Additive manufacturing ultrasonic printing device and printing method

Abstract

The additive manufacturing ultrasonic printing device comprises a mounting bracket and a control system, a forming bin is mounted at the top of the mounting bracket, and a first moving part is mounted in the forming bin; a second moving part is vertically mounted in the mounting bracket, a vibrating part is mounted at the top of the second moving part, the top of the vibrating part extends into the forming bin, and a forming platform is arranged on the vibrating part; the first moving part comprises a first moving part, the first moving part is horizontally installed in the forming bin, a second moving part is horizontally installed on the first moving part, a powder feeding printing part is installed on the second moving part, and one end of the powder feeding printing part is opposite to the forming platform; the moving direction of the first moving part, the telescopic direction of the second moving part and the moving direction of the second moving part are perpendicular to one another. According to the device, refined grains and bubbles in a molten pool formed by melting a powder material can be removed, and the printing quality is improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of 3D printing, and more specifically, to an additive manufacturing ultrasonic printing device and a printing method. Background Art

[0002] With the development of additive manufacturing technologies (such as laser powder bed fusion, electron beam melting, etc.), additive manufacturing technologies have been gradually applied to high-end manufacturing fields such as aerospace, automotive manufacturing, and biomedicine. It is particularly suitable for the processing of complex structures and high-precision metal parts. The core process of additive manufacturing is to use layer-by-layer deposited powder materials to generate three-dimensional objects through laser or electron beam melting scanning. This process involves a series of precise controls such as material deposition, melt pool control, and cooling and solidification. Among them, the fluidity and uniformity of the melt pool, as well as the crystal grain structure during the cooling process, directly affect the mechanical properties and density of the finished product.

[0003] Currently, during the additive manufacturing process, the fluidity and uniformity of the melt pool are the core factors determining the quality of the additive manufacturing finished product. Since the heat transfer rate and temperature distribution changes in the melt pool will directly affect the crystal grain growth mode, any non-uniform cooling and solidification process will produce coarse grains and internal stresses, thereby leading to a decrease in the strength and ductility of the material. In addition, during the rapid melting and cooling process of additive manufacturing, there will be tiny bubbles. These tiny bubbles will cause defects to form inside the material, resulting in an increase in the porosity of the material, affecting the density of the material, and thus reducing the overall strength of the finished product. In practical applications, the defects existing during the rapid melting and cooling process of additive manufacturing will not only lead to a decrease in the physical properties of the material, but may also cause cracking or deformation in the stress concentration area of the part. Especially for parts that need to withstand high loads or long-term use, the non-uniform distribution and porosity of the material will significantly reduce their stability and service life. Summary of the Invention

[0004] In order to solve the problem that during the existing additive manufacturing process, the heat transfer rate and temperature distribution in the melt pool are non-uniform, resulting in coarse grains and internal stresses in the material, and thus a decrease in the strength and ductility of the material, the present invention provides an additive manufacturing ultrasonic printing device and a printing method.

[0005] To achieve the above object, the present invention provides the following technical solutions: The present invention proposes an additive manufacturing ultrasonic printing device, including a mounting bracket and a control system. A forming chamber is installed at the top of the mounting bracket, and a first moving part is installed inside the forming chamber. A second moving part is vertically installed inside the mounting bracket. A vibrating part is installed at the top of the second moving part. The top of the vibrating part extends into the forming chamber, and a forming platform is horizontally arranged at the top of the vibrating part. The first moving part includes a first moving member, which is horizontally installed in the forming chamber. A second moving member is horizontally installed on the first moving member, and a powder feeding and printing part is installed on the second moving member. One end of the powder feeding and printing part faces the forming platform; wherein, the moving direction of the first moving member, the telescopic direction of the second moving part, and the moving direction of the second moving member are perpendicular to each other; The control system is communicatively connected to the first moving member, the second moving member, the powder feeding and printing part, the second moving part, and the vibration part. The control system adjusts the working parameters of the first moving member, the second moving member, the powder feeding and printing part, the second moving part, and the vibration part based on the obtained printing parameters.

[0006] Preferably, the first moving member includes a servo motor, which is installed on the inner wall of the forming chamber. A first synchronous pulley is connected to the output shaft of the servo motor. A second synchronous pulley is rotatably installed on the inner wall of the forming chamber at the same height as the first synchronous pulley. A synchronous belt is connected between the first synchronous pulley and the second synchronous pulley; A synchronous belt follower plate is slidably connected in the forming chamber. One end of the synchronous belt follower plate is connected to the synchronous belt, and the second moving member is installed on the synchronous belt follower plate.

[0007] Preferably, the second moving member includes an electric slide table, which is installed on the synchronous belt follower plate. A printing connection plate is installed on the electric slide table, and the powder feeding and printing part is installed on the printing connection plate.

[0008] Preferably, the powder feeding and printing part includes an energy beam printing head, which is installed on the printing connection plate. An annular powder feeder is provided at the lower end of the energy beam printing head. A powder conveying pipe is connected to the annular powder feeder, and the powder conveying pipe is externally connected to a powder conveyor through a pipeline.

[0009] Preferably, an adsorber is provided at a position near the top of the energy beam printing head. The adsorber is communicatively connected to a dust concentration sensor, which is installed in the forming chamber; The dust concentration sensor is used to detect the dust concentration in the forming chamber. Based on the dust concentration, it controls the adsorber to absorb the powder material overflowing in the forming chamber; Wherein, the adsorber is one of an electromagnetic adsorber or a vacuum cleaner.

[0010] Preferably, the second moving part includes a telescopic rod, which is vertically installed in the installation bracket. A jacking rod is installed on the telescopic head of the telescopic rod, and the vibration part is installed on the top of the jacking rod.

[0011] Preferably, the vibration part includes a connecting seat fixedly installed at the top of the jacking rod. An ultrasonic vibration generator is installed at the top of the connecting seat, and the top of the ultrasonic vibration generator is connected to the forming platform. An installation groove is provided on the bottom end face of the forming chamber. A seal is installed in the installation groove. A seal groove is provided on the seal, and one end of the ultrasonic vibration generator passes through the seal groove.

[0012] Preferably, a moving part is provided at the bottom of the installation bracket. The moving part includes a fixed seat, and a moving wheel is connected to the fixed seat.

[0013] Preferably, the control system includes an oxygen sensor, a closed-loop temperature control module, and a detection and adjustment module. The oxygen sensor is installed on the forming chamber and is used to detect the oxygen concentration in the forming chamber. The closed-loop temperature control module includes a temperature sensor and a controller. The controller is communicatively connected to the temperature sensor and the powder feeding and printing part. Among them, the temperature sensor is used to collect the temperature of the molten pool formed after the powder is melted. The controller is used to control the laser or electron beam power for melting the powder input on the powder feeding and printing part by obtaining the temperature data collected by the temperature sensor. The detection and adjustment module includes a detector and a regulator. The regulator is communicatively connected to the detector, the powder feeding and printing part, the first moving part, and the second moving part. Among them, the detector is used for the uniformity of the molten pool formed after the powder is melted. The regulator is used to control the working parameters of the powder feeding and printing part, the first moving part, and the second moving part by obtaining the uniformity collected by the detector.

[0014] The present invention provides an additive manufacturing ultrasonic printing method applied to the above-mentioned additive manufacturing ultrasonic printing device, including the following steps: According to the powder delivery amount set by the manufacturing parameters, powder material is delivered to the powder feeding and printing part, and then the first moving part is controlled to move in the forming chamber according to the set feeding trajectory to lay the powder material layer by layer on the forming platform. The first moving part drives the powder feeding and printing part to perform melting scanning on the powder material laid layer by layer in the forming chamber to form a molten pool. At the same time, the vibration part provides vibration with a preset frequency and direction to the molten pool formed layer by layer. After one layer of scanning is completed, the second moving part drives the vibration part and the forming platform to descend a distance of the next layer, and repeats the above scanning and vibration process until the finally formed three-dimensional object is obtained.

[0015] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention proposes an additive manufacturing ultrasonic printing device. This device firmly supports the forming chamber and internal moving components through a mounting bracket, ensuring the stability of the printing process. The first moving part in the forming chamber consists of a first moving member and a second moving member, which move perpendicular to each other in the horizontal plane, achieving precise positioning of the powder feeding and printing part in three-dimensional space, providing a strong guarantee for the precise printing of complex structures. At the same time, the combination of the vertical expansion and contraction of the second moving part and the vibration part enables the forming platform to move up and down and apply ultrasonic vibration. The vibration applies ultrasonic vibration to the printing material, effectively promoting the close packing and rapid solidification of the powder material, removing the refined grains and bubbles during the melting process of the metal powder material, and significantly improving the printing efficiency. At the same time, the ultrasonic vibration can also improve the microstructure of the material and enhance the mechanical properties and surface quality of the product. The control system realizes the intelligent management of the printing process by precisely regulating the working parameters of each moving component and the vibration part. It automatically adjusts the movement trajectory, powder feeding speed, vibration frequency, etc. according to the input printing parameters, ensuring the high efficiency, stability, and controllability of the printing process. This highly integrated control system not only simplifies the operation process, reduces manual intervention, but also improves the flexibility and adaptability of printing, enabling the device to easily meet the printing requirements of different materials, different sizes, and different complexities. The additive manufacturing ultrasonic printing device proposed by the present invention, with its excellent performance and broad application prospects, injects new vitality into the additive manufacturing field and promotes the transformation and upgrading and high-quality development of the manufacturing industry.

[0016] Furthermore, in this device, the first moving member is driven by a servo motor. Through the precise cooperation of the first synchronous pulley, the second synchronous pulley, and the synchronous belt, high-precision movement in the horizontal direction is achieved. The servo motor, with its characteristics of high rotational speed, high precision, and high stability, ensures the smoothness and accuracy of the synchronous belt drive. The connection between the synchronous belt follower plate and the synchronous belt enables the second moving member to slide smoothly as the synchronous belt moves, further improving the positioning accuracy during the printing process. The second moving member uses an electric slide table as the driving device. The electric slide table, with its compact structure, smooth movement, and precise positioning, ensures the precise movement of the powder feeding and printing part in the horizontal direction. The printing connection plate, as the installation platform of the powder feeding and printing part, not only firmly supports the powder feeding and printing part but also realizes the flexible adjustment of the powder feeding and printing part during the printing process through the drive of the electric slide table, meeting the requirements of complex structure printing. It not only improves the positioning accuracy and movement stability of the printing system but also makes the entire printing process more smooth and efficient. The combined use of the servo motor and the electric slide table reduces the noise and vibration during the printing process and further improves the printing quality and user experience.

[0017] Furthermore, an adsorber is added to the energy beam print head of the present device. The dust concentration sensor monitors the dust concentration in the forming chamber in real time. Once the concentration exceeds the standard, the adsorber is triggered to work, efficiently absorbing the spilled powder material, which not only maintains a clean environment in the forming chamber but also avoids waste of the powder material. This not only improves the environmental friendliness of the printing process but also helps to maintain stable printing conditions, ensuring continuous improvement of printing quality and finished product accuracy. Description of the Drawings

[0018] Figure 1 One of the structural schematic diagrams of an additive manufacturing ultrasonic printing device proposed by the present invention; Figure 2 Another structural schematic diagram of an additive manufacturing ultrasonic printing device proposed by the present invention; Figure 3 The front view structural schematic diagram of an additive manufacturing ultrasonic printing device proposed by the present invention; Figure 4 The side view structural schematic diagram of an additive manufacturing ultrasonic printing device proposed by the present invention; Figure 5 The connection schematic diagram of the mounting bracket, the first moving part and the second moving part in an additive manufacturing ultrasonic printing device proposed by the present invention; Figure 6 The connection schematic diagram of the mounting bracket and the vibrating part in an additive manufacturing ultrasonic printing device proposed by the present invention; Figure 7 The front view structural schematic diagram of the connection between the mounting bracket and the vibrating part in an additive manufacturing ultrasonic printing device proposed by the present invention; Figure 8 One of the connection schematic diagrams of the first moving part and the powder feeding and printing part in an additive manufacturing ultrasonic printing device proposed by the present invention; Figure 9 Another connection schematic diagram of the first moving part and the powder feeding and printing part in an additive manufacturing ultrasonic printing device proposed by the present invention; Figure 10 The structural schematic diagram of the vibrating part in an additive manufacturing ultrasonic printing device proposed by the present invention; Figure 11 The top view structural schematic diagram of the vibrating part in an additive manufacturing ultrasonic printing device proposed by the present invention; Figure 12 The connection schematic diagram of the powder feeding and printing part and the adsorber in an additive manufacturing ultrasonic printing device proposed by the present invention; In the accompanying drawings: 10, mounting bracket; 11, forming chamber; 110, mounting groove; 12, seal; 120, sealing groove; 13, moving part; 14, forming platform; 15, molten pool; 16, powder delivery pipeline; 20, first moving part; 200, first moving member; 200-1, servo motor; 200-2, first synchronous pulley; 200-3, second synchronous pulley; 200-4, timing belt; 200-5, timing belt follower plate; 201, second moving member; 201-1, electric slide; 201-2, printing connection plate; 21, powder feeding and printing part; 210, energy beam printing head; 211, annular powder feeder; 22, second moving part; 23, vibrating part; 230, ultrasonic vibration generator; 24, oxygen sensor; 25, adsorber; 251, adsorption port. Detailed implementation manners

[0019] In the following text, only some exemplary embodiments are simply described. As those skilled in the art can recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the present invention. Therefore, the accompanying drawings and the description are regarded as being exemplary in nature rather than restrictive.

[0020] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

[0021] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "a plurality of" means two or more unless otherwise specifically defined.

[0022] In the present invention, unless otherwise clearly defined and limited, terms such as "installed", "connected", "linked", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection, an electrical connection, or a communication connection; it may be directly connected, or indirectly connected through an intermediate medium, and may be the internal communication of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0023] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through additional features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely means that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely means that the horizontal height of the first feature is lower than that of the second feature.

[0024] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0025] The present invention provides an additive manufacturing ultrasonic printing device, as Figures 1 to 12As shown in the figure, it includes an installation bracket 10 and a control system. A forming chamber 11 is installed on the top of the installation bracket 10. The forming chamber 11 is the processing area of the additive manufacturing equipment, responsible for accommodating metal powder and three-dimensional objects. In this area, the metal powder material is laid layer by layer, and then the selectively melted layer-by-layer laid metal powder material is formed into a three-dimensional structure stacked layer by layer through an energy beam. The forming chamber 11 needs to have airtightness to prevent external air from affecting the printing quality and avoid the oxidation of metal powder at the same time. A first moving part 20 is installed in the forming chamber 11; a second moving part 22 is vertically installed in the installation bracket 10, and a vibration part 23 is installed on the top of the second moving part 22. The top of the vibration part 23 extends into the forming chamber 11, and a forming platform 14 is horizontally arranged at the top of the vibration part 23. In this equipment, the first moving part 20 enables the powder feeding and printing part 21 to move arbitrarily within the same plane in the forming chamber 11, realizing the flexible positioning of the powder feeding and printing part 21 in three-dimensional space, providing the possibility for accurately printing complex structures, broadening the printing range, and improving the printing accuracy; the vertical installation of the second moving part 22 in combination with the vibration part 23, and the vibration part 23 applies ultrasonic vibration to the printing material through the forming platform at its top, effectively promoting the close packing and rapid solidification of the powder material, removing the refined grains and bubbles in the melting process of the metal powder material, and significantly improving the printing efficiency. At the same time, the ultrasonic vibration can also improve the microstructure of the material and enhance the mechanical properties and surface quality of the product.

[0026] As Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 8 and Figure 9 As shown in the figure, the first moving part 20 includes a first moving member 200. The first moving member 200 is horizontally installed in the forming chamber 11. A second moving member 201 is horizontally installed on the first moving member 200. A powder feeding and printing part 21 is installed on the second moving member 201. One end of the powder feeding and printing part 21 faces the forming platform 14. Through the precise cooperation of the first moving member 200 and the second moving member 201, the flexible positioning of the powder feeding and printing part 21 in three-dimensional space is realized; among them, the moving direction of the first moving member 200, the telescopic direction of the second moving part 22, and the moving direction of the second moving member 201 are perpendicular to each other. Furthermore, through the cooperation of the three, the device realizes the function of printing parts layer by layer and improves the printing quality.

[0027] Exemplarily, as Figure 8 and Figure 9As shown, the first moving member 200 includes a servo motor 200-1, which is vertically installed on the inner wall of the forming chamber 11, that is, the output shaft of the servo motor 200-1 is vertically downward, and the axis of the output shaft is parallel to the moving direction of the second moving part 22. A first synchronous pulley 200-2 is connected to the output shaft of the servo motor 200-1. A second synchronous pulley 200-3 is rotatably installed on the inner wall of the forming chamber 11 at the same height as the first synchronous pulley 200-2. The first synchronous pulley 200-2 and the second synchronous pulley 200-3 are installed on the inner wall of the same side of the forming chamber 11, and a synchronous belt 200-4 is connected between the first synchronous pulley 200-2 and the second synchronous pulley 200-3; on the same side wall of the forming chamber 11 where the first synchronous pulley 200-2 and the second synchronous pulley 200-3 are located, and above the synchronous belt 200-4, there is a slide table, and a synchronous belt follower plate 200-5 is slidably connected to the slide table. One end of the synchronous belt follower plate 200-5 is connected to the synchronous belt 200-4, and a second moving member 201 is installed on the synchronous belt follower plate 200-5. By the rotation of the servo motor 200-1, the first synchronous pulley 200-2 and the second synchronous pulley 200-3 rotate synchronously under the cooperation of the synchronous belt 200-4, driving the synchronous belt follower plate 200-5 to horizontally reciprocate between the first synchronous pulley 200-2 and the second synchronous pulley 200-3, so that the powder feeding and printing part 21 is on the same horizontal plane in the forming chamber 11 and moves along one direction (if the second moving part 22 is defined as the movement in the Z-axis direction, then this direction is the X-axis direction or the Y-axis direction). Then, in cooperation with the second moving member 201, the powder feeding and printing part 21 can move multi-axially on the same horizontal plane in the forming chamber 11, and then the position of the powder feeding and printing part 21 can be adjusted arbitrarily, so that it can lay the metal powder material layer by layer and evenly above the forming platform 14.

[0028] As Figure 5 , Figure 8 and Figure 9 shown, the second moving member 201 includes an electric slide table 201-1, which is installed on the synchronous belt follower plate 200-5, and the moving direction of the forming platform 14 is perpendicular to the moving direction of the first moving member 201 in the same plane. A printing connection plate 201-2 is installed on the electric slide table 201-1, and the powder feeding and printing part 21 is vertically installed on the printing connection plate 201-2, and the powder feeding and printing part 21 is opposite to the forming platform 14.

[0029] As Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 12, the powder feeding and printing unit 21 includes an energy beam printing head 210. The energy source for the energy beam printing head 210 mainly includes a laser or an electron beam emitter. High-power lasers are used in laser powder bed melting, while electron beam melting utilizes an electron beam to rapidly melt metal powder. The beam of the energy source is projected onto the laid metal powder layer through focusing and a controller, providing sufficient energy to melt it. Different types of energy sources are suitable for different materials and manufacturing requirements. Laser melting is suitable for high-precision parts, while electron beam melting is suitable for large-size and thick-layer forming; the energy beam printing head 210 is installed on the printing connection plate 201-2. An annular powder feeder 211 is provided at the lower end of the energy beam printing head 210. A powder conveying pipe 16 is connected to the annular powder feeder 211. The powder conveying pipe 16 is externally connected to a powder conveyor through a pipeline. The powder conveyor is mainly responsible for precisely conveying the powder of metal or other materials to the forming area to achieve a high-quality printing effect. Usually, the powder conveyor includes a powder storage cylinder and a conveyor. The powder storage cylinder stores the powder material for additive manufacturing, and the conveyor conveys the powder material stored in the powder storage cylinder into the forming chamber 11.

[0030] As Figure 12 , an adsorber 25 is provided at a position near the top of the energy beam printing head 210. The adsorber 25 is communicatively connected to a dust concentration sensor, and the dust concentration sensor is installed in the forming chamber 11; the powder concentration diffused in the forming chamber 11 is detected by the dust concentration sensor. When the powder concentration exceeds the preset concentration threshold, a signal is sent to the adsorber 25, and the power of the adsorber 25 is adjusted according to the concentration range. The powder material diffused in the forming chamber 11 is absorbed by the adsorber 5. The greater the concentration, the higher the power of the adsorber 25, and the smaller the concentration, the lower the power of the adsorption part 25. The adsorber 5 moves along with the energy beam printing head 210 to improve the adsorption effect and adsorption range, preventing the excessive adsorption force at some positions from affecting the uniformity of the laid powder material; a dust storage container is provided at the top of the adsorber 25, and the powder material absorbed by the adsorber 25 is recovered through the dust storage container. A one-way valve is provided at the connection between the adsorber 5 and the dust storage container to prevent the powder material recovered in the dust storage container from flowing back into the adsorber 25. Among them, the adsorber 25 is one of an electromagnetic adsorber or a vacuum cleaner.

[0031] As Figures 1 to 7 As shown, the second moving part 22 includes a telescopic rod. In this embodiment, the telescopic rod is an electric telescopic cylinder. The telescopic rod is vertically installed in the mounting bracket 10. A jacking rod is installed on the telescopic head of the telescopic rod, and a vibrating part 23 is installed at the top of the jacking rod.

[0032] As Figures 1 to 7As shown in the figure, the vibration part 23 includes a connecting seat which is fixedly installed at the top of the jacking rod. Multiple ultrasonic vibration generators 230 are installed on the top of the connecting seat. The tops of the multiple ultrasonic vibration generators 230 are connected to the forming platform 14. The ultrasonic vibration generators 230 are used to provide ultrasonic vibration with a preset frequency and direction for the molten pool 15 formed after the powder material is melted, so as to remove the refined grains and bubbles in the molten pool 15. Exemplarily, the multiple ultrasonic vibration generators 230 are arranged in an array along the telescopic direction of the telescopic rod to evenly cover the forming area and form an ultrasonic vibration area, so as to ensure that the ultrasonic vibration area can act on the molten pool 15 comprehensively. Set the values of the ultrasonic frequency and amplitude of the ultrasonic vibration generator 230 to control the intensity and penetration depth of the vibration. The ultrasonic frequency range is 20~100kHz, and the amplitude is set according to the characteristics of the powder material and the vibration effect required in practice. During the working process of the ultrasonic vibration generator 230, according to the absorption coefficient of the powder material and the ultrasonic frequency, calculate the attenuation depth of the ultrasonic wave in the molten pool 15: The calculation process is as follows:

[0033] Among them, is the attenuation depth, is the absorption coefficient of the powder material, is the ultrasonic frequency; In the above, during the working process of the ultrasonic vibration generator 230, the calculation process of the vibration energy density in the molten pool 15 is as follows:

[0034] Among them, is the vibration energy density, is the material density, is the propagation speed of the ultrasonic wave in the powder material, is the ultrasonic amplitude, is the ultrasonic frequency; During the working process of the ultrasonic vibration generator 230, the calculation process of the removal efficiency of the ultrasonic wave on the bubbles is as follows:

[0035] Among them, is the removal efficiency of the bubbles, is the size of the molten pool 15.

[0036] Further, the ultrasonic vibration area vibrates at a set vibration frequency and direction according to different printing levels, and dynamically adjusts the vibration according to the temperature and fluidity of the molten pool 15; specifically, different ultrasonic vibration frequencies and directions are set according to different levels of the printing process, and the temperature and fluidity of the molten pool 15 are monitored in real time to judge the state of the molten pool 15, and the parameters of ultrasonic vibration are dynamically adjusted according to the real-time data to ensure that the ultrasonic vibration can always effectively optimize the state of the molten pool 15 in different printing levels; thus, the relationship between the fluidity and temperature of the molten pool 15 is defined. Usually, when the temperature of the molten pool 15 is higher, the fluidity is better; the formula can be:

[0037] Wherein, is the fluidity of the molten pool 15, is the fluidity parameter of the material, is the activation energy, is the gas energy, is the temperature of the molten pool 15; the process of dynamically adjusting the vibration frequency and vibration direction of the ultrasonic wave according to the change of the fluidity of the molten pool 15 is:

[0038]

[0039] Wherein, is the initially set ultrasonic frequency, is the frequency adjustment coefficient, is the initially set ultrasonic direction, is the direction adjustment coefficient, is the set reference coefficient.

[0040] As Figures 1 to 7 shown, an installation groove 110 is provided on the bottom end surface of the forming chamber 11. A seal 12 is installed in the installation groove 110. A seal groove 120 is provided on the seal 12. One end of the ultrasonic vibration generator 230 passes through the seal groove 120, and the ultrasonic vibration generator 230 is abutted and sealed in the installation groove 110 through the seal 12, increasing the sealing performance of the device; in this embodiment, the seal 12 is a rubber film.

[0041] In the present invention, the control system is communicatively connected to the first moving member 200, the second moving member 201, the powder feeding and printing unit 21, the second moving unit 22 and the vibration unit 23. The control system adjusts the working parameters of the first moving member 200, the second moving member 201, the powder feeding and printing unit 21, the second moving unit 22 and the vibration unit 23 based on the acquired printing parameters. The control system includes an oxygen sensor 24, a closed-loop temperature control module and a detection and adjustment module; The oxygen sensor 24 is installed on the forming chamber 11 to detect the oxygen concentration in the forming chamber 11, ensuring that the oxygen content in the forming chamber 11 is controlled at an extremely low level to avoid the oxidation of metal powder in the forming chamber 11 due to the concentration exceeding the set threshold, which affects the three-dimensional object forming quality. The closed-loop temperature control module includes a temperature sensor and a controller. The controller is communicatively connected to the temperature sensor and the powder feeding and printing unit 21. Among them, the temperature sensor is used to collect the temperature of the molten pool formed after the powder is melted. The controller is used to control the laser or electron beam power input to the powder feeding and printing unit 21 for melting the powder by obtaining the temperature data collected by the temperature sensor. The controller sets the optimal temperature range of the molten pool 15 according to the material characteristics and process requirements, and then monitors the temperature of the molten pool 15 in real time and compares it with the set threshold. The controller adjusts the power output of the energy beam print head 210 according to the differential feedback. In this application, integral and differential control existing in the controller is adjusted in real time (the controller uses a PID controller) to ensure that the molten pool 15 is maintained within the set optimal temperature range in real time, avoiding temperature fluctuations caused by vibrations, and improving the stability of the additive manufacturing process and the final quality of three-dimensional object forming.

[0042] The detection and adjustment module includes a detector and a regulator. The regulator is communicatively connected to the detector, the first moving member 200, the second moving member 201, the powder feeding and printing unit 21, the second moving part 22, and the vibration part 23. Among them, the detector is used for the uniformity of the molten pool formed after the powder is melted. The regulator is used to control the working parameters of the powder feeding and printing unit 21, the first moving part 20, and the second moving part 22 by obtaining the uniformity collected by the detector.

[0043] As Figure 1 and Figure 2 shown, a moving part 13 is provided at the bottom of the mounting bracket 10. The moving part 13 includes a fixed seat, and a moving wheel is connected to the fixed seat. The printing device can be moved to any position through the moving wheel, improving the convenience of moving the device.

[0044] The present invention also proposes an additive manufacturing ultrasonic printing device, which is applied to the above-mentioned additive manufacturing ultrasonic printing device, and is characterized by including the following steps: Convey the powder material to the powder feeding and printing unit 21 according to the powder delivery amount set according to the manufacturing parameters, and then move the control first moving part 20 in the forming chamber 11 according to the set feeding trajectory to lay the powder material layer by layer on the forming platform 14. The first moving part 20 drives the powder feeding and printing unit 21 to perform melting scanning on the powder material laid layer by layer along the set trajectory in the forming chamber 11 to form a molten pool 15. At the same time, the vibration part 23 provides vibrations with a preset frequency and direction to the molten pool 15 formed layer by layer. After one layer of scanning is completed, the second moving part 22 drives the vibrating part 23 and the forming platform 14 to descend by the distance of one layer, and the above scanning and vibrating processes are repeated until the finally formed three-dimensional object is obtained.

[0045] In the present invention, the movements of the first moving part 200 and the second moving part 201 are preset according to the current scanning layer of the current energy beam print head 210. The first moving part 200 and the second moving part 201 can be set to run synchronously or separately. The control of the vibrating part 23 can be divided into multiple controls in this application, including vibration during the powder delivery process, vibration during the molten pool 15 forming process, and vibration after the molten pool 15 is formed.

[0046] Among them, during the vibration in the powder delivery process, the vibration parameters are automatically adjusted through real-time feedback to achieve better fluidity of the molten pool 15 and printing quality. The specific process is as follows: Obtain the situation characteristics of the powder material deposition in the forming area, such as surface flatness data, and use the mean square error (MSE) to evaluate the uniformity of the current powder deposition. That is, assume the ideal thickness of the deposited powder per layer is H, and the currently measured surface height is (at different monitoring points), and calculate the mean square error; The calculation process of the mean square error is:

[0047] Among them, is the number of monitoring points, is the deposited thickness of the powder at the i-th point; If the MSE value exceeds the set value, it indicates that the current powder distribution is uneven, and the vibration frequency or direction needs to be adjusted; then, according to the relationship between the powder fluidity and the vibration frequency, the vibration frequency and vibration direction are optimized; The process of optimizing the vibration frequency is:

[0048] Among them, is the adjusted vibration frequency, is the current vibration frequency, is the vibration frequency adjustment coefficient, which is set by the operator according to the vibration response characteristics of the equipment and the powder characteristics; The process of optimizing the vibration direction is:

[0049] Among them, is the adjusted vibration direction, is the current vibration direction, is the vibration direction adjustment coefficient, is the gradient of the current surface height of the powder material, reflecting the non-uniformity of the powder deposition directionality; after each adjustment, data is collected again to calculate the new MSE value. If the MSE is still higher than the threshold, the vibration frequency and vibration direction are continuously adjusted until the printing accuracy requirements are met.

[0050] Therefore, during the vibration in the forming process of the molten pool 15, the key lies in real-time adjusting the vibration frequency and direction to ensure the stability and uniformity of the molten pool 15. The specific process is as follows: The temperature and depth of the molten pool 15 are used to evaluate the stability of the molten pool 15, and a stability index during the forming process of the molten pool 15 is defined:

[0051] Among them, is the temperature weight coefficient, is the depth weight coefficient, is the depth of the molten pool 15, reflecting the shape and stability of the molten pool 15, is the temperature of the molten pool 15.

[0052] According to this stability index , the vibration frequency is dynamically adjusted: The process of dynamically adjusting the vibration frequency is as follows:

[0053] Among them, is the vibration frequency adjustment coefficient during the forming process of the molten pool 15.

[0054] The process of adjusting the vibration direction according to the depth gradient of the molten pool 15 is as follows:

[0055] Among them, is the vibration direction adjustment coefficient during the forming process of the molten pool 15, is the gradient of the depth of the molten pool 15, indicating the trend of the surface change of the molten pool 15.

[0056] Therefore, after the vibration in the forming process of the molten pool 15, a certain vibration needs to be maintained to remove the refined grains and bubbles in the molten pool 15. The specific process is as follows: Define the stability index after the forming of the molten pool 15 as the evaluation criterion for removing the refined grains and bubbles:

[0057] Among them, is the weight coefficient of the refined grains and bubble concentration, is the temperature weight coefficient, is the concentration of the refined grains in the molten pool 15, is the concentration of bubbles in the molten pool 15, is the temperature of the molten pool 15; Dynamically adjust the vibration frequency according to the stability index ; The process of adjusting the vibration frequency is as follows:

[0058] wherein, is the vibration frequency adjustment coefficient after the formation of the molten pool 15.

[0059] Adjust the vibration direction according to the distribution of bubbles and grains in the molten pool 15; The process of adjusting the vibration direction is as follows:

[0060] wherein, is the vibration direction adjustment coefficient after the formation of the molten pool 15, is the gradient of refined grains and bubble concentration, indicating their distribution trend in the molten pool 15.

[0061] During the process of the vibration part 23 providing vibration to the molten pool 15, it also includes: Cover the forming area through one or more formed ultrasonic vibration regions, and then provide vibration to the molten pool 15 at a set vibration frequency and direction according to different printing levels, and dynamically adjust the vibration parameters according to the temperature and fluidity of the molten pool 15.

[0062] Exemplarily, set the values of the ultrasonic frequency and amplitude to control the intensity and penetration depth of the vibration. The ultrasonic frequency range is 20~100kHz, and the amplitude is set according to the characteristics of the powder material and the vibration effect required in practice; Thus, according to the absorption coefficient of the powder material and the ultrasonic frequency, calculate the attenuation depth of the ultrasonic wave in the molten pool 15; The process of calculating the attenuation depth of the ultrasonic wave in the molten pool 15 is as follows:

[0063] wherein, is the attenuation depth, is the absorption coefficient of the powder material, is the ultrasonic frequency; Calculate the vibration energy density in the molten pool 15:

[0064] wherein, is the vibration energy density, is the material density, is the propagation speed of the ultrasonic wave in the powder material, is the ultrasonic amplitude, is the ultrasonic frequency; Calculate the removal efficiency of ultrasonic waves on bubbles:

[0065] Among them, is the removal efficiency of bubbles, and r is the size of the molten pool 15.

[0066] Specifically, according to different layers of the printing process, set different ultrasonic vibration frequencies and directions, and monitor the temperature and fluidity of the molten pool 15 in real time to judge the state of the molten pool 15, and dynamically adjust the parameters of ultrasonic vibration according to real-time data to ensure that ultrasonic vibration can always effectively optimize the state of the molten pool 15 in different printing layers; Thus, define the relationship between the fluidity and temperature of the molten pool 15. Usually, when the temperature of the molten pool 15 is higher, the fluidity is better; That is:

[0067] Among them, is the fluidity of the molten pool 15, k is the fluidity parameter of the material, is the activation energy, R is the gas energy, is the temperature of the molten pool 15; Dynamically adjust the vibration frequency and vibration direction of the ultrasonic wave according to the change of the fluidity of the molten pool 15; That is:

[0068]

[0069] Among them, is the initially set ultrasonic frequency, is the frequency adjustment coefficient, θ 0 is the initially set ultrasonic direction, direction adjustment coefficient, is the set reference coefficient.

[0070] The above shows and describes the basic principles, main features and advantages of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention. Any reference signs in the claims should not be construed as limiting the claimed rights.

[0071] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above content is only to illustrate the technical idea of the present invention, and the protection scope of the present invention cannot be limited thereby. Any modification made on the basis of the technical solution according to the technical idea proposed by the present invention falls within the protection scope of the claims of the present invention.

Claims

1. An additive manufacturing ultrasonic printing device, characterized in that, It includes a mounting bracket (10) and a control system. A forming bin (11) is installed at the top of the mounting bracket (10), and a first moving part (20) is installed in the forming bin (11). A second moving part (22) is vertically installed in the mounting bracket (10). A vibration part (23) is installed at the top of the second moving part (22). The top of the vibration part (23) extends into the forming bin (11). A forming platform (14) is horizontally arranged at the top of the vibration part (23). The first moving part (20) includes a first moving member (200). The first moving member (200) is horizontally installed in the forming bin (11). A second moving member (201) is horizontally installed on the first moving member (200). A powder feeding and printing part (21) is installed on the second moving member (201). One end of the powder feeding and printing part (21) faces the forming platform (14). Among them, the moving direction of the first moving member (200), the telescopic direction of the second moving part (22), and the moving direction of the second moving member (201) are perpendicular to each other. The control system is communicatively connected to the first moving member (200), the second moving member (201), the powder feeding and printing part (21), the second moving part (22), and the vibration part (23). The control system adjusts the working parameters of the first moving member (200), the second moving member (201), the powder feeding and printing part (21), the second moving part (22), and the vibration part (23) based on the obtained printing parameters.

2. The additive manufacturing ultrasonic printing device according to claim 1, wherein The first moving member (200) includes a servo motor (200-1). The servo motor (200-1) is installed on the inner wall of the forming bin (11). A first synchronous pulley (200-2) is connected to the output shaft of the servo motor (200-1). A second synchronous pulley (200-3) is rotatably installed at a position on the inner wall of the forming bin (11) at the same height as the first synchronous pulley (200-2). A synchronous belt (200-4) is connected between the first synchronous pulley (200-2) and the second synchronous pulley (200-3). A synchronous belt follower plate (200-5) is slidably connected in the forming bin (11). One end of the synchronous belt follower plate (200-5) is connected to the synchronous belt (200-4). The second moving member (201) is installed on the synchronous belt follower plate (200-5).

3. The additive manufacturing ultrasonic printing device according to claim 2, wherein, The second moving member (201) includes an electric slide table (201-1). The electric slide table (201-1) is installed on the synchronous belt follower plate (200-5). A printing connection plate (201-2) is installed on the electric slide table (201-1). The powder feeding and printing part (21) is installed on the printing connection plate (201-2).

4. The additive manufacturing ultrasonic printing device according to claim 3, characterized in that, The powder feeding and printing unit (21) includes an energy beam printing head (210). The energy beam printing head (210) is installed on the printing connection plate (201-2). An annular powder feeder (211) is provided at the lower end of the energy beam printing head (210). A powder conveying pipe (16) is connected to the annular powder feeder (211), and the powder conveying pipe (16) is externally connected to a powder conveyor through a pipeline.

5. The additive manufacturing ultrasonic printing device according to claim 4, characterized in that, An adsorber (25) is provided at a position near the top of the energy beam printing head (210). The adsorber (25) is communicatively connected to a dust concentration sensor, and the dust concentration sensor is installed in the forming chamber (11). The dust concentration sensor is used to detect the dust concentration in the forming chamber (11). Based on the dust concentration, it controls the adsorber (25) to absorb the powder material that overflows in the forming chamber (11). Among them, the adsorber (25) is one of an electromagnetic adsorber or a vacuum cleaner.

6. The multi-axis motion 3D printing device according to claim 1, characterized in that, The second moving part (22) includes a telescopic rod. The telescopic rod is vertically installed in the mounting bracket (10). A jacking rod is installed on the telescopic head of the telescopic rod, and the vibration part (23) is installed at the top of the jacking rod.

7. An additive manufacturing ultrasonic printing device according to claim 6, wherein, The vibration part (23) includes a connecting seat. The connecting seat is fixedly installed at the top of the jacking rod. An ultrasonic vibration generator (230) is installed at the top of the connecting seat, and the top of the ultrasonic vibration generator (230) is connected to the forming platform (14). An installation groove (110) is provided on the bottom end face of the forming chamber (11). A seal (12) is installed in the installation groove (110). A seal groove (120) is provided on the seal (12), and one end of the ultrasonic vibration generator (230) passes through the seal groove (120).

8. A multi-axis motion 3D printing device according to claim 1, characterized in that, A moving part (13) is provided at the bottom of the mounting bracket (10). The moving part (13) includes a fixed seat, and a moving wheel is connected to the fixed seat.

9. The additive manufacturing ultrasonic printing device according to claim 1, wherein, The control system includes an oxygen sensor (24), a closed-loop temperature control module, and a detection and adjustment module. The oxygen sensor (24) is installed on the forming chamber (11) and is used to detect the oxygen concentration in the forming chamber (11). The closed-loop temperature control module includes a temperature sensor and a controller. The controller is communicatively connected to the temperature sensor and the powder feeding and printing unit (21). Among them, the temperature sensor is used to collect the temperature of the molten pool formed after the powder is melted. The controller is used to control the laser or electron beam power input to the powder feeding and printing unit (21) for melting the powder by obtaining the temperature data collected by the temperature sensor. The detection and adjustment module includes a detector and a regulator. The regulator is communicatively connected to the detector, the powder feeding and printing unit (21), the first moving part (20), and the second moving part (22). Among them, the detector is used for the uniformity of the molten pool formed after the powder is melted. The regulator is used to control the working parameters of the powder feeding and printing unit (21), the first moving unit (20), and the second moving unit (22) by obtaining the uniformity collected by the detector.

10. An additive manufacturing ultrasonic printing method, applied to an additive manufacturing ultrasonic printing device according to any one of claims 1 to 9, characterized in that, It includes the following steps: Powder material is conveyed to the powder feeding and printing unit (21) according to the powder conveying amount set by the manufacturing parameters, and then the first moving unit (20) is controlled to move in the forming chamber (11) according to the set feeding trajectory to lay the powder material layer by layer on the forming platform (14); The first moving unit (20) drives the powder feeding and printing unit (21) to perform a melting scan on the powder material laid layer by layer along the set trajectory in the forming chamber (11) to form a molten pool (15). At the same time, the vibrating unit (23) provides vibration with a preset frequency and direction to the molten pool (15) formed layer by layer; After one layer of scanning is completed, the second moving unit (22) drives the vibrating unit (23) and the forming platform (14) to descend by the distance of the next level, and the above scanning and vibration processes are repeated until the finally formed three-dimensional object is obtained.

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