opposite the first shell 104. The first shell 104 and the second shell 132 may be configured to be removably fixed to each other so that the blade 10 undergoing a high temperature process is retained therein.

[0066] Fig. 7A , Figure 7B and Figure 7C A front view, a rear view, and a perspective view are respectively shown of the first housing 104 of the case 102. In some non-limiting examples, the first housing 104 can be a unitary structure.

[0067] The first housing 104 may have an outer portion 106 ( Fig. 7A ) and the inner portion 108 ( Figure 7B ). In some aspects of the present disclosure, the exterior 106 of the first housing 104 may include a first exterior 110 and a second exterior 112 extending from the first exterior 110. In some examples, the first exterior 110 may be generally truncated cylindrical and convex, and the second exterior 112 may be generally rectangular. In other examples, either of the first exterior 110 and the second exterior 112 may be spherical, polygonal, pyramidal, or take other regular or irregular shapes. The width W1 of the first exterior 110 may be greater than the width W2 of the second exterior 112 in various aspects. The second exterior 112 may be tapered so that its width W2 may decrease as the second exterior 112 extends away from the first exterior 110.

[0068] In some examples, the outer portion 106 may have a first recessed section 114. In some examples, a portion of the first recessed section 114 may be disposed on the first outer portion 110, and a portion of the first recessed section 114 may be disposed on the second outer portion 112. The first recessed section 114 may have a first opening or window 116. The first window 116 may correspond to a portion of the blade 10 to be coated, such as portion 40A (or portion 40B), etc.

[0069] Similar to the outer portion 106, the inner portion 108 may include a first inner portion 120 and a second inner portion 118. The first inner portion 120 may be opposite the first outer portion 110 and the second inner portion 118 may be opposite the second outer portion 112. The first inner portion 120 may be generally truncated cylindrical and concave. In other examples, the first inner portion 120 may be rectangular, spherical, polygonal, or take other regular or irregular shapes.

[0070] The second interior 118 may include a first receiving area or recess 121. The first receiving area 121 may be configured to receive the liner 162. In some examples, the first receiving area 121 may be generally V-shaped. In some examples, the first receiving area 121 may have a first inclined surface 123A and a second inclined surface 123B that together form a generally V-shaped first receiving area 121. The first window 116 may extend through the second inclined surface 123B. In other examples, instead of a V-shape, the first receiving area 121 may take other symmetrical or asymmetrical shapes suitable for receiving the liner 162.

[0071] In some examples, the interior 108 of the first housing 104 can include one or more features configured to allow the first housing 104 to mate (e.g., lockingly engage or retain) with the second housing 132. For example, the interior 108 can include one or more protrusions 124. As discussed herein, the protrusions 124 can be configured to mate with corresponding features of the second housing 132. In some examples, the protrusions 124 can be generally U-shaped. In other examples, the protrusions 124 can be rectangular, circular, or take other symmetrical or asymmetrical shapes.

[0072] Fig. 8A , Figure 8B and Figure 8C A front view, a rear view, and a perspective view of the second housing 132 of the housing 102 are shown, respectively. In some non-limiting examples, the second housing 132 can have a unitary structure.

[0073] Similar to the first housing 104, the second housing 132 may have an outer portion 134 ( Fig. 8A ) and the inner portion 136 ( Figure 8B). In some aspects of the present disclosure, the outer portion 134 of the second housing 132 may include a first outer portion 138 and a second outer portion 140 extending from the first outer portion 138. In some examples, the first outer portion 138 may be generally truncated cylindrical and convex, and the second outer portion 140 may be generally rectangular. In other examples, either of the first outer portion 138 and the second outer portion 140 may be spherical, polygonal, or take other regular or irregular shapes. The width W3 of the first outer portion 138 may be greater than the width W4 of the second outer portion 140 in various aspects. The second outer portion 140 may be tapered so that its width W4 decreases as the second outer portion 140 extends away from the first outer portion 138. The widths W3 and W4 of the second housing 132 may or may not be equal to the widths W1 and W2 of the first housing 104, respectively.

[0074] In some examples, the outer portion 134 may have a second recessed section 142. In some examples, the second recessed section 142 of the second outer portion 132 may generally correspond to the first recessed section 114 of the first outer portion 104. In some examples, a portion of the second recessed section 142 may be disposed on the first outer portion 138 and a portion of the second recessed section 142 may be disposed on the second outer portion 140. The second recessed section 142 may have a second opening or window 144. Similar to the first window 116 of the first outer portion 104, the second window 144 may correspond to a portion of the blade 10 to be coated, such as portion 40B (or portion 40A), etc.

[0075] The interior 136 may include a first interior 146 and a second interior 148. The first interior 146 may be generally truncated cylindrical and concave. In other examples, the first interior 146 may be rectangular, spherical, polygonal, or take other regular or irregular shapes. The first interior 146 may be opposite the first exterior 138, and the second interior 148 may be opposite the second exterior 140.

[0076] The second interior 148 may include a second receiving area or recess 150. The second receiving area 150 may also be configured to receive the liner 162. In some examples, the second receiving area 150 may be generally V-shaped. In some examples, the second receiving area 150 may have a first inclined surface 151A and a second inclined surface 151B that together form a generally V-shaped second receiving area 150. The second window 144 may extend through the second inclined surface 151B. In other examples, instead of a V-shape, the second receiving area 150 may take other symmetrical or asymmetrical shapes suitable for receiving the liner 162.

[0077] In some examples, the interior 136 of the second housing 132 can include one or more features that are configured to allow the second housing 132 to mate with (e.g., lockably engage or retain) the first housing 104. For example, the interior 136 can include one or more channels 154. The channels 154 of the second housing 132 can be configured to receive the protrusions 124 of the first housing 104 in a mating manner. In some examples, the channels 154 can be generally U-shaped. In other examples, the channels 154 can be rectangular, circular, or have other symmetrical or asymmetrical shapes.

[0078] Figure 5B The liner 162 is shown. The liner 162 may include a first portion 170 ( Fig.9A and Fig. 9B ) and the second part 180( Fig. 10A and Fig. 10B ). In some examples, such as in Figure 5B In the example shown, the first portion 170 and the second portion 180 of the liner 162 can be spaced apart. In other examples, the liner 162 can have a unitary structure, for example, the first portion 170 and the second portion 180 of the liner 162 can be formed together as part of a one-piece shell.

[0079] Fig.9A and Fig. 9B The front side 172 and the rear side 174 of the first portion 170 of the liner 162 are shown, respectively. In some examples, the rear side 174 can be generally V-shaped. Specifically, the rear side 174 can include a first inclined surface 175A and a second inclined surface 175B that together form the V-shape of the rear side 174. In other examples, the rear side 174 can take other symmetrical or asymmetrical shapes.

[0080] The rear side 174 of the first portion 170 of the liner 162 may generally correspond to the first receiving area 121 of the first shell 104. Specifically, the first inclined surface 175A of the first portion 170 of the liner 162 may generally correspond to the first inclined surface 123A of the first receiving area 121 of the first shell 104. Similarly, the second inclined surface 175B of the first portion 170 of the liner 162 may generally correspond to the second inclined surface 123B of the first receiving area 121 of the first shell 104. The first portion 170 of the liner 162 may be arranged within the first receiving area 121 of the first shell 104 such that: (a) the first inclined surface 123A of the first receiving area 121 of the first shell 104 is adjacent to and in contact with the first inclined surface 175A of the first portion 170 of the liner 162; and (b) the second inclined surface 123B of the first receiving area 121 of the first shell 104 is adjacent to and in contact with the second inclined surface 175B of the first portion 170 of the liner 162. Fig. 9C and Fig.9D Each shows a first portion 170 of a liner 162 arranged within a first receiving area 121 of a first shell 104 such that a front side 172 of the first portion 170 of the liner 162 is accessible for receiving a blade 10 to be subjected to a high temperature process.

[0081] The front side 172 of the first portion 170 of the liner 162 may include a retaining feature configured to securely retain at least a portion of the blade 10. For example, the front side 172 of the first portion 170 of the liner 162 may have a groove or other retaining feature 176. The groove 176 may be configured to generally correspond to and retain the blade 10. For example, the groove 176 may be configured to generally correspond to and retain the dovetail serrations 22 of the blade 10 that will be received within the shell 102 for coating.

[0082] The pressure side of the blade 10 to be housed in the housing 102 (e.g., its dovetail 18) may not be the same as the suction side of the blade 10. In some non-limiting examples, the groove 176 may be configured to hold the blade 10 to be coated in only one direction. For example, the front side 172 including its groove 176 may correspond to only one of the dovetail suction side and the dovetail pressure side of the blade 10. Such a configuration can ensure that the blade that will undergo a high temperature process is located in the housing 102 in only one orientation.

[0083] Fig. 10A and Fig. 10B The front side 182 and the rear side 184 of the second portion 180 of the liner 162 are shown, respectively. In some examples, the rear side 184 can be generally V-shaped. Specifically, the rear side 184 can include a first inclined surface 185A and a second inclined surface 185B, which together form the V-shaped rear side 184. In other examples, the rear side 184 can take other symmetrical or asymmetrical shapes.

[0084] The rear side 184 of the second portion 180 of the liner 162 may generally correspond to the second receiving area 150 of the second shell 132. Specifically, the first inclined surface 185A of the second portion 180 of the liner 162 may generally correspond to the first inclined surface 151A of the second receiving area 150 of the second shell 132. Similarly, the second inclined surface 185B of the second portion 180 of the liner 162 may generally correspond to the second inclined surface 151B of the second receiving area 150 of the second shell 132. The second portion 180 of the liner 162 may be arranged within the second receiving area 150 of the second shell 132 such that: (a) the first inclined surface 151A of the second receiving area 150 of the second shell 132 is adjacent to and in contact with the first inclined surface 185A of the second portion 180 of the liner 162; and (b) the second inclined surface 151B of the second receiving area 150 of the second shell 132 is adjacent to and in contact with the second inclined surface 185B of the second portion 180 of the liner 162. Fig. 10C and Fig. 10D Each shows a second portion 180 of the liner 162 disposed within the second receiving area 150 such that a front side 182 of the liner second portion 180 is accessible to receive a blade 10 (eg, blade 10 ) that will undergo a high temperature process.

[0085] The front side 182 of the liner second portion 180 may include a groove or other retaining feature 186. The groove 186 may be configured to generally correspond to and retain the blade 10 to be coated. For example, the groove 186 may be configured to generally correspond to and retain the dovetail serrations 22 of the blade 10 that will be received within the shell 102 for coating.

[0086] In some examples, the grooves 176 of the first portion 170 of the liner 162 may be configured to retain one side of the blade 10, and the grooves 186 of the second portion 180 of the liner 162 may be configured to retain the other side of the blade 10. For example, where the front side 172 of the first portion 170 of the liner 162 is configured to retain the pressure side of the dovetail 18 of the blade 10, the front side 182 of the second portion 180 of the liner 162 may be configured to retain the suction side of the dovetail 18 of the blade 10, and vice versa. The corresponding configuration of the front sides 172, 182 of the first portion 170 and the second portion 180 of the liner 162 can ensure that the blade 10 to be coated can be assembled within the shell 102 in only one orientation.

[0087] Each of the first liner portion 170 and the second liner portion 180, specifically the front sides 172, 182 thereof, may be configured to retain the blade 10. When the first liner portion 170 is located within the first shell 104, the first liner portion 170 may not block the first window 116. That is, the shape and geometry of the first liner portion 170 may be configured such that when the first liner portion 170 is disposed within the first shell 104, the first liner portion 170 does not completely or partially block the first window 116. Similarly, the shape and geometry of the second liner portion 180 may be configured such that when the second liner portion 180 is disposed within the second shell 132, the second liner portion 180 does not completely or partially block the second window 144. The liner 162 (i.e., each of the first portion 170 and the second portion 180 thereof) may help retain the blade 10 within the shell 102 for high temperature processes without being affected by high temperature processes (e.g., HVOF coating).

[0088] In an example, the first portion 170 of the liner 162 may include a notch or opening 178 ( Fig.9A and Fig. 9B ), the notch or opening 178 is adjacent to the first window 116 when the liner first portion 170 is received within the first receiving area 121 of the first shell 104. The notch 178 can be at least as large as the first window 116, and in embodiments, the notch 178 can be larger than the first window 116. The notch 178 in the first portion 170 of the liner 162 need not have a close tolerance and need not exactly correspond to the first window 116. Rather, all that is required is to make the notch 178 large enough so that the liner first portion 170 does not block the first window 116. As described above, creating fine features in the elastomeric material may result in flashing and irregularities. Because the shell 102 (rather than the liner first portion 170) is used to selectively shield the blade 10 from heat, and the liner first portion 170 is instead used to allow the blade 10 to fit securely within the shell 102, the notch 178 does not need to precisely correspond to the portion of the blade 10 that will be subjected to the high temperature process. In the same manner, the liner second portion 180 may have a notch 188 ( Fig. 10B ), the recess 188 is adjacent to the second window 144, but the recess 188 does not need to strictly correspond to the second window 144 as long as the liner second portion 180 does not block the second window 144.

[0089] In certain non-limiting examples, one or more portions of the masking system 100 or the entire masking system 100 may be additively manufactured. Additive manufacturing, also known as 3D printing, may be performed by dividing the shape of a three-dimensional object (i.e., in this example, the mask 100) into a plurality of two-dimensional cross-sections having uniform or variable thicknesses, and forming the two-dimensional cross-sections stacked one on top of the other. There are several known additive printing methods, such as material extrusion, material jetting, binder jetting, sheet lamination, vat photopolymerization, powder bed fusion, directed energy deposition (DED), and the like. Any one or more of these methods or any other additive manufacturing method now known or developed hereinafter may be used to manufacture the mask 100, including the shell 102 and its liner 162.

[0090] In some examples, each of the housing 102 (i.e., each of the first shell 104 and the second shell 132 thereof) and the liner 162 (i.e., each of the first portion 170 and the second portion 180 thereof) can be manufactured using vat photopolymerization. Vat photopolymerization, such as stereolithography, direct light processing, continuous liquid interface production, solid milling curing, etc., is a class of additive manufacturing methods that selectively cure materials (e.g., resins or other photopolymers) by targeted light-activated polymerization to produce three-dimensional objects. When exposed to certain wavelengths of light, liquid photopolymer molecules can rapidly bond together and cure into a solid state through a process called photopolymerization. The liquid photopolymer can be contained in a container or vat with a build platform partially immersed near the surface of the liquid. Using information provided by a CAD or other design file, the printer can direct the light source to selectively cure the liquid photopolymer into a solid layer. The build platform can then be re-immersed in the remaining resin, and the process can be repeated for the next layer until the housing 102 has been completely printed. The liner 162 can also be printed using vat photopolymerization or another suitable additive manufacturing technology.

[0091] In some aspects of the present disclosure, the shell 102 can be additively manufactured using a high temperature, low elongation material, and the liner 162 can be additively manufactured using an elastomeric material. The phrase "high temperature material" is defined herein to mean a material having a heat deformation temperature of at least about 300° C. The phrase "high temperature process" is defined herein to mean a process associated with a temperature of at least about 300° C., such as thermal coating (e.g., HVOF coating) or other high temperature processes.

[0092] In some examples of the present disclosure, the housing 102 may be provided using The 3D 3955 is manufactured by additive manufacturing. 3D 3955 is a halogen-free high temperature high modulus material having a Shore hardness between about 85D. In other examples, the housing 102 can be additively manufactured using, for example, resins, pellets, filaments, powders, and / or other suitable materials having a Shore hardness between about 60D and about 100D, and in some examples between about 70D and about 90D. The material used to manufacture the housing 102 can be a high temperature material and can withstand excessive temperatures encountered during HVOF coating and other high temperature processes. For example, the material used to manufacture the housing 102 and the housing 102 manufactured thereby can be able to withstand temperatures above about 500°C, above about 400°C, and / or above about 300°C. The housing 102 can be generally rigid.

[0093] In some examples of the present disclosure, the liner 162 can be additively manufactured using an elastomeric material. Additively manufacturing the liner 162 using an elastomeric material can provide one or more benefits compared to manufacturing the liner 162 using conventional techniques (e.g., molding, which requires tooling to be made before the part is manufactured and, therefore, can be more laborious and expensive than additive manufacturing). In addition, additively manufacturing the liner 162 using an elastomeric material can ensure that the liner 162 is flexible and conforms to the surface of the blade 10 being coated.

[0094] In examples of the present disclosure, the liner 162 can be additively manufactured using a silicone elastomer having a Shore durometer in a range between about 50 and about 90A. IND402 can be used for additive manufacturing of liner 162. In other examples, elastomeric three-dimensional printable polymers (e.g., resins, pellets, filaments, powders, and similar materials) providing a minimum Shore hardness of about 75A and a minimum tear strength of about 28 kN / m can be used for additive manufacturing of liner 162.

[0095] As noted, particularly in applications involving repairing blades, one blade in the group may be different from another blade in the same group, for example, due to different wear patterns of the blades. Due to its elastomeric material construction, the front side 172 of the first portion 170 of the liner 162 (including its groove 176) can be stretched and made to conform to one of the suction and pressure sides of the dovetail of a different blade in the same group, despite the differences between the blades. Similarly, the elastic construction of the front side 182 of the second portion 180 of the liner 162 can allow the second portion 180 of the liner 162 to be stretched so that it conforms to the other of the suction and pressure sides of the blade, despite the slight variations between the blades. If the rigid shell 102 alone includes features of the dovetail that are configured to closely correspond to and conform to a particular blade in a group, such that once the blade is secured within the shell 102, the blade does not move relative to the shell 102, then the shell 102, due to its rigidity, may not be able to be used to properly retain other blades in the same group. Thus, the liner 162 may allow blades with minor variations to fit within the same housing 102 due to its flexibility, such that once the blade is retained within the housing 102 , there is little or no relative movement between the blade and the housing 102 .

[0096] Once the first portion 170 of the liner 162 is disposed within the first receiving area 121 of the first shell 104 of the housing 102, and the second portion 180 of the liner 162 is disposed within the second receiving area 150 of the second shell 132 of the housing 102, the blade 10 may be positioned within the housing 102 such that one of the suction side and the pressure side of the dovetail 18 conforms to the front side of one of the first portion 170 and the second portion 180 of the liner 162, and the other of the suction side and the pressure side of the dovetail 18 conforms to the front side of the other of the first portion 170 and the second portion 180 of the liner 162. The housing 102 may then be closed. For example, the first housing 104 may be secured to the second housing 132 such that the protrusion 124 of the first housing 104 is received within the channel 154 of the second housing 132. In some examples, instead of or in addition to the protrusion 124 and the channel 154, the first housing 104 and the second housing 132 may have a ball joint or other suitable locking feature to allow the first housing 104 to be secured to the second housing 132. In some examples, once the first shell 104 and the second shell 132 are mated or otherwise in contact with each other, a zipper, fastener, or other suitable lock may be used to secure the first shell 104 to the second shell 132 so that the blade 10 remains within the shell 102 and does not move relative to the shell 102. A portion of the blade 10 may now undergo a high temperature process while another portion of the blade 10 is protected by the shell 102. For example, portions 40A, 40B of the blade 10 may be HVOF coated through the windows 116, 144 while other portions of the dovetail 18 are protected by the shell 102.

[0097] Fig.11A portion 40A of the serrations 22 of the blade 10 is shown being HVOF coated using the masking system 100. Specifically, the first portion 170 of the liner 162 may be disposed within the first receiving area 121 of the first shell 104, and the second portion 180 of the liner 162 may be disposed within the second receiving area 150 of the second shell 132. The blade 10 may then be positioned within the shell 102 such that one of the pressure side and the suction side of the dovetail 18 fits within the front side 172 of the liner first portion 170, and the other of the pressure side and the suction side of the dovetail 18 fits within the front side 182 of the liner second portion 180. The first shell 104 and the second shell 132 may now be locked or otherwise contacted to one another by the dovetail 18 secured within the shell 102 such that there is no relative movement between the blade 10 and the shell 102 of the masking system 100. Each of the portions 40A, 40B of the blade 10 to be coated can now be accessed and coated via one of the first window 116 and the second window 144. The nozzle 200 of the HVOF apparatus can be used to coat the portions 40A, 40B through the first window 116 and the second window 144, and the housing 102 of the masking system 100 can prevent other portions of the blade 10 from coming into contact with the coating. Once the coating process is complete, the housing 102 can be opened by separating the first housing 104 from the second housing 132, and the blade 10 can be removed. The same masking system 100 can then be used to coat other blades 10 in the same group.

[0098] Fig.12A flow chart illustrating a method 300 of manufacturing and using the masking system 100 to selectively mask the blade 10 during a high temperature process is shown. At step 302, the shell 102 (e.g., each of the first shell 104 and the second shell 132) can be additively manufactured using a high temperature rigid material. At step 304, the liner 162 (e.g., each of the first portion 170 and the second portion 180 of the liner 162) can be additively manufactured using an elastomeric material. At step 306, the liner 162 can be arranged in the receiving area of ​​the first shell 104 and the second shell 132. For example, the first portion 170 of the liner 162 can be arranged in the first receiving area 121 of the first shell 104, and the second portion 180 of the liner 162 can be disposed in the second receiving area 150 of the second shell 132. At step 308, the blade 10 subjected to the high temperature process can be arranged in the shell 102 so that the blade 10 is retained by the liner 162. For example, one of the suction side and the pressure side of the dovetail 18 may be retained by the groove 176 of the first portion 170 of the liner 162, and the other of the suction side and the pressure side of the dovetail 18 may be retained by the groove 186 of the second portion 180 of the liner 162. At step 310, the shell 102 may be closed so that the blade 10 within the shell 102 is fixed relative to the shell 102. For example, the protrusion 124 of the first shell 104 may cooperate with the channel 154 of the second shell, and / or the first shell 104 may be fixed to the second shell 132 using a ball lock, a zipper, or other means. At step 312, the portions 40A, 40B may be subjected to a high temperature process (e.g., may be HVOF coated) via the first window 116 and the second window 144. At step 314, once the high temperature process is completed, the shell 102 may be opened to remove the blade 10. The shell 102 may be used for high temperature processes of other blades 10.

[0099] Although the liner 162 shown in these figures includes two parts, in some examples, the liner 162 can be a unitary liner. In addition, although the present disclosure explains the use of the masking system 100 with a gas turbine blade 10 that is subject to a high temperature process, the masking system 100 can be used to selectively shield other components (e.g., other gas turbine components in the gas path or elsewhere, or components of other machines and assemblies). In addition, although the masking system 100 is shown for use with an HVOF coating process, the masking system 100 can be used to selectively mask components that are subject to any high temperature process, such as welding, brazing, coating, or any other high temperature process now known or later developed.

[0100] As discussed above, the size of one or more portions of a component requiring HVOF or other coating may vary from one component to the next. Thus, the mask 100 (including the window through which such coating is accomplished) may be configured to meet the operational requirements of a particular component.

[0101] Without departing from the spirit and scope of the present disclosure, many different arrangements of the various components depicted and components not shown are possible. The embodiments of the present disclosure have been described with illustrative, but not restrictive, intent. Alternative embodiments that do not deviate from the scope thereof will become clear to those skilled in the art. Those skilled in the art may develop alternative means for implementing the aforementioned improvements without departing from the scope of the present disclosure.

[0102] It will be understood that certain features and subcombinations are of utility and may be employed without reference to other features and subcombinations and are contemplated to be within the scope of the claims.Not all steps listed in the various figures need to be performed in the particular order described.

Claims

1. A masking system for selectively masking a component, the masking system comprising: a housing made of a high temperature material, the housing having a first shell and a second shell, the first shell having a first receiving area and a first window extending through the first shell; as well as a liner comprising an elastomeric material having a rear side configured to fit within the first receiving area and a front side having a retention feature configured to receive and retain the component; Wherein, when the liner is disposed in the first receiving area and the component is received by the retention feature, the first window corresponds to at least a portion of the component that is accessible.

2. The shielding system according to claim 1, wherein: The second housing includes a second receiving area and a second window extending through the second housing.

3. The masking system according to claim 2, wherein: The liner has a first portion and a second portion, the second portion being different from the first portion.

4. The masking system of claim 1, wherein: The housing is manufactured in an additive manner.

5. The masking system of claim 4, wherein: The liner is additively manufactured.

6. The masking system of claim 1, wherein: The first housing is configured to be retained together with the second housing.

7. The masking system of claim 6, wherein: The first housing has a groove configured to fit within the channel of the second housing to retain the first housing to the second housing.

8. The masking system of claim 1, wherein: The masking system is configured for use with the component that is to be a gas turbine component.

9. The masking system of claim 8, wherein: The gas turbine component is at least one of a blade and a bucket.

10. The masking system of claim 9, wherein: The masking system is configured to enable the gas turbine component to be subjected to a high temperature process.

11. The masking system of claim 10, wherein: The high temperature process includes HVOF coating.

12. The masking system of claim 1, wherein: The first window is not blocked by the liner.

13. The masking system of claim 1, wherein: The retention feature includes a groove configured to correspond with a dovetail of the blade.

14. The masking system of claim 1, wherein: The first receiving area is generally V-shaped.

15. A method of masking a component, the method comprising: additively manufacturing a closable housing having a first outer shell and a second outer shell using a rigid high temperature material, the first outer shell having a first receiving area and a first window; additively manufacturing a liner comprising an elastomeric material, the liner having a rear side configured to fit within a first receiving area and a front side having a retention feature configured to receive a component; placing the liner in the first receiving area; causing the retaining feature to receive the component; as well as The housing is closed so that the component is secured within the housing and the first window corresponds to at least an accessible portion of the component.

16. The method according to claim 15, wherein: The second housing has a second receiving area and a second window.

17. The method of claim 15, comprising HVOF coating the at least a portion of the component through the first window.

18. The method according to claim 15, wherein: The first housing has a frusto-cylindrical portion and a rectangular portion.

19. A masking system for selectively masking a gas turbine component during a high temperature process, the masking system comprising: A closable housing made of a high temperature material and having a window; as well as An elastomeric liner is disposed within the shell and configured to receive the component such that when the shell is closed, there is no relative movement between the shell and the component, and the window corresponds to at least a portion of the component that will undergo the high temperature process.

20. The masking system of claim 19, wherein: Each of the closable shell and the elastomeric liner is additively manufactured.

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