DE102017223259A1 - METHOD AND DEVICE FOR CLEANING PARTIALLY MANUFACTURED COMPONENTS DURING GENERATIVE PRODUCTION - Google Patents

Abstract

The present invention relates to a method and apparatus for the generative production of components by layered application of powder material on a substrate or a previously prepared part of a component and at least partially cohesive bonding of the powder material in the powder layer corresponding to the component sectional contour along the powder layer and with an underlying Solid material of the component or substrate for forming a plurality of superposed solid layers (14) by a high-energy beam (13), wherein after the material connection of the powder material, the just-generated solid layer (14) of powder material is cleaned by vibration.

Description

BACKGROUND OF THE INVENTION

FIELD OF THE INVENTION

The present invention relates to a method for the generative production of components by layered application and cohesive bonding of powder material and an apparatus for performing a corresponding method.

STATE OF THE ART

Generative manufacturing processes for the production of a component are used in the industry for so - called rapid - tooling, rapid - pototyping or in the production of series products within the scope of rapid manufacturing. Examples of generative methods of production by means of a high-energy beam are selective laser melting, selective laser sintering, electron beam melting and comparable methods.

In these methods, the component to be produced is built up in layers of powder material, wherein the powder material is applied according to the applied layer in a powder layer on a substrate or an already manufactured part of a component to then by melting or sintering of the powder by the high-energy beam connection of the powder material with each other and to create the component. Other generative methods, such as in the WO 2017/087572 A1 described, use the selective application of adhesive or the like to fix powder particles at least in an intermediate step in the desired shape and after removal of excess powder material, the resulting green body by melting or sintering into the finished component.

In order to produce a powder layer with a high-energy beam on the component, a powder bed can be used, in which the already produced part of the component is arranged and is covered in the direction of the construction of the component by a powder layer, which selectively according to the contour in the Cutting plane of the component to be produced is to be deposited on the component. The surface of the powder bed is chosen so that between the already produced component and the surface of the powder bed, the powder layer is present with the desired thickness, which is to be deposited in the next step as a solid state layer on the component by melting or sintering and subsequent re-solidification. By selective melting or sintering according to the pattern of the component to be produced in the respective layer and subsequent solidification three-dimensional objects can be generated.

Corresponding devices and methods are already known from the prior art, as described inter alia in the DE 10 2013 223 587A1 and the WO 2015/196 149 A1 are described. Furthermore, methods and devices for the aftertreatment of generatively produced components are known, such as from US 2017/0036401 A1 ,

In the generative production must be ensured that no impurities are introduced into the deposited powder layer in order to avoid a negative effect on the properties of the generatively produced component.

DISCLOSURE OF THE INVENTION

OBJECT OF THE INVENTION

It is therefore an object of the present invention to provide a method for the generative production of components, in which the introduction of defects can be avoided or at least greatly reduced. In particular, a method and a corresponding device for the production of generatively produced components are therefore to be provided, which make it possible to produce error-free and homogeneous components as possible, although the method should be efficient and reliable feasible and the cost of a corresponding device are kept low should.

TECHNICAL SOLUTION

This object is achieved with a method for the generative production of components with the features of claim 1 and a device with the features of claim 10. Advantageous embodiments are the subject of the dependent claims.

The present invention proposes to improve the accuracy of generatively produced components, that after the deposition of a solid state layer, so after the application of powder material and cohesive bonding of the powder material itself and with an underlying material of a substrate or an already manufactured component, at least the last deposited solid layer is cleaned of the powder material by vibration. This ensures that no loose powder particles are incorporated into the next layer to be applied.

In particular, the cleaning of the solid state layer of powder material by vibration take place after each deposition of a solid state layer, so that in each case a cleaning by vibration is performed between each two successive deposits of solid layers.

In addition, the cleaning by vibration to remove loosely adhering powder material depending on the geometry of the component or the requirements for freedom only before or near the deposition of certain solid layers, for example, in the production of particularly stressed or thin component areas or particularly thick powder layers in one Separating process can be applied so that loose powder particles in underlying layers can no longer be sintered or melted.

In particular, however, the cleaning by vibration during the manufacturing process, ie before the final completion of the component can be used to prevent defects in the component.

The vibration used for the cleaning or removal of loosely adhering powder particles can be carried out by appropriate vibration of the already partially produced component and / or by vibration of a component receptacle on which the component to be produced is mounted during the manufacturing process. For this purpose, a corresponding device for the generative production of components has a vibration device, which may comprise at least one actuator for vibration generation and / or at least one ultrasonic transmitter.

Accordingly, the vibration can be carried out in particular with ultrasonic frequency.

The cleaning of the solid-state layer of loosely adhering powder material by vibration can be assisted by a variety of different cleaning methods that can be performed simultaneously or with a time lag and allow for proper removal of loose powder material. In particular, mechanical methods for removing the powder material, such as brushing, stripping, or non-contact methods for removing powder material can be used, such as the suction or spraying or spraying with a fluid, in particular with compressed air or other gases. When using the suction of powder material, the corresponding device may have a suction device, which may be arranged in particular on a slider for the application of a powder layer.

For cleaning, the already partially manufactured component can be lifted from a surrounding powder bed.

The cohesive bonding of the powder material can be carried out by any known methods for the generative production of components by selective irradiation with a high-energy beam, in particular by selective laser beam melting, selective laser beam sintering, selective electron beam melting or selective electron beam sintering.

list of figures

• 1 eine schematische Darstellung einer Ausführungsform einer erfindungsgemäßen Vorrichtung zur generativen Herstellung von Bauteilen am Beispiel des selektiven Laserschmelzens und in
• 2 eine Darstellung des Verfahrensablaufs gemäß einem Ausführungsbeispiel des erfindungsgemäßen Verfahrens.

The accompanying drawings show in a purely schematic manner in FIG

• 1 a schematic representation of an embodiment of a device according to the invention for the generative production of components using the example of selective laser melting and in
• 2 a representation of the process flow according to an embodiment of the method according to the invention.

EMBODIMENTS

Further advantages, characteristics and features of the present invention will become apparent in the following detailed description of embodiments, wherein the invention is not limited to these embodiments.

The 1 shows in a purely schematic representation of a device 1 as can be used, for example, for the selective laser melting for the generative production of a component. The device 1 includes a lift table 2 on whose platform a semi-finished product 3 (Part of a component) is arranged on the layer-by-layer material is deposited to produce a three-dimensional component. For this purpose, by means of the slider 8th powder 10 that is above a lift table 9 in a powder supply, layer by layer over the semifinished product 3 pushed and then by the laser beam 13 a laser 4 by melting with the already existing semi-finished product 3 connected. The compound of the powder material in a powder layer with the semifinished product 3 done by the laser 4 depending on the desired contour of the component to be manufactured, so that any, three-dimensional shapes can be generated. Accordingly, the laser beam becomes 13 over the powder bed 12 guided to melt by different impact points on the powder bed according to the contour of the three-dimensional component in the layer plane to be produced corresponding cutting plane powder material and to connect with the already generated part of a component or an initially provided substrate. Here, the laser beam 13 by a suitable deflection unit over the surface of the powder bed 12 be guided and / or that Powder bed or the lifting table 2 could be compared to the laser beam 13 to be moved.

To avoid unwanted reactions with the ambient atmosphere during melting or sintering, the process can take place in a closed space through a housing 11 the device 1 is made available, and it can also be provided an inert gas atmosphere, for example, to avoid oxidation of the powder material and the like during deposition. As an inert gas, for example, nitrogen can be used, which can be provided via a gas supply, not shown.

Instead of the inert gas and another process gas could be used, for example, if a reactive deposition of the powder material is desired.

In addition, other types of radiation are conceivable, such as electron beams or other particle beams or light beams, which are used in stereolithography.

The slider 8th is simultaneously designed as a leveling and smoothing slider to the powder layer above the semifinished product 3 to smooth and set to a specific layer thickness. However, it is also conceivable that the slider 8th merely causes the coarse provision of the powder material and an additional (not shown here) leveling and smoothing slide is used.

The leveling and smoothing slider 8th serves to the desired thickness D of the powder layer 5 as seen in the detail view of the 1 is shown to set defined and also to ensure that the powder bed surface 6 the powder layer 5 smooth and flat, otherwise inaccuracies and irregularities in the component produced could arise.

The device 1 further comprises a cleaning device in the form of a suction device 7 on, for cleaning the last deposited solid state layer and the already manufactured component 3 serves. After the powder layer 5 or the powder material present therein with the laser beam 13 the laser 4 according to the shape of the component to be produced in section along the powder layer 5 has been melted and after the solidification of the molten powder material to a solid state layer 14 has become (as in the representations 15 and 16 in 2 shown), the cleaning device in the form of a suction device 7 used to the solid state layer 14 and to clean parts of the previously produced component of powder material. The suction device 7 is here on the slide 8th arranged so that the suction device 7 through the slider 8th over the already partially produced component 3 can be moved.

In addition, the device has a vibration device 18 on, in the example shown on the lift table 2 is arranged to allow the lift table 2 and thus to put the component receptacle and the component arranged thereon in vibrations, so that loosely adhering powder particles can be solved.

For cleaning with the vibration assembly 18 and the suction device 7 becomes the component 3 with the lift table 2 raised so that the component 3 at least with the last-produced solid-state layer 14 , preferably with several, for example, 5 to 20 of the last-produced solid layers of the powder bed 12 protrudes. Then the suction device 7 by a movement according to the arrow in 1 over the already manufactured component 3 guided by the movement relative to the component 3 the last produced solid layer and parts of the component 3 clean from loose powder material. At the same time we the lift table 2 through the vibration device 18 vibrated so that the already partially manufactured component 3 vibrates and loose powder particles are shaken loose.

The procedure is described in the 2 through the representations 15 to 17 shown in detail. In the process step 1 as shown 15 is at an in 2 not shown in detail powder layer by the laser beam 13 the laser 4 the powder material partially according to the shape of the component to be produced 3 melted and thus forms after solidification a solid state layer 14 according to the sectional plane of the component to be produced 3 out. In the second process step according to the illustration 16 becomes the component 3 with the solid state layer formed thereon 14 from the powder bed 12 raised so that the component 3 at least with the last-produced solid-state layer 14 and preferably further, previously generated solid layers protruding from the powder bed. Then in the third step of the representation 17 the suction device 7 over the powder bed 12 protruding part of the already manufactured component 3 while at the same time the lift table 2 with the partially manufactured component 3 vibrates to the last solid state layer produced 14 and adjacent parts of the previously manufactured component 3 from the powder material. The cleaning step may be repeated several times in succession, so that the suction device 7 can be reciprocated several times to remove loose powder material.

Although the present invention has been described in detail with reference to the embodiments, it will be understood by those skilled in the art that the invention is not limited to these embodiments, but rather changes in the manner that individual features can be omitted or other combinations of features can be realized as long as the scope of protection of the appended claims is not abandoned. The present disclosure includes all combinations of the features presented.

LIST OF REFERENCE NUMBERS

1

device

2

Lift table

3

semis

4

laser

5

powder layer

6

Powder bed surface

7

suction

8th

pusher

9

Lift table

10

powder

11

casing

12

powder bed

13

laser beam

14

Solid layer

15

step 1

16

Procedural step 2

17

step 3

18

vibrator

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• WO 2017/087572 A1 [0003]
• DE 102013223587 A1 [0005]
• WO 2015/196149 A1 [0005]
• US 2017/0036401 A1 [0005]

Claims (12)

A method for the generative production of components by layered application of powder material on a substrate or a previously manufactured part of a component and at least partially cohesive bonding of the powder material in the powder layer corresponding to the component sectional contour along the powder layer and with an underlying solid material of the component or substrate for the formation of a plurality of superposed solid layers (14) by a high-energy beam, characterized in that after the cohesive bonding of the powder material, the just-generated solid state layer (14) of powder material is cleaned by vibration. Method according to Claim 1 , characterized in that the cleaning of the solid state layer (14) of powder material takes place after each deposition of a solid layer. Method according to Claim 1 characterized in that the cleaning of the solid state layer (14) comprises the removal of powder material from one or more solid layers deposited prior to the last applied solid state layer. Method according to one of the preceding claims, characterized in that the cleaning takes place by removal of powder material from the solid state layer (14) prior to the application of a new solid state layer, in particular before each application of a new solid state layer. Method according to one of the preceding claims, characterized in that the vibration by vibration of the partially manufactured component and / or the component takes place. Method according to one of the preceding claims, characterized in that the vibration takes place with ultrasonic frequency. Method according to one of the preceding claims, characterized in that the cleaning of the partially manufactured component is assisted by additional cleaning methods which are applied simultaneously or with a time delay, in particular methods from the group, the mechanical removal of the powder material, brushing, stripping, suction, cleaning Spraying or spraying with a fluid, blowing off with compressed air or other gases. Method according to one of the preceding claims, characterized in that for the application of the powder material, a powder bed is provided, in which the partially manufactured component or substrate is arranged, wherein the partially manufactured component is lifted for cleaning at least partially from the powder bed. Method according to one of the preceding claims, characterized in that the cohesive bonding of the powder material is effected by selective laser melting or sintering or by selective electron beam melting or sintering. Device for carrying out the method according to one of the preceding claims, having a component receptacle (2) for receiving a substrate or an already partly manufactured component and having a powder applicator with a powder bed (12) which at least partially surrounds the component or substrate in the component receptacle, wherein a powder layer to be deposited as a layer can be applied to the substrate or the component with the powder application device and wherein the component receptacle is adjustable relative to the surface of the powder bed, characterized in that the device comprises a vibration device (18) with which the partially manufactured component (3 ) and / or the component holder can be vibrated. Device after Claim 10 , characterized in that the vibration device (18) comprises at least one actuator for generating vibrations and / or at least one ultrasonic transmitter. Device after Claim 10 or 11 , characterized in that the device comprises a suction device (7) which is in particular integrated on a slide (8) for applying the powder material.

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