Laser powder bed additive manufacturing device and method

Abstract

The invention relates to the technical field of additive manufacturing, and discloses a laser powder bed additive manufacturing device and method.The laser powder bed additive manufacturing device comprises a laser emitting device, a bearing bottom plate, a forming chamber, a lifting rod, a powder supply device and a workbench; the forming chamber is arranged at the upper part of the bearing bottom plate; the lifting rod is arranged at the inner top of the forming chamber, the output end of the lifting rod is connected with the workbench, and the lifting rod can do lifting motion and is used for driving the workbench to move up and down; the powder supply device is arranged on the inner wall of the forming chamber and used for supplying metallurgical powder to the position below the workbench. The lower portion of the workbench is used for part forming and manufacturing. The laser emitting device is arranged below the bearing bottom plate and used for emitting laser to the position below the workbench through the bearing bottom plate. The process production efficiency can be improved, the use amount of metallurgical powder is reduced, material waste is reduced, and the post-treatment procedure after the part is taken out is simplified.

Description

Technical Field

[0001] The invention belongs to the technical field of additive manufacturing and relates to a laser powder bed additive manufacturing device and method. Background Art

[0002] Additive manufacturing is a processing method that slices and layers a three-dimensional model and then stacks materials layer by layer to manufacture parts or objects. Compared with traditional subtractive and equal-material processing methods, additive manufacturing can simplify complicated processing steps and process flows while producing lightweight parts with complex structures and high personalization. It has been widely used in aerospace, medical, automotive and nuclear power fields. Among them, laser powder bed fusion (LPBF) technology is a very promising metal additive manufacturing technology. LPBF is also known as laser selective melting. During the forming process, the powder-laying device lays a certain layer of metal powder on the substrate. The laser selectively scans and melts the metal powder according to the slice contour to process a thin layer of metal structure. Then the substrate is lowered to a certain height (a slice layer thickness), and the above steps are repeated until the metal part is finally processed. After processing a layer of metal structure in the additive manufacturing process, this method needs to go through the process of substrate lowering and powder laying. For part production and manufacturing, this increases the time cost and reduces the processing efficiency. In order to ensure the powder laying effect, a large amount of powder will be laid on the substrate each time the powder is laid, which increases the cost of raw materials and is not conducive to improving resource utilization. When manufacturing a structure with cavity features, the interior of the cavity of the manufactured structure will be filled with metallurgical powder, which not only causes waste of metallurgical powder and reduces material utilization, but also increases the difficulty of subsequent structure cleaning.

[0003] Chinese patent CN201910185600.2 discloses a liquid floating powder bed additive manufacturing device and method. Specifically, a floating liquid with a density greater than that of the forming powder is used to make the forming powder float on the surface of the floating liquid under the action of buoyancy to form a powder bed covering the forming area, and a high-energy beam emission focusing scanning device is used to deposit the forming powder layer by layer to form a three-dimensional part. This technology enables the powder layer (bed) to exist only within a certain thickness range of the surface of the floating liquid, greatly reducing the amount of powder required to maintain the powder bed, but still requires a large amount of floating liquid formed by melting metal or non-metallic materials to fill the forming (cylinder) container, which increases the cost of purchasing the floating liquid raw materials and processing and melting. At the same time, when the processed parts are taken out, the floating liquid will inevitably adhere to the surface of the parts, increasing the difficulty of post-processing. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention provides a laser powder bed additive manufacturing device and method, which can improve process production efficiency, reduce the amount of metallurgical powder used, reduce material waste, and simplify the post-processing process after the parts are removed.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] In the first aspect, the present invention provides a laser powder bed additive manufacturing device, including a laser emitting device, a bearing base plate, a molding chamber, a lifting rod, a powder supply device and a workbench; the molding chamber is arranged on the upper part of the bearing base plate; the lifting rod is arranged on the inner top of the molding chamber, and the output end of the lifting rod is connected to the workbench, which can perform lifting movement and is used to drive the workbench to move up and down; the powder supply device is arranged on the inner wall of the molding chamber, and is used to supply metallurgical powder to the bottom of the workbench; the bottom of the workbench is used for part molding and manufacturing; the laser emitting device is arranged below the bearing base plate, and is used to emit laser to the bottom of the workbench through the bearing base plate. The laser emitting device is placed at a certain distance below the bearing base plate, and the laser is emitted through the bearing base plate to melt and sinter the metallurgical powder above the bearing base plate, thereby realizing the manufacturing of the single-layer structure of the part, and can move according to the specified trajectory to realize the manufacturing and molding of parts with different structures, and the laser intensity can be controlled by a computer.

[0007] It should be noted that the laser emitting device is a mature device in the prior art, and how to specify the trajectory of the laser work and how to control the laser intensity by computer are also prior art. The workbench is inverted, and the laser emitting device is arranged under the powder bed. The workbench is raised to perform layer-by-layer additive manufacturing, which reduces the waste of metallurgical powder, improves the utilization rate of metallurgical powder, and greatly simplifies the post-processing process after the parts are taken out.

[0008] In combination with the first aspect, further, the laser powder bed additive manufacturing device of the present invention also includes a vibration powder spreading device, which is arranged on the side of the supporting base plate, can perform ultrasonic vibration at a certain frequency, and the vibration direction is left and right. The left and right vibration can not affect the forming accuracy of the parts, and semi-automatic powder spreading is achieved by the gravity of the metallurgical powder itself. Further, the metallurgical powder is vibrated after falling, thereby realizing automatic powder spreading. The vibration of the vibration powder spreading device can ensure the quality of powder spreading, thereby improving the manufacturing production efficiency of the additive manufacturing process.

[0009] In combination with the first aspect, further, there are two vibration powder spreading devices, and the two vibration powder spreading devices are respectively arranged on both sides of the supporting base plate, one on the left and one on the right, and the two vibration powder spreading devices can perform the same frequency ultrasonic vibration at a certain frequency.

[0010] In combination with the first aspect, further, the vibration powder spreading device includes an ultrasonic transducer, a horn and an ultrasonic generator, wherein the ultrasonic generator is connected to the ultrasonic transducer, and the ultrasonic transducer is connected to the horn. The ultrasonic transducer and the bearing base are connected by screws, and the horn contacts the side of the bearing base. The ultrasonic generator converts electrical energy into mechanical energy through the ultrasonic transducer, and applies mechanical vibration to the bearing base after amplifying the amplitude of the mechanical vibration through the horn.

[0011] In combination with the first aspect, further, the molding chamber is provided with an air inlet and an exhaust port, which can be used to fill with protective gas and adjust the air pressure in the molding chamber during the part molding and manufacturing process, so as to provide a suitable space and environment for the additive manufacturing process.

[0012] In combination with the first aspect, further, the air inlet and the exhaust port are respectively arranged on the left and right sides of the top of the molding chamber, and the exhaust port is connected to an exhaust purification device. Inert gas can be charged through the air inlet, and the molding chamber is filled with inert gas through an exhaust-filling cycle. When the exhaust port is closed, the air inlet is continuously filled with inert gas to increase the air pressure in the molding chamber until the required air pressure is reached; when the air inlet is closed, the exhaust port is continuously exhausted to reduce the air pressure in the molding chamber until the required air pressure is reached.

[0013] In combination with the first aspect, further, the lower surface of the workbench has a certain roughness so that the first layer of additive material adheres to the lower surface of the workbench to prevent the semi-finished parts from falling off during the processing. When the processing is completed, the parts can be removed with tools such as shovels; the workbench is used for part molding and manufacturing, and can be moved up and down to a specified height driven by a lifting rod.

[0014] It should be noted that: when the size of the middle part of the part increases sharply (that is, when the cross-sectional size of the middle layer increases sharply relative to the cross-sectional size of the upper layer), a similar method to conventional 3D printing in the prior art is adopted to add some inverted auxiliary support structures to solve the problem of the sharp increase in size.

[0015] In combination with the first aspect, further, the lifting rod is a three-section push rod, which can accurately extend and retract up and down to a specified distance. The upper part is connected to the top of the inner side of the molding chamber by screws, and the lower part is connected to the upper surface of the workbench by screws, thereby realizing precise control of the upper and lower positions of the workbench.

[0016] In combination with the first aspect, further, the side of the workbench does not contact the powder supply device, that is, a certain distance is maintained between the two to ensure smooth lifting and lowering of the workbench.

[0017] In combination with the first aspect, further, the powder supply device is arranged above the supporting base plate, and is used to place metallurgical powder inside. A feeding port is provided on the top, and the feeding port is used to add metallurgical powder. The bottom surface is an inclined surface, and a discharge port is provided on the side surface close to the workbench side, and the metallurgical powder slides from the discharge port onto the supporting base plate.

[0018] Combined with the first aspect, further, the opening size of the discharge port of the powder supply device can be adjusted as needed, and can be fully open, half open, or fully closed, and its maximum opening height has a limit value. The discharge port of the powder supply device is completely closed before part molding and manufacturing. During the part molding and manufacturing process, the size of the discharge port opening increases with the rise of the workbench. Usually, the discharge port opening height is higher than the distance of a single layer height of the workbench until the entire part is manufactured. At this time, the discharge port opening height reaches the maximum, that is, the total height of the molded part plus the single layer height.

[0019] In combination with the first aspect, further, the discharge port of the powder supply device is provided with an opening end cover, and the opening size of the discharge port is realized by changing the position of the opening end cover. Specifically, the opening end cover is installed on a slide module, and the slide module is controlled by a motor through a ball screw structure.

[0020] In combination with the first aspect, further, the lower portion of the powder supply device is in contact with the upper portion of the supporting base plate, which can avoid the probability of metallurgical powder entering under the powder supply device and improve the utilization rate of the metallurgical powder.

[0021] In combination with the first aspect, further, a layer of anti-reflection film is coated on the lower surface of the supporting base plate.

[0022] In combination with the first aspect, further, the bearing base plate is made of a material that is laser-transmissive, has low energy absorption and has a certain bearing capacity, such as optical quartz glass, sapphire glass, and calcium fluoride that can be used when the mechanical strength requirement is relatively low.

[0023] In a second aspect, the present invention provides a laser powder bed additive manufacturing method, using the above-mentioned laser powder bed additive manufacturing device, comprising the following steps:

[0024] Step S1, set the layer height and laser power of the single-layer structure of the part, open the discharge port of the powder supply device to the set height, and the metallurgical powder slides down to the bottom of the workbench under the action of gravity; the workbench starts to descend from the top to press down the metallurgical powder below, and keep the distance between the lower surface of the workbench and the upper surface of the supporting bottom plate as the distance of a single layer height; the thickness of the metallurgical powder piled up under the action of gravity should be greater than the single layer height, the initial position of the workbench is at the top of the molding chamber, and the workbench descends to press down the metallurgical powder, so that the excess metallurgical powder overflows from the gap between the side of the workbench and the powder supply device to the top of the workbench, which can also make the first layer of metallurgical powder denser. In addition, the vibration powder spreading device is vibrated at the same time to further ensure the quality of the first layer of powder spreading.

[0025] Step S2, start the laser emitting device, move the laser light source to the specified starting position, emit laser, and move the laser light source along the specified path to melt and sinter the metallurgical powder under the workbench and adhere it to the lower surface of the workbench;

[0026] Step S3, after the current layer of parts is formed, the laser light source is turned off and moved to a specified end position;

[0027] Step S4, the workbench rises by a layer height; the opening height of the discharge port of the powder supply device rises by a layer height accordingly until the opening limit height is reached.

[0028] Step S5, repeating steps S2 to S4 until the molding and manufacturing of all cross sections of the three-dimensional part are completed.

[0029] In combination with the second aspect, further, before step S2, the following steps are also included: turning on the vibration powder spreading device, the vibration powder spreading device performs ultrasonic vibration at a set frequency to ensure the powder spreading quality.

[0030] Compared with the prior art, the present invention provides a laser powder bed additive manufacturing device and method, which has the following beneficial effects:

[0031] (1) The present invention can improve process production efficiency, reduce the amount of metallurgical powder used, reduce material waste, and simplify the post-processing process after the parts are removed.

[0032] (2) Compared with the conventional technology, the present invention adopts the form of an inverted workbench. After the single-layer part structure is formed, the workbench rises by a layer height. When printing each layer, only the metallurgical powder required for part manufacturing needs to be covered on the bottom, which greatly reduces the amount of metallurgical powder, improves the powder utilization rate, and greatly reduces the cost of metallurgical powder. In addition, the present invention adopts the form of an inverted workbench. The parts are formed and manufactured under the workbench, so that the cavity of the formed part will not be filled with a large amount of metallurgical powder, which greatly reduces the difficulty of cleaning the parts later.

[0033] (3) The metallurgical powder of the present invention is firstly spread under the action of gravity, and then ultrasonic vibration is used to ensure the quality of the powder spreading, thereby realizing automatic powder spreading. Compared with the traditional method, the powder spreading time is reduced and the production efficiency is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the three-dimensional structure of the additive manufacturing device of the present invention;

[0035] Figure 2 It is a schematic diagram of the additive manufacturing device of the present invention in the process of forming and manufacturing a part;

[0036] Figure 3 It is a schematic diagram of the three-dimensional structure of a single powder supply device in the present invention in an open and closed state;

[0037] Figure 4 A schematic diagram of a three-dimensional structure of a single powder supply device in the present invention in a semi-open state;

[0038] Figure 5 It is a schematic diagram of the three-dimensional structure of a single powder supply device in the present invention in a fully open state.

[0039] The meanings of the reference numerals in the figures are:

[0040] 1-laser emitting device; 2-carrying base plate; 3-vibrating powder spreading device; 4-molding chamber; 5-lifting rod; 6-powder supply device; 7-workbench; 8-molding and manufacturing parts; 9-metallurgical powder; 10-air inlet; 11-exhaust port; 12-exhaust purification device. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0042] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present invention. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to actual proportional relationships. The technology, methods and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, methods and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may also include different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0043] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the protection content of the present invention.

[0044] Example 1

[0045] like Figure 1 and Figure 2 As shown, the additive manufacturing device proposed in this embodiment includes a laser emitting device 1, a bearing base plate 2, a vibrating powder spreading device 3, a molding chamber 4, a lifting rod 5, a powder supply device 6 and a workbench 7; the molding chamber 4 is connected to the bearing base plate 2 at the bottom, and a lifting rod 5 is installed on the upper part of the molding chamber 4; the lower part of the workbench 7 is used for material molding and manufacturing, and the upper part of the workbench 7 is connected to the lifting rod 5; the upper part of the lifting rod 5 is connected to the top of the inner side of the molding chamber 4, and the lower part is connected to the upper part of the workbench 7; the laser emitting device 1 is placed at a certain distance below the bearing base plate 2, and the laser is emitted through the bearing base plate 2 to melt and sinter the metallurgical powder 9 above the base plate to realize the manufacturing of the single-layer structure of the part; the powder supply device 6 is installed on the inner wall of the molding chamber 4, and the bottom is in contact with the upper part of the bearing base plate 2; the bearing base plate 2 is installed below the molding chamber 4. In this embodiment, the workbench 7 is inverted. After the single-layer part structure is formed, the workbench 7 rises a distance of the layer height. When printing each layer, it is only necessary to cover the metallurgical powder 9 required for part manufacturing on the lower part, which greatly reduces the amount of metallurgical powder 9 and greatly reduces the cost of metallurgical powder 9. The inverted form of the workbench 7 allows the part to be manufactured and formed under the workbench 7, and the cavity of the molded part will not be filled with a large amount of metallurgical powder 9, which greatly reduces the difficulty of cleaning the part later.

[0046] In a specific implementation of this embodiment, the molding chamber 4 is used to provide a suitable space and environment for the additive manufacturing process, and is provided with an air inlet 10 and an exhaust port 11, which can be filled with protective gas and control the air pressure in the molding chamber 4 during the part molding process. The exhaust port 11 is provided with an exhaust purification device 12 to prevent the metallurgical powder 9 from contaminating the environment outside the molding chamber.

[0047] In a specific implementation of this embodiment, the lower surface of the workbench 7 has a certain roughness so that the molded parts can be attached thereto, which is convenient for part molding and manufacturing. The upper surface of the workbench 7 is connected to the lifting rod 5 and can be moved up and down a specified distance. The side of the workbench 7 maintains a certain distance from the powder supply device 6 to ensure that the workbench 7 can be lifted and lowered smoothly.

[0048] In a specific implementation of this embodiment, the lifting rod 5 can be precisely extended and retracted up and down to a specified distance under computer control, and its upper part is connected to the inner top of the molding chamber 4, and its lower part is connected to the upper part of the workbench 7, thereby realizing precise control of the upper and lower positions of the workbench 7. During the part molding process, after each single-layer part manufacturing is completed, the lifting rod 5 drives the workbench 7 to rise by a single layer height to facilitate the manufacturing of the next layer of parts.

[0049] In a specific implementation of the present embodiment, the laser emitting device 1 is placed at a certain distance below the supporting base plate 2, and can emit laser to penetrate the supporting base plate 2, so that the metallurgical powder 9 above the supporting base plate 2 is melted and sintered to form a single-layer structure of the part. The laser light source can move along a specified trajectory to realize the manufacturing of parts with different structures, and the laser intensity can be controlled by a computer.

[0050] In a specific implementation of this embodiment, the powder supply device 6 is installed on the inner wall of the molding chamber 4, and its bottom is in contact with the upper part of the supporting bottom plate 2, and metallurgical powder 9 is installed inside; the top of the powder supply device is provided with a feeding port, and its bottom surface is an inclined surface, and a discharge port is provided on the side surface close to the workbench 7. The opening size of the discharge port can be controlled and adjusted according to needs, and the maximum opening height has a limit value, such as Figures 3 to 5 As shown, Figure 3 The opening of the middle discharge port is closed, which means that the parts have not been processed yet; Figure 4 The opening of the middle discharge port is in a half-open state, which occurs during the parts processing; Figure 5 The opening of the middle discharge port is fully open, which means that the part has been processed to the last layer or has been processed. The maximum opening height is related to the height of the part to be processed, and the maximum opening height = part height + single layer height.

[0051] In a specific implementation of this embodiment, the supporting base plate 2 is installed at the lower part of the molding chamber 4. A material that is laser-penetrable, has low energy absorption and has a certain bearing capacity is used. A layer of anti-reflection film (anti-reflection film) is coated on the lower surface of the supporting base plate 2 to ensure the laser penetration effect.

[0052] Example 2

[0053] The difference between Example 2 and Example 1 is that the additive manufacturing device of Example 2 further includes a vibrating powder spreading device 3, such as Figure 1 and Figure 2 As shown, the vibrating powder spreading device 3 is arranged on both sides of the supporting base plate 2, and can perform ultrasonic vibration at a certain frequency (set frequency), and the vibration direction is left and right. The left and right vibration will not produce vertical displacement, so as not to affect the part molding accuracy. The metallurgical powder 9 is used to achieve semi-automatic powder spreading by its own gravity, and further vibrates after the metallurgical powder 9 falls, thereby realizing automatic powder spreading. The vibration of the vibrating powder spreading device 3 can ensure the powder spreading quality, thereby improving the manufacturing production efficiency of the additive manufacturing process.

[0054] The specific method of additive manufacturing in this embodiment is as follows:

[0055] Before the part is formed and manufactured, first fill the powder supply device 6 with a sufficient amount of metallurgical powder, then use the exhaust purification device 12 on the molding chamber 4 to extract the air in the molding chamber 4 and fill it with protective gas from the air inlet 10, and keep the air pressure in the molding chamber 4 at an appropriate value. After the air pressure in the molding chamber 4 is stabilized, control the workbench 7 to descend, and keep the lower surface of the workbench 7 and the upper surface of the bearing bottom plate 2 at an appropriate distance, then open the side opening of the powder supply device 6, and the metallurgical powder 9 is automatically filled under the workbench 7 under the action of gravity. The workbench 7 moves down and presses down the metallurgical powder 9 at the bottom, and the vibration powder spreading device 3 cooperates with vibration until the distance between the lower surface of the workbench 7 and the upper surface of the bearing bottom plate 2 is the single-layer height of the part manufacturing, and the first layer of powder spreading is completed. The vibration powder spreading device 3 cooperates with vibration to ensure the quality of powder spreading. The laser light source of the laser emitting device 1 moves to the specified position, turns on the laser, moves along the specified route, and performs the molding and manufacturing of the first layer of parts. After the first layer of parts is manufactured, the laser light source is turned off. The workbench 7 rises by a layer height, and the metallurgical powder 9 is filled under the workbench 7 under the action of gravity. The vibrating powder spreading device 3 vibrates to evenly distribute the metallurgical powder 9 to ensure the quality of the powder spreading and realize automatic powder spreading. The laser light source moves to the specified position, and the laser is turned on to form and manufacture the second layer of parts. After the manufacturing is completed, the laser light source is turned off. Repeat the steps after the first layer of parts is manufactured until the entire part is manufactured. After the parts in the molding chamber are cooled, adjust the air pressure in the molding chamber 4 to the outdoor atmospheric pressure, open the molding chamber 4, and take out the parts on the lower surface of the workbench 7.

[0056] Specifically, the air inlet 10 and the exhaust port 11 of the molding chamber 4 are respectively arranged on the left and right sides of the upper part of the molding chamber 4. The air inlet 10 can be filled with inert gas into the molding chamber 4 through a pipeline, and the exhaust port 11 is connected to a vacuum purification device 12 through a pipeline. Before the start of manufacturing, the air inlet 10, the exhaust port 11 and the vacuum purification device 12 are used to realize the vacuum-filling cycle, so that the molding chamber is filled with inert gas. The specific method of controlling the air pressure in the molding chamber 4 is: when a high-pressure environment is required, the exhaust port 11 is closed, and the air inlet 10 is continuously filled with inert gas to increase the air pressure in the molding chamber until the required air pressure is reached; when a low-pressure environment is required, the air inlet 10 is closed, and the exhaust port 11 is continuously exhausted to reduce the air pressure in the molding chamber 4 until the required air pressure is reached. Furthermore, a barometer is provided on the molding chamber 4 for reading the air pressure value in the molding chamber 4, so that the operator can adjust the air pressure in the molding chamber 4 according to the needs.

[0057] It should be noted that the exhaust purification device 12 in the present invention is an existing mature exhaust gas purification device.

[0058] Compared with the prior art, the present invention adopts an inverted workbench 7. After the single-layer part structure is formed, the workbench rises a layer height. When printing each layer, only the required metallurgical powder needs to be spread on the lower part, which significantly reduces the amount of metallurgical powder 9, improves the utilization rate of metallurgical powder 9, and greatly reduces the cost of metallurgical powder 9. The present invention first uses gravity to achieve the initial spreading of metallurgical powder 9, and then uses ultrasonic vibration to ensure the quality of spreading powder, and realizes automatic spreading of powder, which greatly shortens the spreading time and improves production efficiency compared with the existing method. The inverted workbench 7 is adopted, so that the parts are formed below the workbench 7, which effectively avoids the filling of a large amount of metallurgical powder 9 in the cavity of the molded part, and greatly reduces the difficulty of later cleaning.

[0059] It should be noted that, in this application, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements.

[0060] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A laser powder bed additive manufacturing device, characterized in that: It includes a laser emitting device, a bearing base plate, a molding chamber, a lifting rod, a powder supply device and a workbench; the molding chamber is arranged on the upper part of the bearing base plate; the lifting rod is arranged on the inner top of the molding chamber, and the output end of the lifting rod is connected to the workbench and can perform lifting movement to drive the workbench to move up and down; the powder supply device is arranged on the inner wall of the molding chamber and is used to supply metallurgical powder to the bottom of the workbench; the bottom of the workbench is used for part molding and manufacturing; the laser emitting device is arranged below the bearing base plate and is used to emit laser to the bottom of the workbench through the bearing base plate.

2. The laser powder bed additive manufacturing device according to claim 1, characterized in that: It also includes a vibrating powder spreading device, which is arranged on the side of the supporting bottom plate and can perform ultrasonic vibration at a certain frequency, and the vibration direction is left and right.

3. The laser powder bed additive manufacturing device according to claim 1, characterized in that: The molding chamber is provided with an air inlet and an exhaust port, which can be used to fill protective gas and adjust the air pressure in the molding chamber during the part molding and manufacturing process.

4. The laser powder bed additive manufacturing device according to claim 1, characterized in that: The lower surface of the workbench has a certain degree of roughness; the workbench is used for parts molding and manufacturing, and can be moved up and down to a specified height driven by a lifting rod.

5. The laser powder bed additive manufacturing device according to claim 1, characterized in that: The powder supply device is arranged above the supporting base plate, and is used to place metallurgical powder inside. A feeding port is arranged on the top, and the feeding port is used to add metallurgical powder. The bottom surface is an inclined surface, and a discharge port is arranged on the side close to the workbench. The metallurgical powder slides from the discharge port to the supporting base plate.

6. The laser powder bed additive manufacturing device according to claim 1, characterized in that: The lower surface of the bearing base plate is coated with an anti-reflection film.

7. A laser powder bed additive manufacturing method, characterized in that: Using the laser powder bed additive manufacturing device according to any one of claims 2 to 6 comprises the following steps: Step S1, setting the layer height and laser power of the single-layer structure of the part, opening the discharge port of the powder supply device to the set height, and allowing the metallurgical powder to slide down to the bottom of the workbench under the action of gravity; the workbench begins to descend from the top to press down the metallurgical powder below, and the distance between the lower surface of the workbench and the upper surface of the supporting bottom plate is kept at the distance of a single layer height; the thickness of the metallurgical powder accumulated under the action of gravity is greater than the single layer height, the initial position of the workbench is located at the top of the molding chamber, and the workbench descends to press down the metallurgical powder; Step S2, start the laser emitting device, move the laser light source to the specified starting position, emit laser, and move the laser light source along the specified path to melt and sinter the metallurgical powder under the workbench and adhere it to the lower surface of the workbench; Step S3, after the current layer of parts is formed, the laser light source is turned off and moved to a specified end position; Step S4, the workbench rises by a layer height; the opening height of the discharge port of the powder supply device rises by a layer height accordingly until the opening limit height is reached; Step S5, repeating steps S2 to S4 until the molding and manufacturing of all cross sections of the three-dimensional part are completed.

8. The laser powder bed additive manufacturing method according to claim 7, characterized in that: Before step S2, the following steps are also included: starting a vibrating powder spreading device, wherein the vibrating powder spreading device performs ultrasonic vibration at a set frequency.

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