JP2021008079A - Three-dimensional molding device, and method for producing three-dimensional molding - Google Patents

Abstract

To provide a technique to prevent unintended projections from being formed when a powder layer is formed using a mixed powder including, for example, a silicon carbide powder and a metal boride powder having a lower melting point than a sublimation temperature of the silicon carbide, and the irradiation with an energy beam are repeated to laminate solidified layers.SOLUTION: A method for producing a three-dimensional molding repeats formation processing for forming a powder layer with a powder layer-forming part and irradiation processing for irradiating the powder layer with an energy beam. In the method, after the irradiation processing of the energy beam is conducted and before the formation processing of a next powder layer is conducted, removal processing is conducted to remove powder on the powder layer-forming part.SELECTED DRAWING: Figure 2

Description

The present invention relates to a three-dimensional modeling apparatus according to a so-called powder lamination and melting method, and a method for manufacturing a three-dimensional model using the same.

In recent years, so-called 3D printers have been actively developed, and various methods have been tried. For example, various methods such as a hot melt lamination modeling method, a stereolithography method using a photocurable resin, and a powder lamination fusion method are known.
In the powder additive manufacturing method (Power Bed Fusion), a step of laying raw material powders such as nylon resin, ceramics, and metal in layers and a step of irradiating a laser beam to selectively melt a part of the powder layer are repeated. This is a method of forming a three-dimensional model. In some cases, instead of the laser beam, another heating means such as an electron beam is used to selectively melt a part of the powder layer.

In recent years, additive manufacturing and melting methods using metal powder as a raw material have begun to be used as a method for producing articles that require high mechanical strength and good thermal conductivity.
In the powder laying process of laying metal powder in layers, a powder laying member (recoater) such as a squeegee or a roller is used to form a layer of powder on the modeling stage. As an example, a method in which an appropriate amount of powder is carried on the modeling stage by a squeegee or the like in the forward direction of the reciprocating operation of the recorder, and the powder is smoothed to a layer thickness with a roller adjusted to an appropriate interval from the modeling stage in the return direction. Can be mentioned. The method for forming the powder layer is not limited to this example, but the beam irradiation process is performed after the powder laying process. In the beam irradiation process, the above-mentioned laser beam or electron beam is scanned and irradiated on the powder layer according to the shape of the modeled object to be produced, and the powder is sintered or melted. After the beam irradiation, the modeling stage is lowered by one layer and the powdering process is performed again. By repeating the above operation, a three-dimensional three-dimensional object is formed.

In modeling using metal powder as a raw material, when heated by irradiating a beam, the powder layer locally becomes extremely hot, so metal vapor is generated, and the metal vapor aggregates in the space above the powder layer. Micrometer-level fine particles are generated. These fine particles are called fume, and the fume floats in the laser optical path and further adheres to the irradiation window for incident laser light from the light source. When the fume stays in the optical path or adheres to the irradiation window, it absorbs or reflects the laser light, affects the intensity of the laser light irradiating the powder layer, and changes the melting and sintering state of the powder layer, resulting in poor modeling. Become stable.

Patent Document 1 describes a method in which a gas supply nozzle and an exhaust nozzle are arranged to face each other on a modeling area to exhaust air in an air curtain shape to remove fume.
Further, Patent Document 2 describes a method for ensuring the stability of the irradiation intensity of the laser by heating the irradiation window on which the laser is incident to prevent the adhesion of fume.

By the way, in recent years, silicon carbide, which is a material that is excellent in lightness, wear resistance, thermal shock, chemical stability, etc. and is expected to be used in a wide range of fields but is difficult to machine, is a molding method using powder. Is being considered. However, silicon carbide is a material that does not have a melting point at normal pressure and sublimates at around 2545 ° C (or there are various theories such as 2700 ° C).

Patent Document 3 discloses a method in which a powder layer is formed from a mixed powder containing silicon carbide powder and a booxide powder having a melting point lower than the sublimation temperature of silicon carbide, and an energy beam is irradiated to perform modeling. Has been done. This is a method in which a mixture of silicon carbide and a metal booxide is eutectic or subeutectic by heating, and when heated, a transient liquid phase is formed in the silicon carbide to melt and solidify the powder layer.

International Publication No. 2011/049143 Japanese Patent Application Laid-Open No. 2008-510633 JP-A-2019-64226

Using the mixed powder containing the above-mentioned silicon carbide powder and the booxide powder having a melting point lower than the sublimation temperature of silicon carbide, the solidified layer is laminated by repeating the formation of the powder layer and the irradiation of the energy beam. In some cases, unintended protrusions were formed on the solidified layer. Unintended protrusions are hard, and when the protrusions are formed, not only the shape accuracy of the 3D model is reduced, but also the protrusions and the powder laying mechanism interfere with each other, causing the 3D model to tip over on the modeling stage. There was a problem that the dusting mechanism stopped or was damaged.
The problem caused by such a protrusion could not be solved by the countermeasure technique for fume described in Patent Document 1 and Patent Document 2.

Therefore, when forming a powder layer using a mixed powder containing silicon carbide powder and a booxide powder having a melting point lower than the sublimation temperature of silicon carbide, and repeating irradiation with an energy beam to stack the solidified layer. , There has been a demand for a technique for suppressing the formation of unintended protrusions. Further, even when other powders are used as raw materials, a technique for suppressing the formation of unintended protrusions has been required.

In one aspect of the present invention, the powder layer forming portion forming the powder layer, the energy beam source for irradiating the powder layer formed by the powder layer forming portion with an energy beam, and the powder adhering to the powder layer forming portion are removed. It is a three-dimensional modeling apparatus characterized in that it is provided with a removing portion.

Further, another aspect of the present invention is a method for manufacturing a three-dimensional modeled product, which repeatedly performs a powder layer forming process by a powder layer forming portion and an energy beam irradiation process on the powder layer. Manufacture of a three-dimensional model characterized by performing a removal treatment for removing powder adhering to the powder layer forming portion after performing an energy beam irradiation treatment and before performing a next powder layer forming treatment. The method.

According to the present invention, for example, a powder layer using a mixed powder containing silicon carbide powder and a booxide powder having a melting point lower than the sublimation temperature of silicon carbide is formed, and irradiation with an energy beam is repeated to solidify the powder layer. It is possible to prevent the formation of unintended protrusions when laminating the layers.

The schematic diagram which shows the state of irradiating a laser in the 3D modeling apparatus of Embodiment 1. (A) Schematic diagram showing a state after irradiation with a laser in the first embodiment. (B) The schematic diagram which shows the state which cleans the right side surface of the recorder by using the rotary brush roll in Embodiment 1. FIG. (C) The schematic diagram which shows the state which cleans the upper surface of a recorder by using a rotary brush roll in Embodiment 1. FIG. (A) Schematic diagram showing a state at the end of cleaning in the first embodiment. (B) The schematic diagram which shows one step of the powder layer formation process after the completion of cleaning in Embodiment 1. FIG. (C) The schematic diagram which shows the next one step of the powder layer formation process after the completion of cleaning in Embodiment 1. FIG. (A) The schematic diagram which shows the next one step of the powder layer formation process after the completion of cleaning in Embodiment 1. FIG. (B) The schematic diagram which shows the state which cleans the upper surface of the recorder by using the rotary brush roll in Embodiment 2. FIG. (A) The schematic diagram which shows the state which cleans the upper surface of a recorder by using the nozzle which blows an air flow in Embodiment 3. (B) The schematic diagram which shows the state of cleaning the upper surface of a recorder by using a scraper in Embodiment 4. FIG. (A) Schematic diagram for explaining a state in which a powder layer is irradiated with a laser beam in a conventional three-dimensional modeling apparatus. (B) Schematic diagram for explaining a situation in which deposits fall when forming a powder layer in a conventional three-dimensional modeling apparatus. (A) Schematic diagram for explaining a situation in which a laser is irradiated in a state where deposits have fallen on a powder layer in a conventional three-dimensional modeling apparatus. (B) Schematic diagram for explaining a state in which a protrusion is formed in a conventional three-dimensional modeling apparatus. A plan photograph of the powder layer after laser irradiation. The schematic diagram for demonstrating the situation which the powder scatters by sublimation.

The three-dimensional modeling apparatus and the method for manufacturing a three-dimensional model according to the embodiment of the present invention will be described with reference to the drawings. In the drawings referred to in the following description, unless otherwise specified, members having the same function are designated with the same reference number.

[Embodiment 1]
FIG. 1 is a schematic view showing a state in which the powder layer 18 is irradiated with the laser beam 12 in the three-dimensional modeling apparatus 200 of the first embodiment.
First, the configuration of the three-dimensional modeling apparatus 200 will be described. The three-dimensional modeling apparatus 200 capable of modeling by the powder lamination melting method includes a chamber 1 capable of introducing gas. The chamber 1 is provided with, for example, a gas introduction port 4 for introducing nitrogen gas and a vacuum pump 19 for exhausting the inside of the chamber at the time of gas replacement.
In the chamber 1, a modeling plate 11 which is a base for forming a three-dimensional model, a modeling stage 2 to which the modeling plate 11 is detachably mounted, a powder supply tank 3 for storing raw material powder, and a powder supply tank A powder supply stage 20 and a recorder 5 that support 3 are provided. The modeling stage 2 and the powder supply stage 20 can move up and down independently of each other.

The recoater 5 as the powder layer forming portion conveys the powder from the powder supply tank 3 onto the modeling plate 11 to form the powder layer 18 having a predetermined thickness of about 10 to 100 μm. The recorder 5 includes a squeegee 6 and a roller 7. The squeegee 6 has a function of transporting the powder of the powder supply tank 3 to the vicinity of the modeling plate while moving in the R direction. The roller 7 transports the powder onto the modeling plate 11 or the modeled object in the process of modeling while moving in the R direction or the L direction, and compresses or extrudes the powder to flatten the upper surface of the powder layer 18 and determine the powder layer. It has the function of adjusting to the thickness of. The height of the lower end surface of the squeegee 6 can be appropriately changed so that the powder can be conveyed by the squeegee 6 and the powder layer is flattened by the roller 7. That is, the squeegee 6 is configured to be in a posture in which the height of the lower end surface is the same as the lower end of the roller 7, or the height of the lower end surface is higher than the lower end of the roller 7. .. The roller 7 moves in the horizontal direction (L direction, R direction) while pressing the powder, but the roller 7 is made of a highly rigid and hard-to-deform material so that the height of the lower end does not fluctuate. A high-rigidity drive device with suppressed vertical movement is used for this.

In order to recover the excess powder when the powder layer is formed by the recorder 5, recovery grooves 21 are arranged on the left side of the powder supply tank 3 and the right side of the modeling stage 2. When the operation of forming the powder layer is not performed, the recorder 5 is arranged at a position separated from the modeling stage 2 as shown in FIG. 1, and this position is called a standby position.

A rotating brush roll 8 as a removing portion, which is a characteristic portion of the present embodiment, is provided in the vicinity of the standby position of the recorder 5. The rotating brush roll 8 as a removing portion is supported so as to be able to move up, down, left, and right while rotating in order to remove scattered matter adhering to the surface of the recorder 5. The rotary brush roll 8 used in the present embodiment has, for example, a diameter of Φ18 mm, and fibers made of, for example, carbon or horsehair are used for the brush. When the rotating brush roll 8 removes scattered matter (powder) adhering to the surface of the recoater 5, the above-mentioned material is used in order to suppress the generation of static electricity and damage to the surface of the recoater. Below the standby position of the recoater 5, a collection container 9 for collecting the powder removed from the surface of the recoater 5 is arranged. The operation of the rotary brush roll 8 will be described in detail later.

Outside the chamber 1, a scanning optical system 14 including a laser oscillator 15 as an energy beam source, a galvanometer mirror 16 for scanning the laser beam, and an f-θ lens 17 for condensing the laser beam is provided. .. On the upper side of the modeling plate 11, there is a transmission window 13 that transmits the laser beam 12 emitted from the scanning optical system 14, and the laser beam 12 is appropriately irradiated to the powder layer 18 on the modeling plate 11 through the transmission window 13. To.
In this embodiment, for example, a fiber laser having a wavelength of 1070 nm (maximum output 300 W) is used as the laser oscillator 15. The laser beam 12 output from the laser oscillator 15 is driven by a galvanometer mirror 16 and an f-θ lens 17 driven according to the shape data of the three-dimensional modeled object at a desired position on the surface of the powder layer 18 on the modeling plate 11. It is focused and scanned.

Next, the process of forming a three-dimensional model using the three-dimensional model device 200 will be described.
First, the raw material powder that can be used in this embodiment will be described. In the present embodiment, for example, silicon carbide (SiC) powder having an average particle size of Φ14.7 μm (manufactured by Taiheiyo Random) and chromium diboride (CrB ₂ ) powder having an average particle size of Φ3 to 6 μm (manufactured by Nippon Shinkinzoku) are used. Two kinds of powders can be mixed and used. Weigh each powder so that the atomic composition ratio of silicon carbide and chromium diboride is silicon carbide: chromium diboride = 70:30 (at.%), And put the weighed powder in a polyethylene bottle and mix. .. The powder supply tank 3 is filled with the mixed powder.

Next, the inside of the chamber 1 is evacuated using the vacuum pump 19. After sufficient evacuation, an inert gas is introduced from the gas inlet 4 so that the pressure in the chamber 1 becomes equal to the atmospheric pressure. As the inert gas, nitrogen (N ₂ ), argon (Ar) or the like can be mainly used, but in this embodiment, N ₂ gas is used.

Next, in preparation for the powder layer forming process, the origin of the modeling plate 11 is set in the vertical direction. The modeling stage 2 to which the modeling plate 11 is attached is lowered to a region that does not interfere with the operating region of the roller 7 of the recorder 5, and in that state, the recorder 5 is moved in the operating region including directly above the modeling plate 11 in the L direction −R direction. To reciprocate. After that, the modeling stage 2 is raised in a stepped manner, and the position (height) where the modeling plate 11 and the roller 7 are in contact with each other is set as the origin of the modeling plate 11. In the present embodiment, in order to determine that the contact has occurred, a load sensor (not shown) is incorporated in the modeling stage 2, and the contact is determined by detecting an increase in the load due to the contact. How much the load rises to determine contact depends on the rigidity of the device, but in the device of the present embodiment, it is determined that contact is made when a load of 10 N is applied, and that position is set as the origin of the modeling stage 2.

In order to form the powder layer on the modeling plate 11, first, the modeling stage 2 is lowered slightly larger than the thickness of the powder layer to be formed. For example, when the thickness of the powder layer to be formed is 50 μm, it is lowered by 70 μm. After that, the powder supply stage 20 supporting the powder supply tank 3 is raised by 120 μm to push the powder upward. Then, the recorder 5 whose posture of the squeegee 6 is adjusted so that the lower end surface of the squeegee 6 is at the same height as the lowermost portion of the roller 7 is driven in the R direction and moved from the standby position to the right side of the powder supply tank 3. Carry the amount of powder required for powder laying to the left side of the modeling stage 2.

Subsequently, the recorder 5 whose posture of the squeegee 6 is adjusted so that the lower end surface of the squeegee 6 is higher than the lowermost portion of the roller 7 is driven in the R direction, the recorder 5 is moved to the right side of the modeling stage 2, and the roller 7 is moved. Spread the powder on the modeling stage 2 using only.
Finally, after raising the modeling stage 2 by 20 μm, the recorder 5 is driven in the L direction with the squeegee 6 raised so that the lower end surface of the squeegee 6 is above the lowermost portion of the roller 7. Excess powder is pushed out of the modeling area while being compressed in the vertical direction using only the roller 7, and a powder layer having a uniform thickness of 50 μm is formed on the modeling stage 2. As described above, the powder layer forming process by the recoater 5 as the powder layer forming portion is completed for one layer.

Next, an irradiation process is performed in which the formed powder layer is irradiated with a laser beam. The modeling model created by CAD or the like is converted into a laser irradiation pattern for each layer by slicer software. The galvanometer mirror 16 is controlled according to the converted laser irradiation pattern, and the powder layer 18 is irradiated with the laser beam 12. For example, the laser power is 100 W, the laser scan speed is 500 mm / s, and the scan pitch is 0.05 mm, but the present invention is not limited thereto. Further, when irradiating the laser beam 12, it is desirable to operate a fume collector (not shown) to recover the fume generated when irradiating the laser beam 12. The powder in the region irradiated with the laser beam 12 melts and solidifies as a bulk body through the eutectic phenomenon described in Patent Document 3, and the other regions remain in the state of the powder layer.

When the irradiation of the laser beam 12 is completed for one powder layer, the above-mentioned powder laying process is repeated to lay a powder layer made of a mixed powder of silicon carbide and chromium diboride, and the laser is laid according to the pattern of the next layer. The beam is applied onto the powder layer. By repeating the above operation, layers containing silicon carbide as a main component can be sequentially stacked to form a three-dimensional three-dimensional object.

In the present embodiment, after the irradiation of the laser beam 12 for a certain powder layer is completed and before the next powder laying process is started, the scattered matter adhering to the surface of the recoater 5 using the rotating brush roll 8 is used. Performs the characteristic action of removing.
In order to facilitate understanding of this characteristic operation, the cause of unintended protrusions formed in the conventional device when the solidified layer is laminated by repeating the formation of the powder layer and the irradiation of the laser beam is described in this book. The findings obtained by the inventor will be explained.

FIG. 6A is a schematic diagram for explaining a situation in which the powder layer is irradiated with a laser beam in the conventional three-dimensional modeling apparatus 300. The elements common to the apparatus of the first embodiment shown in FIG. 1 are designated by the same numbers and the description thereof will be omitted. However, the conventional three-dimensional modeling apparatus 300 is not provided with the rotary brush roll 8. pay attention to.

When the present inventor irradiates the laser beam 12 after forming the powder layer 18 made of a mixed powder of silicon carbide and chromium diboride in the conventional three-dimensional modeling apparatus 300, the powder around the irradiated portion is released. It was found that it scatters and flies to the recorder 5. As schematically shown in FIG. 6A, the powder 100 that flew to the recoater 5 adhered to the side surface of the recoater 5 or was loaded on the upper surface. Examination of the powder 100 adhering to the side surface of the recorder 5 or loaded on the upper surface revealed that the composition was similar to that of the raw material powder used in the powder layer 18.

FIG. 8 is a photomicrograph (plan view) taken from above after linearly scanning a laser beam on a powder layer composed of a mixed powder of silicon carbide and chromium diboride. There is a model (solid) containing silicon carbide and chromium diboride in the area irradiated with the laser (line in the center of the drawing), but the powder disappears around the model and the model plate is exposed. I understand. In the photograph, the part that looks whitish along the line is the exposed part of the modeling plate. It is probable that the powder that was on the exposed part of the modeling plate was scattered, and at least a part of it reached the recorder 5.

With reference to FIG. 9, the mechanism by which the powder around the portion irradiated with the laser beam is scattered will be considered. As shown in FIG. 9, when a mixed powder of silicon carbide and chromium diboride is irradiated with a laser, the locally heated portion becomes a liquid state (hereinafter, also referred to as a melt pool) due to the eutectic phenomenon. In the process of changing from the powder state to the liquid state, some silicon carbide sublimates without going through the eutectic process. That is, silicon carbide powder exists near the surface of the powder layer to be irradiated with the laser, but when the temperature of the silicon carbide powder rises sharply due to the irradiation of the laser beam, a part of it is eutectic with chromium diboride. Before doing so, it will sublimate beyond the sublimation temperature. It is presumed that the partial sublimation of silicon carbide blows off the powder 100 around the laser irradiation portion and eliminates the powder at the peripheral portion of the line.

This phenomenon becomes remarkable when the energy input to the powder from the laser beam is increased, so I tried to reduce the laser energy within the range where modeling is possible, but completely prevent the powder 100 from reaching the recorder 5. I couldn't. In addition, during laser irradiation, the flow rate (intake and exhaust amount) of the air curtain that was flowing on the modeling stage was adjusted as a measure against fume, but in the adjustment of the intake and exhaust amount within the range that does not affect the powder layer, the recorder 5 It was not possible to prevent the adhesion to. This is because the blown powder 100 has a much larger mass and momentum than the fume in which the vapor aggregates and floats as submicrometer-level fine particles.

As schematically shown in FIG. 6A, if the powder 100 adheres to the side surface of the recoater 5 or is loaded on the upper surface during laser irradiation, the recoater 5 forms the next powder layer after laser irradiation. , Powder 100 may fall.

FIG. 6B is a schematic view for explaining a situation in which the next powder layer is formed by using the recorder 5 in which the powder 100 adheres to the side surface or is loaded on the upper surface. As shown in the figure, the recorder 5 is driven in the R direction in a state where the lower end of the squeegee 6 is higher than the lowermost portion of the roller 7, and then the recorder 5 is driven in the L direction to form a powder layer. In this way, while the recorder 5 is horizontally moved on the modeling stage 2, the powder 100 that adheres to the side surface of the recorder 5 or is loaded on the upper surface may fall as a lump. In particular, when the recoater 5 is finally driven in the L direction and heads for the standby position while being pressed against the powder layer, if a lump of powder 100 falls from the rear end side (right side in the figure) onto the powder layer, the roller has already Since 7 has passed, the dropped mass of powder 100 is piled up on the powder layer as it is.

FIG. 7A schematically shows a state in which a mass of powder 100 is piled up on the powder layer 18 and a laser beam 12 for forming the next solidified layer is irradiated. It is a figure. When the laser beam is applied to the portion where the lumps of the powder 100 are piled up, as shown in FIG. 7B, a hard protrusion 101 unintended for the three-dimensional model is formed. When the protrusion 101 is formed, of course, the shape accuracy of the three-dimensional model is lowered. Further, when forming the next powder layer, there is a problem that the protrusion 101 and the recorder 5 interfere with each other and the three-dimensional modeled object falls on the modeling stage, or the recorder 5 is stopped or damaged. Was there.

Therefore, in the present embodiment, after the powder layer is irradiated with the laser beam 12 and before the next powder laying process is started, the scattered matter adhering to the surface of the recorder 5 using the rotating brush roll 8 is used. A process for removing (powder 100) is performed.

FIG. 2A schematically shows the state of the recorder 5 after irradiating the laser beam to form the solidified portion 31 constituting the three-dimensional modeled object as shown in FIG. The powder 100 is attached to the upper surface and the right side surface of the recorder 5 in the standby position. The rotary brush roll 8 is located above the standby position of the recorder 5.

In order to remove the scattered matter adhering to the surface of the recorder 5, first, as shown in FIG. 2B, the rotary brush roll 8 is moved downward by using an actuator while rotating. At this time, the rotation speed of the rotating brush roll 8 is set to, for example, 200 [rpm], and the rotating brush is moved downward while sliding on the right side surface (front surface of the squeegee 6) of the recorder 5, and the adhering scattered matter (powder). 100) is removed. It is also possible to reciprocate the rotary brush roll 8 up and down a plurality of times.

After that, as shown in FIG. 2C, the height of the rotary brush roll 8 is adjusted to the upper surface of the recorder 5, and the rotary brush roll 8 is rotated while using a horizontal movement mechanism (for example, a rail) (not shown). Move in the direction to remove the scattered matter accumulated on the upper part of the recorder 5. It is also possible to reciprocate the rotary brush roll 8 a plurality of times in the left-right direction (L direction-R direction).

Since the left side surface of the recorder 5 is a place where scattered matter does not adhere so much, it is often unnecessary to use the removal process as described above. However, in the process of removing the scattered matter on the upper part of the recoater 5, it may adhere to the rear surface of the recoater 5. Therefore, after removing the scattered matter on the upper part of the recoater 5, the rotating brush roll 8 is moved along the left side surface. It may be moved downward to remove the scattered matter on the left side surface of the recorder 5.

The above-mentioned scattered matter removal treatment may be carried out layer by layer after irradiating the powder layer with the laser beam and before starting the next powder laying, or after repeating the laser beam irradiation and the powder laying a predetermined number of times. You may.
Further, in the above-described example, the right side surface of the recorder 5 is first cleaned, and then the upper surface surface is cleaned, but the cleaning order may be reversed.

In the present embodiment, the scattered matter removed from the recorder 5 in the above process is collected in the collection container 9 as the collection unit. A dust collector (not shown) is connected to the collection container 9 so that the removed scattered matter does not scatter again in the apparatus. The recovered powder may be reused as a raw material powder for modeling.

FIG. 3A schematically shows the recorder 5 in which the cleaning by the rotating brush roll 8 is completed and the adhering powder 100 is removed. The rotary brush roll 8 is retracted to a position (upward) that does not interfere with the recorder 5.
After that, as shown in FIG. 3B, the powder supply stage 20 supporting the powder supply tank 3 is raised to push the powder upward, and the modeling stage 2 is lowered.
Then, as shown in FIG. 3C, the recorder 5 whose posture of the squeegee 6 is adjusted so that the lower end surface of the squeegee 6 is at the same height as the lowermost portion of the roller 7 is driven in the R direction, which is necessary for dusting. Carry a large amount of powder to the left side of the modeling stage 2.

Subsequently, as shown in FIG. 4A, the recorder 5 whose posture of the squeegee 6 is adjusted so that the lower end surface of the squeegee 6 is higher than the lowermost portion of the roller 7 is driven in the R direction. While moving the recorder 5 to the right side of the modeling stage 2, powder is spread on the modeling stage 2 using only the rollers 7. Further, the recorder 5 is driven in the L direction to form a powder layer having a uniform thickness.

In the present embodiment, as shown in FIG. 4A, the powder 100 adhering to the recoater 5 is removed in advance and then moved onto the modeling stage 2, so that the powder is moved onto the powder layer as in the conventional case. There is no need to drop 100 and pile up.
Therefore, when the solidified layer is laminated by repeating the formation of the powder layer and the irradiation of the energy beam using the mixed powder containing the silicon carbide powder and the booxide powder having a melting point lower than the sublimation temperature of the silicon carbide. , It is possible to suppress the formation of unintended protrusions.

According to the above-described embodiment, for example, 400 layers were formed in an area of a maximum of 30 mm × 40 mm, and a modeled object having a maximum part size of 30 mm × 40 mm × 20 mm was obtained. The modeling was completed without stopping, the roller 7 was not damaged, and the shape accuracy of the three-dimensional modeled object satisfied the predetermined standard. When the apparatus was confirmed before forming the powder layer during modeling, there was almost no scattered matter (powder) derived from the powder for modeling on the surface of the recorder 5 after the cleaning operation. As described above, it is possible to prevent the scattered matter accumulated on the recoater 5 from falling into the modeling area, and it is possible to obtain a modeling apparatus having high stability of modeling operation and excellent productivity.

[Embodiment 2]
The second embodiment will be described with reference to FIG. 4 (b). The description of the parts common to the first embodiment will be omitted. The first embodiment has a configuration in which the rotating brush roll 8 as a removing portion is moved up, down, left and right for cleaning, but the rotating brush roll 8 as a removing portion in the second embodiment has a fixed position. As shown in FIG. 4B, the rotating brush roll 8 is fixed at a position where it can come into contact with the recoater 5, and when the recoater 5 moves in the R direction or the L direction during powder laying, the rotating brush roll 8 Is rotated to remove the scattered matter adhering on the recoater 5. The rotary brush roll 8 and the recoater 5 are in the slidable position at the start of powder laying and at the time when the recoater 5 returns to the standby position after finishing the powder laying, so that the scattering on the recoater 5 is performed at that timing. The thing is removed.

The rotation direction of the rotary brush roll 8 is preferably such that the direction in which the brush moves becomes a counter with respect to the direction in which the recorder 5 moves. Further, even if the rotating brush roll 8 is not actively rotated, the recoater 5 can be moved to remove scattered objects to some extent. Therefore, the rotating brush roll 8 may be driven to rotate. In the present embodiment, it is difficult to remove the scattered matter adhering to the front surface and the rear surface of the recoater 5, but since the amount of the scattered matter adhering to the recoater 5 is overwhelmingly large in the upper part of the recoater 5, this embodiment is compared with the conventional apparatus. The form can perform more stable modeling.

In the present embodiment, as shown in FIG. 4B, a recovery groove 21 is provided on the upper portion of the recoater 5 as a recovery unit for recovering the powder adhering to the surface. When cleaning the powder deposited on the recoater 5 while moving the recoater 5 horizontally using the fixed rotary brush roll 8, the powder is dropped and collected in the collection groove 21 having a sufficient depth and capacity. The powder once entered in the recovery groove does not fall out from the recorder 5 during the powder layer forming operation. When the chamber is opened after modeling, the powder collected in the collection groove 21 can be sucked and discharged by connecting a dust vacuum cleaner to a nozzle connection port (not shown) provided near the collection groove 21. Alternatively, during molding or while the chamber after molding is closed, the opening / closing shutter (not shown) provided at the bottom of the recovery groove is opened, and the powder collected in the recovery groove 21 is dropped into, for example, the powder supply tank 3. You may reuse it.
In the example of FIG. 4B, the recovery groove 21 and the recovery container 9 are used in combination, but only one of them may be used. For example, in an apparatus for creating a relatively small size three-dimensional model, recovery is performed. Only the groove 21 may be provided.

According to the second embodiment, for example, 400 layers were formed in an area of a maximum of 30 mm × 40 mm, and a modeled object having a maximum part size of 30 mm × 40 mm × 20 mm was obtained. The modeling was completed without stopping, the roller 7 was not damaged, and the shape accuracy of the three-dimensional modeled object satisfied the predetermined standard. When the apparatus was confirmed before forming the powder layer during modeling, there was almost no scattered matter (powder) derived from the powder for modeling on the surface of the recorder 5 after the cleaning operation. As described above, it is possible to prevent the scattered matter accumulated on the recoater 5 from falling into the modeling area, and it is possible to obtain a modeling apparatus having high stability of modeling operation and excellent productivity.

[Embodiment 3]
The third embodiment will be described with reference to FIG. 5A. The description of the parts common to the first embodiment will be omitted. In the first embodiment or the second embodiment, a rotating brush roller is used as a cleaner for removing the powder adhering to the surface of the recoater 5, but in the present embodiment, a nozzle capable of blowing a gas flow is used as the removing portion. Is different.

In the present embodiment, an air flow is blown toward the recoater 5 to remove the powder adhering to the recoater 5 from the surface of the recoater. In the example shown in FIG. 5A, a removal nozzle 10 capable of ejecting an inert gas is provided above the standby position of the recoater 5. The gas blown out from the removal nozzle 10 is N ₂ like the atmospheric gas introduced into the chamber. The width of the opening of the nozzle from which N ₂ is ejected (in the figure, the depth direction) is 400 mm, and the vertical width is 5 mm. For example, the flow rate to be ejected is set to 600 L / min, and the flow velocity of the ejected gas is adjusted to 5 m / s. Blown from the removal nozzle 10 N ₂ gas to the top of the recoater 5, to remove the debris deposited on the recoater 5. In the case of the mixed powder of silicon carbide powder and chromium diboride powder used in the present embodiment, it can be blown off at 5 m / s, but the flow rate and the flow velocity may be appropriately changed according to the raw material powder used.

In the present embodiment, when the recoater 5 a laser beam after the irradiation to the powder layer is stationary at the standby position, the removed nozzle 10 out of the N ₂ gas to remove the powder on the recoater 5. However, the timing at which N ₂ gas is emitted from the removal nozzle 10 is not limited to the above, and a laser beam may be blown during irradiation. Furthermore, as shown, issues a N ₂ gas from the removal nozzle 10 when the recoater 5 is moved to the right (R direction) flour laying operation, to remove the debris that was deposited on top of the recoater 5 Is also good. In short, it suffices to have a relative positional relationship so that the airflow can be blown over the entire upper surface of the recorder 5.

In the present embodiment, a collection port 29 is provided on the left side of the recorder 5 as shown in FIG. 5A so that the powder blown off by the gas flow does not reattach to the inside of the apparatus. A dust collector (not shown) is connected to the collection port 29 as a collection unit so as to reliably collect the scattered matter accumulated on the recorder 5.

In the embodiment shown in FIG. 5A, it is difficult to remove the scattered matter adhering to the front surface and the rear surface of the recoater 5 in the present embodiment, but the amount of the scattered matter adhering to the recoater 5 is overwhelmingly the upper part of the recoater 5. Therefore, the present embodiment can be modeled more stably than the conventional device.
Although the device configuration is rather complicated, the blowing direction of the removal nozzle 10 may be changed so that the spray can be sprayed on the front surface (right side surface) of the recorder 5. In that case, in addition to the collection port 29, it is desirable to provide a collection container 9 as in the first embodiment.

According to the third embodiment, for example, 400 layers were formed in an area of a maximum of 30 mm × 40 mm, and a modeled object having a maximum part size of 30 mm × 40 mm × 20 mm was obtained. The modeling was completed without stopping, the roller 7 was not damaged, and the shape accuracy of the three-dimensional modeled object satisfied the predetermined standard. When the apparatus was confirmed before forming the powder layer during modeling, there was almost no scattered matter (powder) derived from the powder for modeling on the surface of the recoater 5 after the cleaning operation. As described above, it is possible to prevent the scattered matter accumulated on the recoater 5 from falling into the modeling area, and it is possible to obtain a modeling apparatus having high stability of modeling operation and excellent productivity.

[Embodiment 4]
The fourth embodiment will be described with reference to FIG. 5 (b). The description of the parts common to the first embodiment will be omitted. In the first embodiment or the second embodiment, a rotating brush roller is used as a cleaner for removing the powder adhering to the surface of the recoater 5, and in the third embodiment, a nozzle for blowing a gas flow is used, but in the present embodiment, the removing unit is used. The difference is that the scraper 22 is used.
In the present embodiment, the upper surface of the recoater 5 and the scraper are slid to remove the powder adhering to the recoater 5 from the surface of the recoater.

In the present embodiment, when the recoater 5 is stationary in the standby position after irradiating the powder layer with a laser beam, the scraper 22 is horizontally moved to slide the upper surface of the recoater 5 to remove the powder on the recoater 5. .. However, the timing of sliding is not limited to the above, and the laser beam may be slid during irradiation. Further, as shown in the drawing, when the recoater 5 moves to the right side (R direction) by the powder spreading operation, the scraper 22 may be brought into contact with the scraper 5 to remove the scattered matter accumulated on the upper part of the recoater 5. In short, the scraper 22 may be relatively moved so as to slide over the entire upper surface of the recorder 5.

In the present embodiment, a recovery groove 21 is provided on the upper portion of the recorder 5 as a recovery unit for recovering the powder adhering to the surface. The powder is dropped into a recovery groove 21 having a sufficient depth and capacity for recovery. The powder once entered in the recovery groove does not fall out from the recorder 5 during the powder layer forming operation. When the chamber is opened after modeling, the powder collected in the collection groove 21 can be sucked and discharged by connecting a dust vacuum cleaner to a nozzle connection port (not shown) provided near the collection groove 21. Alternatively, during molding or while the chamber after molding is closed, an open / close shutter (not shown) provided at the bottom of the recovery groove is opened, and the powder collected in the recovery groove 21 is dropped into, for example, the powder supply tank 3. You may reuse it.

In the present embodiment, it is difficult to remove the scattered matter adhering to the front surface and the rear surface of the recoater 5, but since the amount of the scattered matter adhering to the recoater 5 is overwhelmingly large in the upper part of the recoater 5, the present invention is compared with the conventional apparatus. The embodiment has the effect of enabling more stable modeling.
Although the device configuration is rather complicated, the scraper 22 may be provided with a vertical movement mechanism so that the front surface (right side surface) of the recorder 5 can also be slidable. In that case, in addition to the collection groove 21, it is desirable to provide a collection container 9 as in the first embodiment.

According to the fourth embodiment, for example, 400 layers were formed in an area of a maximum of 30 mm × 40 mm, and a modeled object having a maximum part size of 30 mm × 40 mm × 20 mm was obtained. The modeling was completed without stopping, the roller 7 was not damaged, and the shape accuracy of the three-dimensional modeled object satisfied the predetermined standard. When the apparatus was checked before forming the powder layer during the molding, there was almost no scattered matter (powder) derived from the molding powder on the surface of the recoater 5 after the cleaning operation. As described above, it is possible to prevent the scattered matter accumulated on the recoater 5 from falling into the modeling area, and it is possible to obtain a modeling apparatus having high stability of modeling operation and excellent productivity.

[Other Embodiments]
The present invention is not limited to the embodiments and examples described above, and many modifications can be made within the technical idea of the present invention.
The method of removing the powder adhering to the recorder 5 is not limited to the method of using the rotary brush roll, the method of blowing airflow, and the method of scraper. For example, the surface of the recoater 5 may be vibrated by using an ultrasonic vibrating device or the like to shake off the powder adhering to the surface of the recoater 5. A non-rotating brush or a flexible member such as a sponge may be used.

In the embodiment, the combination of the silicon carbide powder and the chromium diboride powder has been described, but powders of other combinations may be used. It is not necessary to utilize the eutectic phenomenon as in the embodiment, and for example, a sublimable silicon carbide powder and a metal powder may be used, and the molten metal may be used as a binder for connecting the silicon carbide to each other. Further, as the sublimable material used as a structural material, there is silicon nitride (Si ₃ N ₄ ) in addition to silicon carbide (SiC), and the present invention is the same for a powder layer containing these sublimable materials. Can exert the effect of. In addition to chromium diboride (CrB ₂ ), zirconium diboride (ZrB ₂ ), titanium boride (TiB ₂ ), vanadium boride (VB ₂ ), and the like can be used as materials that eutectic with the sublimable material. Powder may be used. Further, not only sublimable materials such as silicon carbide, but also resin powders and metal powders, depending on the irradiation conditions of the energy beam, the surrounding powder may scatter due to sudden boiling and adhere to the surface of the recoater. The effect of can be expected.

The energy beam used for heating the powder layer is not limited to the laser beam, and may be another light beam or electron beam. Atmosphere is not limited to N ₂ atmosphere in the chamber may be changed according to the type of energy beam and powder materials to be used. When an electron beam source is used as the energy beam source, the inside of the chamber is maintained in a vacuum atmosphere, so it is considered that the surrounding powder is scattered more due to sublimation than in atmospheric pressure, and a greater effect can be expected. ..

1 ... Chamber / 5 ... Recorder / 6 ... Squeegee / 7 ... Roller / 8 ... Rotating brush roll / 10 ... Removal nozzle / 14 ... Scanning optical system / 15 ... ... Laser oscillator / 18 ... Powder layer / 12 ... Laser beam / 22 ... Scraper / 31 ... Solidified part / 100 ... Powder / 101 ... Protrusion part / 200 ... Tertiary Former modeling equipment

Claims (18)

The powder layer forming part that forms the powder layer and
An energy beam source that irradiates the powder layer formed by the powder layer forming portion with an energy beam,
A removing portion for removing powder adhering to the powder layer forming portion is provided.
A three-dimensional modeling device characterized by this. The removing portion removes the powder adhering to the powder layer forming portion after the energy beam source irradiates the powder layer with the energy beam and before the powder layer forming portion forms the next powder layer. To do,
The three-dimensional modeling apparatus according to claim 1, wherein the three-dimensional modeling apparatus is characterized in that. The powder layer forming portion forms a powder layer containing a sublimable material.
The three-dimensional modeling apparatus according to claim 1 or 2. The sublimable material is silicon carbide.
The three-dimensional modeling apparatus according to claim 3, wherein the three-dimensional modeling apparatus is characterized in that. The removing portion has a brush that can slide on the surface of the powder layer forming portion.
The three-dimensional modeling apparatus according to any one of claims 1 to 4, wherein the three-dimensional modeling apparatus is characterized. The removing portion has a nozzle capable of blowing an air flow toward the surface of the powder layer forming portion.
The three-dimensional modeling apparatus according to any one of claims 1 to 4, wherein the three-dimensional modeling apparatus is characterized. The removing portion has a scraper that can slide on the surface of the powder layer forming portion.
The three-dimensional modeling apparatus according to any one of claims 1 to 4, wherein the three-dimensional modeling apparatus is characterized. The removing part has a collecting part for collecting the powder removed from the powder layer forming part.
The three-dimensional modeling apparatus according to any one of claims 1 to 7, wherein the three-dimensional modeling apparatus is characterized. It is a method of manufacturing a three-dimensional modeled product in which a powder layer forming process by a powder layer forming portion and an energy beam irradiation process of the powder layer are repeatedly performed.
After performing the energy beam irradiation treatment and before performing the next powder layer forming treatment, a removal treatment for removing the powder adhering to the powder layer forming portion is performed.
A method for manufacturing a three-dimensional model, which is characterized in that. The removal process is performed every time the energy beam irradiation process is performed.
The method for manufacturing a three-dimensional model according to claim 9. The removal treatment is performed after repeating the powder layer forming treatment and the energy beam irradiation treatment a predetermined number of times, and before the next powder layer forming treatment.
The method for manufacturing a three-dimensional model according to claim 9. The powder layer forming treatment is a treatment for forming a powder layer containing a sublimable material.
The method for manufacturing a three-dimensional model according to any one of claims 9 to 11, characterized in that. The sublimable material is silicon carbide.
The method for manufacturing a three-dimensional model according to claim 12, wherein the three-dimensional modeled object is manufactured. The removal process is a process of sliding the brush on the surface of the powder layer forming portion.
The method for manufacturing a three-dimensional model according to any one of claims 9 to 13, characterized in that. The removal treatment is a treatment of blowing an air flow toward the surface of the powder layer forming portion.
The method for manufacturing a three-dimensional model according to any one of claims 9 to 13, characterized in that. The removal process is a process of sliding a scraper on the surface of the powder layer forming portion.
The method for manufacturing a three-dimensional model according to any one of claims 9 to 13, characterized in that. The powder removed from the powder layer forming portion in the removal treatment is recovered.
The method for manufacturing a three-dimensional model according to any one of claims 9 to 16, characterized in that. The removal treatment is a treatment for removing the powder scattered from the powder layer and adhering to the powder layer forming portion during the irradiation treatment of the energy beam.
The method for manufacturing a three-dimensional model according to any one of claims 9 to 17, characterized in that.