DE102021105991A1 - Process for the production of a three-dimensional component - Google Patents

Abstract

The invention relates to a method for manufacturing a three-dimensional component (1) by means of an additive manufacturing method comprising the steps: providing a metallic powder made of powder particles in a device for additive manufacturing of the component (1); Providing a data set for the fully sealed design of the component (1) or a design of the component (1) which has a porosity; providing a data set with process parameters for controlling the device; successive formation of superposed layers from the powder particles according to the geometry of the component (1); Introducing energy into each applied layer to bond the powder particles together; the introduction of the energy via the data set with the process parameters for controlling the device is controlled in such a way that the data set for the fully sealed component (1) is used to generate a component (1) which has pores (3) at least in areas, or so it is controlled that, with the data set for the component (1) exhibiting the porosity, a component (1) is generated which has a higher porosity than corresponds to the data set.

Description

• - Bereitstellen eines metallischen Pulvers aus Pulverpartikeln in einer Vorrichtung zur additiven Herstellung des Bauteils;
• - Bereitstellen eines Datensatzes für die volldichte Ausführung des Bauteils oder eine Ausführung des Bauteils, die eine Porosität aufweist;
• - Bereitstellen eines Datensatzes mit Prozessparametern zur Steuerung der Vorrichtung;
• - Sukzessives Ausbilden von übereinander liegenden Schichten aus den Pulverpartikeln der Geometrie des Bauteils entsprechend;
• - Einbringen von Energie in jede aufgebrachte Schicht, um die Pulverpartikel miteinander zu verbinden.

The invention relates to a method for manufacturing a three-dimensional component by means of an additive manufacturing method, comprising the steps:

• - Provision of a metallic powder from powder particles in a device for additive manufacturing of the component;
• - Provision of a data set for the fully sealed design of the component or a design of the component that has a porosity;
• - Provision of a data record with process parameters for controlling the device;
• - Successive formation of superposed layers from the powder particles according to the geometry of the component;
• - Introduction of energy into each applied layer in order to bind the powder particles together.

The invention further relates to a metallic component comprising a three-dimensional component body which is produced by means of an additive manufacturing process.

Sintering technology has established itself in the automotive supply industry for the large-scale production of components with complex geometry. In addition, processes have always been described that are known under the term additive manufacturing processes. To put it simply, it is essentially a 3D printing process. Originally only used for prototype production, these processes are now also finding their way into small series production.

Such a method is, for example, from DE 10 2018 203 151 A1 known. This document describes a method for producing a three-dimensional component comprising the following steps: producing a body from a first powdery material by means of metallic 3D printing, which at least partially has a hollow structure, the body having at least one opening in the hollow structure, in particular on a little stressed point of the three-dimensional component to be manufactured; Removing the excess first pulverulent material from the hollow structure of the body via the at least one opening in the hollow structure and then either filling the hollow structure of the body with a second pulverulent material; Re-compacting the second pulverulent material by means of a vibrating device; Removal of additives used during metallic 3D printing; Sintering the body made of the first material with the powdery second material, so that the three-dimensional component is produced; Removal of the finished three-dimensional component; or removing additives used during metallic 3D printing; Sintering the body of first material with a first sintering setting; Filling the hollow structure of the body with a second powdery material; Re-compacting the second material by means of a vibrating device; Sintering the body made of the first material with the powdery second material with a second sintering setting, so that the three-dimensional component is produced; Removal of the finished three-dimensional component.

The present invention is based on the object of reducing the manufacturing costs of three-dimensional (metallic) components with an additive manufacturing process.

The object of the invention is achieved in the method mentioned at the outset in that the introduction of the energy is controlled via the data set with the process parameters for controlling the device so that a component is generated with the data set for the fully sealed component that has pores at least in areas or is controlled in such a way that with the data set for the component having the porosity, a component is generated which has a higher porosity than corresponds to the data set.

Furthermore, the object is achieved with the metallic component mentioned at the outset in that the component body has pores at least in regions.

As a departure from the previously usual procedure that components manufactured using additive manufacturing processes are manufactured in a fully sealed manner in accordance with the CAD data used for manufacturing, the invention generates components that have pores at least in areas by modifying the process parameters accordingly. The procedure is therefore deliberately, i.e. controlled, "poorly" carried out. This in turn allows the component to be built more quickly, which means that the production time and also the energy expenditure for producing the component can be reduced. Surprisingly, it was found that the components produced using the method according to the invention have only slightly poorer mechanical properties than components produced completely. The components manufactured using this method are also lighter in weight, which means that corresponding advantages are achieved when they are installed in motor vehicles, such as lower energy consumption when operating the motor vehicle, lower mass inertia losses, etc.

According to one embodiment variant of the invention, it can be provided that a powder is used that has non-spherical powder particles. This means that individual, non-spherical particles “get stuck” together, preventing the powder gaps from being filled by smaller particles, and therefore promoting the production of porous structures on the basis of the lower bulk density.

According to a further embodiment variant of the invention it can be provided that a water-atomized powder is used as the metallic powder. A gas-atomized powder is normally used in additive manufacturing processes, since gas-atomized powders have more uniform powder grains (powder grain shapes) due to the manufacturing process. Since the method according to the invention deliberately does not produce fully dense structures, it is also possible to use water-atomized powder. This allows the manufacturing costs of the components to be reduced further, since water-atomized powders are cheaper to buy. In addition, the porosity of the components can be increased further.

To further intensify the aforementioned effects, it can be provided according to a further embodiment variant of the invention that a metallic powder is used that has powder particles of grain fractions according to DIN ISO 4497 in the range from 1 μm to 250 μm.

According to one embodiment of the invention, it can be provided that the powder has powder particles from one grain fraction or at least two different grain fractions, the grain fraction being selected or the two grain fractions being selected from five grain fractions, a first grain fraction being powder grains in the range of 1 μm to 45 µm, a second grain fraction of powder grains in the range from 45 µm to 90 µm, a third grain fraction of powder grains in the range of 90 µm to 150 µm, a fourth grain fraction of powder grains in the range of 150 µm to 200 µm and a fifth grain fraction of powder grains in the range from 200 µm to 250 µm. This makes it easier to set the porosity of the component produced in a desired order of magnitude.

For this purpose, according to a further embodiment of the invention, powders are preferably used in which the proportion of each of the first to fifth grain fractions is between 2% by weight and 75% by weight, with the proviso that the proportions of the grain fractions used are 100% by weight .-% sum up.

According to a further embodiment variant of the invention, it can be provided that a component with several mutually different porosities is produced by assigning different process parameter sets to different, predefinable areas of the component. It is thus possible to produce components specifically with areas of low porosity or full density, in which a higher mechanical strength is required, and / or in areas with a higher porosity, in order to reduce the weight of the component or to achieve functional porosity produce, for example, to store liquids such as an oil, to pass them through or to regulate the temperature of the component with a liquid.

According to a special embodiment variant of the invention, it can be provided that the component is manufactured with a denser edge layer by assigning different process parameter sets to different, predefinable areas of the component. It is thus possible to provide a surface layer compaction, as it is produced, for example, in sintered components by rolling, with an additive manufacturing process in just one process step, that is to say without using or changing tools.

According to a further embodiment variant of the invention, a laser beam or an electron beam is preferably used for the energy input, since this allows the targeted setting or changing of the porosity of the component to be carried out more easily.

• - dass der Laserstrahl oder der Elektronenstrahl mit einem Hatchabstand zwischen 0,08 mm und 0,5 mm, insbesondere zwischen 0,08 mm und 0,23 mm, die jeweilige Pulverschicht überstreicht, und/oder
• - dass der Laserstrahl oder der Elektronenstrahl mit einer Scangeschwindigkeit von 500 mm/s bis 1.800 mm/s die jeweilige Pulverschicht überstreicht; oder
• - dass der Laserstrahl oder der Elektronenstrahl mit einer Scangeschwindigkeit von 3200 mm/s bis 5200 mm/s die jeweilige Pulverschicht überstreicht.

In order to further intensify the aforementioned effects, further design variants can be provided,

• - that the laser beam or the electron beam with a hatch distance between 0.08 mm and 0.5 mm, in particular between 0.08 mm and 0.23 mm, sweeps over the respective powder layer, and / or
• - that the laser beam or the electron beam sweeps over the respective powder layer with a scanning speed of 500 mm / s to 1,800 mm / s; or
• - that the laser beam or the electron beam sweeps over the respective powder layer with a scanning speed of 3200 mm / s to 5200 mm / s.

According to another embodiment variant of the invention, it can be provided that the component body has a porosity between 1% and 35% at least in areas. With a porosity of over 35%, the differences in mechanical properties compared to fully sealed components are relatively large, which makes the production of structural components more problematic.

For a better understanding of the invention, it is explained in more detail with reference to the following figures.

• 1 ein Bauteil;
• 2 einen Ausschnitt aus einer ersten Ausführungsvariante des Bauteils nach 1;
• 3 einen Ausschnitt aus einer ersten Ausführungsvariante des Bauteils nach 1;
• 4 Pulverpartikel zur Herstellung des Bauteils.

They each show in a simplified, schematic representation:

• 1 a component;
• 2 a section from a first variant of the component according to 1 ;
• 3 a section from a first variant of the component according to 1 ;
• 4th Powder particles for manufacturing the component.

By way of introduction, it should be noted that in the differently described embodiments, the same parts are provided with the same reference symbols or the same component designations, it being possible for the disclosures contained in the entire description to be transferred accordingly to the same parts with the same reference symbols or the same component designations. The position details selected in the description, such as above, below, to the side, etc., also relate to the figure immediately described and shown and these position details are to be transferred accordingly to the new position in the event of a change in position.

In addition, it should be noted in the introduction that the specification of standards always means the most recent version of the respective standard, unless otherwise stated.

1 shows a component 1 . The component 1 comprises a three-dimensional component body 2 .

The component body 2 preferably comprises or consists of a metallic material. But it is also possible for the component body 2 at least partially use a different material, such as a polymer plastic. It is also possible that the component 1 consists of or has at least two different metallic materials or polymeric plastics.

The component 1 after 1 is designed as a gear. The invention does not apply to gears as components 1 limited. The component 1 can, for example, also be a sliding sleeve, a synchronizer ring, a connecting rod, a bearing cover for a split bearing arrangement, a bearing element, a transmission component, etc. In general, the component can 1 be a structural component, but also a component for a functional application of a porous structure, such as a filter, a porous heating, cooling and / or lubricating structure.

The component 1 is manufactured using an additive manufacturing process. For example, the component 1 by means of powder bed fusion, such as laser powder bed fusion or electron beam powder bed fusion. In this context, the terms Selective Laser Sintering (SLS) or Selective Laser Melting (SLM) or Selective Heat Sintering (SHS) or Electron Beam Melting (EBM) should be mentioned.

Since these methods are known per se, reference is made to the relevant prior art (to avoid repetitions) for further details.

As in particular from the 2 and 3 can be seen, the respective sections from different design variants of the gear 1 show in the area of the spur teeth, the component body 2 Pores 3 on.

Through the pores 3 indicates the component 1 a porosity. This is at least in partial areas or sections or segments of the component 1 educated. For example, the component 1 the pores 3 only in the area of the spur toothing or the edge zone or only in the area of its core, which is formed below the edge zone. But it is also possible that the entire component 1 has this porosity. In addition, it is possible for the component to be designed with a porosity gradient, with the porosity, for example, decreasing or increasing from the edge zone in the direction of the core.

In general, the porosity can be selected from a range from 0% to 55%, with the proviso that a porosity of 0% only in predefinable areas of the component 1 is available. According to a preferred embodiment of the invention, the component 1 however, at least in areas a porosity between 1% and 35%, in particular between 5% and 15%.

The porosity is determined in such a way that the density of the component 1 according to DIN EN ISO 2738 determined and from this determined value based on the density of the corresponding fully dense material, the porosity is calculated. Locally different porosities are determined optically.

The pores 3 can have a length of 5 µm to 2500 µm and a width of 1 µm to 1200 µm. The feret diameter of the pores 3 can have a value between 5 µm and 2000 µm. The equivalent circle diameter can be in the range from 5 µm to 1500 µm.

For the production of the at least partially, in particular completely, metallic three-dimensional component 1 for the time being the at least one in particular metallic, material provided. The at least one material is a powder with powder particles 5 trained like this 4th which shows an electron micrograph of a powder.

The powder is processed using a conventional device (in particular a 3D printer) for the additive manufacturing of components. This device has at least one data memory or at least one data memory is assigned to this device for operation. A first data set (CAD data) for the production of the component is stored in this at least one data memory 1 provided. This data record includes data relating to the geometry.

A second data record with process parameters for controlling the device is also provided in this data memory. The process parameters are used to define, for example, the printing speed or the speed at which the individual layers are formed.

By processing the individual program steps with which the device is operated, the individual layers are used to build up the component 1 successively manufactured one on top of the other or the component in general 1 manufactured.

The device is usually controlled with this data record in such a way that a fully impermeable component is produced, that is to say a component which, apart from imperfections, has no pores. In other words, the individual layers of the component, which are successively deposited on one another, are melted by the input of energy to such an extent that existing cavities between the powder particles are filled with the melt.

In a departure from this procedure known from the prior art, the device is operated with the process parameters in such a way that the component 1 the porosity with the pores 3 having.

In this case, by changing, for example, the speed at which the device for introducing energy into the respectively deposited layer, the device for additive manufacturing of the component 1 has, for example the laser, is moved over the layer or the power output by this device, or the so-called hatch distance or the layer thickness of the deposited layer, etc., the porosity of the component 1 getting produced. The process parameters mentioned can also be referred to as exposure parameters.

Thus, within the scope of the invention, the process parameters are deliberately changed in such a way that no fully sealed component is produced from the first data set for the fully sealed component. In other words, the method for producing a fully sealed component corresponding to the first data set is used 1 deliberately poorly executed.

As is known, the above-mentioned hatch distance denotes the distance between the exposure lines from one another in the horizontal direction.

With the device for the introduction of energy into the respectively deposited layer, the powder particles 5 connected within a layer and with the layer immediately below it, in particular in which the powder particles 5 be melted at least superficially.

A laser beam or an electron beam is preferably used for the energy input.

• Hatchabstand: zwischen 0,08 mm und 0,23 mm
• Scangeschwindigkeit, mit der Laserstrahl oder der Elektronenstrahl über die abgelegten Pulverpartikel 5 bewegt wird: 800 mm/s bis 1300 mm/s oder 3200 mm/s bis 5200 mm/s
• Laserleistung: von 100 Watt bis 1000 Watt

Preferred process parameters (i.e. exposure parameters mentioned in particular) are:

• Hatch spacing: between 0.08 mm and 0.23 mm
• Scanning speed with the laser beam or the electron beam over the deposited powder particles 5 is moved: 800 mm / s to 1300 mm / s or 3200 mm / s to 5200 mm / s
• Laser power: from 100 watts to 1000 watts

In particular, these process parameters are used to produce layer thicknesses between 40 µm and 80 µm, for example from 40 µm to 50 µm.

In particular in the case of a larger or large hatch distance and a fast scanning speed, not enough energy can be introduced to fuse a voxel in a fully sealed manner. The larger the hatch distance and / or the scanning speed, the larger the pores become 3 and / or the number of pores 3 .

According to one embodiment of the invention, preference is given to producing the porous or porous structure in the component 1 non-spherical powder particles 5 used, such as this one from 4th can be seen. In particular, according to a further embodiment variant, so-called water-atomized powders are used as the powder, since, in comparison to gas-atomized powders, these normally non-spherical powder particles due to the manufacturing process 5 exhibit.

In principle, the powder used can be powder particles 5 have different sizes. According to a preferred embodiment of the invention, however, powders are used, the powder particles 5 of grain fractions according to DIN ISO 4497 in the range from 1 µm to 250 µm, or im Range from 1 µm to 150 µm, in particular between 20 µm and 63 µm.

According to a further embodiment variant of the invention, it can be provided that the powder is powder particles 5 of at least two different grain fractions, the two grain fractions being selected from five grain fractions, a first grain fraction having powder grains in the range from 0 µm to 45 µm, a second grain fraction having powder grains in the range from 45 µm to 90 µm, a third grain fraction having powder grains in Range from 90 µm to 150 µm, a fourth grain fraction of powder grains in the range of 150 µm to 200 µm and a fifth grain fraction of powder grains in the range of 200 µm to 250 µm.

According to a further embodiment of the invention, the proportion of each of the first to fifth grain fractions can be between 2% by weight and 75% by weight, with the proviso that the proportions of the grain fractions used add up to 100% by weight.

In the context of the invention, however, it is also possible to use a powder, the powder particles 5 comprises only one of these named grain fractions, that is to say 100% by weight of this grain fraction.

The metallic powder can be a pure metal powder or an alloy powder or a powder mixture of different metallic powders (pure metals and / or alloys). For example, the powder may be an iron powder or an iron alloy powder or a titanium powder or a titanium alloy powder or an aluminum powder or an aluminum alloy powder.

As already stated above, according to a further embodiment variant of the invention it can be provided that a component can be made by assigning different process parameter sets to different, predefinable areas or sections or segments of the component 1 is produced with different porosities, ie a component 1 , which has areas with mutually different porosities.

According to one embodiment variant, it can be provided that by assigning the different process parameter sets to different, predefinable areas or sections or segments of the component 1 the component 1 is made with a denser edge layer.

It is possible with the invention components 1 with a higher build-up rate than is usual with fully dense 3D printing.

In the course of tests, construction rates of approx. 10 cm ³ per hour could be achieved with a fully sealed design of the printed volume. With the method according to the invention this could be increased to 20 cm ³ per hour - 50 cm ³ per hour or even further. By choosing, for example, a layer thickness of 50 µm, a hatch spacing of 0.23 mm and a scanning speed of 1300 m / ^{h, a build rate of 53.82 cm 3} per hour with a porosity of 27% can be achieved.

The exemplary embodiments show possible design variants, whereby it should be noted at this point that combinations of the individual design variants with one another are also possible.

In particular, a device (in particular a 3D printer) for the additive manufacture of a component 1 an invention within the scope of this invention or an independent invention if it has a device for the introduction of energy into a powder that was previously deposited with the device (on a base), in particular a laser, and at least one data memory, in which at least a data memory a data set relating to the fully dense geometry of the component 1 and a data record with process parameters is stored if the data for the fully sealed production of the component is stored with the process parameter data record 1 processed in such a way that instead of a fully sealed component 1 a component 1 with pores 3 will be produced.

For the sake of order, it should finally be pointed out that for a better understanding of the structure, the component 1 is not necessarily shown to scale.

List of reference symbols

1

Component

2

Component body

3rd

pore

4th

diameter

5

Powder particles

QUOTES INCLUDED IN THE DESCRIPTION

This list of the documents listed by the applicant was 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.

Patent literature cited

• DE 102018203151 A1 [0004]

Non-patent literature cited

• DIN EN ISO 2738 [0031]

Claims (15)

Method for manufacturing a three-dimensional component (1) by means of an additive manufacturing method comprising the steps: - providing a metallic powder from powder particles in a device for additive manufacturing of the component (1); - Provision of a data set for the fully sealed design of the component (1) or a design of the component (1) which has a porosity; - Provision of a data record with process parameters for controlling the device; - successive formation of superposed layers from the powder particles according to the geometry of the component (1); Introducing energy into each applied layer in order to bind the powder particles together; characterized in that the introduction of the energy via the data set with the process parameters for controlling the device is controlled in such a way that the data set for the fully sealed component (1) is used to generate a component (1) which has pores (3) at least in areas , or is controlled so that with the data set for the component (1) exhibiting the porosity, a component (1) is generated which has a higher porosity than corresponds to the data set. Procedure according to Claim 1 , characterized in that a powder is used that has non-spherical powder particles (5). Procedure according to Claim 1 or 2 , characterized in that a water-atomized powder is used as the metallic powder. Method according to one of the Claims 1 until 3 , characterized in that a metallic powder is used which has powder particles (5) of grain fractions according to DIN ISO 4497 in the range of 1 µm - 250 µm. Procedure according to Claim 4 , characterized in that the powder has powder particles (5) from at least two different grain fractions, the two grain fractions being selected from five grain fractions, a first grain fraction having powder grains in the range from 1 µm to 45 µm, a second grain fraction having powder grains in the range of 45 µm to 90 µm, a third grain fraction of powder grains in the range of 90 µm to 150 µm, a fourth grain fraction of powder grains in the range of 150 µm to 200 µm and a fifth grain fraction of powder grains in the range of 200 µm to 250 µm. Procedure according to Claim 5 , characterized in that the proportion of each of the first to fifth grain fractions is between 2% by weight and 75% by weight, with the proviso that the proportions of the grain fractions used add up to 100% by weight. Method according to one of the Claims 1 until 6th , characterized in that a component (1) with different porosities is produced by assigning different sets of process parameters to different, predefinable areas of the component (1). Procedure according to Claim 7 , characterized in that by assigning different sets of process parameters to different, predefinable areas of the component (1), the component (1) is produced with a denser edge layer. Method according to one of the Claims 1 until 8th , characterized in that a laser beam or an electron beam is used for the energy input. Procedure according to Claim 9 , characterized in that the laser beam or the electron beam sweeps over the respective powder layer with a hatch distance between 0.08 mm and 0.29 mm. Procedure according to Claim 9 or 10 , characterized in that the laser beam or the electron beam sweeps over the respective powder layer at a scanning speed of 800 mm / s to 1300 mm / s. Procedure according to Claim 9 or 10 , characterized in that the laser beam or the electron beam sweeps over the respective powder layer at a scanning speed of 3200 mm / s to 5200 mm / s. Metallic component (1) comprising a three-dimensional component body (2) which is produced by means of an additive manufacturing process, characterized in that the component body (2) has pores (3) at least in certain areas. Component (1) after Claim 13 , characterized in that it is made from a water-atomized metallic powder. Component (1) after Claim 13 or 14th , characterized in that the component body (2) has a porosity between 1% and 35% at least in areas.

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