Patent Application
20160083829
The present invention is directed toward a coating process. More specifically, the present invention is directed to a coating process including applying more than one coating layer to a component within an enclosed coating system.
Turbine components are often run at high temperatures to provide maximum operating efficiency. However, the temperature at which a turbine can run may be limited by the temperature capabilities of the individual turbine components. In order to increase the temperature capabilities of turbine components, various methods have been developed. One method for increasing the temperature capabilities of a turbine component includes the incorporation of internal cooling holes, through which cool air is forced during turbine engine operation. As cooling air is fed from the cooler side of the component wall through a cooling hole outlet on the hot side, the rushing air assists in lowering the temperature of the hot metal surface. Additionally, the cool air may provide film cooling on the surface of the turbine component.
Another technique for increasing the temperature capabilities of a turbine component includes the application of coatings, such as a bond coat and a thermal barrier coating (TBC). Often, turbine components include both cooling holes and various coatings applied over the surface of the component. Typically, when coatings are applied over the surface of a component having cooling holes formed therein, the cooling holes are masked before coating. However, the application of multiple coatings may diminish the masking material, particularly when multiple application techniques are used. To decrease the diminishing of the masking material, it may be desirable to re-apply the masking material between the application of multiple coating layers.
Often, the masking material is applied manually. Due to the elevated temperatures during the application of the coatings, the component is typically cooled before an operator is able to safely remove the component from the coating fixture and manually apply the masking material. Cooling the component, removing the component from the coating fixture, manually applying the masking material, and re-fixturing the component before applying the next layer of coating increases coating time, increases coating cost, and decrease efficiency of the coating process.
A coating process with improvements would be desirable in the art.
In one embodiment, a coating process includes positioning a component within an enclosed coating system, the enclosed coating system including a coating apparatus, applying a first coating over at least a portion of the component, then robotically applying a mask to the component, then applying a second coating over at least the portion of the component. The component remains within the enclosed coating system throughout the coating process.
In another embodiment, a coating process includes positioning a component within an enclosed coating system, applying a first coating over at least a portion of the component with a coating apparatus; then removing a first coating head portion of the coating apparatus and replacing the first coating head portion with a masking head portion; then robotically applying a mask to the component with the coating apparatus; then removing the masking head portion of the coating apparatus and replacing the masking head portion with a second coating head portion; and then applying a second coating over at least a portion of the component with the coating apparatus; wherein the component remains within the enclosed coating system throughout the coating process.
In another embodiment, a coating process includes positioning a component within an enclosed coating system, high-velocity oxygen fuel coating at least a portion of the component with a coating apparatus, then removing a coating head portion of the coating apparatus and replacing the coating head portion with a masking head portion, then robotically applying a mask to the component with the coating apparatus, then removing the masking head portion of the coating apparatus and replacing the masking head portion with an air-plasma head portion, and then air-plasma spraying the component with the coating apparatus.
Other features and advantages of the present invention will be apparent from the following more detailed description of the preferred embodiment, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.
Wherever possible, the same reference numbers will be used throughout the drawings to represent the same parts.
Provided is a coating process. Embodiments of the present disclosure, in comparison to articles and methods not using one or more of the features disclosed herein, increase masking efficiency, increase coating efficiency, decrease or eliminate cooling of a component prior to masking, provide a removable masking head, decrease total cycle time for a coating process, provide masking within a coating cell, provides automated masking, decrease coating cost, decrease labor cost, decreases or eliminates un-fixturing and re-fixturing of components during coating, or a combination thereof.
Referring to
Referring to
The component 101 includes any suitable component for receiving a coating and/or the mask 107 thereon, such as, but not limited to, a blade or bucket, a nozzle, a shroud, a vane, a transition piece, a liner, any other turbine component, or a combination thereof. In one embodiment, the component 101 includes one or more features formed in a surface thereof, the one or more features including, but not limited to, apertures, such as cooling holes; cavities; recesses; or a combination thereof. In another embodiment, a first masking material 110 is deposited within and/or over the one or more features, prior to the applying the first coating 106 (step 204). The first masking material 110 is applied by any suitable technique, such as, but not limited to, manually, with the coating apparatus 130, prior to positioning the component 101 within the enclosed coating system 103, subsequent to positioning the component 101 within the enclosed coating system 103, or a combination thereof. In a further embodiment, the applying (step 206) of the mask 107 includes depositing a second masking material 112 within the one or more features, and/or over the first masking material 110, the second masking material 112 being the same as or different from the first masking material 110. In one example, the first masking material 110 is diminished during the applying of the first coating 106 (step 204), decreasing an amount and/or level of the first masking material 110 with the one or more features. The second masking material 112 is then deposited over the diminished first masking material 110, forming the mask 107 within and/or over the one or more features. In another example, the second masking material 112 is applied over the first masking material 110, the second masking material 112 providing increased masking during the applying of the second coating 108 (step 208).
The first masking material 110 and/or the second masking material 112 include any suitable material for decreasing or eliminating deposition of the first coating 106, the second coating 108, and/or any other coating onto and/or within an area covered by the mask 107. Suitable masking materials include, but are not limited to, radiation-curable materials; adhesives; silicon-based materials; ceramic and/or ceramic-like materials; graphite; metallic materials, such as Co—Cr—Mo; or a combination thereof. The ceramic materials and/or ceramic-like materials include, but are not limited to, aluminum oxide, zirconium oxide, hafnium oxide, yttria-stabilized zirconium oxide; derivatives of aluminum oxide, zirconium oxide, hafnium oxide, yttria-stabilized zirconium oxide; or a combination thereof. In one embodiment, the first masking material 110 and/or the second masking material 112 are selected based upon an application method of the first coating 106 and/or the second coating 108, respectively. In another embodiment, the mask 107 includes a metallic material formed outside the enclosed coating system 103. The applying (step 206) of the mask 107 formed outside the enclosed coating system 103 includes positioning the mask 107 over the component 101.
The applying of the first coating 106 (step 204) and/or the applying of the second coating 108 (step 208) includes any suitable method for applying one or more coating layers over the component 101. Suitable methods include, but are not limited to, high-velocity oxygen fuel (HVOF) spraying, air-plasma spray (APS), high-velocity air fuel (HVAF) spraying, vacuum plasma spray (VPS), electron-beam physical vapor deposition (EBPVD), chemical vapor deposition (CVD), ion plasma deposition (IPD), combustion spraying with powder or rod, cold spray, sol gel, electrophoretic deposition, tape casting, polymer derived ceramic coating, slurry coating, dip-application, vacuum-coating application, curtain-coating application, brush-application, roll-coat application, agglomeration and sintering followed by spray drying, or a combination thereof.
The first coating 106 and the second coating 108 may be applied by the same or different coating methods. In one example, the first coating 106 and the second coating 108 are applied with the first coating head portion 109, the first coating head portion 109 applying the first coating 106 (step 204) and the second coating 108 (step 208) with the HVOF spraying. In another example, the first coating 106 is applied with the first coating head portion 109 and the second coating 108 is applied with a second coating head portion 113, the first coating head portion 109 applying the first coating 106 (step 204) with the HVOF spraying, and the second coating head portion 113 applying the second coating 108 (step 208) with the APS.
The masking head portion 111 secured to the support member 133 provides the robotically applying (step 206) of the mask 107 to the component 101. In one embodiment, the masking head portion 111 includes an application device, a curing device, and/or a location device. The application device includes any suitable device for depositing the masking material over the surface of the component 101 and/or the one or more features formed therein. As illustrated in
The curing device includes any suitable device for curing the mask 107, such as, but not limited to, an ultraviolet curing device, a thermal curing device, or a combination thereof. In one embodiment, the enclosed coating system 103 is selectively devoid or substantially devoid of conditions that cure the masking material. For example, the enclosed coating system 103 may be devoid or substantially devoid of heat, ultra-violet (UV) light, infrared (IR) light, other forms of radiation that may result in undesirable curing, or a combination thereof. In another embodiment, the curing device of the masking head portion 111 selectively cures the masking material during and/or after the robotically applying (step 206) the mask 107. The selective curing of the masking material with the curing device provides increased control over a geometry of the mask 107. In a further embodiment, the selective curing of the masking material forms the mask 107 having a geometry complementary to the one or more features.
The location device includes any device for detecting the one or more features formed in the surface of the component 101, such as, for example, a laser; a structured laser scanner; an infrared detector; an electromagnetic probe; a visually-aided mechanism for location detection including, but not limited to, a camera and/or optical based metrology; or a combination thereof. In one embodiment, detecting the one or more features formed in the surface of the component 101 includes individually detecting the features with the location device. In another embodiment, detecting the one or more features includes detecting fewer than all of the features and estimating a position of the rest of the features. For example, detecting the one or more features may include obtaining location data from at least a portion of the component by detecting the features with the location device, then interpolating location data of a remainder of the component from the obtained location data. In a further embodiment, the coating apparatus 130 and/or the location device is provided with nominal positions of the one or more features, the nominal positions being provided from a component model (e.g., an original equipment manufacturer (OEM) model, a computer-aided design (CAD) model), a scan of the component 101, or a combination thereof.
Referring to
In one embodiment, as illustrated in
The applying of the first coating 106 (step 204) and/or the second coating 108 (step 208) increases a temperature of the component 101 to a temperature above ambient temperature. In one embodiment, after the applying of the first coating 106 (step 204) or the second coating 108 (step 208), the temperature of the component 101 remains above a safe handling temperature for at least about 20 minutes, at least about 30 minutes, at least about 45 minutes, at least about 30 to about 60 minutes, or any combination, sub-combination, range, or sub-range thereof. Safe handling temperatures include, but are not limited to, up to about 75° F., up to about 100° F., up to about 125° F., or any combination, sub-combination, range, or sub-range thereof. In another embodiment, the masking head portion 111 secured to the support member 133 in addition to the first coating head portion 109 and/or the second coating head portion 113 (
The applying (step 206) of the mask 107 (see
While the invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.
