Magnetic vibration powder spreading device, additive manufacturing equipment and powder spreading method

Abstract

The invention provides a magnetic vibration powder laying device, additive manufacturing equipment and a powder laying method. The magnetic vibration powder laying device comprises a powder laying unit; the at least one heating unit is used for adjusting the temperature of the powder laid by the powder laying unit to a preset temperature according to material characteristics and / or environmental parameters of different powders; the at least one magnetic vibration unit is used for utilizing a magnetic vibration field to assist the powder laying unit to lay the powder on the forming platform on the forming area through a preset flowing path according to the powder distribution condition; wherein the powder uniformity of a plurality of powder laying intervals contained in the preset flowing path is adjusted to be the same or different. In this way, the vibration frequency can be accurately controlled, and uniform powder laying of the superfine metal powder is achieved through magnetic vibration.

Description

Technical Field

[0001] The present application relates to the technical field of additive manufacturing, and more specifically to a magnetically induced vibration powder spreading device, additive manufacturing equipment and a powder spreading method. Background Art

[0002] Metal selective laser melting technology uses metal powder as raw material to build complex multi-dimensional structures. The powder material is melted by focusing a high-energy beam and solidified again to obtain a specified spatial configuration. In traditional SLM technology, metal powder with a D90 of 40 microns is usually used for molding. The specific process is to spread the metal powder in the powder bin on the molding platform through a powder spreading device (usually a scraper), and then use a laser to melt and solidify the area to be molded, and then use a layer-by-layer molding method to finally obtain the desired parts. However, due to the coarse particle size of the metal powder, the final molded metal parts have poor molding accuracy and surface roughness.

[0003] At present, in order to solve the problem of uniform spreading of ultrafine metal powder, a vibrating component is introduced into the powder spreading device in the prior art, and the ultrafine metal powder is evenly spread by the vibrating component. However, in the vibration spreading process, pneumatic vibration is often used. This vibration method has a simple structure, but the vibration effect is often closely related to the gas flow rate, and it is difficult to ensure the digital control process of the vibration frequency during actual production and use. It is usually necessary to experiment with the gas flow rate based on experience to achieve the optimal vibration effect. In addition, in actual use, the vibration effect is often weakened or abnormal due to the occurrence of conditions such as air leakage, and these are usually difficult to feed back to the control system in time to achieve real-time control.

[0004] Therefore, there is an urgent need for a powder spreading device that can accurately control the vibration frequency to achieve uniform spreading of ultrafine metal powder. Summary of the invention

[0005] The present application provides a magnetically induced vibration powder spreading device, additive manufacturing equipment and a powder spreading method, which can accurately control the vibration frequency to utilize magnetically induced vibration to evenly spread ultrafine metal powder.

[0006] In the first aspect, the present application provides a magnetically induced vibration powder spreading device, comprising: a powder spreading unit; at least one heating unit, which is used to adjust the temperature of the powder spread by the powder spreading unit to a preset temperature range according to the material properties and / or environmental parameters of different powders; at least one magnetic vibration unit, which is used to use a magnetic vibration field to assist the powder spreading unit to spread the powder on the forming platform in a forming area through a preset flow path according to the powder distribution; wherein the powder uniformity of several powder spreading intervals included in the preset flow path is adjusted to be the same or different.

[0007] In an optional solution of the first aspect, the heating unit is arranged on the powder spreading unit and / or the forming platform.

[0008] In an optional scheme of the first aspect, the heating unit includes a heater, which is used to adjust the powder laid by the powder laying unit to a preset temperature range according to the material properties of different powders and / or the ambient temperature, so as to eliminate the magnetization of the powder by the magnetic vibration field.

[0009] In an optional solution of the first aspect, the heater forms a plurality of heating zones on the powder spreading unit and / or the forming platform according to the powder spreading target and adjusts the powder temperature zone of each heating zone to be the same or different.

[0010] In an optional scheme of the first aspect, it also includes: an electrostatic eliminator, which is set at a preset distance from the powder flow area according to powder parameters, and is used to eliminate static electricity accumulation of the powder laid by the powder laying unit according to the material properties of different powders and / or ambient humidity.

[0011] In an optional solution of the first aspect, the magnetic vibration unit is arranged on the powder spreading unit and / or the forming platform.

[0012] In an optional solution of the first aspect, the magnetic vibration unit forms a plurality of vibration sections of the powder spreading unit and / or the forming platform according to the powder spreading interval and adjusts the vibration parameters of each vibration section to be the same or different.

[0013] In an optional scheme of the first aspect, it also includes an ultrasonic vibration unit, which is used to use the ultrasonic vibration field and the magnetic vibration field to assist the powder spreading unit to spread the powder on the forming platform in the forming area through a preset flow path according to the powder distribution.

[0014] In an optional solution of the first aspect, the acoustic wave vibration unit is arranged on the forming platform and / or the powder spreading unit.

[0015] In an optional solution of the first aspect, a composite vibration field formed by the cooperative operation of a magnetic vibration unit and an acoustic vibration unit arranged at the same or different positions is used to adjust the powder parameters of the preset powder spreading interval.

[0016] In an optional scheme of the first aspect, the powder parameters include one or more of powder thickness, uniformity, flow direction and stacking position.

[0017] In a second aspect, the present application provides an additive manufacturing device equipped with the magneto-vibration powder spreading device.

[0018] In the third aspect, the present application provides a powder spreading method, which includes the following steps: adjusting the temperature of the powder to be laid to a preset temperature range according to the material properties of different powders and / or the ambient temperature to avoid magnetization of the powder by the magnetic vibration field; using the magnetic vibration field to assist the powder spreading unit to spread the powder on the forming platform in the forming area through several powder spreading intervals included in a preset flow path according to the powder distribution, and adjusting the vibration parameters of the magnetic vibration field passing through each powder spreading interval in real time.

[0019] In an optional scheme of the third aspect, when performing the powder dispersion treatment, the method includes the following steps: performing a static electricity accumulation elimination treatment on the powder to be laid according to the material properties of different powders and / or the ambient humidity.

[0020] In an optional scheme of the third aspect, when the powder on the forming platform is spread on the forming area through several powder spreading intervals, the method includes the following steps: using the ultrasonic vibration field and the magnetic vibration field to cooperate with the auxiliary powder spreading unit to spread the powder on the forming platform through several powder spreading intervals included in a preset flow path according to the powder distribution, and adjusting the vibration parameters of the composite vibration field formed by the collaborative operation of the magnetic vibration field and the acoustic vibration field in real time to adjust the powder parameters of each powder spreading interval to the preset powder parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate one or more embodiments of the present application and, together with the description, serve to explain the principles of the present application and to enable one of ordinary skill in the relevant art to make and use the present application.

[0022] Figure 1 It is a schematic structural diagram of an exemplary additive manufacturing device according to some embodiments of the present application.

[0023] Figure 2 It is a schematic structural diagram of an exemplary powder spreading device according to some embodiments of the present application.

[0024] Figure 3 This is a schematic diagram of a first configuration of an exemplary heater and a magnetic vibration unit according to some embodiments of the present application.

[0025] Figure 4 is a schematic diagram of a second configuration of an exemplary heater and a magnetic vibration unit according to some embodiments of the present application.

[0026] Figure 5 is a third configuration diagram of an exemplary heater and a magnetic vibration unit according to some embodiments of the present application.

[0027] Figure 6It is a schematic diagram of the configuration of an exemplary heater, a magnetic vibration unit and an electrostatic eliminator according to some embodiments of the present application.

[0028] Figure 7 is a fourth configuration schematic diagram of an exemplary heater and a magnetic vibration unit according to some embodiments of the present application.

[0029] Figure 8 is a fifth configuration diagram of an exemplary heater and a magnetic vibration unit according to some embodiments of the present application.

[0030] Fig. 9 is a sixth configuration diagram of an exemplary heater and a magnetic vibration unit according to some embodiments of the present application.

[0031] Fig.10 is a seventh configuration diagram of an exemplary heater and a magnetic vibration unit according to some embodiments of the present application.

[0032] Fig.11 This is a seventh configuration diagram of an exemplary heater, a magnetic vibration unit, and an acoustic vibration unit according to some embodiments of the present application.

[0033] Fig.12 This is a schematic diagram of the structure of an exemplary terminal device according to some embodiments of the present application.

[0034] Description of reference numerals:

[0035] 1. Additive manufacturing equipment, 2. Three-dimensional parts, 3. Terminal equipment, 12. Optical path structure, 13. Powder spreading device, 14. Forming platform, 15. Lifting device, 100. Powder storage cylinder, 101. Overflow powder cylinder, 20. Energy beam, 130. Powder spreading unit, 131. Dispersion unit, 132. Magnetic vibration unit, 133. Sonic vibration unit, 140. Forming area, 131a. Heating zone I, 131b. Heating zone II, 131c. Heating zone III, 131d. Heating zone IV, 131e. Heating zone V, 131f. Heating zone VI, 300. Processor, 310. Memory, 320. Computer program or instruction, 1310. Heater, 1311. Static eliminator, 1401. Powder spreading zone, 1402. Vibration section. DETAILED DESCRIPTION

[0036] Example embodiments will now be described more fully with reference to the accompanying drawings. However, example embodiments can be implemented in a variety of forms and should not be construed as limited to the examples set forth herein; rather, these embodiments are provided so that the present application will be more comprehensive and complete and fully convey the concepts of the example embodiments to those skilled in the art. The described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. In the following description, many specific details are provided to provide a full understanding of the embodiments of the present application.

[0037] refer to Figure 1 As shown, the additive manufacturing device 1 is an advanced manufacturing technology for constructing a three-dimensional part 2 by solidifying powder materials layer by layer. The working principle of the additive manufacturing device 1 is to use an energy beam 120 such as a laser beam or an electron beam to selectively sinter or melt the powder layer laid on the substrate platform, thereby solidifying a specific area and constructing the target part layer by layer. Powder materials usually appear in the form of solid particles, and the most common ones are metal materials, such as stainless steel, copper and aluminum alloys. In addition, ceramics, plastics, resins and composite materials can also be used to manufacture three-dimensional parts 2 of different materials.

[0038] In order to achieve a fine printing effect, the additive manufacturing device 1 selectively heats each layer of powder through an energy beam 120 generated by an optical path system, and uses laser sintering (SLS) or laser melting (SLM) technology to melt or solidify the powder material in a specified area. The unsolidified powder material continues to serve as a support structure or is used to form the basis of the next layer. After each layer of printing is completed, the substrate platform will drop a certain distance to lay a new powder layer, and finally form the entire three-dimensional part 2.

[0039] The core components of the additive manufacturing device 1 include a mechanical structure, an optical path structure 12 and a control system. The mechanical structure is responsible for powder supply, layered construction and precise movement of the platform; the optical path structure 12 generates an energy beam 120 to heat or solidify the material; and the control system is responsible for coordinating the operation of various components of the device to ensure the smooth progress of the printing process; the control system adjusts the printing parameters based on computer model data and monitors sensor feedback in real time to optimize printing quality and accuracy.

[0040] The mechanical structure of the additive manufacturing equipment 1 usually includes a forming bin, a powder supply device, a powder spreading device 13, a forming platform 14 and a lifting device 15. The powder supply device stores and transports the powder materials required for manufacturing, and usually includes at least one powder storage cylinder 100 and an overflow powder cylinder 101; the powder spreading device 13 ensures that the powder is evenly distributed on the forming platform 14, and usually adopts a scraper-type or roller-type powder spreader. The scraper pushes the powder flat, and the roller spreads the powder by rolling. The height of the powder spreading device 13 must be precisely synchronized with the forming platform 14, and a stepper motor or servo motor is usually used for height adjustment to ensure that the thickness of each layer of material is consistent; the forming bin is the main space for material forming in the entire additive manufacturing process, providing a controlled environment to protect the quality of materials and three-dimensional parts 2 during the manufacturing process; the forming platform 14 is the basis for carrying the workpiece and forming layer by layer. The distance between the forming platform 14 and the optical path structure 12 is accurately controlled by the forming lifting device 15. After each printing layer is completed, the lifting device 15 lowers the forming platform 14 by a certain distance to spread new powder to prepare for the next layer of printing.

[0041] In some embodiments of the present application, magnetically driven vibration powder laying is adopted. The magnetic drive can accurately control the frequency of vibration and achieve the target vibration effect according to the set frequency; however, in the actual powder laying process, magnetically induced vibration will cause the metal powder to be magnetized, and this magnetization will further affect the powder laying effect.

[0042] Thus, in some embodiments, reference Figure 2 As shown, the present application proposes a powder spreading device 13 to solve the influence of magnetic vibration on powder during the powder spreading process; the powder spreading device 13 of the present application includes a powder spreading unit 130 (i.e., a powder spreading scraper or a powder spreading roller, which is selected by the operator according to actual needs), at least one dispersion unit 131 and at least one magnetic vibration unit 132, the dispersion unit 131 is installed on the powder spreading unit 130 and / or the forming platform 14 of the additive manufacturing device 1, and is used to disperse the powder to be spread according to the material properties and / or environmental parameters of different powders; the magnetic vibration unit 132 is installed on the powder spreading unit 130 and / or the forming platform 14 of the additive manufacturing device 1, and is used to use the magnetic vibration field to assist the powder spreading unit 130 to spread the powder on the forming platform 14 in the forming area 140 according to the powder distribution through a preset flow path; wherein the preset flow path is divided into a plurality of powder spreading intervals 1401, and the powder uniformity of the plurality of powder spreading intervals 1401 is adjusted to be the same or different by the magnetic vibration unit 132.

[0043] Specifically, when the powder to be laid is dispersed according to the material properties and / or environmental parameters of different powders, the material properties of the current powder to be laid, such as particle size distribution, humidity, melting point, thermal sensitivity, etc., are obtained according to the powder data pre-entered by the operator, and then the optimal dispersion treatment scheme is determined in combination with the environmental parameters in the forming chamber, such as determining the optimal heating rate of the powder; when the magnetic vibration field is used to assist the powder laying unit 130 in laying according to the powder distribution, the powder flow path and laying interval are pre-set according to the forming area 140 of the forming platform 14 and the three-dimensional part 2 design model, wherein different path designs can be adjusted according to factors such as part shape, powder properties, target layer thickness, etc., and the frequency and amplitude of the magnetic vibration field applied by the magnetic vibration unit 132 are dynamically adjusted according to the fluidity and distribution of the powder, and different vibration frequencies and phase adjustments can be used to avoid powder accumulation in local areas, thereby maintaining a uniform thickness of the laying layer.

[0044] Therefore, the powder spreading process of one embodiment of the present application is as follows:

[0045] The powder is transported to the forming platform 14 via the powder supply device of the additive manufacturing equipment 1, and then the powder is spread on the forming area 140 of the forming platform 14 through the powder spreading unit 130; before the powder spreading unit 130 spreads the powder, the dispersion unit 131 disperses the powder by heating and / or static elimination to reduce powder agglomeration; during the powder spreading process of the powder spreading unit 130, the magnetic vibration unit 132 uses the magnetic vibration field to assist the powder spreading unit 130 to adjust to the set matching frequency and amplitude according to the powder distribution, so as to spread the powder on the forming platform 14 in the forming area 140 through a pre-set powder flow path, wherein each time a powder spreading interval 1401 is passed, the powder uniformity in the powder spreading interval 1401 is adjusted to a matching uniformity.

[0046] In some embodiments, reference Figure 3 As shown, the dispersion unit 131 is arranged on the powder laying unit 130, and the dispersion unit 131 adopts a heater 1310, and the heater 1310 is used to adjust the powder to be laid to a preset temperature range according to the material properties of different powders and / or the ambient temperature, and ensure that the powder is evenly heated to the set temperature range by real-time monitoring of the temperature changes in the powder laying process, so as to obtain the best laying effect; wherein, the preset temperature range is set by the operator according to actual needs and powder characteristics. In this application, the upper and lower limits of the temperature are referenced to 50°C-350°C, and the actual preset temperature range is referenced to 200°C, thereby reducing powder agglomeration during the powder laying process and reducing the influence of the magnetic vibration unit 132 on the powder.

[0047] In some embodiments, reference Figure 4As shown, the dispersion unit 131 is arranged on the powder spreading unit 130, and the dispersion unit 131 adopts a heater 1310, which forms a plurality of heating zones of the powder spreading unit 130 according to the powder spreading target, and sets the same or different temperature zones for each heating zone to ensure that during heating, the heater 1310 can adjust the powder temperature of each heating zone to a preset temperature zone.

[0048] Exemplarily, for example: the heater 1310 divides the powder spreading unit 130 into 6 heating zones, namely heating zone I131a, heating zone II131b, heating zone III131c, heating zone IV131d, heating zone V131e and heating zone VI131f, and then sets the heating zone I131a and heating zone VI131f as the first temperature zone, sets the heating zone II131b and heating zone V131e as the second temperature zone, and sets the heating zone III131c and heating zone IV131d as the third temperature zone, wherein the first temperature zone is 150°C, the second temperature zone is 180°C, and the third temperature zone is 210°C.

[0049] In some embodiments, reference Figure 5 As shown, the dispersion unit 131 is arranged on the forming platform 14 of the additive manufacturing equipment 1, and the dispersion unit 131 adopts a heater 1310. The heater 1310 forms a forming area 140 of the forming platform 14 into several heating zones according to the powder spreading target, and sets the same or different temperature zones for each heating zone to ensure that during heating, the heater 1310 can adjust the powder temperature of each heating zone to a preset temperature zone.

[0050] In some embodiments, reference Figure 6 As shown, the dispersion unit 131 includes a heater 1310 and an electrostatic eliminator 1311. The heater 1310 is arranged on the powder spreading unit 130, and the heater 1310 forms a plurality of heating zones of the powder spreading unit 130 according to the powder spreading target; the electrostatic eliminator 1311 is arranged on the side end of the forming platform 14, and the electrostatic eliminator 1311 is set at a preset distance interval with the powder flow area according to the powder parameters, so as to eliminate the static accumulation of the powder spread by the powder spreading unit 130 according to the material properties of different powders and / or the ambient humidity.

[0051] Specifically, during the powder laying process, static electricity will be generated due to the friction of powder particles and the contact with the powder laying unit 130 and the forming platform 14. The static electricity will attract the powder particles to each other, causing the powder particles to agglomerate, thereby affecting the uniformity of the powder laying and the quality of additive manufacturing. Therefore, on the basis of designing the heater 1310 to reduce the magnetism of the powder, an electrostatic eliminator 1311 is set, and the spacing distance between the electrostatic eliminator 1311 and the powder flow area is adjusted according to the powder particle size and material properties. The specific spacing distance is adjusted by the operator according to actual needs. For example, if a short-distance electrostatic eliminator 1311 is used, 0-150mm is used as a reference, and if a long-distance electrostatic eliminator 1311 is used, 1-150cm is used as a reference to ensure effective static dissipation; as long as the electrostatic eliminator 1311 can It is capable of preventing static electricity from generating uneven clusters during the powder laying process, and can be any form of static eliminator 1311, including but not limited to rod-type static eliminators, fan-type static eliminators, air gun-type static eliminators, nozzle-type static eliminators, etc., and in this application, reference is made to rod-type static eliminators; wherein, in the actual implementation process, powder materials such as plastic or ceramic powders have a higher resistivity and are prone to accumulate a large amount of static electricity during friction, or, in a low-humidity environment, the static electricity problem of the powder is more prominent due to drying. Therefore, matching operating parameters of the static eliminator 1311, such as power, operating time, etc., are set according to the material properties of different powders and / or the ambient humidity, and then the static eliminator 1311 is adjusted to matching operating parameters according to the material properties of the powder to be laid and / or the ambient humidity.

[0052] In some embodiments, to ensure that powders of different materials can be heated to a preset temperature range during powder spreading during the additive manufacturing process, a relevant temperature control method is designed according to the powder material properties (such as thermal conductivity, specific heat capacity, melting point, etc., which affect the heating rate and heating target temperature of the powder), the ambient temperature, and the powder spreading target (different powder spreading areas, such as the edge or center of the platform, require different powder temperatures). For example, for example:

[0053] Assuming that each heating interval is controlled by a separate heater 1310, the goal is to calculate the output power of each heater 1310 so that the powder temperature reaches the set interval. During the heating process of the powder material, the input heat energy should satisfy the following equation:

[0054] ;in, is the heat in the ith heating interval (unit: joule), is the mass of powder in the ith heating interval (unit: g), is the specific heat capacity of the powder in the ith heating interval (unit: joule per gram degrees Celsius); , is the temperature difference that the powder needs to be raised, is the target temperature of the i-th heating interval, is the ambient temperature or current powder temperature of the i-th heating interval.

[0055] According to the above equation, assuming that the heating time is t, the power calculation formula of the heater 1310 is:

[0056] ;in, is the heating power of the heater 1310 in the i-th heating interval (unit: watt), and t is the heating time (unit: second).

[0057] Furthermore, the power of the heater 1310 is dynamically adjusted according to the material properties of the powder and the current temperature, and the temperature control relationship is set as: ;in, Heating time The powder temperature in the i-th heating interval is is the powder temperature of the i-th heating interval at the current moment.

[0058] Therefore, according to the above temperature control method, the implementation steps are as follows:

[0059] Obtain powder material properties (powder quality) for each heating zone Specific heat capacity ) and ambient temperature , and then determine the target temperature of each heating interval .

[0060] According to the above power calculation formula of the heater 1310, the initial power is calculated , and set an initial output power for each heater 1310.

[0061] According to the above temperature control relationship, the temperature of each heating zone is updated in real time, and the power output is dynamically adjusted according to the deviation between the real-time powder temperature and the target temperature. The adjustment rules are as follows: , then increase ;like , then reduce Or directly turn off the heater 1310.

[0062] In the temperature control process, feedback control is added to continuously monitor the error between the actual temperature of the powder in each heating interval and the target temperature, and proportional integral control (PID control) is used to adjust the power output to reduce temperature fluctuations: ;in, is the difference between the target temperature and the actual temperature at the current moment; is the proportional gain in PID control, which determines the impact of the current error on the power output; It is the integral gain in PID control, which determines the impact of the accumulation of past errors on power output and is used to eliminate long-term steady-state errors; It is the differential gain in PID control, which determines the impact of the error change speed on the power output and can suppress overshoot or fluctuation.

[0063] Specifically, in PID control, proportional control (P): , according to the current temperature error Directly adjust the power of heater 1310, the goal is to reduce the temperature error as quickly as possible. When it increases, the response to the error is faster. When the actual temperature of the heating zone is lower than the target temperature, the proportional control will increase the output power of the heater 1310, and vice versa. Integral control (I): , by calculating the cumulative value of the error over a period of time and adjusting the power output, integral control helps to eliminate steady-state errors, that is, when the temperature is close to the target value, avoid the inability to reach the precise target temperature, the accumulation of errors (integral term) The purpose is to ensure that the temperature does not deviate from the target value for a long time. When it is larger, the error can be eliminated faster. Differential control (D): By calculating the temperature error change rate and adjusting the power output, it can play a role in suppressing rapid temperature changes. The error change rate (differential term) The purpose of is to mitigate the effects of rapidly changing errors. For example, if the current temperature is rapidly approaching the target temperature, the derivative term will reduce the power to the heater 1310 to prevent temperature overshoot or oscillation.

[0064] In some embodiments, the magnetic vibration unit 132 can be set in the powder spreading unit 130, can also be set in the forming platform 14 of the additive manufacturing device 1, and can also be set in the powder spreading unit 130 and the forming platform 14 of the additive manufacturing device 1 respectively. For example, refer to Figure 7 As shown, in this embodiment, the dispersion unit 131 adopts a heater 1310, and the heater 1310 is arranged on the forming platform 14, and the magnetic vibration unit 132 is arranged on the powder spreading unit 130, so that the dispersion unit 131 and the magnetic vibration unit 132 can reciprocate with the powder spreading unit 130, and the powder is quickly heated to 200°C by heating before spreading the powder, and then the powder is evenly spread by the magnetic vibration unit 132. This powder spreading can effectively reduce the agglomeration of powder in the process of powder spreading, effectively reduce the influence of the magnetic vibration component on the powder, and at the same time, the current printing layer can also be preheated.

[0065] In some embodiments, reference Figure 8As shown, the magnetic vibration unit 132 divides the powder spreading unit 130 and / or the forming platform 14 into a plurality of vibration sections 1402 according to the powder spreading interval 1401, and at least one vibration section 1402 is matched with a powder spreading interval 1401, and the same or different vibration parameters are set for each vibration section 1402 to ensure that during the vibration process, the magnetic vibration unit 132 can adjust the vibration parameters of each vibration section 1402 to the preset vibration parameters.

[0066] Specifically, the configuration of the dispersion unit 131 and the magnetic vibration unit 132 at least includes: Figure 1 As shown, the dispersion unit 131 and the magnetic vibration unit 132 are both arranged in the powder spreading unit 130, the dispersion unit 131 divides the powder spreading unit 130 into a plurality of heating intervals, and the magnetic vibration unit 132 divides the powder spreading unit 130 into a plurality of vibration sections 1402; Fig. 9 As shown, the dispersion unit 131 is arranged on the powder spreading unit 130, and the magnetic vibration unit 132 is arranged on the forming platform 14. The dispersion unit 131 divides the powder spreading unit 130 into a plurality of heating intervals, and the magnetic vibration unit 132 divides the forming platform 14 into a plurality of vibration sections 1402; Figure 7 As shown, the dispersion unit 131 is arranged on the forming platform 14, and the magnetic vibration unit 132 is arranged on the powder spreading unit 130. The dispersion unit 131 divides the forming platform 14 into a plurality of heating zones, and the magnetic vibration unit 132 divides the powder spreading unit 130 into a plurality of vibration sections 1402; Fig.10 As shown, the dispersion unit 131 and the magnetic vibration unit 132 are both arranged on the forming platform 14, the dispersion unit 131 divides the forming platform 14 into a number of heating intervals, and the magnetic vibration unit 132 divides the forming platform 14 into a number of vibration sections 1402; therefore, the operator designs and adjusts the corresponding line connection and installation methods according to the different settings of the dispersion unit 131 and the magnetic vibration unit 132, and the operator makes a selection according to actual needs.

[0067] In some embodiments, the uniform laying of powder is ensured by means of a magnetic vibration field during the additive manufacturing process. According to the powder distribution and the vibration requirements of different regions, the uniformity and accuracy of the powder laying are achieved by controlling vibration parameters (such as amplitude and frequency). A related vibration control method is designed, for example:

[0068] Assuming that each vibration section 1402 has different vibration parameters (such as amplitude, frequency), the goal is to adjust these parameters by calculation and in real time. Considering the influence of the magnetic vibration field, the vibration equation of the following form is adopted:

[0069] ;in, is the displacement of the i-th vibration segment 1402 at time t, is the amplitude of the i-th vibration segment 1402, is the frequency of the i-th vibration segment 1402, is the phase of the i-th vibration segment 1402.

[0070] According to the above equation, in order to ensure the powder uniformity of each vibration section 1402, a powder distribution uniformity function is introduced, which is defined as: ;in, is the powder uniformity of the i-th vibration section 1402, and the smaller the value, the higher the uniformity; is the standard deviation of the powder height distribution in the i-th vibration section 1402, is the average height of the powder in the i-th vibration section 1402; the goal of vibration control is to adjust and ,Will Control within the set range, that is , is the target uniformity threshold.

[0071] Furthermore, since the amplitude and frequency have a direct impact on the fluidity and uniform laying of the powder, increasing the amplitude and frequency can increase the fluidity of the powder and make the powder easier to spread. However, too high an amplitude and frequency may cause excessive movement of the powder, which in turn affects the uniformity. Therefore, it is necessary to dynamically adjust the vibration parameters through feedback control, and the update formula is: , ;in, is the amplitude at the next moment, is the frequency at the next moment, is the amplitude at the current moment, is the amplitude at the current moment; is the gain coefficient of the amplitude, which is used to adjust the speed of amplitude change; is the frequency gain coefficient, which is used to adjust the frequency change speed; is the powder uniformity at the current moment.

[0072] Therefore, according to the above vibration control method, the implementation steps are as follows:

[0073] Set the initial vibration parameters of each vibration segment 1402 and , and set the target uniformity threshold , and initialize the powder height distribution parameters of each vibration section 1402 and .

[0074] Calculate the powder uniformity of each vibration section 1402 based on the real-time monitored powder distribution data .

[0075] The amplitude and frequency are dynamically adjusted using the update formula above until the target uniformity threshold for the powder uniformity setting is reached.

[0076] In the vibration control process, feedback control is also added, and proportional integral control (PID control) is introduced to further improve the accuracy of vibration control:

[0077] , ;in, In this embodiment, , that is, the current uniformity error; adjust the vibration parameters (amplitude and frequency) of the vibration section 1402 according to feedback control to reduce the uniformity error and gradually improve the uniformity of the powder spreading.

[0078] In some embodiments, reference Fig.11 As shown, the powder spreading device 13 of the present application also includes an ultrasonic vibration unit 133, which is arranged on the forming platform 14 and / or the powder spreading unit 130, and is used to use the ultrasonic vibration field and the magnetic vibration field to assist the powder spreading unit 130 to spread the powder on the forming platform 14 in the forming area 140 through a preset flow path according to the powder distribution.

[0079] Specifically, in this embodiment, the sonic vibration unit 133 and the magnetic vibration unit 132 are arranged at different positions. For example, if the sonic vibration unit 133 is arranged on the forming platform 14, the magnetic vibration unit 132 is arranged on the powder spreading unit 130; if the sonic vibration unit 133 is arranged on the powder spreading unit 130, the magnetic vibration unit 132 is arranged on the forming platform 14; in this embodiment, reference Fig.11 As shown, the sonic vibration unit 133 is disposed on the forming platform 14 , and the magnetic vibration unit 132 is disposed on the powder spreading unit 130 .

[0080] In some embodiments, the sonic vibration unit 133 and the magnetic vibration unit 132 may also be arranged at the same position, that is, the sonic vibration unit 133 and the magnetic vibration unit 132 may both be arranged on the powder spreading unit 130 or the forming platform 14 .

[0081] Therefore, the powder parameters of the preset powder spreading interval 1401 are adjusted by utilizing the composite vibration field formed by the cooperative operation of the magnetic vibration unit 132 and the acoustic vibration unit 133 arranged at the same or different positions; wherein the powder parameters include one or more of powder thickness, uniformity, flow direction and stacking position.

[0082] In some embodiments, in combination with the above-mentioned vibration control method, according to the thickness, uniformity, flow direction and stacking position of the powder, by combining the effects of the magnetic vibration unit 132 and the ultrasonic vibration unit 133, the vibration parameters of each vibration section 1402 are dynamically adjusted to ensure the uniform laying and precise distribution of the powder, thereby designing a composite vibration control method in which a related magnetic vibration field and an ultrasonic vibration field work in coordination, aiming to use the magnetic vibration field to provide large-scale powder motion control, adjust the flow path and direction of the powder, and use the ultrasonic vibration field to optimize the micro-scale powder distribution by high-frequency vibration; illustratively, for example: the control of the magnetic vibration field is based on the simple harmonic vibration of magnetically induced vibration, and vibration is applied by the frequency and amplitude of the magnetic vibration unit 132; the control of the ultrasonic vibration field is based on high-frequency ultrasound, and vibration is applied by regulating the frequency and amplitude of the acoustic vibration unit 133; the magnetic vibration and the acoustic vibration are respectively expressed as: , ;in, The vibration section 1402 corresponding to the magnetic vibration is exemplary refers to the displacement of the vibration section 1402 corresponding to the i-th magnetic vibration at time t; The vibration section 1402 corresponding to the sound wave vibration is exemplified Refers to the displacement of the vibration section 1402 corresponding to the i-th sound wave vibration at time t. Furthermore, a composite vibration field is formed by combining the effects of the magnetic vibration field and the ultrasonic vibration field, which is expressed as:

[0083] ;

[0084] Right now , which represents the total vibration response of the i-th segment. The laying behavior of the powder is controlled by adjusting the vibration parameters of the magnetic vibration field and the ultrasonic vibration field.

[0085] Furthermore, according to the above-mentioned composite vibration field, the control methods of powder thickness, uniformity, flow direction and stacking position are set in sequence:

[0086] The powder thickness is controlled by adjusting the vibration amplitude. After setting the target thickness, we then use feedback control to adjust the vibration parameters: ;in is the amplitude of the vibration section 1402 corresponding to the composite vibration formed by the i-th magnetic vibration and the acoustic vibration, is the thickness control gain, is the target powder thickness, is the current powder thickness.

[0087] The uniformity of the powder is measured by the standard deviation of the powder distribution. The uniformity can be adjusted by finely vibrating the ultrasonic vibration field to adjust the microscopic distribution of the powder: ;in is the uniformity control gain, is the standard deviation of the target powder distribution, is the standard deviation of the current powder distribution; the high-frequency vibration of the acoustic vibration unit 133 can better control the microscopic flow of the powder, thereby adjusting the uniformity.

[0088] The flow direction of the powder is mainly controlled by the magnetic vibration field. The flow path of the powder can be adjusted by adjusting the phase and vibration frequency of the magnetic vibration field: ;in is the phase of the vibration section 1402 corresponding to the i-th magnetic vibration, is the flow direction control gain, is the target flow direction angle, is the current powder flow direction angle.

[0089] The accumulation position of the powder is mainly controlled by the high frequency of the ultrasonic vibration field, specifically:

[0090] ;in, is the stacking position control gain, is the target powder accumulation position, The current stacking position.

[0091] Therefore, according to the above-mentioned composite vibration control method, its implementation steps are as follows:

[0092] Determine the initial parameters of each vibration segment 1402: , , , , and set the target powder parameters , , and .

[0093] Based on the feedback from the powder laying process (thickness, uniformity, flow direction and stacking position), the parameters of the magnetic vibration field and ultrasonic vibration field are dynamically adjusted to ensure that the target values ​​are achieved.

[0094] In the process of composite vibration control, feedback control is also added, and proportional integral control (PID control) is introduced to further improve the accuracy of vibration control:

[0095] , ;in, In this embodiment, it is the difference between the current powder parameter and the target value.

[0096] In some embodiments, the present application also relates to a powder spreading method, which is implemented using the additive manufacturing device 1 having the powder spreading device 13, and the method includes the following steps:

[0097] According to the material properties of different powders and / or the ambient temperature, the powder to be laid is adjusted to a preset temperature range for powder dispersion processing.

[0098] Specifically, in this step, the material properties of the current powder to be laid are obtained based on the powder data pre-entered by the operator, such as particle size distribution, humidity, melting point, thermal sensitivity, etc., and then combined with the environmental parameters in the forming chamber to determine the best dispersion treatment plan, such as determining the optimal heating rate of the powder; thus, the heater 1310 is used to adjust the powder to be laid to the set temperature range, and the temperature changes during the powder laying process are monitored in real time to ensure that the powder is evenly heated to the set temperature range, so as to obtain the best laying effect.

[0099] In actual implementation, during thermal heating, the heater 1310 can adjust the powder temperature of each heating interval formed according to the powder spreading target to a preset temperature interval.

[0100] The magnetic vibration field-assisted powder spreading unit 130 spreads the powder on the forming platform 14 in the forming area 140 through several powder spreading intervals 1401 included in a preset flow path according to the powder distribution, and adjusts the vibration parameters of the magnetic vibration field passing through each powder spreading interval 1401 in real time.

[0101] Specifically, in this step, the flow path and laying interval of the powder are pre-set according to the forming area 140 of the forming platform 14 and the design model of the three-dimensional part 2, wherein different path designs can be adjusted according to factors such as part shape, powder properties, and target layer thickness, and the frequency and amplitude of the magnetic vibration field applied by the magnetic vibration unit 132 are dynamically adjusted according to the fluidity and distribution of the powder. By adjusting different vibration frequencies and phases, powder accumulation in local areas can be avoided, thereby maintaining a uniform thickness of the laying layer.

[0102] In the actual implementation process, when vibrating, the magnetic vibration unit 132 divides the powder spreading unit 130 and / or the forming platform 14 into a plurality of vibration sections 1402 according to the powder spreading interval 1401, and at least one vibration section 1402 is matched with a powder spreading interval 1401, and the same or different vibration parameters are set for each vibration section 1402 to ensure that during the vibration process, the magnetic vibration unit 132 can adjust the vibration parameters of each vibration section 1402 to the pre-set vibration parameters.

[0103] In some embodiments, when performing the powder dispersion process, the method includes the following steps:

[0104] The powder to be laid is treated to eliminate static electricity accumulation according to the material properties of different powders and / or the ambient humidity.

[0105] Specifically, the powder dispersion treatment is divided into a thermal dispersion treatment and a static elimination treatment.

[0106] In the actual implementation process, powder materials such as plastic or ceramic powders have a high resistivity and are prone to accumulate a large amount of static electricity during friction, or in a low humidity environment, the static electricity problem of the powder is more prominent due to drying. Therefore, the static eliminator 1311 operating parameters such as power, operating time, etc. are set to match the material properties of different powders and / or the ambient humidity, and then the static eliminator 1311 is adjusted to the matching operating parameters according to the material properties of the powder to be laid and / or the ambient humidity.

[0107] In some embodiments, when the powder on the forming platform 14 is spread on the forming area 140 through a plurality of powder spreading sections 1401, the method includes the following steps:

[0108] The ultrasonic vibration field and the magnetic vibration field are used to assist the powder spreading unit 130 to spread the powder on the forming platform 14 in the forming area 140 through several powder spreading intervals 1401 included in the preset flow path according to the powder distribution, and the vibration parameters of the composite vibration field formed by the collaborative operation of the magnetic vibration field and the ultrasonic vibration field are adjusted in real time to adjust the powder parameters of each powder spreading interval 1401 to the preset powder parameters.

[0109] Specifically, the magnetic vibration field can generate a large amplitude and guide the powder to be distributed on the forming platform 14 according to the preset flow path. Then, by controlling the magnetic force of different areas on the forming platform 14, different vibration intensities can be applied to different powder spreading intervals 1401, and the laying speed and thickness of the powder can be adjusted to ensure the uniform laying of the powder in the forming area 140. The high-frequency vibration characteristics of ultrasound can generate fine micro-vibrations, locally disturb the powder particles, and improve their fluidity and dispersibility. The high-frequency vibration of the ultrasonic vibration field can break the weak intermolecular forces between the powders and reduce the agglomeration and accumulation of the powder during the laying process. Thus, the magnetic vibration field is combined with the ultrasonic vibration field to form a composite vibration field. The magnetic vibration field guides the macroscopic distribution of the powder through a large amplitude to ensure that it is laid according to the preset flow path, while the ultrasonic vibration field mainly acts on the microscopic level of the powder to ensure the dispersibility and fluidity of the powder.

[0110] In the actual implementation process, first, the powder enters the forming platform 14, and the magnetic vibration field is started. According to the preset flow path, the auxiliary powder spreading unit 130 guides the powder to each powder spreading interval 1401 of the forming area 140. At this time, the ultrasonic vibration field acts on the powder at a lower frequency to assist the powder dispersion; when the powder enters the powder spreading interval 1401, the frequency of the ultrasonic vibration field gradually increases to enhance the disturbance of the powder particles and prevent the powder from agglomerating in a local area. At the same time, the magnetic vibration field adjusts the vibration intensity and frequency of each powder spreading interval 1401 according to the real-time powder thickness and / or uniformity to ensure the uniform distribution of the powder on the forming platform 14. At the same time, the vibration parameters of the composite vibration field formed by the magnetic vibration field and the ultrasonic vibration field are dynamically adjusted according to the real-time state of the powder. The parameters include the frequency, amplitude and phase of the vibration field. Through dynamic adjustment, it is ensured that the powder parameters of each powder spreading interval 1401 are always in the optimal state, thereby improving the accuracy and quality of additive manufacturing.

[0111] Fig.12 A block diagram of the terminal device 3 of the present application is shown. In some embodiments, the terminal device 3 includes a processor 310 and a memory 320, wherein the number of the processor 310 and the memory 320 can be one or more. The memory 320 is coupled to the processor 310 and is used to store a computer program or instruction 330 executed by the processor 310. When the computer program or instruction 330 is executed by the processor 310, the terminal device 3 executes any of the above-described powder spreading methods.

[0112] Specifically, the processor 310 communicates with the memory 320, and the memory 320 may include a read-only memory 320 and a random access memory 320, and provides instructions and data to the processor 310. In addition, a part of the memory 320 may also include a non-volatile random access memory 320 (NVRAM). In the memory 320, operation instructions, executable modules, data structures or their subsets, or even their extended sets are stored. These operation instructions cover various operations for implementing various operations. The powder spreading method described in the embodiment of the present application can be applied to the processor 310, or implemented by the processor 310. The processor 310 can be any applicable computer processor 310, such as a central processing unit (CPU), a graphics processing unit (GPU), a programmable logic device (FPGA), etc. In an embodiment of the present application, the processor 310 is responsible for executing each step of the powder spreading method.

[0113] The computer program or instructions 330 include a computer program for executing a computer process on a computing device. In some embodiments, the computer program or instructions 330 are provided using a signal-bearing medium. The signal-bearing medium may include one or more program instructions that, when executed by one or more processors 310, may provide the functions or portions of the functions described in the above embodiments of the powdering method. Thus, for example, one or more features in the powdering method may be undertaken by one or more instructions associated with the signal-bearing medium.

[0114] In some embodiments, the present application further provides a computer-readable storage medium storing a computer program, which, when executed by the processor 310, implements the powder spreading method described in any of the above items.

[0115] Specifically, a computer-readable storage medium refers to a medium that can be read by a computer system, such as a hard disk, a solid-state drive, an optical disk, a flash drive, etc. In some embodiments of the present application, a computer-readable storage medium stores a set of computer programs, which are executed by the processor 310 to implement the various steps and functions described in the powder spreading method. These computer programs may include operating systems, embedded software, applications, etc., for controlling and managing the process of the powder spreading method. By reading and executing programs stored on a computer-readable storage medium, a computer system can effectively implement the powder spreading method of the present application.

[0116] In some embodiments, the present application further provides a computer program product, which includes computer executable instructions. When the computer executable instructions are executed by the processor 310, the computer implements the powder spreading method described in any of the above items.

[0117] Specifically, a computer program product is a product storing computer executable instructions, the purpose of which is to implement the various steps and functions described in the powder spreading method when executed by the processor 310 of the computer system. The computer executable instructions may include an operating system, an application, an embedded software, etc., to control and manage the process of the powder spreading method. By using such a computer program product, a user can execute the powder spreading method of the present application on a computer system.

[0118] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art who is familiar with the present technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A magnetically induced vibration powder spreading device, characterized in that: include: Powder spreading unit; At least one heating unit, which is used to adjust the temperature of the powder laid by the powder laying unit to a preset temperature range according to the material properties of different powders and / or environmental parameters; At least one magnetic vibration unit is used to use a magnetic vibration field to assist the powder spreading unit to spread the powder on the forming platform in the forming area through a preset flow path according to the powder distribution, and adjust the powder uniformity of several powder spreading intervals included in the preset flow path to be the same or different.

2. The device according to claim 1, characterized in that The heating unit is arranged on the powder spreading unit and / or the forming platform.

3. The device according to claim 1 or 2, characterized in that: The heating unit adopts a heater, and the heater is used to adjust the temperature of the powder laid by the powder laying unit to a preset temperature range according to the material properties of different powders and / or the ambient temperature, so as to avoid magnetization of the powder by the magnetic vibration field.

4. The device according to claim 3, characterized in that The heater forms a plurality of heating zones in the powder spreading unit and / or the forming platform according to the powder spreading target and adjusts the powder temperature zone of each heating zone to be the same or different.

5. The device according to claim 1, characterized in that Also includes: An electrostatic eliminator is provided with a preset distance interval from the powder flow area according to powder parameters, and is used for eliminating static electricity accumulation of the powder laid by the powder laying unit according to the material properties of different powders and / or the ambient humidity.

6. The device according to claim 1, characterized in that The magnetic vibration unit is arranged on the powder spreading unit and / or the forming platform.

7. The device according to claim 1 or 6, characterized in that: The magnetic vibration unit forms a plurality of vibration sections of the powder spreading unit and / or the forming platform according to the powder spreading interval and adjusts the vibration parameters of each vibration section to be the same or different.

8. The device according to claim 7, characterized in that Also includes: The sonic vibration unit is used to utilize the ultrasonic vibration field and the magnetic vibration field to assist the powder spreading unit to spread the powder on the forming platform in the forming area through a preset flow path according to the powder distribution.

9. The device according to claim 8, characterized in that The sonic vibration unit is arranged on the forming platform and / or the powder spreading unit.

10. The device according to claim 9, characterized in that The powder parameters in the preset powder spreading interval are adjusted by using a composite vibration field formed by the cooperative operation of a magnetic vibration unit and an acoustic vibration unit arranged at the same or different positions.

11. The device according to claim 10, characterized in that in, The powder parameters include one or more of powder thickness, uniformity, flow direction and stacking position.

12. An additive manufacturing device comprising the device according to any one of claims 1 to 11.

13. A powder spreading method, characterized in that: The method comprises: Adjust the temperature of the powder to be laid to a preset temperature range according to the material properties of different powders and / or the ambient temperature to avoid magnetization of the powder by the magnetic vibration field; The magnetic vibration field is used to assist the powder spreading unit to spread the powder on the forming platform in the forming area through several powder spreading intervals included in the preset flow path according to the powder distribution, and the vibration parameters of the magnetic vibration field passing through each powder spreading interval are adjusted in real time.

14. The powder spreading method according to claim 13, characterized in that: When performing the powder dispersion process, the method comprises the following steps: The powder to be laid is treated to eliminate static electricity accumulation according to the material properties of different powders and / or the ambient humidity.

15. The powder spreading method according to claim 13, characterized in that: When the powder on the forming platform is spread on the forming area through a plurality of powder spreading sections, the method comprises the following steps: The ultrasonic vibration field and the magnetic vibration field are used in conjunction with the auxiliary powder spreading unit to spread the powder on the forming platform in the forming area through several powder spreading intervals included in the preset flow path according to the powder distribution situation, and the vibration parameters of the composite vibration field formed by the collaborative operation of the magnetic vibration field and the acoustic vibration field are adjusted in real time to adjust the powder parameters of each powder spreading interval to the preset powder parameters.

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