DE102023123492A1 - process for producing a component - Google Patents

Abstract

In a method for producing a component (1) from at least two different materials (2, 4), a mold (2a) is produced from a first material (2) in powder form by means of selective laser melting. A second material (4) in powder form is introduced into the mold (2a) formed by the first material. Pressure and heat are applied to the second material so that it forms a filling (4a) in the mold (2a).

Description

The invention relates to a method for producing a component from at least two different materials. Furthermore, the invention relates to a method for producing a component from a powdered material with magnetic properties.

The general state of the art provides a wide variety of processes for producing components from materials in powder form. The process of selective laser melting or laser powder bed fusion (LPBF), which is often colloquially referred to as 3D printing, is often used for this purpose.

In order to produce components from two or more different materials, the known processes usually use two or more print heads or similar devices, which, however, represents a considerable amount of effort.

It is therefore an object of the present invention to provide a method for producing a component from at least two different materials, which can be carried out using simple means and with which high-quality components can be produced.

According to the invention, this object is achieved by the features mentioned in claim 1.

In the method according to the invention for producing a component, a mold is created from a first material, which is in powder form, by means of selective laser melting. During selective laser melting, the first material is melted and then solidifies into the mold. A second material, also in powder form, is introduced into this mold formed by the first material and pressure and heat are applied to it so that it forms a filling within the mold formed by the first material. In other words, the second material is attached to the mold formed by the first material by means of sintering and is thus connected to the first material.

The method according to the invention can be carried out with comparatively little effort, in particular with regard to the use of machines, apparatus and the like. In particular, only one device is required for carrying out the selective laser melting and not, as in the methods known from the prior art, at least two or more such devices.

The component produced using the method according to the invention is of very high quality, particularly in the transition area between the two materials, since the application of pressure and heat causes the second material, which is in powder form, to take up the entire cavity created by the first material. However, the shape produced from the first material is not changed. The method according to the invention can therefore be used to produce very high-quality and, in particular, very individual components, since selective laser melting enables a very large variety of shapes to be produced.

A very advantageous development of the invention can consist in the second material having at least one different property than the first material. This makes it possible to produce a component that has different properties in different areas. For example, the second material can have a lower strength than the first material. In this way, damage to the shape formed from the first material is prevented when the second material is introduced and in particular when pressure is applied to it. Additionally or alternatively, the two materials can have very different properties, for example high or low electrical conductivity. Thanks to three-dimensional additive manufacturing, these properties can also be designed to be direction-dependent and locally different. This makes it possible to realize component properties that are not possible by using a single material alone.

In a further advantageous embodiment of the invention, it can be provided that the mold formed by the first material has a frame that forms a cavity for receiving the second material. In this case, a mold is formed from the first material by means of selective laser melting, which mold has a frame so that the second material can be introduced into the cavity formed by the frame. In this way, it is ensured that the entire second material in powder form remains in the mold and thus contributes to the formation of the component. In this case, the frame becomes a component of the component produced using the method according to the invention.

Alternatively, it can be provided that an additional frame is arranged on the form formed by the first material, which forms a cavity for receiving the second material. This allows greater freedom in the design of the form formed from the first material. The additional frame, which in this case does not become part of the component produced by the method according to the invention, the second material is limited in its expansion and the force acting on the second material due to the pressure exerted on it is absorbed.

Particularly high-quality components are produced when both materials are metals.

A further improvement in the quality of the components produced by the method according to the invention results if at least one surface thereof is ground and/or polished.

An alternative solution to the problem is given in claim 7.

In this process, a first part of a powdered material with magnetic properties is processed into a solid component using selective laser melting. A second part of the powdered material is not processed using selective laser melting and remains in powder form. The part of the powdered material processed into the solid component using selective laser melting forms a casing for the material that is not processed using selective laser melting and remains in powder form.

This method makes use of the phenomenon that certain materials are magnetic in powder form, but lose these magnetic properties when processed using selective laser melting. As a result, the second part of the powdered material, which is not processed using selective laser melting and remains in powder form, retains its magnetic properties and is, according to the invention, encased by the material processed into the solid component using selective laser melting.

Such a component produced by the method according to the invention, which has a magnetic region enclosed in a non-magnetic region, can be used for a wide variety of applications.

A very advantageous development of this method can consist in aligning the part remaining in powder form in a magnetic field and filling any cavities in the part remaining in powder form with a polymer or glass. In this way, a specific magnetic property of the second part of the magnetic material remaining in powder form can be fixed.

Furthermore, it can be provided that the powdered material is an alloy that passes through a multi-phase region when solidifying. For example, the powdered material can be a stainless steel, usually completely or partially austenitic, designated 1.4401, 1.4404 or 1.4435. The inventors have surprisingly found that when this material is converted from solid form to powder form, which can be carried out using an atomization process, for example using the known ultrasonic plasma atomization process, the powdered material has magnetic properties and a ferritic structure. The atomization process should enable the melt to cool down sufficiently quickly so that a ferritic structure is created. The rapid cooling stabilizes one phase and suppresses the formation of the second phase. It is even possible for each powder particle to form a single crystal with a ferritic structure. However, when this powder is converted from powder form back into solid form using selective laser melting, these magnetic properties and the ferritic structure are lost. The properties of a component made from the powder produced by the atomization process correspond to those of a component made from a normal powder made from the same alloy. However, the process described can also be applied to other alloys that pass through a multiphase region when solidifying, for example alloys based on titanium, nickel or copper.

In the following, embodiments of the invention are shown in principle with reference to the drawing.

• 1 einen ersten Schritt bei der Durchführung eines ersten erfindungsgemäßen Verfahrens;
• 2 einen zweiten Schritt bei der Durchführung des erfindungsgemäßen Verfahrens;
• 3 ein mittels des Verfahrens aus den 1 und 2 hergestelltes Bauteil;
• 4 einen ersten Schritt bei der Durchführung eines zweiten erfindungsgemäßen Verfahrens; und
• 5 ein mittels des zweiten erfindungsgemäßen Verfahrens hergestelltes Bauteil.

It shows:

• 1 a first step in carrying out a first method according to the invention;
• 2 a second step in carrying out the method according to the invention;
• 3 a by means of the procedure from the 1 and 2 manufactured component;
• 4 a first step in carrying out a second method according to the invention; and
• 5 a component produced by means of the second method according to the invention.

In the 1 to 3 are several steps of a process for producing a 3 in its finished state. The component 1 consists of at least two different materials, in the present case of exactly two different materials, both of which are in powder form. Preferably, the two materials are metals or alloys, such as bronze and silver. Of course, other metals and alloys are also conceivable, such as two different gold alloys with different colors, a combination of gold and titanium alloys, a combination of gold and platinum alloys, a silver alloy with stainless steel, bronze with stainless steel or a cobalt-chromium alloy with a silver alloy or stainless steel.

In 1 A process step is shown in which a mold 2a is produced from a first material 2 by means of selective laser melting. For this purpose, a very schematic device 3 is used, of which 1 only a laser head suitable for selective laser melting is shown. Since the process of selective laser melting is known per se, it will not be discussed in more detail here.

In the 2 In the process step shown, a second material 4, also in powder form, is introduced into the mold made from the first material 2. In a further step, the second material is connected to the first material 2 by applying pressure and heat and forms a filling 4a within the mold 2a formed by the first material 2. The connection between the first material 2 and the second material 4 or between the mold 2a and the filling 4a is preferably such that all surfaces of the component 1 are completely sealed. The pressure can be applied on one side or all sides at room temperature or elevated temperatures. One or more surfaces of the component 1 can then be ground and/or polished. In the present case, the second material 4 has a lower strength than the first material 2. Furthermore, the second material 4 preferably has a lower melting point than the first material 2.

The mold 2a formed by the first material 2 has a frame 5 which forms a cavity 6 for receiving the second material 4.

In a manner not shown, an additional frame could also be arranged on the mold 2a formed by the first material 2, which could then form the cavity 6 for receiving the second material 4.

In 5 another component 7 is shown, which is manufactured using a method described below. A powdered material 8 with magnetic properties is used as the material for the component 7. The powdered material 8 is preferably a stainless steel with the designation 1.4404 or AISI 316L. The powdered material 8 is preferably brought from its previously solid state into the powdered state by means of ultrasonic plasma atomization. It has been found that after the ultrasonic plasma atomization of the material mentioned from the solid form into the powder form, the previously non-magnetic material with an austenitic structure has magnetic properties and a ferritic structure in its powder form. During ultrasonic plasma atomization, the current strength of the burner, the amplitude of the ultrasonic oscillation and/or the strength of the protective gas flow in the process chamber can be varied.

A first part 9 of the powdered material 8 is processed into a solid component by means of selective laser melting. For this purpose, as in 4 shown, the device 3 already described above can be used. During this processing by means of selective laser melting, the magnetic properties of the powdered material 8 described above are lost. A second part 10 of the powdered material 8 is not processed by means of selective laser melting and remains in powder form.

As in 5 As can be seen, the part 9 of the powdered material 8 processed into the solid component by means of selective laser melting forms a casing for the second part 10 of the material 8 which has not been processed by means of selective laser melting and remains in powder form. The second part 10 of the powdered material 8 can then be aligned in a magnetic field and cavities present in the second part 10 of the powdered material 8 can be filled with a polymer or glass. In particular, it can be metallic glass, which can be filled into the cavities in a manner known per se, for example as a melt or by thermoplastic molding, and then solidifies in a manner also known per se.

A further advantage resulting from the above-described magnetic and non-magnetic properties of the powdered material 8 is that when magnetic and non-magnetic materials are used simultaneously, they can be separated from one another after a printing process by means of the known method of magnetic separation, thus reducing the amount of waste. Such a separation method could be used independently of the method described with reference to the 4 and 5 described procedures.

Claims (10)

Method for producing a component (1) from at least two different materials (2,4), wherein a first material (2) in powder form is melted by means of selective laser zen a mold (2a) is created, wherein a second material (4) in powder form is introduced into the mold (2a) formed by the first material, and wherein pressure and heat are applied to the second material so that it forms a filling (4a) in the mold (2a). procedure according to claim 1 , characterized in that the second material (4) has at least one different property than the first material (2). procedure according to claim 1 or 2 , characterized in that the mold (2a) formed by the first material (2) has a frame (5) which forms a cavity (6) for receiving the second material (4). procedure according to claim 1 or 2 , characterized in that an additional frame is arranged on the mold (2a) formed by the first material (2), which frame forms a cavity (6) for receiving the second material (4). Method according to one of the Claims 1 until 4 , characterized in that the two materials (2,4) are metals. Method according to one of the Claims 1 until 5 , characterized in that at least one surface of the component (1) is ground and/or polished. Method for producing a component (7) from a powdery material (8) with magnetic properties, wherein a first part (9) of the powdery material (8) is processed into a solid component by means of selective laser melting, wherein a second part (10) of the powdery material (8) is not processed by means of selective laser melting and remains in powder form, and wherein the part (9) of the powdery material (8) processed into the solid component by means of selective laser melting forms a casing for the part (10) not processed by means of selective laser melting and remaining in powder form. procedure according to claim 7 , characterized in that the part (10) remaining in powder form is aligned in a magnetic field and cavities present in the part (10) remaining in powder form are filled with a polymer or glass. procedure according to claim 7 or 8 , characterized in that the powdered material (8) is an alloy which passes through a multi-phase region during solidification. procedure according to claim 7 , 8 or 9 , characterized in that the powdery material (8) is produced by means of an atomization process.

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