# US 10,865,644 B2 · Aircraft engine rotor repaired with microstructural enhancement > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,865,644 B2 - Document ID: US10865644B2 - Status: Granted - Kind: B2 - Application number: 15/467,173 - Filed: 2017-03-23 - Published: 2017-10-19 - Granted: 2020-12-15 - Earliest claimed: 2011-02-16 - Assignees: Keystone Synergistic Enterprises, Inc. - Applicants: Keystone Synergistic Enterprises, Inc. - Inventors: Bryant Walker; Raymond Walker - Web page: https://patentgrep.com/patent/US10865644B2 ## CPC - F01D 5/005: {Repairing methods or devices} - B23K 15/0006: {specially adapted for particular articles or work} - B23K 15/0093: {characterised by the properties of the materials to be welded} - B23K 26/0006: {taking account of the properties of the material involved (B23K26/32, B23K26/40 take precedence)} - B23K 26/20: Bonding (soldering by means of radiant energy B23K1/005) - B23K 26/21: by welding - B23P 6/005: {using only replacement pieces of a particular form} - F01D 5/147: {Construction, i.e. structural features, e.g. of weight-saving hollow blades (F01D5/148, F01D5/16 and F01D5/20 take precedence; blade shape F01D5/141; blades with cooling or heating channels or cavities F01D5/18; heating, heat-insulating or cooling means on blades F01D5/18)} - F02K 9/52: Injectors - F02K 9/58: Propellant feed valves - F02K 9/62: Combustion or thrust chambers - B23K 2101/001: {Turbines} - F05D 2250/41: with one degree of freedom - Y10T 29/49318: Repairing or disassembling - F01D: NON-POSITIVE DISPLACEMENT MACHINES OR ENGINES, e.g. STEAM TURBINES (machines or engines for liquids F03; non-positive displacement pumps F04D) - B23K: SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM - B23P: METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS (arrangements for copying or controlling B23Q) - F02K: JET-PROPULSION PLANTS (features of jet-propulsion plants common to gas-turbine plants, air intakes or fuel supply control of air-breathing jet-propulsion plants F02C7/00, F02C9/00) - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract A rotor for use in an aircraft engine, that has been repaired by (a) welding together a first portion of a damaged blade of the rotor and a second portion of metal to form a weld nugget, (b) compressively stressing the weld nugget throughout its volume, and (c) heat treating the compressively stressed weld nugget to recrystallize metal therein. ## Claims ### Claim 1 A rotor for use in an aircraft engine, that has been repaired by: welding together a first portion of a damaged blade of the rotor and a second portion of metal to form a weld nugget; locally compressively stressing the weld nugget throughout its volume, said locally compressively stressing comprising indenting the weld nugget with a series of overlapping indentations; and locally heat treating the compressively stressed weld nugget to recrystallize metal therein. ### Claim 2 (depends on 1) The rotor of claim 1, after said locally heat treating, the weld nugget having same grain size as the first portion, prior to damage, and the second portion. ### Claim 3 (depends on 1) The rotor of claim 1, after said locally heat treating, grain size of the weld nugget differing by no more than three ASTM-112 grain sizes from grain size of either one of the first portion and the second portion. ### Claim 4 (depends on 1) The rotor of claim 1, after said locally heat treating, grain size of the weld nugget differing by no more than one ASTM-112 grain size from grain size of either one of the first portion and the second portion. ### Claim 5 (depends on 1) The rotor of claim 1, the first portion and the second portion being formed of the same alloy. ### Claim 6 (depends on 1) The rotor of claim 1, the first portion and the second portion being formed of a nickel-based alloy. ### Claim 7 (depends on 6) The rotor of claim 6, having further been repaired by before said welding, preheating a preheat zone that includes overlap sections of each of the first portion and the second portion, to a preheat temperature substantially close to one of a gamma prime solvus temperature and a gamma double prime solvus temperature of the nickel-based alloy forming the first portion and the second portion; performing said welding while the preheat zone remains substantially at the preheat temperature; and forging the preheat zone during said locally compressively stressing. ### Claim 8 (depends on 7) The rotor of claim 7, having further been repaired by performing said welding with equipment also utilized for said preheating, and wherein the equipment performs the welding within 10 seconds of discontinuing the preheating. ### Claim 9 (depends on 8) The rotor of claim 8, having further been repaired by performing said welding with equipment also utilized for said preheating, and wherein the equipment performs the welding within one second of discontinuing the preheating. ### Claim 10 (depends on 7) The rotor of claim 7, having further been repaired by performing said welding while maintaining the preheat zone at the preheat temperature. ### Claim 11 (depends on 7) The rotor of claim 7, said preheating comprising heating the preheat zone to a temperature within a range of 300 degrees Fahrenheit below the one of the gamma prime and the gamma double prime solvus temperatures, to the respective gamma prime or gamma double prime solvus temperature. ### Claim 12 (depends on 11) The rotor of claim 11, said preheating comprising heating the preheat zone to a temperature within a range of 150 degrees Fahrenheit below the one of the gamma prime and the gamma double prime solvus temperature, to the respective gamma prime or gamma double prime solvus temperature. ### Claim 13 (depends on 7) The rotor of claim 7, having further been repaired by cooling the preheat zone in a controlled manner after said welding. ### Claim 14 (depends on 13) The rotor of claim 13, said cooling comprising lowering a temperature of the preheat zone at a rate of 500 degrees Fahrenheit, or less, per minute. ### Claim 15 (depends on 1) The rotor of claim 1, the first portion and the second portion being formed of a titanium-based alloy. ### Claim 16 (depends on 1) The rotor of claim 1, said locally compressively stressing further comprising indenting a heat affected zone adjacent to the weld nugget with a series of overlapping indentations. ### Claim 17 (depends on 16) The rotor of claim 16, said locally compressively stressing comprising forming each of the overlapping indentations with a primary dimension such that each of the indentations overlaps an adjacent one of the indentations by 10% to 50% of the primary dimension. ### Claim 18 (depends on 1) The rotor of claim 1, further having been repaired by locally compressively stressing the weld nugget subsequent to said locally heat treating. ### Claim 19 (depends on 18) The rotor of claim 18, further having been repaired by locally compressively stressing a heat affected zone adjacent to the weld nugget subsequent to said locally heat treating. ### Claim 20 (depends on 1) The rotor of claim 1, further having been repaired by overlapping the first portion with a flange of the second portion. ### Claim 21 (depends on 20) The rotor of claim 20, said welding comprising utilizing either an electron beam or a laser beam, with the flange acting as a beam stop. ### Claim 22 (depends on 1) The rotor of claim 1, said welding comprising generating an as-welded structure having at least one dimension that exceeds a desired dimension of a corresponding portion of a finished metal part. ### Claim 23 (depends on 1) The rotor of claim 1, said locally heat treating comprising heating the weld nugget to a temperature sufficient to recrystallize metal thereof. ### Claim 24 (depends on 1) The rotor of claim 1, said locally heat treating comprising heating the weld nugget to a temperature that, in combination with the compressively stressing, is sufficient to recrystallize metal thereof to a parent metal metallurgical state of the first portion and the second portion. ### Claim 25 (depends on 1) The rotor of claim 1, further having been repaired by maintaining a substantially constant force on the first portion and the second portion, to keep the first portion in intimate contact with the second portion during said welding, while allowing for thermal expansion of at least one of the first portion and the second portion. ### Claim 26 (depends on 1) The rotor of claim 1, after said locally heat treating, fatigue properties of the compressively stressed weld nugget matching parent metal fatigue properties.