DETAILED DESCRIPTION OF THE INVENTION (US 9,849,510)
Provided are an article and a method of forming an article. Embodiments of the present disclosure, for example, in comparison to concepts failing to include one or more of the features disclosed herein, increase cooling hole surface area, increase a heat transfer coefficient of a cooling hole, increase cooling hole heat transfer, increase manufacturing efficiency, increase cooling hole uniformity, increase cooling hole surface area, provide substantially symmetrical cooling holes from additive manufacturing, increase control of cooling hole geometry during vertical builds using additive manufacturing, decrease cooling hole machining after formation, decrease material waste, or a combination thereof.
When introducing elements of various embodiments of the present invention, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of the elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.
Systems used to generate power include, but are not limited to, gas turbines, steam turbines, and other turbine assemblies such as land based aero-derivatives used for power generation. In certain applications, the power generation systems, including the turbomachinery therein (e.g., turbines, compressors, and pumps) and other machinery may include articles that are exposed to heavy wear conditions. For example, the articles may include certain power generation system components, such as blades, buckets, casings, rotor wheels, shafts, shrouds, nozzles, and so forth, may operate in high heat and high revolution environments. These components may include apertures, openings, and/or hollow spaces that form cooling holes therein. The present disclosure provides methods to form these articles and the cooling holes therein.
Referring to FIGS. 1-3, in one embodiment, a method 100 for forming an article 200 includes an additive method. Additive methods include any manufacturing method for making and/or forming net or near-net shape structures. As used herein, the phrase "near-net" refers to a structure, such as the article 200, being formed with a geometry and size very similar to the final geometry and size of the structure, requiring little or no machining and processing after the additive method. As used herein, the phrase "net" refers to the structure being formed with a geometry and size requiring no machining and processing. The structure formed by the additive manufacturing method includes any suitable geometry, such as, but not limited to, square, rectangular, triangular, circular, semi-circular, oval, trapezoidal, octagonal, pyramidal, geometrical shapes having features formed therein, any other geometrical shape, or a combination thereof. For example, the additive method may include forming cooling features, such as one or more apertures, openings, hollow spaces, or other cooling holes, in the article 200.
Suitable additive manufacturing methods include, but are not limited to, the processes known to those of ordinary skill in the art as Direct Metal Laser Melting (DMLM), Direct Metal Laser Sintering (DMLS), Laser Engineered Net Shaping (LENS), Selective Laser Sintering (SLS), Selective Laser Melting (SLM), Electron Beam Melting (EBM), Fused Deposition Modeling (FDM), or a combination thereof.