# US 12,110,799 B2 · Abradable coating > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,110,799 B2 - Document ID: US12110799B2 - Status: Granted - Kind: B2 - Application number: 17/904,264 - Filed: 2021-02-15 - Published: 2023-03-23 - Granted: 2024-10-08 - Earliest claimed: 2020-02-25 - Assignees: Safran Aircraft Engines - Applicants: Safran Aircraft Engines - Inventors: Guillaume Fradet; Laurent Paul Dudon; Serge Georges Vladimir Selezneff - Web page: https://patentgrep.com/patent/US12110799B2 ## CPC - F01D 11/122: {with erodable or abradable material (blades having cutting or grinding tips F01D5/20)} - C23C 4/04: characterised by the coating material - F01D 5/288: {Protective coatings for blades} - F01D 11/125: {with a reinforcing structure} - C23C 4/129: Flame spraying - F05D 2230/90: Coating; Surface treatment - F05D 2300/43: Synthetic polymers, e.g. plastics; Rubber - F05D 2300/506: Hardness - F05D 2300/514: Porosity - F05D 2300/611: Coating - Y02T 50/60: Efficient propulsion technologies, e.g. for aircraft - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - C23C: COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL (making metal-coated products by extrusion B21C23/22; covering with metal by connecting pre-existing layers to articles, see the relevant places, e.g. B21D39/00, B23K; metallising of glass C03C; metallising mortars, concrete, artificial stone, ceramics or natural stone C04B41/00; enamelling of, or applying a vitreous layer to, metals C23D; treating metal surfaces or coating of metals by electrolysis or electrophoresis C25D; single-crystal film growth C30B; by metallising textiles D06M11/83; decorating textiles by locally metallising D06Q1/04) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract The invention relates to an abradable coating for a turbomachine, comprising a mineral compound having a Mohs hardness of 6 or less and a melting temperature of more than 450° C. or even 800° C., and a polymeric compound with a content of between 40% and 70% by volume. ## Claims ### Claim 1 An abradable coating for a turbomachine, comprising: a mineral compound, the Mohs hardness of which is less than or equal to 6 and the melting temperature of which is greater than 450° C., and a polymeric compound, with a content of between 40% and 70% by volume of the abradable coating, wherein the mineral compound is selected from: calcium fluoride, hydroxyapatite, lanthanum phosphate, diatomite, muscovite or barium sulfate, and wherein the porosity is less than 5%. ### Claim 2 (depends on 1) The abradable coating according to claim 1, wherein the polymeric compound is a polyester or a projectable polymer. ### Claim 3 (depends on 1) The abradable coating according to claim 1, wherein the mineral compound is hydroxyapatite and the polymeric compound is polyester. ### Claim 4 (depends on 1) The abradable coating according to claim 1, wherein the coating is insoluble in water and acetone. ### Claim 5 (depends on 1) A turbomachine module, comprising: a rotor provided with a plurality of moving vanes, a stator, and at least one abradable coating according to claim 1 provided at an interface between a portion of the rotor and a portion of the stator. ### Claim 6 (depends on 5) The module according to claim 5, comprising at least one underlayer with a roughness Ra between 9 μm and 40 μm on the portion of the rotor and on the portion of the stator, under the abradable coating. ### Claim 7 (depends on 6) The module according to claim 6, wherein the roughness underlayer is located between the portion of the stator and the abradable coating. ### Claim 8 (depends on 6) The module according to claim 6, wherein the roughness underlayer is composed of a Nickel-Aluminum alloy or a Nickel-Chromium-Aluminum alloy. ### Claim 9 (depends on 5) An aircraft turbomachine comprising a module according to claim 5. ### Claim 10 (depends on 1) A method of making the abradable coating according to claim 1, comprising the steps of: mixing a powder of the mineral compound and a powder of the polymeric compound, forming the abradable coating from said powder mixture, applying the abradable coating to an interface between a portion of a rotor having a plurality of moving vanes and a portion of a stator of a turbomachine module. ### Claim 11 (depends on 10) The method of claim 10, wherein the formation of the abradable coating is performed by single or double injection thermal spraying, extrusion, or hot molding. ### Claim 12 (depends on 10) The method of claim 10, wherein the application of the abradable coating is performed by bonding with an adhesive film or by direct injection between the portion of the rotor and the portion of the stator. ### Claim 13 (depends on 10) The method according to claim 10, wherein a roughness underlayer is deposited on the stator portion by plasma spraying in the area, wherein said underlayer has a roughness Ra of 10 μm and said underlayer is composed of a Nickel-Aluminum alloy or a Nickel-Chromium-Aluminum alloy. ### Claim 14 (depends on 10) The method of claim 10, wherein a roughness underlayer is deposited on the stator portion by arc-wire spraying, said underlayer has a roughness Ra of 40 μm and said underlayer is composed of a Nickel-Aluminum alloy or a Nickel-Chromium-Aluminum alloy. ### Claim 15 (depends on 1) The abradable coating according to claim 1, wherein the mineral compound has a content of between 30% and 60% by volume of the abradable coating. ### Claim 16 (depends on 1) The abradable coating according to claim 1, wherein the polymeric compound is a liquid crystal polyester. ### Claim 17 An abradable coating for a turbomachine, comprising: a mineral compound, the Mohs hardness of which is less than or equal to 6 and the melting temperature of which is greater than 450° C., and a polymeric compound, with a content of between 40% and 70% by volume of the abradable coating, wherein the mineral compound is selected from: calcium fluoride, hydroxyapatite, lanthanum phosphate, diatomite, muscovite or barium sulfate, wherein the mineral compound is hydroxyapatite and the polymeric compound is polyester. ### Claim 18 An abradable coating for a turbomachine, comprising: a mineral compound, the Mohs hardness of which is less than or equal to 6 and the melting temperature of which is greater than 450° C., and a polymeric compound, with a content of between 40% and 70% by volume of the abradable coating, wherein the mineral compound is selected from: calcium fluoride, hydroxyapatite, lanthanum phosphate, diatomite, muscovite or barium sulfate, wherein the coating is insoluble in water and acetone. ### Claim 19 (depends on 17) A turbomachine module, comprising: a rotor provided with a plurality of moving vanes, a stator, and at least one abradable coating according to claim 17 provided at the interface between a portion of the rotor and a portion of the stator. ### Claim 20 (depends on 18) A turbomachine module, comprising: a rotor provided with a plurality of moving vanes, a stator, and at least one abradable coating according to claim 18 provided at the interface between a portion of the rotor and a portion of the stator. ### Claim 21 (depends on 19) An aircraft turbomachine comprising a module according to claim 19. ### Claim 22 (depends on 20) An aircraft turbomachine comprising a module according to claim 20. ### Claim 23 A turbomachine module, comprising: a rotor provided with a plurality of moving vanes, a stator, and at least one abradable coating provided at the interface between a portion of the rotor and a portion of the stator, said at least one abradable coating comprising: a mineral compound, the Mohs hardness of which is less than or equal to 6 and the melting temperature of which is greater than 450° C., and a polymeric compound, with a content of between 40% and 70% by volume of the abradable coating, wherein the mineral compound is selected from: calcium fluoride, hydroxyapatite, lanthanum phosphate, diatomite, muscovite or barium sulfate, wherein the turbomachine module comprising at least one underlayer with a roughness Ra between 9 μm and 40 μm on the portion of the rotor and on the portion of the stator, under the abradable coating. ### Claim 24 (depends on 23) An aircraft turbomachine comprising a module according to claim 23.