Additive manufacturing using particle beam
By separating the X-ray shield from the vacuum chamber wall and setting up an X-ray shield to surround the particle beam source, vacuum chamber and vacuum pump, the problem of X-ray leakage in additive manufacturing equipment is solved, achieving efficient and safe X-ray Ray shielding effect.
Patent Information
- Application Number
- CN202380051132.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Priority Date
- 2022-07-01
- Filing Date
- 2023-06-29
- Publication Date
- 2025-02-18
AI Technical Summary
In additive manufacturing equipment using particle beams, X-rays may leak through openings in the vacuum chamber wall, causing operators to be exposed to radiation, and prior art is difficult to design efficient X-ray shields that adapt to different materials.
By separating the X-ray shield from the vacuum chamber wall, the X-ray shield is provided to at least surround the particle beam source, the vacuum chamber and the vacuum pump, thereby forming an X-ray barrier independent of any opening in the vacuum chamber wall.
The leakage-free X-ray shielding is achieved, reducing the manufacturing cost and complexity of the equipment, while improving the safety of the operator.
Smart Images
Figure CN119486828A_ABST
Abstract
Description
Technical Field
[0001] The present disclosure generally relates to additive manufacturing using particle beams. Background Art
[0002] In additive manufacturing using particle beams, such as electron beam powder bed fusion (E-PBF), the powder bed generates backscattered electrons and X-rays (so-called primary X-rays). These backscattered electrons can collide with other surfaces and generate more X-rays (so-called secondary X-rays). For the safety of operators of such equipment, it is necessary to provide an X-ray shield to protect the equipment operator from exposure to the generated X-rays. Since additive manufacturing using particle beams requires a vacuum so that the particle beam is not deflected by hitting gas molecules on the way to the build, the additive manufacturing equipment usually includes a vacuum chamber that surrounds the particle beam all the way from the particle beam source to the build. The X-ray shield is usually integrated into the vacuum chamber wall of the additive manufacturing equipment.
[0003] Problems with existing technology
[0004] When X-ray shielding is integrated into the walls of the vacuum chamber of an AM machine, X-rays can leak through any openings in these walls. Since openings must be left for vacuum pumps, vacuum gauges, sight glasses, etc., it is difficult to manufacture an X-ray shield that does not leak, especially since both primary and secondary X-rays must be considered. Since different materials produce different X-ray intensities, the X-ray shield must also be optimized to accommodate all materials to be manufactured in the AM machine.
[0005] There is therefore a need for an additive manufacturing apparatus with improved X-ray shielding. Summary of the invention
[0006] The claimed additive manufacturing apparatus solves the above problems. The apparatus may include: a particle beam source, a build box, a vacuum chamber (arranged to surround the particle beam from the particle beam source to the build box), one or more vacuum pumps (arranged to provide a vacuum in the vacuum chamber), and an X-ray shield (arranged to surround at least one of the one or more vacuum pumps, the particle beam source, and the vacuum chamber).
[0007] The above problems are further solved by a method for constructing an additive manufacturing apparatus including a particle beam source and a build box as claimed. The method may include providing an X-ray shield in the additive manufacturing apparatus to at least surround the particle beam source, providing a vacuum chamber to surround the particle beam from the particle beam source to the build box, and providing at least one vacuum pump to provide a vacuum in the vacuum chamber.
[0008] This enables a simple manufacture of an X-ray shield that does not leak by separating the X-ray shield from the vacuum chamber wall.The vacuum chamber itself does not necessarily have to be a chamber, it may just be an enclosure consisting of different parts that may be tightly connected to each other.
[0009] In an embodiment, the X-ray shield is arranged to also surround the build box. This enables more components of the additive manufacturing apparatus to be surrounded by the X-ray shield.
[0010] In an embodiment, the X-ray shield is arranged to also surround the powder box included in the additive manufacturing device. This enables all components of the additive manufacturing device to be surrounded by the X-ray shield.
[0011] In an embodiment, the X-ray shield is configured to include a door, and preferably also includes a door sensor for sensing whether the door is open. In an embodiment, if the door sensor senses that the door is open, the particle beam source is configured to automatically shut down, and preferably the particle beam source is configured to remain disabled as long as the door remains open. This ensures that the particle beam source does not generate harmful X-rays when the door in the X-ray shield is open.
[0012] In an embodiment, the door is configured to automatically lock as long as the particle beam source is activated. This ensures that no one can enter the X-ray shielding enclosure when the particle beam source is generating harmful X-rays.
[0013] In an embodiment, a human sensor is disposed in the X-ray shielding enclosure, and the human sensor senses the presence of a person in the X-ray shielding enclosure. The human sensor can be any type of sensor capable of detecting the possible presence of a person in the X-ray shielding enclosure, such as an infrared camera.
[0014] In an embodiment, the particle beam source is configured to automatically shut down if the human body sensor senses the presence of a person in the X-ray shield. This ensures that the particle beam source does not generate harmful X-rays when there is a person in the X-ray shield. In an embodiment, the particle beam source is configured to remain disabled as long as the human body sensor senses the presence of a person in the X-ray shield.
[0015] In an embodiment, the particle beam source is an electron beam source, such as an electron gun.
[0016] In an embodiment, multiple additive manufacturing devices are arranged to form an additive manufacturing production facility. In an embodiment, the X-ray shielding enclosures surrounding the additive manufacturing devices are arranged so that at least one X-ray shielding wall is shared between at least two different additive manufacturing devices. This is an effective method for arranging an additive manufacturing production facility.
[0017] The above mentioned problem is further solved by the claimed additive manufacturing production facility, which comprises a plurality of the above mentioned additive manufacturing devices, wherein at least two different additive manufacturing devices share at least one wall of the X-ray shielding enclosure.
[0018] The scope of the present invention is defined by the claims, which are incorporated into this section by reference. By considering the following detailed description of one or more embodiments, those skilled in the art will more fully understand the embodiments of the present invention and recognize the additional advantages of the present invention. Reference will be made to the accompanying drawings, which are first briefly described. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1a -b schematically illustrates an embodiment of an additive manufacturing apparatus according to one or more embodiments described herein.
[0020] Figure 2 One embodiment of an additive manufacturing apparatus according to one or more embodiments described herein is schematically illustrated.
[0021] Figure 3 One embodiment of an additive manufacturing production facility according to one or more embodiments described herein is schematically illustrated.
[0022] Figure 4 A method of additive manufacturing using a particle beam according to one or more embodiments described herein is schematically illustrated.
[0023] Embodiments of the present disclosure and their advantages may be best understood by referring to the following detailed description.It should be appreciated that like reference numerals are used to identify like elements shown in one or more of the Figures. DETAILED DESCRIPTION
[0024] In additive manufacturing using particle beams, such as electron beam powder bed fusion (E-PBF), the powder bed generates backscattered electrons and X-rays (so-called primary X-rays). These backscattered electrons can collide with other surfaces and generate more X-rays (so-called secondary X-rays). For the safety of operators of such equipment, it is necessary to provide an X-ray shield to prevent the equipment operator from being exposed to the generated X-rays. However, it is difficult to design an additive manufacturing equipment with an X-ray shield that is sufficient to cope with various processing conditions.
[0025] The wall thickness required for shielding against X-rays depends on the accelerating voltage used in the particle beam source. A typical electron gun for an E-PBF system may, for example, have an accelerating voltage of 60 kV. The X-ray shielding efficiency of a material depends essentially on its atomic number. If the vacuum chamber is made of steel, a 20 mm thick steel wall is required to shield the X-rays of a 60 kV electron gun. If the chamber walls are made of aluminum, the required wall thickness is much greater than 20 mm. A vacuum chamber with such wall thickness becomes very heavy and expensive to manufacture. Thick walls also make it more difficult to have a good view of the additive manufacturing equipment. Thicker walls mean that a larger viewing window is required in order to get the same viewing angle into the chamber.
[0026] In addition, it is believed that it would also be advantageous to develop E-PBF systems with accelerating voltages higher than 60 kV. For example, an accelerating voltage of 120 kV is believed to improve the E-PBF process in terms of energy efficiency, productivity, and robustness. However, for a 120 kV system, extremely thick steel walls are required. Alternatively, high atomic number materials (such as tungsten or lead) can be attached to the outside of thinner steel walls. But such materials are expensive, and lead also presents environmental issues. In addition, the windows require extremely thick lead glass protection. Lead glass has poor optical properties, so it will be more difficult to use cameras and optical instruments to monitor and control the additive manufacturing process. In summary, it is technically very difficult and costly to build X-ray shielding in the vacuum chamber walls of additive manufacturing equipment with accelerating voltages higher than 60 kV.
[0027] Therefore, an additive manufacturing apparatus is proposed, whose X-ray shield is at least partially separated from the wall of the vacuum chamber (enclosing the particle beam all the way from the particle beam source to the build box). The at least partially separated X-ray shield can be made of low-cost materials and does not have some technical limitations associated with X-ray shields integrated into the walls of the vacuum chamber of the additive manufacturing apparatus. The X-ray shield is arranged to surround at least the vacuum chamber, the particle beam source and at least one vacuum pump arranged to provide a vacuum within the vacuum chamber, will produce an X-ray barrier independent of any openings in the vacuum chamber wall. The vacuum chamber itself is not necessarily a chamber, it can be just a shell composed of different parts that can be closely connected to each other.
[0028] The AM equipment may include a distance barrier surrounding the entire AM equipment to ensure that people cannot get too close while the AM equipment is in operation. The X-ray shield may be integrated into or become such a distance barrier instead of being integrated into the vacuum chamber wall. Such an X-ray shield will also act as a barrier to prevent people from getting too close while the AM equipment is in operation. Since such an X-ray shield will be located farther from the X-ray source, the X-ray shielding effect will also produce a greater protection distance because the radiation level decreases with increasing distance from the X-ray source.
[0029] This concept makes the use of the vacuum chamber much simpler, because if the vacuum chamber does not have to be shielded from X-rays, a wall thickness of only a few millimeters is sufficient to ensure the mechanical stability of the vacuum chamber. This concept also means that X-ray shielding does not have to be integrated in windows and feedthroughs (e.g. vacuum pumps).
[0030] The present disclosure generally relates to an additive manufacturing device. Embodiments of the disclosed solution are described in more detail with reference to the accompanying drawings.
[0031] Figure 1a An embodiment of an additive manufacturing apparatus 100 is schematically shown. The additive manufacturing apparatus 100 shown includes a particle beam source 110, two vacuum pumps 140 (configured to provide vacuum in a vacuum chamber 130), a build box 150, a powder box 160, and a vacuum chamber 130 (configured to surround the particle beam from the particle beam source 110 to the build box 150). The additive manufacturing apparatus 100 shown also includes an X-ray shield 120, which is configured to surround at least the electron beam source 110, the vacuum chamber 130, and the vacuum pump 140. Figure 1a In the schematically shown embodiment, the X-ray shield 120 also surrounds the build box 150 and the powder box 160, which in the illustrated embodiment are located within the vacuum chamber 130. This allows all components of the additive manufacturing apparatus to be surrounded by the X-ray shield 120.
[0032] Figure 1b Another embodiment of an additive manufacturing apparatus 100 is schematically shown. The additive manufacturing apparatus 100 shown includes a particle beam source 110, a build box 150, two powder boxes 160, and a vacuum chamber 130, wherein the vacuum chamber is configured to surround the particle beam from the particle beam source 110 to the build box 150. The additive manufacturing apparatus 100 shown also includes an X-ray shield 120, which is configured to surround at least the electron beam source 110, the vacuum chamber 130, and the vacuum pump 140 ( Figure 1b (not shown). Figure 1b In the schematically shown embodiment, the X-ray shield 120 also surrounds the build box 150 and the powder box 160, which are located within the vacuum chamber 130 in the illustrated embodiment. This allows all components of the additive manufacturing apparatus to be surrounded by the X-ray shield 120. Figure 1b In the schematically shown embodiment, the vacuum chamber 130 is not a chamber itself, but is merely a housing formed when different components of the additive manufacturing apparatus 100 are tightly connected to each other.
[0033] The additive manufacturing apparatus 100 may include multiple vacuum pumps connected to each other. If a very high vacuum is required, the vacuum pump 140 that provides vacuum to the vacuum chamber 130 may be connected to an additional vacuum pump that delivers a "pre-vacuum" to the vacuum pump 140. Such additional vacuum pumps do not have to be surrounded by the X-ray shield 130.
[0034] The particle beam source 110 may be any type of particle beam source, such as an electron gun. The particle beam source 110 may be enclosed in a vacuum chamber 130, or attached to a vacuum chamber 130 having an opening for the particle beam, as schematically shown in FIG1 . In any case, it is advantageous if the vacuum levels in the particle beam source 110 and the vacuum chamber 130 are approximately the same.
[0035] The vacuum chamber 130 also typically has feedthroughs or other openings for other equipment besides the vacuum pump 140, such as for one or more thermocouples. To control the pressure in the vacuum chamber 130, one or more pressure sensors may be used, and this may require providing one or more openings in the vacuum chamber 130 for such pressure sensors. Other types of openings may also be present, such as windows and / or openings for lights. It is advantageous if the X-ray shield 120 encloses all equipment connected to openings in the vacuum chamber 130, so that no openings are required in the X-ray shield 120.
[0036] In an embodiment, an X-ray shield 120 may be provided to surround the entire additive manufacturing apparatus 100, for example, in the form of a wall comprising a thin layer of lead. Such an X-ray shield is preferably constructed so that it independently protects the surrounding environment from the X-rays from the additive manufacturing apparatus 100, even if, for example, a vacuum chamber 130 would also contribute to the protection. Figure 2 This embodiment of an additive manufacturing device 100 (particularly an E-PBF device) is schematically shown. In this embodiment, the X-ray shield 120 allows an operator to approach the additive manufacturing device 100 by opening a door 170 on the X-ray shield 120 and entering the space between the X-ray shield 120 and the rest of the additive manufacturing device 100.
[0037] In such embodiments, it is advantageous if a device is provided to ensure that the particle beam source 110 in the additive manufacturing device 100 is automatically closed if the door 170 is opened while the additive manufacturing device 100 is still running. This ensures that when the door 170 on the X-ray shield 120 is opened, the particle beam source 110 does not generate harmful X-rays. The additive manufacturing device 100 may, for example, include a door sensor 180 that senses whether the door 170 is opened. In an embodiment, the particle beam source 110 is configured to automatically close and cannot be opened if the door sensor 180 senses that the door 170 is opened. In an embodiment, the door 170 is configured to automatically lock as long as the particle beam source 110 is activated. This ensures that when the particle beam source 110 generates harmful X-rays, no one can enter the X-ray shield 120.
[0038] However, typically, an operator will only enter the space between the X-ray shield 120 and the rest of the additive manufacturing apparatus 100 to remove builds from the build box 150 and refill the powder box 160, so the particle beam source 110 in the additive manufacturing apparatus 100 will not typically be operating when the operator opens the door 170 on the X-ray shield 120. The operator will control the additive manufacturing apparatus 100 using, for example, cameras and sensors installed inside the additive manufacturing apparatus 100 (e.g., in the space between the X-ray shield 120 and the rest of the additive manufacturing apparatus 100).
[0039] In an embodiment, a human sensor 190 is disposed within the X-ray shield 120. The human sensor 190 may be configured to sense the presence of a person within the X-ray shield 120. The human sensor 190 may be any type of sensor capable of detecting the possible presence of a person within the X-ray shield 120, such as an infrared camera.
[0040] In an embodiment, if the human sensor 190 senses the presence of a person in the X-ray shield 120, the particle beam source 110 is automatically turned off. This ensures that the particle beam source 110 does not generate harmful X-rays when there is a person in the X-ray shield 120. In an embodiment, the particle beam source 110 is configured to remain disabled as long as the human sensor 190 senses the presence of a person in the X-ray shield 120.
[0041] An additive manufacturing production facility may include a plurality of different additive manufacturing apparatuses 100 arranged adjacent to each other. Figure 3One embodiment of such an additive manufacturing production facility is schematically shown, in which additive manufacturing devices 100 are arranged in different units, each of which is surrounded by an X-ray shield 120. To improve efficiency, these units can share part of the wall of the X-ray shield 120. However, it is preferred that each unit includes a door 170 that can be opened independently of the doors 170 in other units, so that each additive manufacturing device 100 can be maintained independently of other devices.
[0042] The X-ray shield 120 may be made of a variety of different materials, such as metal, concrete, plaster, or stone, as long as the thickness is sufficient to prevent X-rays from passing through the X-ray shield 120 .
[0043] Figure 4 A method 400 for constructing an additive manufacturing apparatus 100 including a particle beam source 110 and a build box 150 is schematically shown. The method 400 may include:
[0044] Step 410: An X-ray shield 120 is set in the additive manufacturing device 100 to at least surround the particle beam source 110, a vacuum chamber 130 configured to surround the particle beam from the particle beam source 110 to the build box 150, and at least one vacuum pump 140 configured to provide vacuum in the vacuum chamber 130.
[0045] This enables the X-ray shield 120 to be easily manufactured without leakage by separating the X-ray shield 120 from the wall of the vacuum chamber 130. The vacuum chamber 130 itself is not necessarily a chamber, and may be only a housing composed of different parts that may be tightly connected to each other.
[0046] The method 400 may further include one or more of the following steps:
[0047] Step 420 : Using an electron beam source (eg, an electron gun) as the particle beam source 110 .
[0048] Step 430 : Arrange the X-ray shield 120 to also surround the build box 150 . This enables more components of the additive manufacturing apparatus 100 to be surrounded by the X-ray shield 120 .
[0049] Step 435 : The X-ray shielding cover 120 is arranged to also surround the powder box 160 included in the additive manufacturing apparatus 100 . This allows all components of the additive manufacturing apparatus 100 to be surrounded by the X-ray shielding cover 120 .
[0050] Step 440 : Configure the X-ray shield 120 to include the door 170 .
[0051] Step 450: Configure the X-ray shield 120 to include a door sensor 180 that senses whether the door 170 is opened.
[0052] Step 455: The particle beam source 110 is set to automatically close if the door sensor 180 senses that the door 170 is opened. This ensures that the particle beam source 110 does not generate harmful X-rays when the door 170 on the X-ray shield 120 is opened.
[0053] Step 460: Set the door 170 to automatically lock whenever the particle beam source 110 is activated. This ensures that no one can enter the X-ray shield 120 when the particle beam source 110 generates harmful X-rays.
[0054] Step 470: a human sensor 190 is provided in the X-ray shielding cover 120, and the human sensor 190 senses the presence of a person in the X-ray shielding cover 120. The human sensor 190 may be any type of sensor capable of detecting the presence of a person in the X-ray shielding cover 120, such as an infrared camera.
[0055] Step 475: The particle beam source 110 is set to automatically shut down if the human body sensor 190 senses the presence of a person in the X-ray shielding cover 120. This ensures that when there is a person in the X-ray shielding cover 120, the particle beam source 110 does not generate harmful X-rays.
[0056] Step 480: Arrange a plurality of additive manufacturing apparatuses 100 to form an additive manufacturing production facility.
[0057] Step 490: Arrange an X-ray shielding enclosure 120 around the additive manufacturing apparatus 100 so that at least two additive manufacturing apparatuses 100 share at least one X-ray shielding wall. This is an effective method for arranging an additive manufacturing production facility.
[0058] The above steps may be performed in any order that is technically reasonable, and some of the steps may be performed simultaneously with each other.
[0059] The foregoing disclosure is not intended to limit the invention to the precise form disclosed or to the specific field of use. It is contemplated that various alternative embodiments and / or modifications of the invention (whether explicitly described or implied herein) are possible in light of the present disclosure. Therefore, the scope of the invention is limited only by the claims.
Claims
1. An additive manufacturing device (100), comprising: a particle beam source (110); BuildBox(150); A vacuum chamber (130) configured to surround the particle beam from the particle beam source (110) to the construction box (150); one or more vacuum pumps (140) configured to provide a vacuum within the vacuum chamber (130); and An X-ray shield (120) is configured to surround at least one of the one or more vacuum pumps (140), the particle beam source (110), and the vacuum chamber (130).
2. The additive manufacturing device (100) according to claim 1, wherein: The X-ray shield (120) also surrounds the build box (150).
3. The additive manufacturing device (100) according to claim 2, further comprising a powder box (160), wherein the X-ray shielding cover (120) further surrounds the powder box (160).
4. The additive manufacturing device (100) according to any one of claims 1 to 3, wherein: The X-ray shield (120) includes a door (170).
5. The additive manufacturing device (100) according to claim 4, further comprising a door sensor (180), wherein the door sensor (180) senses whether the door (170) is opened, wherein: The particle beam source (110) is configured to automatically close if the door sensor (180) senses that the door (170) is opened.
6. The additive manufacturing device (100) according to claim 5, wherein: The particle beam source (110) is arranged to remain disabled as long as the door sensor (180) senses that the door (170) remains open.
7. The additive manufacturing device (100) according to any one of claims 4 to 6, wherein: The door (170) is configured to automatically lock once the particle beam source (110) is activated.
8. The additive manufacturing device (100) according to any one of the preceding claims, further comprising a human sensor (190) in the X-ray shield (120), the human sensor (190) sensing the presence of a person in the X-ray shield (120), wherein: The particle beam source (110) is configured to automatically shut down if the human body sensor (190) senses the presence of a person in the X-ray shielding cover (120).
9. The additive manufacturing device (100) according to claim 8, wherein: The particle beam source (110) is configured to remain disabled as long as the human sensor (190) senses the presence of a person within the X-ray shield (120).
10. The additive manufacturing apparatus (100) according to any one of the preceding claims, wherein: The particle beam source (110) is an electron beam source.
11. An additive manufacturing production facility, comprising a plurality of additive manufacturing devices (100) according to any one of claims 1 to 10, wherein at least one wall of the X-ray shield (120) is shared between at least two different additive manufacturing devices (100).
12. A method (400) for constructing an additive manufacturing device (100) comprising a particle beam source (110) and a build box (150), the method (400) comprising setting (410) an X-ray shield (120) in the additive manufacturing device (100) to at least surround the particle beam source (110), a vacuum chamber (130) configured to surround the particle beam from the particle beam source (110) to the build box (150), and at least one vacuum pump (140) configured to provide a vacuum in the vacuum chamber (130).
13. The method (400) of claim 12, further comprising positioning (430) the X-ray shield (120) to also surround the build box (150).
14. The method (400) of claim 13, further comprising arranging (435) the X-ray shield (120) to also surround a powder box (160) included in the additive manufacturing apparatus (100).
15. The method (400) of any one of claims 12 to 14, further comprising configuring (440) the X-ray shield (120) to include a door (170).
16. The method (400) of claim 15, further comprising configuring (450) the X-ray shield (120) to include a door sensor (180) that senses whether the door (170) is opened, and configuring (455) the particle beam source (110) to automatically close if the door sensor (180) senses that the door (170) is opened.
17. The method (400) of claim 16, wherein: Configuring (455) the particle beam source (110) to automatically shut down if the door sensor (180) senses that the door (170) is open includes configuring the particle beam source (110) to remain disabled as long as the door sensor (180) senses that the door (170) remains open.
18. The method (400) of any one of claims 15 to 17, further comprising configuring (460) the door (170) to automatically lock whenever the particle beam source (110) is activated.
19. The method (400) according to any one of claims 12 to 18, further comprising setting (470) a human body sensor (190) in the X-ray shielding cover (120), the human body sensor (190) sensing the presence of a person in the X-ray shielding cover (120), and setting (475) the particle beam source (110) to automatically shut down if the human body sensor (190) senses the presence of a person in the X-ray shielding cover (120).
20. The method (400) of claim 19, wherein: The particle beam source (110) is configured (475) to automatically shut down if the human body sensor (190) senses the presence of a person in the X-ray shield (120), including configuring the particle beam source (110) to remain disabled as long as the human body sensor (190) senses the presence of a person in the X-ray shield (120).
21. The method (400) of any one of claims 12 to 20, further comprising using (420) an electron beam source as the particle beam source (110).
22. The method (400) according to any one of claims 12 to 21, further comprising setting up (480) a plurality of additive manufacturing devices (100) to form an additive manufacturing production facility, and setting up (490) the X-ray shielding cover (120) surrounding the additive manufacturing device (100) so that at least two different additive manufacturing devices (100) share at least one X-ray shielding wall.