DE102004022385B4 - Device for the rapid production of microbodies - Google Patents

Abstract

Device for the rapid production of microbodies, each having at least one installation space with a support for microbodies, a storage space for particles, a transport device for particles from the storage space to the installation space and a laser, wherein either unmodulated or modulated laser beams can be guided over the cross-sectional area of the installation space and at Impact of laser beams on a particle layer both sinter and / or fuse particles with each other and with at least one layer of sintered and / or fused particles below, characterized in that at least one electromagnet interconnected with a source of alternating current or pulsating direct current or asymmetrical alternating current forms an integral part the installation space (1) and / or the installation space (1) is arranged, that the annular doctor blade (5) with a piston (6) or a punch is provided so that of the annular blade (5) horizontally enclosed and guided Piston (6) or punch vertically against the surface of the particle layer in the space (1) is movable, and that the piston (6) or the punch of a ...

Description

The The invention relates to devices for the rapid production of microbodies in each case at least one installation space with a carrier for micro bodies, a storage space for particles, a squeegee as a transport device for particles from the storage room to the installation space and a laser, whereby either unmodulated or modulated laser beams over the cross-sectional area the installation space feasible are and upon impact of laser beams on a particle layer both particles together and at least one below sintered arranged layer of sintered and / or fused particles and / or melt.

method and devices for producing bodies from successively applied layers from particles and the irradiation of these layers with laser beams a laser, particles being with each other and with the underlying layer sinter and / or merge are known through publications.

A method and an apparatus for producing bodies of layered powder and a selective sintering of the respective applied layer are known from US 4863538 A (Method and device for producing bodies by selective sintering) known. In this case, the powder of the respective layer is partially sintered by high-energy radiation. About the impact of radiation on the powder layer while the body is realized. To generate the respective body volume, the high-energy radiation is scanned. It mainly uses CO ₂ or Nd: YAG lasers with scanners, with a power of 50 W to 200 W and a focus of 100 μm to 300 μm. The result is a sintered body. However, this is characterized by the fact that a compound, without a melt is formed as in welding, arises. This results in body that only partially z. B. are used as die-cast tools. By subsequent infiltration, the density of the sintered body can be increased. A major disadvantage continues to be the very long sintering time, especially for larger bodies, which is up to 100 hours, depending on the size of the component. Another disadvantage is the relatively large surface roughness of the sintered body. The device of this solution consists of a process controlled by a microcomputer. Other such publications are the US 5314003 A and US 5393613 A in which the bodies are made from a previously prepared mixed powder of various metals. One of the metals has a low melting point, so that sinter in a partial heating these powder parts. By the DE 43 09 524 C2 (Method for producing a three-dimensional object), a method is known, wherein the radiation effect in the core region of an object to a minimum deformation and in the envelope region to the smoothest possible and accurate surface. The determination of the envelope region is effected by subtraction in three-dimensional fashion of individual regions of the core region from the overall body. The irradiation takes place in different ways, depending on whether it is a single area in the core area or one in the shell area. In addition to the determination of the envelope areas different irradiation technologies for the realization of the object are necessary. In the DE 195 38 257 C2 (Method of manufacturing a three-dimensional object), the object to be manufactured is provided with a three-dimensional supporting structure of an inner core portion and an outer enveloping portion. The core region is preferably exposed twice, so that a strong solidification is achieved, while the envelope region is exposed only once. The envelope area is located wholly between the object and the supporting structure. The envelope region is soft, so that a separation of the object from the support structure should be carried out with the least expenditure of force and tools. At the same time, the thickness of the envelope region to ensure the function as a support structure is very low. However, difficulties arise in the separation of very small or microstructured objects from the support structure, which can be easily destroyed during separation. At the same time there must be attack surfaces for the tools. In the case of several objects on a support, such a separation is difficult to realize without destruction, so that such support structures are not suitable for producing a plurality of miniature bodies or microstructured bodies on a support. By the DE 199 52 998 C2 (Device for the direct production of bodies in the layer structure of powdery substances) devices are known with an evacuable processing chamber, in which at least two sub-chambers are integrated. One of the sub-chambers is the installation space and the other of the reservoir for the powder. As a result, there is no reactive atmosphere, by the joining of the powder particles arise both dense and non-porous layers and there is no heat conduction instead. Through the publication DE 199 53 000 C2 (Method and device for the rapid production of bodies) methods and devices are known, wherein advantageously body can be made dimensionally accurate sharp and fast with high density. Shape-correcting aftertreatments are avoided as far as possible, so that such bodies can be produced very economically. This is achieved by the use of two sources of radiation during sintering or welding, the first of the generation of the contour and the second used for rapid realization of the interior of the body to be generated. The first radiation source is predominantly a laser of good beam quality, since a small focus is to be achieved. As the second radiation source, a high-power diode laser with line focus is advantageously used. A compaction of the powder applied is not provided, so that occur in aggregates of particles as particle agglomerates defects in the body.

Through the publication EP 0 416 852 A2 is a generic device for the production of bodies of particle layers, wherein the particles are made of a ferromagnetic material, known. The particles are exposed to a magnetic field, so that the particles are pressed by the acting magnetic field in the direction of the carrier. Thus, with this device, only ferromagnetic particles can be usefully used for the production of a body, other particles are not compressible for the production of bodies.

Of the The invention defined in claim 1 is based on the object micro body from successively layered applied and interconnected To produce particles quickly.

These The object is achieved with the features listed in claim 1.

devices for the production of microbodies each with at least one space with a carrier for microbody, a Storage room for particles, a squeegee as a transport device for particles from the storage room to the installation space and a laser, whereby either unmodulated or modulated laser beams over the cross-sectional area the installation space feasible are and upon impact of laser beams on a particle layer both particles with each other and with at least one arranged underneath Sintering and / or sintering layer of sintered and / or fused particles merge, characterized in particular by the fact that these microbodies both can be made with a high strength as well as fast.

To is at least one with a source of alternating or pulsating DC or asymmetrical AC interconnected Electromagnet a component of the installation space and / or space arranged. Furthermore, the ring doctor with a piston or a Stamp provided so that the horizontally enclosed by the squeegee and guided Piston or punch vertically against the surface of the particle layer in Space is movable. About that In addition, the piston or the stamp consists of a para- or ferromagnetic material.

With the effect of the magnetic field become the respective applied layers compacted from particles, so that largely dense microbody can be produced are. This is advantageously done by the particles themselves or realized the piston or punch, the force of the magnetic field either on para- or ferromagnetic particles of the layer or acts on the piston or punch. In the former case both all particles as well as part of the particles from the para- or ferromagnetic material. In both cases, the particles get through the action of the magnetic field moves in the direction of the carrier.

One Another advantage is that in the presence of para- or ferromagnetic particles through the respective powder surface the effect of the magnetic field is roughened. This is when doctoring a good adhesion even the thinnest powder layers reached. This is advantageously achieved even on smooth carriers.

advantageous Embodiments of the invention are in the claims 2 to 13 indicated.

The Developments of claim 2, wherein the electromagnet a Component of the carrier and / or the carrier and / or around the wearer and / or to the space and / or opposite the space under the carrier is arranged, make favorable Embodiments

With the use of a core according to the development of the claim 3 becomes the magnetic field strength significantly enhanced by magnetic induction. Advantageously the carrier at the same time the core.

By the presence of several transport devices, one after the other over the Space available are coupled with a drive according to the embodiment of the claim 4 can be economical Advantageously, different particles are applied to the carrier. So can with a first transport device, the material to be sintered and with a second transport device the para- or ferromagnetic Particles are applied. This also allows layers of different materials for microbody with vertical property gradients are generated.

An advantageous transport device for a layered application of particles on the carrier is according to the embodiment of claim 5, the ring doctor blade with a self-contained blade, the at least one structural element in at least one plane horizontally parallel to the carrier either rotatably mounted as well as with a drive coupled or is movable in both horizontal and vertical direction via coupled drives. With such an implementation, the ring doctor can at least either over the storage space or a surface adjacent to the carrier and the carrier to be pivoted or moved, wherein layered particles are applied either from a separate pantry or the ring doctor as a reservoir in the doctor blade on the carrier. The squeegee ensures a uniform application of layers from all directions. This gives a homogeneous layer application.

A Coupling of the ring doctor to either a flat pivot joint or a device which is both movable and adjustable in length according to the Further development of claim 6 allows a movement of the ring doctor to the most different positions in the doctoring plane with the Advantage that different pantries in any order can be approached and over different structured areas of the squeegee level for the purpose of mixing several components or the cleaning of the ring doctor be performed can.

advantageously, become according to the embodiment of claim 7, the particles by the action of ultrasound on the piston or punch compacted so that there is minimal spacing of the particles before irradiation the surface result with the laser beams. The result is dense microbodies.

The Further development of claim 8, wherein a protective device for a Laser beam interface window over at least one device horizontally at least in one plane parallel to the carrier either both rotatably mounted and coupled to a drive is coupled over or in both horizontal and vertical directions Drives is movable and the protective screen between the installation space and the laser beam injecting window is movable prevents Misting of laser beam docking window.

advantageously, can the drive for the rotatably mounted ring doctor also at the same time the drive for the protection device be. These are the squeegee and the protective disc over a Construction element coupled together.

One flexible, transparent and band-shaped body or transparent Disc according to the embodiment of claim 9 provides a simple and economical favorable Realization of the protective device.

The Drives for a vertical movement of the carrier and / or the bottom of the storage space according to the development of the Guarantee patent claim 10 the realization of the microbody in a plane.

About one heat up the respective applied layer of particles according to the development of claim 11 is a drying and preheating the respective layer. At the same time, the surface tensions increase the particle. The activation threshold or induction phase of the subsequent sintering is achieved by irradiating the layer with the laser beams decreased and the number of stochastic overheating as well the amount of fluctuating thermal stresses during the Structure of the microbody reduced.

One external acoustooptic modulator for laser beam control of a Lasers in pulsed operation or in cw operation after further training of claim 12 leads to a controllable and thus uniform effect of the laser beams on the particle layer surface without the excessive performance the first pulse. As a result, both very uniform sintered layers can advantageously be produced as well as targeted beam power distributions within a sintered layer and thus horizontal property gradients of the layer and the micro body realizable.

One Beam splitter or a beam switch in the beam path of the pulsed Lasers according to the embodiment of claim 13 causes economically advantageous a use of the laser in two sintering processes, wherein doctoring and sintering in two installation spaces can be carried out alternately at the same time.

One embodiment The invention is illustrated in principle in the drawings and will be closer in the following described.

It demonstrate:

1 a device for the rapid production of microbodies with a carrier as a permanent magnet and a ring doctor with a piston as a permanent magnet,

2 a space of a device with an electromagnet and

3 two annular doctor blade and a protective disk on a rotation axis in a plan view.

A device for the rapid production of microbodies 3 consists essentially of both a device with a space 1 for the microbody 3 with at least one magnetic field forming device and / or at least one magnetic field device, a storage space 7 for particles 4 in powder form and a transport device for particles 4 from the pantry 7 to the installation space 1 as well as a laser 9 , where either not modulated or modulated laser beams over the cross-sectional area of the installation space 1 are feasible.

The 1 shows a schematic representation of an apparatus for the rapid production of microbodies 3 with a carrier 2 as a permanent magnet and a ring doctor 5 with pistons 6 as a permanent magnet.

In the installation space 1 is the carrier 2 for the or more microbody 3 , When laser beams strike a particle layer, both particles sinter and / or melt 4 this layer with each other as well as with at least one underlying layer, so that the micro body 3 is produced. The microbody 3 exists according to the particles used 4 from a ceramic, a metal, an alloy or a composite material z. As metal / ceramic.

The transport device is a ring doctor 5 with a self-contained blade. The at least one squeegee 5 performs a circular movement, wherein in the movement path at least one space 1 with the carrier 2 and at least one pantry 7 are arranged. In a further embodiment, the installation space 1 also be arranged in the middle of the device, with several squeegee 5 rotatable about this space 1 are arranged. The installation space 1 is located in the rotation range of all ring doctor 5 , In further embodiments, on a rotation axis 12 also one or more squeegee 5 and a transparent pane 11 be attached as protection for an anti-reflective laser beam input window. The disc 11 is a protective glass. The 3 shows in principle two ring doctor 5 and a slice 11 on a rotation axis 12 , With the at least one squeegee 5 become the particles 4 as a powder as a layer to and in the installation space 1 transported. In one embodiment of the embodiment, the carrier is made 2 made of a hard magnetic magnetic material of ferromagnetic material and is a permanent magnet. The squeegee 5 has a piston 6 , which is also formed of a hard magnetic magnetic material as a permanent magnet (shown in the 1 ).

In a further embodiment, the interior of a connected to a power source coil 10 as an electromagnet as a magnetic field forming device at the same time the space 1 (Presentation in the 2 ). Between the interior and the coil 10 is advantageously a space 1 limiting wall arranged so that a smooth smooth inner wall is present. The power source is a source of alternating or direct current or pulsating direct current or asymmetric alternating current. The carrier 2 can in a further embodiment of ferromagnetic material and at the same time the core for this coil 10 be such that the field strength of the magnetic field is substantially increased.

The device having a magnetic field or forming a magnetic field may in a further embodiment also under the carrier 2 are located. Furthermore, the piston 6 also a part of the squeegee 5 be, with the inner wall of the squeegee 5 advantageously at the same time a guide for the piston 6 is.

In another embodiment, particles can become 4 made of a ferromagnetic material in the powder or the powder consists only of particles 4 made of a ferromagnetic material.

Both the carrier 2 as well as the ground 8th of the pantry 7 are each a drive relative to the ring doctor 5 movable.

The laser 9 is arranged so that the laser beams through a scanner and a coupling window in the device with the installation space 1 and the pantry 7 on the carrier 2 reach.

In a further embodiment of the exemplary embodiment, a heating device is for heating layers of particles 4 a component of the carrier 2 or the carrier 2 or at one the installation space 1 forming object or as a spotlight over the space 1 arranged. In particular, the simultaneous use of a heater in the carrier 2 and one on the surface of the particles 4 acting radiant heating z. B. in the form of a powerful halogen lighting lead to a uniform warming of the layers of the particles 4 , and especially the sintered layers, that is, the microbody 3 , so that stresses in the microbody 3 be degraded and the coupling of the laser radiation can be increased in transparent materials.

Claims (13)

Device for the rapid production of microbodies, each having at least one installation space with a support for microbodies, a storage space for particles, a transport device for particles from the storage space to the installation space and a laser, wherein either unmodulated or modulated laser beams can be guided over the cross-sectional area of the installation space and at Laser radiation impinging on a particle layer both sinters and / or fuses particles with one another and with at least one layer of sintered and / or fused particles underneath, characterized in that at least one merges with a source of alternating current or pulsating direct current or asymmetrical alternating current switched electromagnet is a component of the installation space ( 1 ) and / or on the installation space ( 1 ) is arranged, that the squeegee ( 5 ) with a piston ( 6 ) or a stamp is provided so that the of the ring doctor ( 5 ) horizontally enclosed and guided pistons ( 6 ) or stamp vertically against the surface of the particle layer in the installation space ( 1 ) is movable, and that the piston ( 6 ) or the stamp is made of a para or ferromagnetic material. Device according to Patent Claim 1, characterized in that the electromagnet forms part of the carrier ( 2 ) and / or the carrier ( 2 ) and / or around the carrier ( 2 ) and / or the installation space ( 1 ) and / or with respect to the installation space ( 1 ) under the carrier ( 2 ) is arranged so that the magnetic field at least in the space ( 1 ) acts. Device according to claim 1, characterized in that the electromagnet has a field-enhancing core or that the carrier ( 2 ) is a field enhancing core. Device according to claim 1, characterized in that a plurality of transport devices are coupled to a drive in such a way that they are successively conveyed over the installation space ( 1 ). Device according to claim 1, characterized in that the annular doctor blade ( 5 ) via at least one structural element at least in one plane horizontally parallel to the carrier ( 2 ) is either both rotatably mounted and coupled to a drive or is movable in both horizontal and vertical direction via coupled drives, so that the annular blade ( 5 ) at least either over both the storage room ( 7 ) as well as the installation space ( 1 ) or over both a free surface next to the installation space ( 1 ) as well as the installation space ( 1 ) is pivotable or movable, whereby layered particles ( 4 ) either from the storage room ( 7 ) or the ring doctor blade ( 5 ) to the carrier ( 2 ) are transported and applied to this. Device according to claim 5, characterized in that the ring doctor blade ( 5 ) is coupled to either a planar hinge mechanism or a device both movable and changeable in length. Device according to claim 1, characterized in that the piston ( 6 ) or the stamp is coupled to an ultrasound generating device. Device according to one of the claims 1 or 5, characterized in that at least one protective device for a laser beam coupling window via at least one device at least in one plane horizontally parallel to the carrier ( 2 ) either rotatably mounted as well as with a drive / the drive of the annular blade ( 5 ) is coupled or in both the horizontal and vertical direction via coupled drives is movable, so that the protective device between the space ( 1 ) and a laser beam input window is movable. Device according to claim 8, characterized in that the protective device is a flexible, transparent and band-shaped body or a transparent pane ( 11 ), the one or more between the space ( 1 ) and the coupling window is arranged and coupled to a drive. Device according to claim 1, characterized in that the carrier ( 2 ) via a drive or both the carrier ( 2 ) and the ground ( 8th ) of the storage room ( 7 ) is arranged vertically movable in each case via a drive. Device according to claim 1, characterized in that a heating device for heating layers of particles ( 4 ) a component of the carrier ( 2 ) or the carrier ( 2 ) or at one of the installation space ( 1 ) forming object or as a radiator above the installation space ( 1 ) is arranged. Device according to claim 1, characterized in that at least one external acousto-optical modulator for the laser beam control of the laser ( 9 ) in pulsed mode or in cw mode in the beam direction after the laser ( 9 ) is arranged. Device according to claim 1, characterized in that in the beam path of the laser ( 9 ) at least one beam splitter or a beam switch is located.