Patent application EP19212598A (EP), filed 2019-11-29
Publication number: EP3756794A1
Title: METHOD OF MAKING A RADIAL TURBINE WHEEL USING ADDITIVE MANUFACTURING
Abstract: Disclosed is a method of making a part, comprising: forming the part via an additive manufacturing process, wherein the additive manufacturing process comprises layering, melting, and solidifying a metal alloy based on a three dimensional numerical model, wherein the formed part comprises a microstructure, wherein the microstructure comprises an average columnar grain length; and heat treating the formed part, wherein heat treating comprises heating to between 750°C and 1200°C for a time between 0.5 hours and 10 hours and then cooling the formed part below 750°C, wherein after heat treating, the formed part has an average columnar grain length of about 400 micrometers to about 1000 micrometers, as measured using electron backscattered diffraction.
IPC codes: B22F   3/   105            A I
B22F   3/    24            A I
B22F   5/    00            A I
B22F   5/    04            A I
B23K  26/   342            A I
B33Y  10/    00            A I
B33Y  80/    00            A I
C22C   1/    04            A I
C22F   1/    10            A I
F01D   5/    00            A I
Claims: number: 1
text: A method of making a part, comprising:
number: 2
text: The method of Claim 1, wherein the additive manufacturing process includes laser beam melting, electron beam melting, laser metal deposition, electron beam metal deposition, or a combination thereof.
number: 3
text: The method of Claims 1 or 2, wherein the metal alloy comprises nickel alloy, and preferably wherein the nickel alloy comprises Haynes 282, Inconel 625, Inconel 713, Inconel 718, Inconel 738, Inconel 792, or a combination comprising at least one of the foregoing.
number: 4
text: The method of any preceding Claim, wherein the formed part is a radial turbine wheel.
number: 5
text: The method of any preceding Claim, wherein the heat treating is repeated for two or more cycles.
number: 6
text: The method of any preceding Claim, wherein after heat treating, the formed part has an average columnar grain width of about 100 micrometers to about 400 micrometers, as measured using electron backscattered diffraction.
number: 7
text: The method of any preceding Claim, wherein a ratio of creep rupture life of the formed part in hours of operation before failure, to fatigue cycle life of the formed part in start to stop cycles of operation before failure, is about 1:1.
number: 8
text: The method of any preceding Claim, wherein the method does not comprise casting of the metal alloy or wrought manufacturing of the metal alloy.
number: 9
text: The method of any preceding Claim, wherein the formed part is an additional portion of an already existing structure.
number: 10
text: The method of any preceding Claim, wherein the microstructure is oriented toward a stress direction of the formed part, and preferably wherein the microstructure is oriented in a direction radially outward from a center of the formed part, in a direction of rotation of the formed part, or a combination thereof.
number: 11
text: The method of any preceding Claim, wherein the heat treating increases the average grain width of the formed part by greater than or equal to about 300%, as compared to the formed part prior to the heat treating; and/or
wherein the metal alloy is in powder form, wire form, or a combination thereof.
number: 12
text: The method of any preceding Claim, wherein the microstructure comprises a porosity, wherein the porosity of the formed part is about 1 micrometer to about 100 micrometers, as measured using optical microscopy, electron microscopy, x-ray tomography, or a combination thereof.
number: 13
text: The method of any preceding Claim, wherein after heat treating, the formed part has an average columnar grain length of about 600 micrometers to about 800 micrometers, as measured using electron backscattered diffraction.
number: 14
text: A part formed by the method of Claim 1.
number: 15
text: The part of Claim 14, wherein the part is a radial turbine wheel, and preferably wherein the radial turbine wheel is part of a gas turbine, and more preferably wherein the gas turbine is part of an auxiliary power unit for an aircraft.
Office action: search_report, dated 2020-12-30
Rejection reasons: novelty_epc_54
inventive_step_epc_56
Prior art cited: ref_id: US2019039183A1
ref_type: patent
severity: background
ref_id: US2018002795A1
ref_type: patent
severity: background
ref_id: US9283593B2
ref_type: patent
severity: background
ref_id: WO2015108599A2
ref_type: patent
severity: background
ref_id: US2019134711A1
ref_type: patent
severity: background
ref_id: US2019047049A1
ref_type: patent
severity: background
ref_id: JP2016102257A
ref_type: patent
severity: background
ref_id: WO2015108599
ref_type: patent
severity: background
ref_id: US9283593
ref_type: patent
severity: background
ref_id: US2018002795
ref_type: patent
severity: obviousness
ref_id: US2019039183
ref_type: patent
severity: novelty_destroying
ref_id: US2019047049
ref_type: patent
severity: background
ref_id: US2019134711
ref_type: patent
severity: background
Final disposition: pending (2020-12-30)