Method for operating an apparatus for processing powder material for manufacturing three-dimensional work pieces and process container of an apparatus for processing powder material for manufacturing three-dimensional work pieces

Abstract

The invention relates inter alia to a method for operating an apparatus (A) for processing powder material for manufacturing three-dimensional work pieces, wherein the apparatus (A) has at least one process container (20, 100) for providing powder material (10) for the manufacturing process, in particular a powder mixture, for the manufacturing process, wherein before a filling step of the process container (20, 100) a reservoir container (40), containing, in particular fresh, powder material (10) to be filled in the process container (20, 100), is supplied and pressurized with vacuum at a predetermined vacuum level, and the process container (20, 100) to be filled with the powder material (10) is supplied and pressurized with vacuum at a predetermined vacuum level, wherein during the filling step the, preferably fresh, powder material (10) is moved via a transport channel (24.1) from the reservoir container (40) to the process container (20, 100), in particular by means of gravitational forces and / or in particular in presence of the, preferably permanent, vacuum in the reservoir container (40) and the process container (20, 100).

Description

[0001] Method for operating an apparatus for processing powder material for manufacturing three-dimensional work pieces and process container of an apparatus for processing powder material for manufacturing three-dimensional work pieces

[0002] Description

[0003] The invention relates to a method for operating an apparatus for processing powder material for manufacturing three-dimensional work pieces and process container of an apparatus for processing powder material for manufacturing three-dimensional work pieces.

[0004] Moreover, the invention relates also to a use of a powder guiding member and to an apparatus for processing powder material for manufacturing three-dimensional work pieces, in particular an apparatus for manufacturing three-dimensional work pieces, further in particular an apparatus for manufacturing three-dimensional work pieces by exposing powder layers to electromagnetic radiation or particle radiation in a process chamber.

[0005] The powder bed fusion process is an additive manufacturing process. In this process, powder layers are added on top of each other to form a powder bed on a support plate. Before adding a new layer of powder, the existing layer is heated to bond the powder particles and the previous layer. The powder bed fusion process fuses cross sections of a work piece with corresponding powder layers to form the work piece. This is done by scanning the cross sections with a radiation beam. The term “powder bed fusion process” (PBFP) includes in particular all other processes that allows to stick parts of a powder bed together using radiation. The powder bed fusion process can be used to make metal parts by fusing metal powder particles. Moreover, Laser powder bed fusion (LPBF) is a type of 3D printing where a layer of powder is exposed to a beam of energy, such as a laser, to fuse the particles together. The work piece is made in layers of powder.

[0006] In the prior art, the upper layer of a powder bed is irradiated with an energy source in a process chamber in so-called powder bed processes as an additive manufacturing process, whereby the particles of the powder bed are bonded to each other, e.g. by sintering and / or welding and / or melting and / or by triggering a chemical reaction. After irradiating a layer, e.g. by means of electromagnetic radiation, another powder layer is applied by a powder bed coater so that another powder layer can then be irradiated again. These processes are repeated until the work piece to be produced can be removed from the powder bed.

[0007] Powder management and powder handling are important in the manufacturing process, as new or recycled powder is regularly fed into the process chamber via powder tanks. In addition, powder that has already been used is collected in powder tanks and then fed to a processing system or device.

[0008] The powder bed process is an additive or generative layering process for the production of three-dimensional work pieces, with which powdery, in particular metallic and / or ceramic raw materials are processed into three-dimensional, complex-shaped work pieces. For this purpose, a raw material powder layer is applied to a carrier in a process chamber and, depending on the desired geometry of the work piece to be produced, is exposed to laser radiation or partial radiation as electromagnetic radiation in a location-selective manner. The electromagnetic radiation penetrating the powder layer causes heating and thus fusion or sintering of the raw material powder particles. Further layers of raw material powder are then successively applied to an already solidified layer on the carrier until the finished work piece has the appropriate shape and size. For example, ceramic, metal or plastic materials as well as material mixtures are used as raw material powder layers.

[0009] For example, EP 3 023 227 A1 describes a device for producing three-dimensional work pieces by powder bed fusion, the device having a process chamber in which a carrier for the work piece to be produced and a powder application device for applying a layer of a raw material powder to the carrier are located. The process chamber is provided, for example, with a powder inlet for feeding raw material powder to the powder application device and a powder outlet for discharging excess raw material powder from the process chamber. A powder circuit line, in which a conveying device for conveying the raw material powder through the powder circuit line is arranged, connects the powder outlet of the process chamber with the powder inlet of the process chamber.

[0010] It is an object of the invention to prevent a segregation of a powder material when filling a container or the like for an apparatus for processing powder material for manufacturing three-dimensional work pieces. The object is solved by a method for operating an apparatus for processing powder material for manufacturing three-dimensional work pieces, in particular an apparatus for manufacturing three-dimensional work pieces, further in particular an apparatus for manufacturing three-dimensional work pieces by exposing powder layers to electromagnetic radiation or particle radiation in a process chamber, wherein the apparatus has at least one process container for providing powder material for the manufacturing process, in particular a powder mixture, for the manufacturing process, wherein before a filling step of the process container a reservoir container, containing, in particular fresh, powder material to be filled in the, preferably at least partly empty, process container, is supplied and pressurized with vacuum at a predetermined vacuum level, and the process container to be filled with the, preferably fresh, powder material is supplied and pressurized with vacuum at a predetermined vacuum level, wherein before the filling step the reservoir container and the process container are fluidically connected with each other such that the vacuum of the reservoir container and the vacuum of the process container are equalized at a, in particular common and / or same or nearly same, vacuum level, wherein after the equalization of the vacuum of the reservoir container and the vacuum of the process container and during the filling step the, preferably fresh, powder material is moved via a transport channel from the reservoir container to the process container, in particular by means of gravitational forces and / or in particular in presence of the, preferably permanent, vacuum in the reservoir container and the process container.

[0011] The basic idea of the invention is to fill process container with a mixed powder material, wherein after the filling process the powder material in the process container is not segregated and / or is provided as a homogenized powder material. According to the invention a, in particular closed, reservoir container with, preferably fresh or virgin or new or reprocessed, powder material is supplied, wherein the reservoir container is pressurized with vacuum at a predetermined vacuum level. Moreover, before the filling step a at least partly empty process container is supplied and is also pressurized with vacuum at a predetermined vacuum level. Before the filling step, the vacuum of the reservoir container and the vacuum of the process container are equalized at least nearly the same vacuum level. After the equalization of the vacuum levels, the transport channel, which connects and outlet port of the reservoir container with an inlet port of the process container, is opened in order to move the powder material through the transport channel from the reservoir container to the process container by means of at least one or more forces acting on the powder material, for example gravitational force(s). In particular, the vacuum in the reservoir container and in the process container is present during the filling step. During the powder material filling process and under pressure is present in both the reservoir container and the process container.

[0012] Due to the absence of an atmospheric pressure level in both the reservoir container and the process container, the powder material is preferably moved through the transport channel by means of gravitational forces, wherein during and after the filling step the accommodated powder material in the process container is not segregated. Advantageously the apparatus for processing powder material for the manufacturing three-dimensional work pieces is provided with homogenized powder material, so that the manufacturing process is improved, in particular as the powder material can contain various and different powder particles. Moreover, within the scope of the invention it is conceivable that the movement of the powder material from the reservoir container into the process container through the transport channel can be carried out using forces or under the effect of further or other forces like centrifugal forces, weight forces, magnetic forces, etc. or a combination of different forces.

[0013] Within the scope of the invention, the provided powder material can be inter alia ceramic, metal or plastic materials, for example, or mixtures of these or mixtures of different types of ceramic, metal or plastic materials.

[0014] The apparatus for processing the powder material for the manufacturing of three-dimensional work pieces can be provided as an apparatus for manufacturing three-dimensional work pieces by exposing powder layers to electromagnetic radiation or particle radiation in the process chamber or as an apparatus for powder preparation and / or powder post-processing. An example, an apparatus for powder preparation could be provided as a powder unpacking station (to remove unmelted powder from a formed work piece after a completed manufacturing step and to process it). Within the scope of the invention, the method can be carried out for a unpacking process or unpacking device, wherein in particular the powder material can be filled into a transport container and then into a sieving device or machine. Moreover, the powder material can be fed back, preferably according to a further step, into the cycle of a manufacturing apparatus or the like. It is also conceivable within the scope of the invention that the method is carried out for the transfer from one container to another and / or for the transfer to an intermediate storage tank. The method can also take place, for example, to transfer the powder material from one container into another container in a closed powder circuit.

[0015] Furthermore, within the scope of the invention the process container and the reservoir container can also be connected in series at any point within a powder-conveying system in order to fill powder material from one container into the other container.

[0016] According to an embodiment, the powder material can be a powder mixture consisting of fresh or virgin (new) powder and powder returned from the overflow container of an additive manufacturing machine or apparatus is present as a powder mixture and that this powder mixture is conveyed from one container to the other using the powder conveying method according to the invention.

[0017] In addition, the powder material can be also new or fresh or used or reprocessed powder (mixtures) and also a mixture of used and sieved powder, etc..

[0018] Within the scope of the invention, the transport channel between the reservoir container and the process container can be provided with a at least one or more tubular components and / or hoses and / or inclined surfaces, etc.. Preferably, the transport channel can be designed in such a way that the inner surfaces come into contact with the powder to be conveyed as hardly as possible or not at all.

[0019] Moreover, an embodiment of the method is characterized in that before the filling step the reservoir container and the process container are fluidically connected with each other such that the vacuum of the reservoir container and the vacuum of the process container are equalized at a, in particular common and / or same or nearly same, vacuum level, wherein after the equalization of the vacuum of the reservoir container and the vacuum of the process container the filling step is carried out.

[0020] Pursuant to a preferred embodiment, the reservoir container and the process container are pressurized with vacuum independently from each other. For the generation of the vacuum in the reservoir container and the process container, a shared vacuum pump can be used, wherein in particular the pressurization of the reservoir container and the process container is carried out one after the other in a chronological order. In an alternative embodiment, a vacuum pump for the reservoir container and a vacuum pump for the process container can be operated, in particular independently of one another, to pressurize the reservoir container and process container with vacuum.

[0021] According to a further aspect of the method it is provided that the, in particular closed and / or dimensionally stable and / or vacuum stable, reservoir container has an outlet port for the powder material in a lower part of the reservoir container, wherein the outlet port of the reservoir container is connected with the transport channel, in particular via a, preferably actuatable and / or controllable, valve.

[0022] Another embodiment of the method is characterized in that the, in particular closed, process container has an inlet port for the powder material in an upper part of the process container, wherein the inlet port of the process container is connected with the transport channel, in particular via a, preferably actuatable and / or controllable, valve.

[0023] Preferably, the reservoir container is or will be arranged above the process container, wherein in particular an or the outlet port of the reservoir container is or will be connected with an or the inlet port of the process container.

[0024] In addition, the method is further characterized in that before the filling step the reservoir container and the process container are pressurized, preferably simultaneously or in a chronological order, by means of a, in particular single and / or shared, vacuum pump or that before the filling step the reservoir container and the process container are pressurized independently from each other by means of a, in particular single and / or shared, vacuum pump.

[0025] In particular, the reservoir container and the process container are not fluidically connected during the pressurization with vacuum.

[0026] Advantageously, the reservoir container has a vacuum supply pipe, wherein the vacuum supply pipe has an upper, preferably open, end, which is in particular arranged inside the reservoir container in the upper part of the reservoir container, preferably above the level of the powder material.

[0027] Furthermore, according to another embodiment the method is characterized in that the vacuum supply pipe has a lower end, preferably in the lower part of the reservoir container, which is or will be connected to a vacuum pump. Preferably, the vacuum supply pipe can consist of a porous material, wherein in particular the porosity of the porous material is selected in such a way that the powder particles of the powder material are retained, but at the same time are permeable to gas.

[0028] Optionally, the vacuum level of the process container and / or the vacuum level of the reservoir container are monitored by means of a pressure sensor, wherein in particular the pressure sensor is arranged in the upper part of the process container and / or the pressure sensor is arranged in the upper part of the reservoir container and / or the pressurization of the process container and / or the pressurization of the reservoir container, preferably by means of a vacuum pump, is stopped after reaching the predetermined vacuum level. In an embodiment, a shared pressure sensor is provided to monitor the vacuum level of the process container and / or the vacuum level of the reservoir container. According to a further alternative embodiment, a pressure sensor is provided for the monitoring of the vacuum level of the process container and an additional pressure sensor is provided for the monitoring of the vacuum level of the reservoir container.

[0029] According to another preferred embodiment of the method, a filling level of the powder material in the process container is monitored by means of a level sensor, wherein in particular the filling step is stopped after reaching a predetermined filling level of the process container monitored by the level sensor.

[0030] In another aspect, the method is further characterized in that before the filling step the vacuum level of the reservoir container is between -500 mbar to -1500 mbar, preferably between -700 mbar to -1200 mbar or between -800 mbar to -1000 mbar, in comparison to the atmosphere pressure outside the reservoir container and / or that before the filling step the vacuum level of the process container is between -500 mbar to -1500 mbar, preferably between -700 mbar to -1200 mbar or between -800 mbar to -1000 mbar, in comparison to the atmosphere pressure outside the process container.

[0031] Moreover, it is preferred in a further embodiment that during the filling step the, in particular permanent, vacuum level of the reservoir container and the vacuum level of the process container is between -500 mbar to -1500 mbar, preferably between -700 mbar to -1200 mbar or between -800 mbar to -1000 mbar, in comparison to the atmosphere pressure outside the reservoir container and the process container, wherein in particular the pressurization with vacuum of the reservoir container and of the process container is or will be terminated after the filling step.

[0032] Preferably, the powder material is provided as a powder mixture, in particular metal powder mixture, wherein the powder mixture comprises a mixture of at least two sorts of powder particles, wherein in particular the two sorts of powder particles differ in chemical composition and / or chemical properties and / or particle size and / or particle form and / or physical properties.

[0033] The object is further solved by a process container of an apparatus for processing powder material for manufacturing three-dimensional work pieces, in particular an apparatus for manufacturing three-dimensional work pieces, further in particular an apparatus for manufacturing three-dimensional work pieces by exposing powder layers to electromagnetic radiation or particle radiation in a process chamber, having an inner cavity for accommodating powder material, in particular metal powder material or metal powder mixture, wherein a powder guiding member for guiding the powder material is provided inside the inner cavity of the, in particular closed, process container.

[0034] The basic idea of this invention is that by means of the powder guiding member the powder material is guided softly into the process container, wherein the segregation of the powder material is reduced and the accommodated powder material is not segregated in the process container after the filling step of the process container.

[0035] The powder guiding member is preferably designed as a device having an inclined powder guiding surface, preferably with regard to the horizontal plane, in particular having an inclined, and preferably open, channel or an inclined passage through which the powder material is guided in the process container. Preferably, the powder guiding member, having an inclined powder guiding surface, is configured to guide the powder material, which is filled into the process container via an upper inlet port, inside the process container, preferably in the upper part of the process container, to the bottom part of the process container.

[0036] A further embodiment of the process container is characterized in that the powder guiding member is arranged in an upper area of the inner cavity of the process container.

[0037] Advantageously, the powder guiding member is arranged at an inclination angle greater than 0° (> 0°) to the horizontal plane, wherein the inclination angle of the powder guiding member is between 15° and 60°, preferably between 25° to 55°.

[0038] Preferably, the inclination angle of the powder guiding member is adjustable or can be varied.

[0039] According to another advantageous aspect of the invention, the powder guiding member has a longitudinal extended sliding surface for the powder material.

[0040] Another embodiment of the process container is characterized in that the powder guiding member has at least one lateral margin along the longitudinal extended sliding surface, preferably one lateral margin at each side of the longitudinal extended sliding surface, and / or the powder guiding member has an, preferably upper, end area with a, preferably one, lateral margin and / or the powder guiding member has at least one contact end for contacting the inner side of the cavity, preferably at the upper end of the powder guiding member and / or the powder guiding member has at least one recess, preferably at the lower end of the powder guiding member.

[0041] In another advantageous embodiment of the process container, a holding unit is provided for holding the powder guiding member inside the cavity. Optionally, the powder guiding member has a one-piece sliding surface for the powder material or the powder guiding member comprises at least two or more powder guiding member segments with sliding surfaces for the powder material.

[0042] The sliding surface has in particular a smooth surface for low frictional forces between powder (material) and sliding surface.

[0043] In addition, an embodiment of the process container provides that the sliding surface of the powder guiding member for the powder material has a rectangular or rectangular-like form or the sliding surface of the powder guiding member for the powder material has a trapezoidal form or a trapezoidal-like form.

[0044] According to a preferred embodiment, the powder guiding member is rotatable or pivotable around the vertical axis.

[0045] Advantageously, a drive, in particular an electric drive, is provided for the rotation of the powder guiding member, in particular around the vertical axis of the powder guiding member.

[0046] Preferably, the process container comprises a lower conical section and an upper cylindrical section, wherein in particular the powder guiding member is arranged inside the cylindrical section.

[0047] In addition, the object is solved by a use of a powder guiding member for guiding the powder material in a, in particular closed, process container of an apparatus for processing powder material for manufacturing three-dimensional work pieces, in particular an apparatus for manufacturing three-dimensional work pieces, further in particular an apparatus for manufacturing three-dimensional work pieces by exposing powder layers to electromagnetic radiation or particle radiation in a process chamber, as explained above in detail.

[0048] Moreover, the object is solved by an apparatus for processing powder material for manufacturing three-dimensional work pieces, in particular an apparatus for manufacturing three-dimensional work pieces, further in particular an apparatus for manufacturing three-dimensional work pieces by exposing powder layers to electromagnetic radiation or particle radiation in a process chamber, wherein the apparatus has at least one process container, as described above, and / or wherein the apparatus is configured to be operated according to a method as described above. In order to avoid unnecessary repetition, reference is explicitly made to the above explanations and details.

[0049] Further features of the invention will become evident from the description of embodiments according to the invention, together with the claims and the appended drawings. Embodiments according to the invention can fulfill individual features or a combination of several features.

[0050] Within the context of the invention features which are labeled with “in particular” or “preferably” are to be understood to be optional features.

[0051] The invention is described below, without restricting the general idea of the invention, based on exemplary embodiments in reference to the drawings, whereby we expressly refer to the drawings with regard to the disclosure of all details according to the invention that are not explained in greater detail in the text. In the drawings: Fig. 1 shows schematically an arrangement of a process container and a reservoir container of an apparatus for the production of three-dimensional work pieces.

[0052] Fig. 2a shows schematically a perspective view of a process container according to a first embodiment and

[0053] Fig. 2b shows schematically a cross-sectional view of the process container of Fig. 2a.

[0054] Fig. 3a shows schematically a cross-sectional view of a process container according to a further embodiment.

[0055] Fig. 3b illustrates a schematic perspective view of a powder guiding member for the process container of Fig. 3a.

[0056] Fig. 4a shows schematically a cross-sectional view of a process container according to a further embodiment.

[0057] Fig. 4b illustrates a schematic perspective view of a powder guiding member for the process container of Fig. 4a.

[0058] In the drawings, the same or similar elements and / or parts are, in each case, provided with the same reference numerals such that they are not introduced again in each case.

[0059] The schematic illustration of Fig. 1 shows an arrangement of a process container 20 and a reservoir container 40 for fresh powder material 10 of an apparatus A for the production of three-dimensional work pieces. In particular, the apparatus A is provided as an apparatus for manufacturing three-dimensional work pieces by exposing powder layers to electromagnetic radiation, like of at least one laser, or particle radiation in a process chamber.

[0060] The process container 20 is filled with fresh or virgin powder material 10 or a mixture of powder from the reservoir container 40. The process container 20 comprises an inlet port with a, preferably actuatable, valve 22, which is arranged on the upper side or top of the process container. The valve 22 is connected with a Y-piece-like or the Y-shaped pipe 24 with two connection portions 24.1 and 24.2. The straight connection portion 24.1 of the Y-shaped pipe 24 is connected with a valve 42, which is arranged at the outlet port on the bottom side of the reservoir container 40.

[0061] The second connection portion 24.2 of the Y-shaped pipe 24 is connected with a valve 32. The other side of the valve 32 is connected with a vacuum pump 30. In the connection pipe between the valve 32 and the vacuum pump 30 a filter 34, a pressure sensor 36 and a flow sensor 38 are provided.

[0062] Moreover, the valve 32 is connected with a, in particular porous, vacuum supply line 44 of the reservoir container 40, which is arranged inside the reservoir container 40 and extends from the bottom to the top of the reservoir container 40.

[0063] Depending on the setting or the actuation of the valves 22, 32 and 42, either the reservoir container 40 or the process container 20 are pressurized with vacuum provided by the vacuum pump 30.

[0064] In order to monitor the pressure inside the process container 20 and / or inside the reservoir container 40, a pressure sensor 26 is connected with the interior cavity of the process container 20 and / or of the reservoir container 40. Furthermore, the process container comprises a filling level sensor 28 in order to monitor the filling level of the process container 20 and to prevent and overfilling of the process container 20.

[0065] After the pressurization of the process container 20 and the reservoir container 40 with vacuum, the process container 20 and the reservoir container 40 are fluidically connected with each other in order to equalize the vacuum level both in the process container 20 and the reservoir container 40, while the valve 22 and the valve 42 are closed. After the equalization of the vacuum level in the process container 20 and the reservoir container 40, the valves 22 and 42 are opened in order to allow the powder material 10, accommodated in the reservoir container 40 move into the process container 20 via the bottom outlet port of the, preferably closed, reservoir container 40 and the connection pipe 24.1 (as transport channel) to the inlet port of the, preferably closed, process container 20. The powder material 10 is moved by gravitational forces, while the vacuum is present in the process container 20 and the reservoir container 40.

[0066] According to an embodiment of the filling process of the process container 20, in a first step all valves 22, 32 and 42 are closed and the vacuum pump 30 is off. Then the reservoir container 40 is arranged above the process container 20, wherein the valves 22 and 42 are connected via the connection portion 24.1 and the vacuum supply line 44 is connected with the valve 32, for example a secondary hose. In a following step, after the valve 22 for the process container 20 and the valve 32 for the vacuum pump 30 are opened, the vacuum pump 30 is activated in order to pressurize simultaneously the process container 20 and the reservoir container 40 with vacuum. The evacuation of the process container 20 and the reservoir container 40 is performed for the certain time limit or until a predetermined pressure is achieved or until a steady state is reached, which prevents the powder material 10 to convey into the vacuum filter 34.

[0067] In an alternative embodiment, evacuation of the reservoir container 40 and the process container 20 is stopped, if a predetermined pressure level, measured by the pressure sensor 36, is achieved, in order to prevent powder conveying into the pump filter 34. After the evacuation of the reservoir container 40 and the process container 20, the valve 32 can be optionally closed again.

[0068] After the evacuation of the reservoir container 40 and the process container 20 at a predetermined vacuum level, which is present in both containers, the valve 42 is opened, in order to allow the powder material 10 to move or fall directly into the evacuated process container 20 without swirling or segregation. When the transfer of the powder material 10 from the reservoir container 40 to the process container 20 is completed, the valves 22, 42 are closed. For the removal of the reservoir container 40, the reservoir container 40 can be optionally aerted or supplied with air according to an embodiment. The transferred powder material is present as a homogenized and not segregated powder in the process container 20 after the filling step according to the invention.

[0069] The illustrations in Fig. 2a to 4b show several embodiments of a process container 100, which can be used for an apparatus A for processing powder material for manufacturing three-dimensional work pieces, in particular an apparatus for manufacturing three-dimensional work pieces, further in particular an apparatus for manufacturing three-dimensional work pieces by exposing powder layers to electromagnetic radiation or particle radiation in a process chamber.

[0070] In Fig. 2a perspective view of the process container 100 according to a first embodiment is shown, while Fig. 2b illustrates schematically a cross-sectional view of the process container 100 of Fig. 2a.

[0071] The, preferably closed, process container 100 has a cavity 102 for accommodating powder material, which is transferred from for example another container. The process container 100 has a bottom cone- shaped portion 104 and a top portion 106. Inside the process container a powder guiding member 110 for guiding the powder material inside the cavity 102 is arranged in the area of the top portion 106. The powder guiding member 110 has a sliding surface 112, which is inclined to the horizontal plane. The inclination angle of the sliding surface 112 is preferably between 35° and 50°.

[0072] The powder material is introduced into the cavity 102 via an inlet port 108 of the top portion 106. The inlet port 108 is arranged on the top side of the top portion 106. Preferably, the sliding surface 112 is preferably characterized in that it has a smooth surface for low frictional forces between inserted powder (material) and sliding surface 1 12.

[0073] The sliding surface 112 and / or the powder guiding member 110 have a longitudinal extension, so that the inserted powder material does not fall directly into the lower cone-shaped bottom portion 104. When filling the process container 100, the inserted powder material falls onto the sliding surface 112 and the inlet port 108 and slides to the bottom end of the sliding surface 1 12. From the bottom end of the sliding surface 112 the powder material falls into the lower bottom portion 104.

[0074] For the arrangement of the powder guiding member 110 inside the process container 100, a holding unit 120 is provided for the powder guiding member. The holding unit 120 is positioned in the upper part of the top portion 106 and holds the powder guiding member 1 10 in a fixed position. Alternatively, the holding unit 120 is configured to rotate the powder guiding member 110 around the vertical axis.

[0075] The sliding surface 112 can be provided as a single sliding surface. Alternatively, the powder guiding member 110 comprises several segments with sliding surfaces for the powder material.

[0076] The embodiment of the process container 100, shown schematically in Fig. 3a in a cross-sectional view, comprises a powder guiding member 110 for guiding the inserted powder material. Details of the powder guiding member 1 10 of the embodiment in Fig. 3a are shown in the schematic perspective view of Fig. 3b.

[0077] The embodiment of the powder guiding member 110 in Fig. 3a is arranged inside the process container by means of a holding unit or a support structure having supporting elements or holding elements or the like. The powder guiding member 110 is spaced from the interior surfaces of the process container 100. The powder guiding member 110 is provided with edges 114, 116 along the longitudinal extension and at the top end side. The lower end side of the powder guiding member has a straight end.

[0078] The further embodiment of the process container 100, shown schematically in Fig. 4a in a cross-sectional view, comprises a powder guiding member 110 for guiding the inserted powder material. Details of the powder guiding member 110 of the embodiment in Fig. 4a are shown in the schematic perspective view of Fig. 4b.

[0079] The powder guiding member 110 in Fig. 4a is in contact with the interior surface of the process container 100 or the interior surface the top portion 106. In particular the powder guiding member 1 10 can be manually removed for cleaning etc.. The bottom end of the powder guiding member 110 is provided with a recess in order to allow the powder material to fall into the bottom portion 104 of the process container. Moreover, the distance between the side edges 1 14 increases from the top and to the bottom end of the sliding surface 1 12.

[0080] All of the indicated features, including those which are to be inferred from the drawings alone, as well as individual features which are disclosed in combination with other features, are deemed to be essential to the invention both alone and in combination. Embodiments accord- ing to the invention can be fulfilled by individual features or a combination of several features.

[0081] List of reference numbers

[0082] 10 powder material

[0083] 20 process container

[0084] 22 valve

[0085] 24 Y-shaped pipe

[0086] 24.1 , 24.2 connection portion

[0087] 26 pressure sensor

[0088] 28 filling level sensor

[0089] 30 vacuum pump

[0090] 32 valve

[0091] 34 filter

[0092] 36 pressure sensor

[0093] 38 flow sensor

[0094] 40 reservoir container

[0095] 42 valve

[0096] 44 vacuum supply line

[0097] 100 process container

[0098] 102 cavity

[0099] 104 bottom portion

[0100] 106 top portion

[0101] 108 inlet port

[0102] 110 powder guiding member

[0103] 112 sliding surface

[0104] 114 edge

[0105] 116 edge

[0106] 120 holding unit

[0107] A apparatus

Claims

1. Method for operating an apparatus for processing powder material for manufacturing three-dimensional work pieces and process container of an apparatus for processing powder material for manufacturing three-dimensional work piecesClaims1. Method for operating an apparatus (A) for processing powder material for manufacturing three-dimensional work pieces, in particular an apparatus (A) for manufacturing three-dimensional work pieces, further in particular an apparatus (A) for manufacturing three-dimensional work pieces by exposing powder layers to electromagnetic radiation or particle radiation in a process chamber, wherein the apparatus (A) has at least one process container (20, 100) for providing powder material (10) for the manufacturing process, in particular a powder mixture, for the manufacturing process, wherein before a filling step of the process container (20, 100) a reservoir container (40), containing, in particular fresh, powder material (10) to be filled in the, preferably at least partly empty, process container (20, 100), is supplied and pressurized with vacuum at a predetermined vacuumlevel, and the process container (20, 100) to be filled with the, preferably fresh, powder material (10) is supplied and pressurized with vacuum at a predetermined vacuum level, wherein during the filling step the, preferably fresh, powder material (10) is moved via a transport channel (24.1 ) from the reservoir container (40) to the process container (20, 100) ), in particular by means of gravitational forces and / or in particular in presence of the, preferably permanent, vacuum in the reservoir container (40) and the process container (20, 100).

2. Method according to claim 1 , characterized in that before the filling step the reservoir container (40) and the process container (20, 100) are fluidically connected with each other such that the vacuum of the reservoir container (40) and the vacuum of the process container (20, 100) are equalized at a, in particular common and / or same or nearly same, vacuum level, wherein after the equalization of the vacuum of the reservoir container (40) and the vacuum of the process container (20, 100) the filling step is carried out.

3. Method according to claim 1 or 2, characterized in that the reservoir container (40) and the process container (20, 100) are pressurized with vacuum independently from each other.

4. Method according to one of the claims 1 to 3, characterized in that the, in particular closed and / or dimensionally stable and / or vacuum stable, reservoir container (40) has an outlet port for the powder material (10) in a lower part of the reservoir container (40), wherein the outlet port of the reservoir container (40) is connected with the transport channel (24.1 ), in particular via a, preferably actuatable and / or controllable, valve (42).

5. Method according to one of the claims 1 to 4, characterized in that the, in particular closed, process container (20, 100) has an inlet port for the powder material (10) in an upper part of the process container (20, 100), wherein the inlet port of the process container (20, 100) is connected with the transport channel (24.1 ), in particular via a, preferably actuatable and / or controllable, valve (22).

6. Method according to one of the claims 1 to 5, characterized in that the reservoir container (40) is or will be arranged above the process container (20, 100), wherein in particular an or the outlet port of the reservoir container (40) is or will be connected with an or the inlet port of the process container (20, 100).

7. Method according to one of the claims 1 to 6, characterized in that before the filling step the reservoir container (40) and the process container (20, 100) are pressurized, preferably simultaneously or in a chronological order, by means of a, in particular single and / or shared, vacuum pump or that before the filling step the reservoir container (40) and the process container (20, 100) are pressurized independently from each other by means of a, in particular single and / or shared, vacuum pump (30).

8. Method according to one of the claims 1 to 7, characterized in that the reservoir container (40) has a vacuum supply pipe (44), wherein the vacuum supply pipe (44) has an upper, preferably open, end, which is in particular arranged inside the reservoir container (40) in the upper part of the reservoir container (40), preferably above the level of the powder material (10).

9. Method according to claim 8, characterized in that the vacuum supply pipe (44) has a lower end, preferably in the lower part ofthe reservoir container (40), which is or will be connected to a vacuum pump (30).

10. Method according to one of the claims 1 to 9, characterized in that the vacuum level of the process container (20, 100) and / or the vacuum level of the reservoir container (40) are monitored by means of a pressure sensor (26, 36), wherein in particular the pressure sensor (26, 36) is arranged in the upper part of the process container (20, 100) and / or the pressure sensor (26, 36) is arranged in the upper part of the reservoir container (40) and / or the pressurization of the process container (20, 100) and / or the pressurization of the reservoir container (40), preferably by means of a vacuum pump (30), is stopped after reaching the predetermined vacuum level.11 . Method according to one of the claims 1 to 10, characterized in that a filling level of the powder material (10) in the process container (20, 100) is monitored by means of a level sensor (28), wherein in particular the filling step is stopped after reaching a predetermined filling level of the process container (20, 100) monitored by the level sensor (28).

12. Method according to one of the claims 1 to 11 , characterized in that before the filling step the vacuum level of the reservoir container (40) is between -500 mbar to -1500 mbar, preferably between -700 mbar to -1200 mbar or between -800 mbar to -1000 mbar, in comparison to the atmosphere pressure outside the reservoir container (40) and / or that before the filling step the vacuum level of the process container (20, 100) is between -500 mbar to -1500 mbar, preferably between -700 mbar to -1200 mbar or between -800 mbar to -1000 mbar, in comparison to the atmosphere pressure outside the process container (20, 100).

13. Method according to one of the claims 1 to 12, characterized in that during the filling step the, in particular permanent, vacuum level of the reservoir container (40) and the vacuum level of the process container (20, 100) is between -500 mbar to -1500 mbar, preferably between -700 mbar to -1200 mbar or between -800 mbar to -1000 mbar, in comparison to the atmosphere pressure outside the reservoir container (40) and the process container (20, 100), wherein in particular the pressurization with vacuum of the reservoir container (40) and of the process container (20, 100) is or will be terminated after the filling step.

14. Method according to one of the claims 1 to 13, characterized in that the powder material (10) is provided as a powder mixture, in particular metal powder mixture, wherein the powder mixture comprises a mixture of at least two sorts of powder particles, wherein in particular the two sorts of powder particles differ in chemical composition and / or chemical properties and / or particle size and / or particle form and / or physical properties.

15. Process container (20, 100) of an apparatus (A) for processing powder material for manufacturing three-dimensional work pieces, in particular an apparatus (A) for manufacturing three- dimensional work pieces, further in particular an apparatus (A) for manufacturing three-dimensional work pieces by exposing powder layers to electromagnetic radiation or particle radiation in a process chamber, having an inner cavity (102) for accommodating powder material, in particular metal powder material or metal powder mixture, wherein a powder guiding member (1 10) for guiding the powder material is provided inside the inner cavity (102) of the, in particular closed, process container (20, 100).

16. Process container (20, 100) according to claim 15, characterized in that the powder guiding member (1 10) is arranged in an upper area of the inner cavity (102) of the process container (20, 100).

17. Process container (20, 100) according to claim 15 or 16, characterized in that the powder guiding member (1 10) is arranged at an inclination angle greater than 0° (> 0°) to the horizontal plane, wherein the inclination angle of the powder guiding member (1 10) is between 15° and 60°, preferably between 25° to 55°.

18. Process container (20, 100) according to claim 17, characterized in that the inclination angle of the powder guiding member (1 10) is adjustable or can be varied.

19. Process container (20, 100) according to one of the claims 15 to18, characterized in that the powder guiding member (1 10) has a longitudinal extended sliding surface (1 12) for the powder material.

20. Process container (20, 100) according to one of the claims 15 to19, characterized in that the powder guiding member (1 10) has at least one lateral margin along the longitudinal extended sliding surface (1 12), preferably one lateral margin at each side of the longitudinal extended sliding surface (1 12), and / or the powder guiding member (1 10) has an, preferably upper, end area with a, preferably one, lateral margin (1 14, 1 16) and / or the powder guiding member (1 10) has at least one contact end for contacting the inner side of the cavity (102), preferably at the upper end of the powder guiding member (1 10) and / or the powder guiding member (1 10) has at least one recess, preferably at the lower end of the powder guiding member (1 10).21 . Process container (20, 100) according to one of the claims 15 to 18, characterized in that a holding unit (120) is provided for holding the powder guiding member (1 10) inside the cavity (102).

22. Process container (20, 100) according to one of the claims 15 to21 , characterized in that the powder guiding member (1 10) has a one-piece sliding surface (1 12) for the powder material or the powder guiding member (1 10) comprises at least two or more powder guiding member (1 10) segments with sliding surfaces (1 12) for the powder material.

23. Process container (20, 100) according to one of the claims 15 to22, characterized in that the sliding surface (112) of the powder guiding member (1 10) for the powder material has a rectangular or rectangular-like form or the sliding surface (1 12) of the powder guiding member (1 10) for the powder material has a trapezoidal form or a trapezoidal-like form.

24. Process container (20, 100) according to one of the claims 15 to23, characterized in that the powder guiding member (1 10) is rotatable or pivotable around the vertical axis.

25. Process container (20, 100) according to claim 24, characterized in that a drive, in particular an electric drive, is provided for the rotation of the powder guiding member (1 10), in particular around the vertical axis of the powder guiding member (1 10).

26. Process container (20, 100) according to one of the claims 15 to 25, characterized in that the process container (20, 100) comprises a lower conical section (104) and an upper cylindrical section (106), wherein in particular the powder guiding member (1 10) is arranged inside the upper cylindrical section (106).

27. Use of a powder guiding member (1 10) for guiding the powder material in a, in particular closed, process container (20, 100) of an apparatus (A) for processing powder material for manufacturing three-dimensional work pieces, in particular an apparatus (A) for manufacturing three-dimensional work pieces, further in particular an apparatus (A) for manufacturing three-dimensional work pieces by exposing powder layers to electromagnetic radiation or particle radiation in a process chamber, according to one of the claims 15 to 26.

28. Apparatus (A) for processing powder material for manufacturing three-dimensional work pieces, in particular an apparatus (A) for manufacturing three-dimensional work pieces, further in particular an apparatus (A) for manufacturing three-dimensional work pieces by exposing powder layers to electromagnetic radiation or particle radiation in a process chamber, wherein the apparatus (A) has at least one process container (20, 100) according to one of the claims 15 to 26 and / or wherein the apparatus (A) is configured to be operated according to a method according to one of the claims 1 to 14.

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