# US 7,744,348 B2 · Method of producing a hot gas component of a turbomachine including an embedded channel > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,744,348 B2 - Document ID: US7744348B2 - Status: Granted - Kind: B2 - Application number: 11/763,610 - Filed: 2007-06-15 - Published: 2007-11-01 - Granted: 2010-06-29 - Earliest claimed: 2004-12-24 - Assignees: ALSTOM Technology Ltd - Inventors: Cyrille Bezencon; Bernd Fehrmann; Matthias Hoebel; Maxim Konter; Wilfried Kurz; Jean-Daniel Wagnière - Web page: https://patentgrep.com/patent/US7744348B2 ## CPC - C30B 29/52: Alloys - B23P 15/02: turbine or like blades from one piece - B23P 15/04: turbine or like blades from several pieces - C30B 13/24: using electromagnetic waves - F01D 5/187: {Convection cooling} - C30B: SINGLE-CRYSTAL GROWTH (by using ultra-high pressure, e.g. for the formation of diamonds, B01J3/06); UNIDIRECTIONAL SOLIDIFICATION OF EUTECTIC MATERIAL OR UNIDIRECTIONAL DEMIXING OF EUTECTOID MATERIAL; REFINING BY ZONE-MELTING OF MATERIAL (zone-refining of metals or alloys C22B); PRODUCTION OF A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (casting of metals, casting of other substances by the same processes or devices B22D; working of plastics B29; modifying the physical structure of metals or alloys C21D, C22F); SINGLE CRYSTALS OR HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE; AFTER-TREATMENT OF SINGLE CRYSTALS OR A HOMOGENEOUS POLYCRYSTALLINE MATERIAL WITH DEFINED STRUCTURE (for producing semiconductor devices or parts thereof H10); APPARATUS THEREFOR - B23P: METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS (arrangements for copying or controlling B23Q) - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) ## Abstract A component, especially a hot gas component of a turbomachine, has at least one passage (7, 7′), especially a cooling passage, which is embedded in an outer wall (5) of the component (1) of the turbomachine and basically extends parallel to the surface (6) of the component (1). The component (1) has a basic body (8) and at least one coating (9) which is applied to the basic body on the outside, and the passage (7, 7′) on one hand is formed by a cavity which is formed in the basic body (8), and on the other hand is closed off towards the surface (6) of the component (1) by the coating (9). ## Claims ### Claim 1 A method for producing a hot gas component of a turbomachine, the component having at least one passage embedded in an outer wall of the component, the method comprising: forming at least one passage-like cavity in a basic body of the component; covering the at least one passage-like cavity by applying a coating material to the basic body; locally surface melting the basic body at least on two sides of the cavity simultaneous with said applying and with melting the coating material at least in the region of the cavities, wherein the coating material, a process temperature, and the width of the cavity are matched to each other so that the molten coating material does not penetrate into the cavity on account of surface tension; and cooling and hardening the molten coating material so that the coating material is epitaxially built up on the basic body, achieving a metallurgical connection to the basic body on the two sides of the cavity. ### Claim 2 (depends on 1) The method as claimed in claim 1, wherein said simultaneous melting of the basic body and said applying of the coating material comprises a process selected from the group consisting of plasma spraying, electron beam evaporation, lasering, and combinations thereof. ### Claim 3 (depends on 2) The method as claimed in claim 2, further comprising: feeding the coating material in the form of powder or wire. ### Claim 4 (depends on 2) The method as claimed in claim 2, wherein lasering comprises an epitaxial laser metal forming process. ### Claim 5 (depends on 1) The method as claimed in claim 1, wherein forming at least one passage-like cavity comprises a process selected from the group consisting of precision investment casting, mechanically forming, electrochemically forming, photochemically forming, laser forming, and combinations thereof. ### Claim 6 (depends on 1) The method as claimed in claim 1, wherein: a first phase of the hardening of the coating material is of the γ-type, or in the coating, a transition from the monocrystal structure to the equiaxial structure is avoided, or in the coating, the formation of new crystallization germs is avoided, or combinations thereof. ### Claim 7 (depends on 1) The method as claimed in claim 1, further comprising: smoothing the surface of the coating after said cooling and hardening by laser melting. ### Claim 8 (depends on 1) The method as claimed in claim 1, further comprising: heating the basic body before and/or during said coating, to reduce stresses which occur by the hardening and/or cooling of the coating. ### Claim 9 (depends on 1) The method as claimed in claim 1, wherein applying the coating comprises applying so that the coating contains a monocrystalline structure and/or is epitaxially connected to the basic body. ### Claim 10 (depends on 1) The method as claimed in claim 1, further comprising: additionally melting the coating material so that a monocrystal structure of the basic body is reproduced in the coating and/or a polycrystalline structure of the coating is transformed into a monocrystal structure. ### Claim 11 (depends on 1) The method as claimed in claim 1, further comprising: processing the coating after said cooling and hardening so that the coating contains a monocrystalline structure and/or is epitaxially connected to the basic body.