WO2019014914A1 - Agencement de buse pour la fusion d'un matériau en poudre - Google Patents

Agencement de buse pour la fusion d'un matériau en poudre Download PDF

Info

Publication number
WO2019014914A1
WO2019014914A1 PCT/CN2017/093818 CN2017093818W WO2019014914A1 WO 2019014914 A1 WO2019014914 A1 WO 2019014914A1 CN 2017093818 W CN2017093818 W CN 2017093818W WO 2019014914 A1 WO2019014914 A1 WO 2019014914A1
Authority
WO
WIPO (PCT)
Prior art keywords
gas
porous portion
powdered material
power source
nozzle
Prior art date
Application number
PCT/CN2017/093818
Other languages
English (en)
Inventor
Edward Feng
Original Assignee
Linde Ag
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Linde Ag filed Critical Linde Ag
Priority to PCT/CN2017/093818 priority Critical patent/WO2019014914A1/fr
Publication of WO2019014914A1 publication Critical patent/WO2019014914A1/fr

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F10/00—Additive manufacturing of workpieces or articles from metallic powder
    • B22F10/30—Process control
    • B22F10/32—Process control of the atmosphere, e.g. composition or pressure in a building chamber
    • B22F10/322—Process control of the atmosphere, e.g. composition or pressure in a building chamber of the gas flow, e.g. rate or direction
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F10/00—Additive manufacturing of workpieces or articles from metallic powder
    • B22F10/20—Direct sintering or melting
    • B22F10/28—Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM]
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B22—CASTING; POWDER METALLURGY
    • B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
    • B22F12/00—Apparatus or devices specially adapted for additive manufacturing; Auxiliary means for additive manufacturing; Combinations of additive manufacturing apparatus or devices with other processing apparatus or devices
    • B22F12/70—Gas flow means
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • 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
    • B23K15/00—Electron-beam welding or cutting
    • B23K15/0046—Welding
    • B23K15/0086—Welding welding for purposes other than joining, e.g. built-up welding
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • 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
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/14—Working by laser beam, e.g. welding, cutting or boring using a fluid stream, e.g. a jet of gas, in conjunction with the laser beam; Nozzles therefor
    • B23K26/1462—Nozzles; Features related to nozzles
    • B23K26/1464—Supply to, or discharge from, nozzles of media, e.g. gas, powder, wire
    • B23K26/1476—Features inside the nozzle for feeding the fluid stream through the nozzle
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • 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
    • B23K26/00—Working by laser beam, e.g. welding, cutting or boring
    • B23K26/34—Laser welding for purposes other than joining
    • B23K26/342—Build-up welding
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • 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
    • B23K9/00—Arc welding or cutting
    • B23K9/04—Welding for other purposes than joining, e.g. built-up welding
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
    • 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
    • B23K9/00—Arc welding or cutting
    • B23K9/16—Arc welding or cutting making use of shielding gas
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B33—ADDITIVE MANUFACTURING TECHNOLOGY
    • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
    • B33Y10/00—Processes of additive manufacturing
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B33—ADDITIVE MANUFACTURING TECHNOLOGY
    • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
    • B33Y30/00—Apparatus for additive manufacturing; Details thereof or accessories therefor
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/25—Process efficiency

Definitions

  • the present invention relates to a nozzle for melting powdered material which comprises a path to guide a power source to a substrate plate on which the powdered material is sintered and at least one gas passage which directs a gas to the powdered material.
  • the present invention also relates to a method which is carried out by the said nozzle for sintering/melting the powdered material.
  • the application of melting powdered material relates generally to produce tooling and prototype parts which particularly uses three-dimensional printing techniques, which is also called as additive manufacture techniques.
  • This application uses a power source to sinter or melt the powdered material which can be metal, ceramic, glass, plastic or mixture thereof to bind the material together to create a solid structure.
  • the powdered material is fused selectively by the power source layer by layer into a mass which has a desired dimensional shape.
  • the power source as like laser or electric beam jets selectively to the powdered material on the surface of a powder bed by scanning cross-sections generated from a 3D digital description. After the top layer is finished by the power source, the powder bed is lowered by one-layer-thickness, a new layer of material is applied on top and the process is repeated until the part is completed.
  • a nozzle is arranged above the powder bed to direct the power source to the desired spot on the powdered material as well as to supply a shielding gas.
  • the nozzle moves above the powder bed according to the preprogrammed cross-sections to selectively scan the powdered material layer by layer.
  • the shielding gas is arranged surrounding the power source to prevent the high temperature spot of the powdered material from contacting any possible impurities in course of the molding.
  • At least one gas passage is arranged within the nozzle which extends axially through the nozzle to introduce a shielding gas to the powder bed.
  • This gas passage is usually formed as a circle which surrounds the power source in the middle of the nozzle so when the power sources struck the powdered material the fused spot of the powdered material, which subjects to a very high temperature, will be shielded by the gas to minimize the introduction of any possible impurities into the materials
  • the gas when the gas flows onto the powdered material directly from the gas passage of the nozzle, the gas would blow up the powdered material or generates some turbulences due to its improper flowrate or velocity which will deteriorate the sintering or melting performance.
  • the nozzle in terms of the gas passage as well as of the corresponding process needs to be improved to overcome the disadvantages.
  • the present invention pertains a device and a corresponding method for melting powdered material in accordance with the independent device claim 1 and the method claim 13 that the nozzle comprises at least one porous portion which is disposed in fluid communication with the gas passage so that the gas flows to the powdered material after it flows through this porous portion.
  • the nozzle comprises a path to guide a power source to a substrate plate on which the powdered material is melted.
  • the nozzle comprises at least one gas passage which extends axially along the direction of the power source, wherein the gas passage has at least one gas outlet which directs a gas to the substrate plate.
  • the nozzle comprises at least one porous portion which is disposed in fluid communication with the gas passage so that the gas flows to the powdered material after it flows through this porous portion.
  • This melting of powdered material is employed in the three-dimensional printing techniques to binding the material together to build an intended three-dimensional structure in a layer-wise fashion on a substrate plate.
  • the nozzle is arranged above the substrate plate with a certain distance to the plate which leads the power source to scan the discrete cross-sections of the intended structure which is preprogrammed by a digital 3D-description.
  • This high-energy power source is focused on the powdered material to melt the particles selectively and thus to bind them in an intended cross-section.
  • the substrate plate moves vertically downwards by one-layer-thickness allowing the deposition of a new layer of material using a recoating system. The process repeats layer by layer until the intended structure is completed.
  • the powdered material can be fully melted or only partially melted which is also termed as sintering.
  • the powder material can be single-component or two-component powders, typically either coated powder or a powder mixture which is only partially melted by the focused power source to fuse the solid non-melted part to each other and to the previous layer.
  • Such processes include direct metal laser sintering (DMLS) and selective laser sintering (SLS) .
  • DMLS direct metal laser sintering
  • SLS selective laser sintering
  • the powdered material can be also fully melted as in the process of selective laser melting (SLM) to bind them together.
  • the power source can be laser beam, electronic beam, electric arc or any comparable high energy density power sources which can be focused onto the substrate plate and melt the material selectively.
  • the nozzle has preferably an overall circular cross-section and the power source path is preferably arranged in the center of the nozzle which extends axially through the nozzle.
  • the gas passage is preferably ring-shaped which surrounds the power source path and extends along the power source path through the nozzle.
  • the gas passage has a ring-shaped cross-section which introduces the gas always embracing the power source to the focused spot on the powdered material.
  • the gas flows preferably vertically to the surface of the powdered material which has the same direction as the power source. The resultative curtain-like gas prevents the spot to be fused by the power source from contacting any possible impurities.
  • the porous portion is disposed in fluid communication with the gas passage in such a way that in course of the gas flowing from the gas source via the nozzle to the powdered material, it must pass the porous portion.
  • the porous portion is disposed near or at the outlet of the gas passage so when the gas flows outwardly it must flow through this porous portion which reduces its velocity and thus prevents the powdered material from being blown up or generating some undesirable turbulences which will impact the product quality adversely e.g. in terms of its porosity, compressive strength etc.
  • the porous portion is disposed at the outlet of the gas passage which fully closes the gas outlet so all the gas will first pass the porous portion and then flows towards the powdered material on the substrate plate.
  • This kind of porous portion is also ring-shaped which corresponds the ring-shaped cross-section of the gas passage to fully close the gas outlet.
  • the porous portion can be engaged with the gas passage by welding, pressing or any other common methods
  • the porous material has a porosity of 10 to 100 microns, preferably of 15 to 50 microns, more preferably of 20 to 30 microns.
  • the porous material is made of steel and preferably made of stainless steel as like 316L or 316.
  • the powdered material can vary very widely in size, but also in shape from spherical to irregular.
  • the powdered material has a preferred diameter of 20 to 100 microns and preferable from 30 to 80 microns.
  • a significant issue in such an additive laying manufacture is the progressive degradation of the powders during the process as a result of the powder being exposed to the oxygen and other contaminants.
  • the resulting porosity and especially the open pores on the additively manufactured part jeopardizes its toughness and fatigue properties which could initiate cracks and lead to part failure.
  • a shielding gas is therefore required to minimize the chance of failure.
  • the gas can be argon, helium, nitrogen or mixture thereof.
  • SLS selective laser sintering process
  • Fig. 1 shows a diagrammatic view of the selective laser sintering process.
  • Fig. 2 shows a longitudinal sectional view of the nozzle in the selective laser sintering process in accordance with the present invention.
  • Fig. 1 demonstrates the fundamental principle of a selective laser sintering (SLS) process.
  • SLS selective laser sintering
  • This process is usually taking place in an enclosed chamber which is not shown in fig. 1.
  • This chamber is filled with inert gas and the atmosphere within the chamber is circulated and filtered to remove the process by-products from the circulating gas.
  • a laser unit 1 for generating a focused laser beam 11 is provided in the chamber.
  • This laser unit 1 connects to a scanner system 2 which is controlled by a computer unit 3.
  • the scanner system functions as a mirror to control the movement of the focused laser beam 11 on the build area to an accurate position.
  • a build chamber 12 provided on the build area which is filled with loosely compacted powdered material 7.
  • This powdered material 7 can be metal, ceramic, glass, plastic or mixture thereof which is to be melted by the laser beam 11 to fabricate the product 8 in a layer-wise fashion.
  • a substrate plate 5 which is also called as powder bed, is arranged on which the powdered material 7 is laid.
  • the substrate plate 5 is secured with a piston 6 which moves vertically downwards allowing the controlled deposition of powder layers at a certain interval as like 50 micrometers.
  • the powder layers have preferably a thickness of 0.06 to 0.15mm.
  • the laser beam 11 is positioned by the scanner system 2 and the computer unit 3 on an accurate spot on the top surface of the powdered material 7 via a nozzle 4.
  • the nozzle 4 is connected to the scanner system 2 and comprises a path to guide the laser beam 11 from the scanner system 2 to the intended spot on the powdered material 7. Simultaneously, it also introduces a gas flow 9 via a gas passage which embraces the central laser beam 11 towards to the powdered material 7.
  • the gas passage has preferably a ring-shaped cross section. It extends along the laser beam path and encircles the laser beam path to generate a curtain-like gas flow 9 surrounding the laser beam 11.
  • the gas flow 9 releases from the gas outlet of the nozzle 4 and flows vertically to the top surface of the powdered material 7 which has the same direction as the laser beam 11.
  • This gas flow 9 shields the laser beam 11 and the spot to be sintered on the powered material 7. It prevents the high-temperature sintering spot from contacting any possible impurities from the atmosphere and thus prevents the impurities from introducing into the material which could impact the quality of the product adversely.
  • the laser beam 11 sinters the powdered material 7 on the top surface such the powder is caused to adhere into a solid mass.
  • the areas not hit by the laser beam remain loose and fall from the product when it is removed from the system.
  • the most recently sintered layer is lowered to a position for the sintering of the next layer by vertical movement of the substrate layer 5.
  • a new layer of the loosely compacted powdered material is spread evenly on the top surface by a recoating mechanism 10 e.g. a rolling mechanism. Each layer is sintered deeply enough to bond it to the preceding layer. Successive layers of powdered material are deposited and sintered one on top of another, until the entire product 8 is complete.
  • Fig. 2 shows the longitudinal section of the nozzle 4.
  • the nozzle comprises a path 15 for guiding the laser beam 11 to the substrate plate 5 on which the powered material is spread.
  • the gas passage 16 is arranged encircling the laser beam path 15 to generate the gas flow 9 surrounding the laser beam 11.
  • a gas inlet 13 is provided on the gas passage. It should be noted that the gas inlet has not to be situated as it illustrated in the fig. 2. It could be in any form and in any conventional way.
  • a porous portion 14 is provided near the outlet of gas passage 16 so that the gas 9 flows to the powdered material after it flows through this porous portion 14.
  • This porous portion 14 is made of steel and preferably made of stainless steel It has a porosity of 20 to 30 microns.
  • the porous portion 14 is engaged with the gas passage 16 and has a cross section as same as the outlet of the gas passage. So, the porous portion 14 can fully cover the gas outlet.
  • This porous portion 14 inhibits the gas 9 from flowing direct to the powdered material which could cause the powder to be blown up or generate undesirable turbulences.
  • the gas 9 passes through the porous portion 14 which reduces the velocity of the gas 9 and makes it flow very gently to the powdered material.
  • This porous portion 14 can be disposed near or at the outlet of the gas passage 16.
  • the thickness, the porosity of the porous portion 14 and its the distance to the outlet of the gas passage should be designed in such a relationship that the gas velocity or flow rate after passing the porous portion 14 falls into a desirable range which benefits the sintering process.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Physics & Mathematics (AREA)
  • Plasma & Fusion (AREA)
  • Mechanical Engineering (AREA)
  • Optics & Photonics (AREA)
  • Automation & Control Theory (AREA)
  • Powder Metallurgy (AREA)
  • Laser Beam Processing (AREA)

Abstract

L'invention concerne une buse (4) permettant de faire fondre un matériau en poudre comprenant un trajet permettant de guider une source d'énergie vers une plaque de substrat (5) sur laquelle le matériau en poudre est fondu, la buse (4) comprenant au moins un passage de gaz (16) qui s'étend le long de la direction de la source d'énergie, le passage de gaz (16) comprenant au moins une sortie de gaz qui dirige un gaz vers la surface, la buse (4) comprenant au moins une partie poreuse (14) qui est disposée en communication fluidique avec le passage de gaz (16) de sorte que le gaz s'écoule vers le matériau en poudre après son écoulement à travers cette partie poreuse (14).
PCT/CN2017/093818 2017-07-21 2017-07-21 Agencement de buse pour la fusion d'un matériau en poudre WO2019014914A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/CN2017/093818 WO2019014914A1 (fr) 2017-07-21 2017-07-21 Agencement de buse pour la fusion d'un matériau en poudre

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CN2017/093818 WO2019014914A1 (fr) 2017-07-21 2017-07-21 Agencement de buse pour la fusion d'un matériau en poudre

Publications (1)

Publication Number Publication Date
WO2019014914A1 true WO2019014914A1 (fr) 2019-01-24

Family

ID=65015279

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/CN2017/093818 WO2019014914A1 (fr) 2017-07-21 2017-07-21 Agencement de buse pour la fusion d'un matériau en poudre

Country Status (1)

Country Link
WO (1) WO2019014914A1 (fr)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5465942A (en) * 1991-11-06 1995-11-14 Kortec Ag Tuyere arrangement for the introduction of agents into a molten bath and method of operating such a tuyere arrangement
CN1486806A (zh) * 2003-06-02 2004-04-07 湖南省顶立新材料工程中心有限公司 采用雾化成形生产球状铸造碳化钨粉的装置
EP1825948A2 (fr) * 2006-02-22 2007-08-29 General Electric Company Buse pour la fabrication laser près des cotes
CN203265636U (zh) * 2013-05-23 2013-11-06 成都大光热喷涂材料有限公司 一种双级雾化制备球形wc粉末的设备
CN205869473U (zh) * 2016-08-04 2017-01-11 浙江亚通焊材有限公司 一种制备增材制造金属粉末的无坩埚气雾化装置

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5465942A (en) * 1991-11-06 1995-11-14 Kortec Ag Tuyere arrangement for the introduction of agents into a molten bath and method of operating such a tuyere arrangement
CN1486806A (zh) * 2003-06-02 2004-04-07 湖南省顶立新材料工程中心有限公司 采用雾化成形生产球状铸造碳化钨粉的装置
EP1825948A2 (fr) * 2006-02-22 2007-08-29 General Electric Company Buse pour la fabrication laser près des cotes
CN203265636U (zh) * 2013-05-23 2013-11-06 成都大光热喷涂材料有限公司 一种双级雾化制备球形wc粉末的设备
CN205869473U (zh) * 2016-08-04 2017-01-11 浙江亚通焊材有限公司 一种制备增材制造金属粉末的无坩埚气雾化装置

Similar Documents

Publication Publication Date Title
Fang et al. Study on metal deposit in the fused-coating based additive manufacturing
JP6717573B2 (ja) 繊維強化を用いた付加製造方法
US20190061005A1 (en) High Quality Spherical Powders for Additive Manufacturing Processes Along With Methods of Their Formation
US10730234B2 (en) Apparatus for additively manufacturing of three-dimensional components
RU2674588C2 (ru) Способ аддитивного сварочно-плавильного изготовления трёхмерных изделий и установка для его осуществления
EP3102362A1 (fr) Fabrication de formes libres solides en superalliage et réparation avec des préformes de métal et de flux
JPH11501258A (ja) 層溶着による形状自在製品
Ghosal et al. Study on direct laser metal deposition
JP2002504024A (ja) 金属の層溶着により作られる製品
US20190099943A1 (en) Additive manufacturing method and apparatus
US20190322050A1 (en) Additive manufacturing system and method
US10919114B2 (en) Methods and support structures leveraging grown build envelope
WO2020126086A1 (fr) Procédé et système de génération d'une pièce tridimensionnelle
Su et al. Investigation of fully dense laser sintering of tool steel powder using a pulsed Nd: YAG (neodymium-doped yttrium aluminium garnet) laser
WO2021008735A1 (fr) Procédé et dispositif de purge d'un espace de fabrication additive
WO2019014914A1 (fr) Agencement de buse pour la fusion d'un matériau en poudre
US20180111191A1 (en) Method of manufacturing metal articles
EP3670030A1 (fr) Procédé et système de génération d'une pièce à usiner tridimensionnelle
EP3444051B1 (fr) Paroi mobile pour lit de poudre additif
EP3984669A1 (fr) Procédé de régénération d'une plaque de construction
EP3587004A1 (fr) Dispositif et procédé de refroidissement d'une chambre de formation de poudres métalliques par fabrication additive
JP7396613B2 (ja) 積層造形装置、三次元形状造形物に対する加工方法、三次元形状造形物及び金型
Adinarayanappa et al. Determination of process parameter for twin-wire weld-deposition based additive manufacturing
EP3797902A1 (fr) Procédé et système pour l'atmosphère dans une fabrication additive
Carreno-Morelli et al. Additive manufacturing by solvent jetting on granule beds

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 17918539

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 17918539

Country of ref document: EP

Kind code of ref document: A1