CN112203858A

CN112203858A - Apparatus for heating a component material, additive manufacturing facility and method of additive manufacturing

Info

Publication number: CN112203858A
Application number: CN201980036158.5A
Authority: CN
Inventors: 米夏埃尔·奥特
Original assignee: Siemens AG
Current assignee: Siemens AG
Priority date: 2018-05-28
Filing date: 2019-05-06
Publication date: 2021-01-08
Also published as: DE102018208400A1; EP3740381A1; WO2019228755A1

Abstract

An apparatus (300) for selectively heating a component material (P) for additively manufacturing a component (10), in particular on the basis of a powder bed, is proposed. The apparatus comprises: a platform (200) with a heating head (L), in particular of the induction type; and a suspension (201) carrying the platform (200) and configured to move the platform (200) in a controlled manner along three perpendicular spatial directions (X, Y, Z) within a build space (AR) of the additive manufacturing facility (100). Furthermore, an additive manufacturing facility (100) and a corresponding method for additive manufacturing are proposed, the additive manufacturing facility comprising the apparatus (300).

Description

Apparatus for heating a component material, additive manufacturing facility and method of additive manufacturing

Technical Field

The invention relates to an apparatus for heating or preheating a component material, in particular selectively, in additive manufacturing. The component material is preferably a powder material for additive manufacturing of the component in a powder bed based manner. Furthermore, an additive manufacturing facility is proposed, which comprises the apparatus, and a method for additive manufacturing a component is proposed.

Background

The component is preferably provided for use in a fluid machine, preferably in the hot gas path of a gas turbine. The component is preferably composed of a nickel-based or cobalt-based superalloy. The alloy can be precipitation hardenable or precipitation hardenable.

Modern gas turbines are the subject of constant improvement in order to increase their efficiency. However, this also leads to higher and higher temperatures in the hot gas path. Recently, metallic materials for rotor blades, especially in the first stage, have been improved with respect to their strength, creep properties and resistance against thermo-mechanical fatigue.

Generative or additive manufacturing is also becoming increasingly interesting for mass manufacturing of the above-mentioned turbine components, such as turbine blades or combustor components, due to their subversive potential for the industry.

Additive manufacturing processes include, for example, as powder bed processes, Selective Laser Melting (SLM) or laser sintering (SLS) or Electron Beam Melting (EBM).

A method for selective laser melting is known, for example, from EP 2601006B 1.

The additive manufacturing method (English: "additive manufacturing") has furthermore proved to be particularly advantageous for components of complex or filament design, such as labyrinth structures, cooling and/or lightweight structures. In particular, additive production by means of a particularly short chain of process steps is advantageous, since the manufacturing or production steps of the component can be carried out almost exclusively on the basis of the respective CAD file and the selection of the respective production parameters.

However, in order to process metals, in particular y' -hardened nickel-based superalloys, without defects or with low defects during additive production or "3D printing" based on powder beds, it is generally necessary to preheat the structure to be built to significantly above 1000 ℃.

Similar methods are known from conventional production (see the technique with the keyword "Hot Box Welding" or "sweet-Welding"). The preheating of the component material or the starting powder via the build platform is, however, not sufficient due to the poor heat conduction of the powdered material, for example, to achieve a corresponding preheating or sufficient heating over the entire build height.

The use of locally acting "induction heating" is described, for example, in WO 2013/152751 a1, where a system of interleaved coils is proposed. However, if the system is integrated in an existing additive manufacturing facility, for example in an SLM facility, in the form of a pre-heating module, the system requires a lot of space, thereby severely limiting the available construction space and or the corresponding build face. Likewise, the system must always be moved back into a "parking position" again when a new powder layer is applied, in order not to collide with the coating device.

Disclosure of Invention

It is therefore an object of the present invention to propose a mechanism that solves the above mentioned problems. In particular, an apparatus is proposed which enables selective or local induction heating of component materials in a simple and intelligent manner. The solution also comprises the operation of the apparatus, for example implemented in an additive manufacturing facility.

The object is achieved by the subject matter of the independent claims. Advantageous embodiments are the subject matter of the dependent claims.

One aspect of the invention relates to a device for, in particular, selectively heating or preheating, component material for the additive, in particular powder bed-based, production of components. The apparatus comprises a platform with a heating head, in particular of the inductive type. A high preheating temperature can be achieved particularly advantageously by means of the described mechanism.

The apparatus further comprises a suspension that carries or holds the platform and is configured to move the platform in three perpendicular spatial directions within a build space of an additive manufacturing facility, for example in a monitored or controlled manner. Contrary to the solutions already described in the prior art, a targeted or controlled movement of the platform along the vertical spatial Z axis in the construction space can also be achieved by the design of the suspension.

The advantages of the proposed solution compared to already known solutions relate, for example, to the possibility of local and intensive preheating at the processing site, i.e. a true local melting process performed "in situ" by a laser or electron beam. The mentioned machining point can thus represent a (movable) melt pool induced in the component material by the energy beam.

Another advantage relates to the simple possibility of flexible three-dimensional positioning of the platform, preferably at every arbitrary location within the construction space and above the construction platform. The device advantageously occupies only a small amount of space within the build area. Since the platform is also able to move along a vertical time axis via the provided apparatus, the space requirements of the additive manufacturing facility in particular in the X and Y directions are not limited.

Furthermore, a reactive atmosphere can be established via the device or the platform (in situ) at the processing site or at the site of the selective curing of the component material, which has a favorable effect on the structural or mechanical properties of the component to be produced (see below).

In one embodiment, the heating head comprises an induction coil, which is particularly water-cooled and can be operated and/or regulated, in particular, by a high-frequency generator, for example, of the device, and which is designed to locally heat the component material to a temperature between 800 ℃ and 1200 ℃, in particular 1000 ℃ or more, or to preheat, i.e. to a suitable preheating temperature, for a true additive-building process. In particular, high temperature gradients at or near the location of the melt bath, which can exceed 1000K/s without corresponding heating, can be prevented by preheating. This advantageously also limits or reduces the occurrence of crack centers or hot cracks.

In one embodiment, the suspension comprises four actuators which are actuated individually and can be placed in the construction space uniformly, for example in a square arrangement. The actuators are preferably each designed to be flexible in order to be able to realize a mobility of the platform in three mutually perpendicular spatial directions.

In one embodiment, the actuators are each designed to be flexible.

In one embodiment, the actuators are each actuated via a gear, a tackle pulley, a telescopic arm, a pneumatic and/or hydraulic mechanism. By means of this embodiment, the actuator can preferably be designed particularly simply and flexibly.

In one embodiment, the device comprises a temperature measuring device, for example an infrared camera or a pyrometer, which is arranged and designed to measure and/or regulate or monitor the temperature of the component material and on the building surface, for example, viewed in a plan view of the building surface. By means of this embodiment, the preheating temperature of the heating head and thus of the component material can advantageously be monitored and controlled.

In one embodiment, the device comprises a protective gas guide which is coupled to the platform and is designed to guide a protective gas, for example an inert gas, in layers or parallel over the component material and/or perpendicularly to the component material during the additive manufacturing of the component. The vertical directing of the protective gas onto the component material can be achieved, for example, via a protective gas directing device or a corresponding shower-like arrangement of gas outlets. By coupling the protective gas guide to the platform, it is advantageously possible to achieve: the protective gas can be conducted locally at or into the region of the component material which is currently just melting and/or has a strong tendency to corrode or oxidize.

Another aspect of the invention relates to an additive manufacturing facility comprising the described apparatus. The manufacturing facility preferably further comprises cladding equipment and irradiation equipment, as in known additive manufacturing facilities. However, the apparatus is arranged in the installation above the building face, for example, as viewed in the building direction of the respective component.

Another aspect of the invention relates to a method, preferably a powder bed method, for preheating and/or additive manufacturing of a component, the method comprising applying a layer of component material on a build surface by means of a cladding apparatus.

The method further comprises lowering or approaching the platform towards the region of the build surface to be irradiated.

The method further comprises heating the area to be irradiated by means of a heating head of the apparatus.

The method further includes irradiating the region with an energy beam to selectively cure the component material according to a predetermined geometry of the component.

In one embodiment, the method, after irradiating the region, comprises lifting or raising the build platform away from the region of action of the irradiation device, and subsequently repeating the steps of coating, lowering, heating and/or irradiating as described.

In one embodiment, the described steps of heating and irradiating are performed at least partially simultaneously.

In one embodiment, the irradiation of the region is carried out simultaneously, preferably simultaneously and/or locally, with the heating, wherein an energy beam is guided during the additive building element, for example through an aperture (Auge) of an induction coil of the device or of the heating head.

In one embodiment, the component material is locally heated to a temperature of more than 800 ℃, preferably to a temperature of 1000 ℃ or more, particularly preferably to a temperature of 1200 ℃ or more.

In one embodiment, the component material is heated locally to a temperature of between 800 ℃ and 1200 ℃, in particular to a temperature of 1000 ℃ or more.

In one design, the build material is a gamma and/or gamma prime hardened nickel-based or cobalt-based superalloy and the component is a component used or disposed in a hot gas path of a gas turbine.

In one embodiment, the component material is only preheated prior to the actual additive building, for example by selective laser melting.

The present design, features and/or advantages relating to the apparatus or the additive manufacturing facility can also relate to a method for additive manufacturing, or vice versa.

Further features, characteristics and advantages of the invention are explained in detail below with reference to the drawings by means of embodiments. All features described so far and in the following are advantageous here individually and in combination with one another. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following description is, therefore, not to be taken in a limiting sense.

The expression "and/or", as used herein, when used in a series of two or more elements, means: each of the listed elements can be used alone or any combination of two or more of the listed elements can be used.

Drawings

Further details of the invention are described below with the aid of the figures.

Fig. 1 shows a powder-based additive manufacturing process of a component according to a schematic cross-sectional view.

Fig. 2 shows a simplified and schematic perspective view of the device according to the invention.

Fig. 3 shows the method steps according to the invention according to a schematic flow chart.

Detailed Description

In the exemplary embodiments and the figures, identical or functionally identical elements can be provided with the same reference symbols. The components shown and their dimensional relationships with one another are not to be considered in principle to be true to scale, but rather individual components can be shown exaggerated in size or in an exaggerated manner for better visibility and/or better understanding.

Fig. 1 illustrates an additive manufacturing facility 100. The plant 100 is preferably an apparatus for additive manufacturing of a component (see reference numeral 10) from a powder bed, for example by selective laser melting or electron beam melting. The facility 100 has a base plate 11. The component 10 is built up on a base plate or baseplate 11 during its additive manufacturing, i.e. preferably also directly connected or "welded" in a material-fit manner.

The component is preferably a component used in the hot gas path of a turbomachine, for example a gas turbine. In particular, the component can represent a rotor blade or guide blade, a section or ring segment, a combustor component or a combustor tip, a frame, a shield, a nozzle, a seal, a filter, a passage or nozzle, a resonator, a ram or a swirler, or a corresponding transition, an insert or a corresponding retrofit.

The component 10 is preferably built in a building space AR of the installation 100.

The component 10 is preferably only partially constructed in fig. 1, for example from only two layers S of component material P.

The component material P can be a gamma and/or gamma prime hardened powder of a nickel-based or cobalt-based superalloy.

The individual layers of material P for the layers S of the component are preferably applied via a coating device 30 and subsequently selectively melted and solidified by means of an energy beam 21 in order to build up the component 10. The energy beam is preferably emitted by an irradiation device 20, which is or comprises, for example, an electron beam source or a laser source.

After the layer S is built up, the base plate 11 is preferably lowered by an amount corresponding to the layer thickness S. Subsequently, for example starting from the powder store shown on the left in fig. 1, a new powder layer is applied to build up the component 10.

The additive building process is preferably performed in an inert or protective gas atmosphere or at least in an atmosphere with a reduced oxygen content in order to avoid corrosion, oxidation or other influences affecting the quality of the component material, i.e. the powder P or the finally manufactured component 10.

In fig. 1, the respective inert gas guide or protective gas guide is not explicitly labeled. However, they can be arranged and designed such that the inert gas is guided over the building surface AF, for example in this manner.

Furthermore, fig. 1 shows a camera, for example an infrared camera 50, which is preferably arranged and designed to measure and/or regulate the temperature of the building material P on the building face AF.

Furthermore, fig. 1 shows a platform 200 according to the invention, for example a platform of a device 300 (see the bottom of fig. 2), via which a targeted or selective heating of the component material P is possible. The platform 200 can be supported and/or moved via a suspension 201 (which is also seen in the lower part of fig. 2).

The build direction (not explicitly labeled) for the component 10 corresponds in fig. 1 to a direction pointing vertically upwards.

Fig. 2 shows a detail of the device 300 or a partial view of the installation 100, which contains the device 300 or in which the device 300 is installed, for example as a retrofit kit. In fig. 2, the apparatus 300 is arranged above the building face AF.

The device 300 is preferably provided for selectively heating or preheating a component material P for the additive production of a component 10, in particular on the basis of powder.

As already indicated with reference to fig. 1, the device 300 comprises a platform 200 with a particularly inductive heating head L and a suspension 201 which carries the platform 200 and is designed to move the platform 200 in three perpendicular spatial directions X, Y, Z within a construction space AR. Thus, in addition to lateral movement in the X or Y direction, the apparatus 300 according to the present invention enables vertical movement of the platform 200 along the Z axis.

The platform 200 can be configured, for example, in a ring shape, such that the energy beam 21 can be guided through the platform, for example, during additive manufacturing of the component 10.

The heating head L comprises, for example, an induction coil, such as a high-frequency coil, which can be operated and/or controlled, in particular, by means of a high-frequency generator, and which is designed to locally heat the building material P to a temperature of more than 800 ℃, preferably 1000 ℃, particularly preferably 1200 ℃ or more, for example (pre-) heated before the actual additive building.

In one embodiment, the build material is locally heated to a temperature in the range between 800 ℃ and 1200 ℃, in particular to a temperature of 1000 ℃ or higher.

The frequency at which the described coils or the respective generators are operated can be, for example, up to 2000kHz in the case of high-frequency generators and up to 200kHz in the case of medium-frequency generators.

Alternatively, the heating head L can have other means for heating, for example a radiant heating device or other means for locally selectively heating the metal powder known in the art.

The suspension 201 preferably includes three or four actuators 201. Fig. 2 shows an exemplary embodiment with four actuators 201 arranged in the corners of the installation space AR. The actuators 201 can preferably be actuated individually and are arranged or fixed uniformly in the building space AR and/or actuated or activated accordingly.

The actuators 201 are preferably also flexibly configurable, meaning that the platform 200, by way of corresponding activation of the actuators 201, can be set or moved, for example, according to arbitrary (cartesian) coordinates X, Y, Z located in the building space AR. This can be done, for example, via a transmission, a tackle pulley, a telescopic arm or a pneumatic and/or hydraulic mechanism. For example, it is possible to activate the actuators in a coordinated and/or coordinated and controlled manner with one another via compressed air or electrically actuated telescopic arms.

The device 300 also has a protective gas guide or protective gas feed 220. The protective gas guide 220 is preferably designed to guide a protective gas, for example an inert gas such as argon or helium or other inert gases, in layers above the component material P and/or vertically onto the component material P during the additive manufacturing of the build 10 (see the arrows in fig. 2 in the region of the melt bath SB).

The vertical directing of the protective gas onto the component material P can be effected, for example, via a gas directing device similar to a shower head or shower head.

The protective gas guide 220 can in particular comprise or be a miniaturized and/or endoscopic protective gas nozzle and thus serves in particular locally for reducing the oxygen content in the selectively preheated or heated region during the additive manufacturing of the component 10.

In particular, in addition to the global or laminar protective gas guide, the protective gas nozzles mentioned (not explicitly shown) can also be provided, which reduce the oxygen content or partial pressure in the additive manufacturing process or in the installation space of a conventional installation.

The apparatus 300 or the facility 100 can also have a corresponding shielding gas outlet (not explicitly shown).

In the present invention or in the device 300 described, the preheating is advantageously carried out by means of high-frequency coils carried by the platform 200, suspended on, in particular, four actuators. The coil can thus be suspended like a spider web or textile body above the construction area or construction surface AF and moved into each XYZ position within the construction space AR by correspondingly activating the actuator 201.

Four actuators 201 are, for example, respectively arranged in the corners of the construction space AR and all engaged in the platform 200.

The shielding gas guide 220, and also, for example, the power supply 210, and also the control of the heating head or coil L and the supply line or supply of the shielding gas guide 220 or the power supply 210, can likewise be arranged on the, in particular, annular platform 200. The mentioned transport path is preferably likewise of flexible design, so that no restrictions of movement of platform 200 or heating head L occur.

Fig. 3 shows, according to a schematic flow chart, method steps of a method according to the invention, in particular of a method for operating the above-mentioned device 300 or of an additive manufacturing method.

The method comprises the following steps: a) a layer S of component material P is applied to the building surface AF by means of the coating device 30.

The method further comprises the following steps: b) the platform 200 is lowered or set in the direction of the area B to be irradiated of the building face AF.

In the mentioned movement of platform 200, the platform is preferably moved at least partially downwards along a vertical axis (Z-axis) in order to move the platform or preferably thus the heating head L in the direction of area B.

The region B preferably describes a region which is provided layer by layer for irradiation for the additive building of the component 10. Accordingly, the region B can laterally (as viewed in a plan view of the building surface AF) encompass or surround the melt pool SB. The region B preferably describes a dynamic or, during the construction of the component 10, a movable region or a corresponding irradiation trajectory.

The method further comprises the following steps: c) the region B to be irradiated, preferably a larger region containing the region B, is heated or preheated by means of the heating head L of the apparatus 300.

The method further comprises the following steps: d) the region B is irradiated with an energy beam 21 according to the predetermined geometry of the component 10.

According to one embodiment, the method further comprises: preferably, after irradiation of the region B (see method steps d) and e), the platform 200 is lifted or raised from the region of action of the irradiation device 30.

The region of action preferably describes a region, which is not far above the building surface AF and in which the irradiation device, in particular a scraper or scraper, is moved laterally, i.e. preferably describes a region which occupies only a small vertical region (height in the Z direction) in the building space.

It is clear that the mentioned method steps can be repeated during the layer-by-layer additive manufacturing of the component 10, depending on the number of subsequent and still required layers to be built.

In one embodiment of the process, the described steps of heating (c)) and irradiating (d)) are carried out at least partially simultaneously. This is indicated in fig. 3 by the dashed circle.

The irradiation of the region B can furthermore take place simultaneously with the heating, wherein an energy beam 21 is guided through the induction coil or heating head and/or an aperture (not explicitly shown) of the device 300, for example during the additive building of the component 10. This advantageously enables a synchronous movement with the working laser (see reference numeral 21 in fig. 1) to build the component 10.

In other words, during the production of the component 10, the energy beam 21 can be aligned in operation always at a predetermined position in the region B on the building surface AF via the "hole" of the induction coil L. The region B is preferably a region which is in any case heated by the heating head L.

The invention is not limited by the description according to the embodiments but comprises any novel feature and any combination of features. This includes in particular any combination of features in the claims, even if the features or the combination itself are not explicitly given in the claims or exemplary embodiments.

Claims

1. An apparatus (300) for selectively heating a component material (P) for additively manufacturing a component (10), in particular based on a powder bed, the apparatus comprising:

-a platform (200) with a heating head (L), in particular of the induction type, and

-a suspension (201) carrying the platform (200) and configured to move the platform (200) along three perpendicular spatial directions (X, Y, Z) within a build space (AR) of an additive manufacturing facility (100).

2. The device (300) of claim 1,

wherein the heating head (L) comprises an induction coil which can be operated and/or regulated, in particular, by means of a high-frequency generator, and which is designed to locally heat the building material (P) to a temperature of between 800 ℃ and 1200 ℃, in particular to a temperature of 1000 ℃ or more.

3. The device (300) of claim 1 or 2,

wherein the suspension comprises four actuators (201), the actuators (201) being individually steerable and evenly arranged in the build space (AR), for example in a square arrangement.

4. The device (300) of claim 3,

wherein the actuator (201) can be actuated pneumatically and/or hydraulically via a gear, a tackle, a telescopic arm, respectively.

5. The device (300) of any of the preceding claims,

the device comprises a temperature measuring instrument, such as an infrared camera or a pyrometer, which is arranged and constructed to measure and/or regulate the temperature of the component material (P) on the building surface (AF).

6. The device (300) of any of the preceding claims,

the device comprises a protective gas guide (220) which is coupled to the platform (200) and which is designed to guide a protective gas, for example an inert gas, in layers above and/or perpendicularly onto the component material (P) during the additive manufacturing of the component (10).

7. An additive manufacturing facility (100) comprising an apparatus (300) according to any of the preceding claims, the additive manufacturing facility further comprising a coating apparatus (30) and an irradiation apparatus (20), and wherein the apparatus (300) is arranged above a build face (AF).

8. A method for additive manufacturing a component (10), the method comprising the steps of:

-a) applying a layer (S) of component material (P) on the building face (AF) by means of a coating device (30),

-B) lowering the platform (200) according to any one of claims 1 to 6 towards a direction of an area (B) of the building face (AF) to be irradiated,

-c) heating the region (B) to be irradiated by means of a heating head (L) of the apparatus (300), and

-d) irradiating the region (B) according to a predetermined geometry of the component (10) by means of an energy beam (21).

9. The method of claim 8, comprising-after irradiating the region (B): lifting the platform (200) away from the region of action of the irradiation device (300) and subsequently repeating the steps a) to d).

10. The method according to claim 8 or 9,

wherein said steps c) and d) are performed at least partially simultaneously.

11. The method according to any one of claims 8 to 10,

wherein the irradiation of the region (B) is performed synchronously with the heating, wherein the energy beam (21) is guided, for example, through an aperture of an induction coil of the apparatus (300) during the additive building of the component (10).

12. The method according to any one of claims 8 to 11,

wherein the component material (P) is locally heated to a temperature between 800 ℃ and 1200 ℃, in particular to a temperature of 1000 ℃ or more.

13. The method according to any one of claims 8 to 12,

wherein the build material (P) is a gamma and/or gamma prime hardened nickel-or cobalt-based superalloy and the component (10) is a component for use in a hot gas path of a gas turbine, and the component material (P) is only preheated prior to actual additive building, for example by selective laser melting.