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
  • B22F10/20—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
  • B22F7/00—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression
  • B22F7/06—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite workpieces or articles from parts, e.g. to form tipped tools
  • B22F7/08—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite workpieces or articles from parts, e.g. to form tipped tools with one or more parts not made from powder
• • 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
  • B22F10/36—Process control of energy beam parameters
• • 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
  • B22F10/60—Treatment of workpieces or articles after build-up
  • B22F10/66—Treatment of workpieces or articles after build-up by mechanical means
• • 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
  • B22F12/30—Platforms or substrates
• • 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
  • B22F12/40—Radiation means
  • B22F12/41—Radiation means characterised by the type, e.g. laser or electron beam
• • 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
  • B23K26/12—Working by laser beam, e.g. welding, cutting or boring in a special atmosphere, e.g. in an enclosure
  • B23K26/123—Working by laser beam, e.g. welding, cutting or boring in a special atmosphere, e.g. in an enclosure in an atmosphere of particular gases
• • 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
  • B23K26/12—Working by laser beam, e.g. welding, cutting or boring in a special atmosphere, e.g. in an enclosure
  • B23K26/127—Working by laser beam, e.g. welding, cutting or boring in a special atmosphere, e.g. in an enclosure in an enclosure
• • 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
  • 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
• • 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
  • B33Y40/00—Auxiliary operations or equipment, e.g. for material handling
  • B33Y40/10—Pre-treatment
• • 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
  • B33Y40/00—Auxiliary operations or equipment, e.g. for material handling
  • B33Y40/20—Post-treatment, e.g. curing, coating or polishing
• • 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
  • B33Y80/00—Products made by additive manufacturing
• • G—PHYSICS
  • G04—HOROLOGY
  • G04D—APPARATUS OR TOOLS SPECIALLY DESIGNED FOR MAKING OR MAINTAINING CLOCKS OR WATCHES
  • G04D3/00—Watchmakers' or watch-repairers' machines or tools for working materials
  • G04D3/0069—Watchmakers' or watch-repairers' machines or tools for working materials for working with non-mechanical means, e.g. chemical, electrochemical, metallising, vapourising; with electron beams, laser beams
• • 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
  • B22F2201/00—Treatment under specific atmosphere
  • B22F2201/10—Inert gases
  • B22F2201/11—Argon
• • 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
  • B22F2301/00—Metallic composition of the powder or its coating
  • B22F2301/05—Light metals
  • B22F2301/052—Aluminium
• • 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
  • B22F2301/00—Metallic composition of the powder or its coating
  • B22F2301/25—Noble metals, i.e. Ag Au, Ir, Os, Pd, Pt, Rh, Ru
  • B22F2301/255—Silver or gold
• • G—PHYSICS
  • G04—HOROLOGY
  • G04B—MECHANICALLY-DRIVEN CLOCKS OR WATCHES; MECHANICAL PARTS OF CLOCKS OR WATCHES IN GENERAL; TIME PIECES USING THE POSITION OF THE SUN, MOON OR STARS
  • G04B37/00—Cases
  • G04B37/22—Materials or processes of manufacturing pocket watch or wrist watch cases
  • G04B37/225—Non-metallic cases
• • G—PHYSICS
  • G04—HOROLOGY
  • G04B—MECHANICALLY-DRIVEN CLOCKS OR WATCHES; MECHANICAL PARTS OF CLOCKS OR WATCHES IN GENERAL; TIME PIECES USING THE POSITION OF THE SUN, MOON OR STARS
  • G04B45/00—Time pieces of which the indicating means or cases provoke special effects, e.g. aesthetic effects
• • 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 method of additive manufacturing by laser beam of mechanical parts.
• the present invention also relates to such mechanical parts, in particular obtained by implementing the additive manufacturing process.
• the method of selective melting by means of a laser beam is a rapid prototyping technique by melting a powder of a metallic material by means of a laser beam such as a CO2 carbon dioxide laser or a YAG laser, the maximum power of which is typically between 100 Watts and 2 to 3 kilowatts.
• This selective melting process is used to create, stratum after stratum, three-dimensional objects from powders of metallic materials which are brought to their melting temperature by the energy supplied by the laser beam.
• the conventional laser additive manufacturing process begins with the development of a CAD (Computer Aided Design) type computer file which will allow the volume of the part that one seeks to design to be defined.
• This computer file includes one or more strata to two dimensions which, when superimposed, make it possible to reconstitute the part that one wishes to design.
• the laser beam After having spread a layer of uniform thickness of a metallic material in the powder state on a platform of a laser beam additive manufacturing machine, the laser beam traces a first 2D layer on the surface of the powder layer metallic. Under the effect of the light energy provided by the laser beam, the metal powder melts and then solidifies according to the outline of the first 2-dimensional layer used to control the movement of the laser beam. A new layer of metal powder is spread over the entire surface of the platform, then the process of bringing the metal powder particles to their melting temperature by means of the laser beam is repeated until the part is finished.
• the manufacture of the part by additive printing is done directly on the surface of the platform as described above. In some cases, this manufacturing begins with the production, layer after layer, of a support on the platform, and continues with the production of the part itself.
• the support in this case serves to mechanically support the part as it is manufactured on the platform of the printing machine and allows the heat produced by the melting of the metal powder to be removed by means of the laser beam.
• the part thus obtained must then be carefully removed from the platform of the additive manufacturing machine and cleaned of the unfused powder which surrounds it. If the part was manufactured with a support, the part is separated from the latter.
• Another laser beam additive manufacturing technique is to have a substrate that is installed in the machine before the start of manufacturing operations. This substrate on which the part will be manufactured comes flush with the surface of the platform of the additive manufacturing machine.
• the substrate which is metallic, makes it possible to efficiently remove the heat caused by the fusion of the powder and therefore to relax at least in part the thermal stresses which are present in the part being manufactured. Additional heat treatment after printing the part will completely eliminate thermal stresses.
• the metal powder by means of which the part is manufactured is most often of the same nature as the material from which the substrate is made because this promotes the attachment of the part to the substrate. Sometimes the composition of the alloy the powder is made from varies slightly from the alloy composition of the substrate. It has also already been proposed to use, to manufacture the part, a powder made from a metal different from that in which the substrate is made, this for cost reasons, for example when a precious metal is used to make the part, or good when using a different metal to machine such as titanium.
• the choice of material for the substrate and for the part manufactured by additive printing on the substrate has most often been limited to the same metal for the substrate. substrate and workpiece.
• the object of the present invention is to provide an additive manufacturing process by laser making it possible to vary the choices of materials which can be used to produce mechanical parts in a reliable and reproducible manner.
• the present invention relates to a method of additive manufacturing by laser of a mechanical part having a technical and / or decorative function, this mechanical part comprising a substrate and a structure formed on the substrate by additive manufacturing by laser, this method comprising the steps of:
• - acquire a laser beam the operation of which will be controlled by means of a computer into which is introduced a 2-dimensional CAD computer file which corresponds to the structure of the desired mechanical part, or else a CAD computer file 3-dimensional which is cut into 2-dimensional layers which, once superimposed, make it possible to form the structure of the desired mechanical part, another computer file containing the operating parameters of the laser beam;
• - have a substrate made of a ceramic material whose melting point is higher than the temperature involved in additive manufacturing by laser;
• the present invention provides an additive manufacturing process by laser allowing the joint use of a solid ceramic substrate and a metal powder to produce mechanical parts with a technical and / or decorative function of very high quality. It has in fact been observed that the metallic structure obtained by laser fusion adheres sufficiently to the ceramic substrate on which this structure is manufactured and makes it possible to obtain mechanical parts which can be directly used in the objects in which the latter are intended to be mounted. This result is quite surprising given that a priori, the chemical affinity (ionic / covalent) between the metal atoms linked together by ionic bonds and the oxygen contained in the ceramics whose atoms are linked by covalent bonds is weak.
• the titanium atoms associate well with the oxygen contained in the ceramic substrate to form molecules of titanium dioxide PO2.
• the aluminum atoms have a good affinity for the oxygen atoms of a substrate made of alumina, sapphire or zirconia, for example.
• the substrate belongs to the mechanical part with a technical and / or decorative function that results from the process of the invention; this substrate is an integral part of this mechanical part, and is not intended to be separated from the structure obtained by laser additive manufacturing at the end of the process. Indeed, it has been observed that this structure adheres sufficiently well to the surface of the substrate on which it was produced so that the resulting mechanical part can be integrated as it is into the object for which it is intended.
• the perilous step of separating the part obtained by additive laser manufacturing from the platform of the additive manufacturing machine is avoided, so that the risks of plastic deformation which can lead to the destruction of the piece, are avoided.
• avoiding this separation step saves time, in particular because it is not necessary to have to fix, for example by gluing, the parts obtained by additive manufacturing on separate substrates.
• the substrate can be subjected to a surface treatment
• the surface treatment consists of an ion implantation operation, a plasma torch treatment or a physical vapor deposition treatment
• the substrate is preheated prior to the step of selective melting of the layer of powdered material; - the substrate is preheated to a temperature not exceeding 400 ° C;
• the thickness of the substrate is at least 100 ⁇ m
• the neutral gas is argon and the volume concentration of oxygen in the manufacturing chamber is less than 0.5%;
• the ceramic material is chosen from the group formed by borosilicate glass, alumina, sapphire, titanium boride, titanium oxide PO2, titanium carbide, tungsten carbide, silicon nitride, zirconia, emerald, ruby and diamond;
• the metallic material is chosen from the group formed by aluminum, steel, titanium, zirconium, palladium, platinum, silver and gold;
• the thickness of a layer of material deposited on the substrate is between 20 ⁇ m and 45 ⁇ m;
• the laser beam is of the Nd: YAG type
• the maximum power of the laser beam is between 100 Watts and 300 Watts;
• the 2-dimensional layer of the desired mechanical part has a contour which delimits at least one surface.
• the size of the particles which form the powders is between 5 ⁇ m and 63 ⁇ m
• the powders of materials used are of the D10-D90 type, that is to say that 90% of the particles which form these powders have a diameter less than 63 ⁇ m, and 10% of these particles have a diameter less than 5 ⁇ m .
• the present invention also relates to a mechanical part with a technical and / or decorative function, this mechanical part comprising a ceramic substrate and a metal structure formed on the substrate by additive manufacturing by laser. It will be noted in particular that subjecting the ceramic substrate to a surface treatment by ion implantation, plasma torch or physical vapor deposition prior to the step of selective melting of the layer of powdered metallic material makes it possible to further improve the force. attachment of the structure formed on the substrate with the latter.
• FIG. 1 is a schematic representation of a laser beam additive manufacturing facility suitable for implementing the method according to the invention
• FIG. 2 is a detailed schematic view which illustrates the situation of the additive manufacturing installation before the start of the additive manufacturing process
• FIG. 3 is a detailed schematic view which illustrates the deposition of the first layer of powder material to be fused onto the substrate
• FIG. 4 is a schematic detail view which illustrates the removal of excess powder material
• FIG. 5 is a detailed schematic view which illustrates the step of selective melting by means of a laser beam of the first layer of powder material
• FIG. 6 is a detailed schematic view which illustrates the step of selectively melting a layer of additional powder material
• - Figure 7 is a detailed schematic view which illustrates the final step of cleaning the substrate
• FIG. 8 schematically illustrates a substrate preparation step by means of a plasma torch prior to the deposition of a first layer of powder material to be fused on the substrate.
• the present invention proceeds from the general inventive idea of producing mechanical parts with a technical and / or decorative function in a single piece by means of an additive manufacturing process by laser beam. More specifically, the invention relates to an additive manufacturing process by laser beam in which the joint use of a solid ceramic substrate and a metal powder to produce the structure by laser additive manufacturing makes it possible to obtain mechanical parts with a function. very high quality technical and / or decorative. It has in fact been observed that the metal structure obtained by laser fusion sufficiently adheres to the ceramic substrate on which this structure is made and makes it possible to obtain mechanical parts that can be directly used in the objects in which they are intended to be mounted. It seems that this is due in particular to the good chemical affinity (ionic / covalent) between the metal atoms and the oxygen contained in the ceramics.
• titanium atoms combine well with the oxygen contained in the ceramic substrate to form molecules of titanium dioxide T1O2.
• aluminum atoms have a great affinity for the oxygen atoms of a substrate such as alumina, sapphire or zirconia. The invention thus demonstrates that it is possible to combine or link together materials which, until now, were considered incompatible.
• the ceramic substrate when we want to grow a gold structure by fusion laser on a ceramic substrate, it will be preferable to subject the ceramic substrate beforehand to a surface treatment, for example of the ion implantation, plasma torch or even physical vapor deposition type.
• the gas used to create the torch will preferably be compressed air containing 22% oxygen and approximately 70% nitrogen.
• the ceramic substrate used to make the desired mechanical part is an integral part of this mechanical part and therefore does not need to be separated from the latter once the manufacturing process is complete.
• This ceramic substrate is therefore not intended to be sacrificed and will serve as a permanent support for the structure obtained through laser additive manufacturing with which it forms the mechanical part according to the invention. The risks of deforming or even destroying this structure that were encountered in the prior art during the separation of such a structure from its manufacturing substrate are thus avoided.
• one begins by providing a substrate on which a structure will be grown by additive manufacturing by means of a laser beam.
• the shapes and dimensions of the substrate are chosen as a function of the subsequent use which will be made of the mechanical part resulting from the implementation of the present method. It will suffice for the substrate to have at least one flat surface on which the additive manufacturing operation can be carried out. For reasons of strength, however, it is preferred that the thickness of the substrate is not less than 100 ⁇ m.
• This substrate is made of a ceramic material, the melting point of which is higher than the temperature involved in additive manufacturing by laser melting.
• the substrate is made of a ceramic material such as alumina AI2O3, sapphire, titanium oxide PO2 or else zirconia ZrÜ2.
• Ceramic materials which are also suitable are silicon nitride S13N4 and titanium carbide TiC.
• a layer of a material in the powder state is deposited on this substrate which will then be selectively fused by means of the laser beam.
• This pulverulent material is different from the material in which the substrate is made.
• This pulverulent material is a metallic material such as aluminum, gold, platinum, titanium, steel or even zirconium.
• the choice will preferably be made on a 6061 aluminum alloy comprising between 95.85 and 98.56% by weight of aluminum, 0.4 to 0.8% by weight of silicon, a maximum of 0.7% by weight of iron (no minimum required), 0.15 to 0.4% by weight of copper, a maximum of 0.15% by weight of manganese (no minimum required), between 0.8 and 1.2% of magnesium, between 0.04 and 0.35% of chromium, a maximum of 0.25% by weight of zinc (no minimum required), a maximum of 0.15% by weight of titanium (no minimum required), the concentration of other elements not to exceed 0.05% by weight each, the total concentration of these other elements must not exceed 0.15% by weight.
• the 6061 aluminum powder used in the context of the present invention is formed from a mixture of particles whose diameter is between 5 and 63 ⁇ m.
• Parts made by depositing 10 to 20 layers of the aluminum powder detailed above have been structured on a zirconia substrate. Likewise, a zirconia substrate was used to fabricate parts from TiAl6V4 titanium powder.
• gold it is preferably 18 carat gold containing 750 thousandths of pure gold, 50 thousandths of silver and 198.5 thousandths of copper.
• the gold powder used in the context of the present invention is formed from a mixture of particles whose diameter is between 5 and 45 ⁇ m. Parts made by depositing 10 to 20 layers of the gold powder detailed above have been structured on sapphire and zirconia substrates.
• the layer of powder material is spread over the substrate, it is leveled by mechanical sweeping to present a substantially uniform thickness, typically in the range of 15-50 ⁇ m. It will be understood that during this scanning operation, the powder particles whose diameter or at least one dimension exceeds the thickness of the layer are removed from the substrate.
• the manufacturing enclosure is closed and an atmosphere of neutral gas is created in the volume of this enclosure.
• the neutral gas chosen is preferably, but not limited to, argon, and the volume concentration of oxygen in the manufacturing chamber is less than 0.5%.
• the laser device used in the context of the present invention is for example a Yb: YAG type laser, the maximum power of which is equal to 100 Watts and which emits continuously.
• the power thereof is set at a working value of between 10 and 35 Watts and its speed of movement on the surface of the substrate is between 100 and 700 mm / s.
• the laser beam melts the layer of powder material spread on the substrate in a pattern determined by a computer in which a computer CAD file is stored.
• This file corresponds to one or more 2-dimensional layers which, once superimposed, make it possible to form in the layer of powder material the structure of the desired mechanical part.
• Another computer file containing, for each stratum of the desired mechanical part, the operating parameters of the laser beam such as the power of the laser beam, the speed of movement of the laser beam and the path that this laser beam must travel is also used.
• Each stratum of molten material therefore has a thickness of between 15 ⁇ m and 50 ⁇ m.
• the thickness of the final structure can be of the order of 500 ⁇ m to 1 mm. The only difference between these values lies in the manufacturing time which is all the longer as the final structure is thick.
• the excess material is removed and then a second layer of powdered material is deposited on the substrate.
• a second layer of powdered material is deposited on the substrate. which can be the same as that used to make the first layer or it can be different.
• the operations are repeated until the desired mechanical part consisting of the substrate and the structure formed on the substrate by additive laser manufacturing is obtained.
• the resulting mechanical part is taken out of the manufacturing enclosure, excess material is removed and the assembly is cleaned. The resulting mechanical part is ready for use.
• FIG. 1 is a schematic representation of an additive manufacturing installation by laser beam which is suitable for implementing the method according to the invention.
• this additive manufacturing installation comprises a manufacturing enclosure 2 inside which is arranged a platform 4 on which is placed a substrate 6.
• the platform 4 is coupled with a first piston 8 so that it can be moved vertically from bottom to top and from top to bottom.
• the additive manufacturing installation 1 also comprises a first reservoir 10 and a second reservoir 12 both arranged inside the manufacturing enclosure 2.
• the first reservoir 10 inside which a second piston 14 moves is used for storage of a powder material to be fused.
• the second reservoir 12 serves as a receptacle for the excess powder of the material to be fused as well as for the waste resulting from the selective melting step.
• the manufacturing enclosure 2 also contains a laser beam 16 arranged directly above the platform 4 on which the substrate 6 is placed as well as a transfer head 18 for the powder of the material to be fused.
• the substrate 6 is placed flush with a printing surface 20 by actuating, if necessary, the first piston 8 which controls the movements of the platform 4 on which the substrate 6 is placed.
• the second piston 14 is actuated so as to bring a quantity of powder 22 of the material to be fused to the height of the printing surface 20.
• the transfer head 18 is responsible for bringing the quantity of powder 22 of the material to be fused onto the substrate 6.
• the transfer head 18 is equipped with a first and a second scraper. 24 and 26 which can be selectively raised or lowered.
• the transfer head 18 is translated to the left of the figure, the first squeegee 24 being raised so as not to oppose the advancement of the quantity of powder 22, and the second scraper 26 being lowered in order to be able to move this quantity of powder 22.
• the transfer head 18 is moved to the right of the figure with the first squeegee 24 lowered and the second squeegee 26 raised to level and compact the layer of powder material 28 which has been fed onto the substrate. 6.
• the layer of powder material 28 is melted using the laser beam 16.
• the operation of the laser beam 16 will be controlled by means of a computer into which is introduced a CAD computer file which is cut into one or more layers which, once superimposed, make it possible to form the structure 30 of the desired mechanical part 32.
• the platform 4 on which the substrate 6 is placed is lowered by actuating the first piston 8 in order to again bring the substrate 6 on the surface of which the first layer of powder material 28 flush with the printing surface 20. Then, if it is desired to structure a new layer of powder material on the surface of the substrate 6, the operations which have been detailed above in conjunction with Figures 2 to 5.
• the desired structure 30 is obtained by having subjected the first layer of powder material 28 to a selective melting step by means of the laser beam 16, it is possible, if necessary, to clean the mechanical part 32 formed by the substrate. 6 and the structure 30 for example by means of a vacuum cleaner 34 (see FIG. 7).

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Manufacturing & Machinery (AREA)
• Materials Engineering (AREA)
• Physics & Mathematics (AREA)
• Plasma & Fusion (AREA)
• Optics & Photonics (AREA)
• Mechanical Engineering (AREA)
• Health & Medical Sciences (AREA)
• General Health & Medical Sciences (AREA)
• Toxicology (AREA)
• Automation & Control Theory (AREA)
• Composite Materials (AREA)
• General Physics & Mathematics (AREA)
• Powder Metallurgy (AREA)
• Other Surface Treatments For Metallic Materials (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=66999617

Family Applications (1)

Country Status (5)

Families Citing this family (3)

Family Cites Families (10)

• 2020
  • 2020-06-09 JP JP2021574969A patent/JP7359877B2/ja active Active
  • 2020-06-09 WO PCT/EP2020/065925 patent/WO2020254145A1/fr active Search and Examination
  • 2020-06-09 CN CN202080045980.0A patent/CN114007781B/zh active Active
  • 2020-06-09 EP EP20730297.7A patent/EP3986643A1/fr active Pending
  • 2020-06-09 US US17/619,873 patent/US20220410269A1/en active Pending
• 2023
  • 2023-08-18 JP JP2023133417A patent/JP2023164848A/ja active Pending

Also Published As

Similar Documents

Legal Events