A global temperature control friction stir deposition additive manufacturing device and intelligent manufacturing method

Abstract

The application relates to the field of additive manufacturing technology and discloses a global temperature control friction stir deposition additive manufacturing device and an intelligent manufacturing method, which comprises a friction stir additive manufacturing mechanism, a cooling assembly for circulating cooling liquid to the shaft shoulder in the circumferential direction, a global temperature monitoring mechanism composed of a thermistor and a microcontroller and capable of monitoring particle migration, metallurgical bonding and plasticization, and a shape control system for receiving and analyzing temperature signals, inputting and outputting temperature thresholds and adjusting process parameters, water cooling speed and additive quality; the device and the method solve the problem that the poor additive quality is caused by the single temperature measurement, temperature control lag and the fact that process parameters cannot be dynamically optimized and controlled in the prior art, real-time and accurate monitoring of global temperature changes of additive manufacturing is carried out, process parameters, water cooling speed and additive quality are intelligently controlled according to temperature signals, a new technical idea is provided for the friction stir additive manufacturing, the device is suitable for additive manufacturing of various materials, and the device has a good industrial application prospect.

Description

Technical Field

[0001] This invention relates to the field of additive manufacturing technology, and in particular to a temperature-controlled stirring friction deposition additive manufacturing apparatus and intelligent manufacturing method. Background Technology

[0002] Friction stir deposition additive manufacturing (FSD) is a novel solid-state additive manufacturing method developed based on the principles of friction stir welding. This technology utilizes the intense plastic deformation and frictional heat during additive manufacturing to thermoplasticize and deposit metallic materials, forming additive bodies layer by layer on a substrate, thus achieving three-dimensional solid-state additive manufacturing. The forming temperature of this technology is far below the material's melting point, eliminating the melting and resolidification process and possessing the low-temperature characteristics of solid-state additive manufacturing. This avoids problems such as porosity, cracks, and alloy element loss that occur during molten additive manufacturing. Under the effect of thermo-mechanical coupling, the material forms a dense, fine equiaxed crystal structure, ultimately producing additive parts with a "forged" microstructure and excellent mechanical properties.

[0003] Currently, friction stir deposition additive manufacturing (FSD) employs either constant displacement or constant pressure control modes. Constant displacement control fixes the axial displacement of the rod material, controlling the thickness of each deposition layer through a preset reduction, and adjusting feed rate and process parameters (such as rotation speed) to ensure consistent layer thickness. However, this method suffers from poor control precision and difficulty in controlling additive manufacturing quality. Constant pressure control maintains a constant axial pressure, using pressure sensors to manually adjust the position of the rod material. Due to the lack of dedicated equipment and constant pressure control systems, this method suffers from significant human error and low dimensional accuracy of the additive body.

[0004] Recently, a device and method for precise temperature control and organization of friction stir additive manufacturing (publication number CN117139814) proposed a device and method for temperature-controlled friction stir additive manufacturing. Specifically, it uses thermocouples arranged on the shoulder to measure and analyze the temperature of the additive region, thereby controlling the friction stir additive manufacturing process. However, it has the following prominent problems: First, temperature measurement is only performed on the outer wall of the shoulder, resulting in low efficiency and poor accuracy. Second, the aforementioned patent only controls the microstructure of the additive body and does not address how to control the forming quality of the additive body. Furthermore, single temperature measurement cannot reflect changes in material migration, metallurgical bonding, and plasticization temperature, and cannot avoid problems such as material migration blockage, poor metallurgical bonding quality, and uneven plasticization, thus leading to uncontrollable additive body forming quality. Third, additive manufacturing involves multi-stage intense plastic deformation and frictional heat generation, and process parameters have a significant impact on the additive manufacturing temperature. However, the aforementioned patent only uses bismuth telluride-based materials to control the temperature, resulting in uncontrollable heat absorption and release rates, low real-time feedback efficiency, and predictably poor temperature control accuracy. Summary of the Invention

[0005] This invention proposes a temperature-controlled stirring friction deposition additive manufacturing device and intelligent manufacturing method to address the shortcomings of the prior art. The device and method solve the problems of poor additive quality caused by single temperature measurement, temperature control lag, and inability to dynamically optimize and control process parameters in the prior art. It can intelligently control the forming quality and microstructure properties of the friction deposition additive manufacturing process.

[0006] The technical solution of this invention is: a temperature-controlled stirring triboelectric additive manufacturing apparatus, comprising:

[0007] The additive manufacturing mechanism includes a shoulder, a screw disposed within the shoulder, and a spindle for driving the screw to rotate;

[0008] The cooling assembly is mounted on the shaft shoulder and is used to circulate coolant into the shaft shoulder circumferentially.

[0009] The global temperature monitoring mechanism includes three thermistors and a microcontroller. The three thermistors are respectively embedded in the top, middle and bottom of the screw stirring section. The three thermistors are used to monitor the particle migration temperature, metallurgical bonding temperature and plasticizing flow temperature in real time from top to bottom. The microcontroller is set on the main shaft and connected to the three thermistors to acquire the particle migration temperature, metallurgical bonding temperature and plasticizing flow temperature monitored by the three thermistors in real time.

[0010] The shape control system is connected to the microcontroller. The shape control system is used to receive the particle migration temperature, metallurgical bonding temperature and plasticizing flow temperature acquired by the microcontroller in real time, and to adjust the spindle speed, forward speed, axial pressure and axial displacement, as well as the coolant flow rate and coolant temperature of the cooling component in real time according to the particle migration temperature, metallurgical bonding temperature and plasticizing flow temperature.

[0011] In at least one embodiment of the present invention, the shape control system includes:

[0012] The spindle control module is used to regulate the spindle speed, forward speed, axial pressure, and axial displacement;

[0013] The cooling control module is used to regulate the coolant flow rate and coolant temperature of the cooling components;

[0014] The temperature control module is connected to the spindle control module, cooling control module, and microcontroller. A target temperature value is preset within the temperature control module. Where y = 1, 2, or 3, the temperature control module is used to receive real-time temperature data acquired by the microcontroller. T x x = 1, 2, or 3, and after identifying and processing abnormal temperature values, compare them with the preset target temperature value. The deviation values ​​at each temperature point were compared and obtained. e x ( t Where x = 1, 2, or 3, the three deviation signals are then weighted and summed to obtain the comprehensive temperature deviation e(t), and then the control quantity is calculated using PID control. u ( t ), control quantity u ( t ) converted into spindle speed adjustment amount Δ N and coolant flow rate adjustment Δ V and Δ N and Δ V The signals are sent in real time to the spindle control module and the cooling control module to adjust the spindle speed and the coolant flow rate of the cooling components.

[0015] In at least one embodiment of the present invention, the bottom end of the screw is provided with one to four stirring pins, each of which is a boss-shaped protrusion.

[0016] In at least one embodiment of the present invention, the cooling assembly includes a cooling ring and a cooling machine. The cooling ring is fitted onto a shoulder, and the cooling machine is connected to the cooling ring. The coolant flow velocity of the cooling assembly is 0 m / s to 3 m / s, the coolant temperature is -40℃ to 30℃, the cooling rate is 0℃ / min to 400℃ / min, and the pressure is 0MPa to 5MPa. The coolant of the cooling assembly is oxygen-free pentane, liquid carbon dioxide, liquid nitrogen, water, or alcohol.

[0017] In at least one embodiment of the present invention, the additive manufacturing mechanism further includes a limiting part, the screw is rotatably connected to the limiting part, and the shoulder bolt is connected to the bottom of the limiting part.

[0018] This invention also discloses a smart manufacturing method for global temperature-controlled stir triboelectric deposition additive manufacturing, comprising the following steps:

[0019] S1: Particle raw material is continuously added into the cavity formed by the shoulder and the screw. Under the action of the screw rotation driven by the main shaft, the particle raw material undergoes particle migration, metallurgical bonding and plastic flow, and is extruded into the cavity under the action of the screw axial pressure.

[0020] S2: The microcontroller collects the particle migration temperature T1, metallurgical bonding temperature T2 and plasticizing flow temperature T3 through the three thermistors, and sends the collected temperature data T1, T2 and T3 to the temperature control module;

[0021] S3: The temperature control module has pre-set target temperatures T1, T2, and T3. Where y = 1, 2, or 3, the temperature control module compares the abnormal temperature value with the preset target temperature value after identifying and processing the abnormal temperature value. The deviation values ​​at each temperature point were compared and obtained. e x ( t Where x = 1, 2, or 3, the three deviation signals are then weighted and summed to obtain the comprehensive temperature deviation. e ( t Then, the control quantity is calculated through PID control. u ( t ), control quantity u ( t ) converted into spindle speed adjustment amount Δ N and coolant flow rate adjustment Δ V and Δ N and Δ V The data is sent in real time to the spindle control module and the cooling control module to adjust the spindle speed and the coolant flow rate of the cooling components, so that the temperature of the additive manufacturing area is maintained at the target temperature.

[0022] In at least one embodiment of the present invention, in step S1, the particulate raw material includes single particulate raw material and mixed particulate raw material. The single particulate raw material includes aluminum alloy, magnesium alloy, copper alloy and titanium alloy. The mixed particulate raw material includes metal matrix composite particles, dissimilar pure metal particles and metal and non-metal mixed particles. The particle size range of the single particulate raw material and the mixed particulate raw material is 0.5 mm to 4 mm, and the feeding speed is 20 g / min to 70 g / min.

[0023] In at least one embodiment of the present invention, in step S3, T set1 The range is 0T m ~0.2T m T set2 The range is 0.2T m ~0.6T m T set3 The range is 0.5T m ~0.8T m T m This is the melting point temperature of the material.

[0024] In at least one embodiment of the present invention, in step S3, the method for identifying abnormal temperature values ​​is the physical limit check method, that is, values ​​that exceed or fall below 100% of the preceding or following temperature values ​​are marked as abnormal and directly deleted.

[0025] In at least one embodiment of the present invention, in step S3, the temperature control module first sends a command to the spindle control module and then sends a command to the cooling control module to achieve priority control of the spindle speed and then adjustment of the coolant flow rate of the cooling component.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] 1. This invention employs a global temperature monitoring mechanism consisting of three thermistors and a microcontroller, along with a shape control system. The three thermistors are embedded at the top, middle, and bottom of the screw agitator to monitor particle migration temperature, metallurgical bonding temperature, and plasticizing flow temperature in real time. The microcontroller transmits these temperatures to the shape control system in real time, enabling the system to adjust the spindle speed and coolant flow rate based on these temperatures. Compared to existing technologies, this invention provides a more comprehensive temperature monitoring system. The sensitive resistor is embedded inside the screw to directly monitor the temperature of the stirring zone, enabling accurate and real-time temperature monitoring and avoiding the temperature measurement lag of traditional external sensors. Simultaneously, the global temperature monitoring mechanism monitors the temperature of three key stages: particle migration, metallurgical bonding, and plasticizing flow, comprehensively covering the additive manufacturing process. This avoids localized temperature runaway caused by single temperature measurement, effectively solving problems such as material migration blockage, poor metallurgical bonding, and uneven plasticizing, significantly improving the quality and microstructure of additive forming. Furthermore, with the cooperation of the shape control system, it achieves closed-loop temperature control throughout the additive process, providing high real-time feedback efficiency and ensuring accurate temperature control.

[0028] 2. This invention establishes a shape control system consisting of a spindle control module, a cooling control module, and a temperature control module. The temperature control module integrates a proportional-integral-derivative (PID) algorithm and an adaptive optimization module to calculate temperature deviation in real time and dynamically adjust the spindle speed and coolant flow rate. This ensures rapid response and no overshoot during the additive manufacturing process, achieving precise closed-loop temperature control and guaranteeing the dimensional accuracy, microstructure, and mechanical properties of the additive layer.

[0029] 3. This invention improves the system's flexibility and convenience by placing the microcontroller between the spindle and the screw and connecting the microcontroller to the shape control system via wireless communication technology, unlike the wired thermocouples in the prior art. It also reduces the limitations of physical wiring on equipment layout, simplifies the operation process, and reduces data acquisition errors.

[0030] 4. The friction stir additive manufacturing apparatus proposed in this invention is adaptable to various raw materials such as aluminum, magnesium, copper, titanium alloys, and metal matrix composites. The temperature control module presets target temperature thresholds for three stages: particle migration, metallurgical bonding, and plasticizing flow. This meets the needs of additive manufacturing of dissimilar metals and forming of hybrid materials, and expands the application scope of friction stir additive manufacturing technology. Attached Figure Description

[0031] Figure 1 This is a diagram of the global temperature-controlled stirring friction deposition additive manufacturing apparatus of the present invention.

[0032] Figure 2 This is a schematic diagram showing the installation location of the global temperature monitoring mechanism of the present invention.

[0033] Figure 3 This is a schematic diagram of the working process of the microcontroller for the global temperature monitoring mechanism of the present invention.

[0034] Figure 4 This is a schematic diagram of the working process of the temperature control module of the present invention.

[0035] Figure 5 This invention provides a flowchart of the intelligent manufacturing process for achieving full-domain temperature-controlled stirring friction additive manufacturing.

[0036] Explanation of reference numerals in the attached figures:

[0037] 1. Additive manufacturing mechanism; 11. Shoulder; 12. Screw; 121. Stirring needle; 13. Spindle; 14. Limiting part; 2. Cooling assembly; 3. Global temperature monitoring mechanism; 31. Thermistor; 32. Microcontroller; 321. Data receiving module; 322. ADC analog-to-digital converter module; 323. Temperature calculation module; 324. Numerical storage module; 325. Wireless communication module; 4. Shape control system; 41. Temperature control module; 42. Spindle control module; 43. Cooling control module; 5. Hopper. Detailed Implementation

[0038] The accompanying drawings in this invention are not strictly drawn to scale, and the specific dimensions and quantity of each structure can be determined according to actual needs. The drawings described in this invention are merely structural schematic diagrams.

[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the described embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "inner," "outer," "upper," "lower," "far," "near," "front," and "rear" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0041] In the prior art, the intelligent temperature-controlled friction stir additive manufacturing device and method (publication number CN117139814) proposes a device and method for temperature-controlled friction stir additive manufacturing. Specifically, it uses thermocouples arranged on the shoulder to measure and analyze the temperature of the additive region, thereby controlling the friction stir additive manufacturing process. However, it suffers from the following prominent problems: First, temperature measurement is only performed on the outer wall of the shoulder, resulting in low efficiency and poor accuracy. Second, the aforementioned patent only controls the microstructure of the additive body and does not address how to control the forming quality of the additive body. Furthermore, single temperature measurement cannot reflect changes in material migration, metallurgical bonding, and plasticization temperature, and cannot avoid problems such as material migration blockage, poor metallurgical bonding quality, and uneven plasticization, leading to uncontrollable additive body forming quality. Third, additive manufacturing involves multi-stage intense plastic deformation and frictional heat generation, and process parameters have a significant impact on the additive manufacturing temperature. However, the aforementioned patent only uses bismuth telluride-based materials to control the temperature, resulting in uncontrollable heat absorption and release rates, low real-time feedback efficiency, and predictably poor temperature control accuracy. Most importantly, current friction stir additive manufacturing uses wired thermocouples for temperature measurement. Before additive manufacturing, drilling, wiring, and placing temperature recorders are required, which is a complex, inefficient, and costly process.

[0042] In view of this, the present invention proposes a full-range temperature-controlled friction stir deposition additive manufacturing apparatus and method. This apparatus and method solve the problems of poor additive quality caused by single temperature measurement, temperature control lag, and inability to dynamically optimize and control process parameters in existing technologies. By monitoring the temperature changes throughout the additive manufacturing process in real time and accurately, and intelligently controlling process parameters, water cooling rate, and additive quality based on temperature signals, this invention provides a new technical approach for friction stir deposition additive manufacturing. It is applicable to additive manufacturing of various materials and has good prospects for industrial application.

[0043] The friction stir additive manufacturing process mainly includes three stages: particle migration, metallurgical bonding, and plasticizing flow. In the particle migration stage, particles are axially transported under the drive of screw rotation, forming a continuous raw material flow and initially accumulating. In the metallurgical bonding stage, thermo-mechanical coupling promotes atomic interdiffusion at the material interface, achieving melting-free metallurgical bonding. In the plasticizing flow stage, high-temperature shearing causes the material to enter a superplastic state, and after dynamic recrystallization, it flows directionally to form a dense deposited layer. These three stages are located at the top, middle, and bottom of the screw, respectively.

[0044] Combination Figures 1 to 2 As shown, a temperature-controlled stir triboelectric additive manufacturing apparatus includes:

[0045] The additive manufacturing mechanism 1 includes a shoulder 11, a screw 12 disposed in the shoulder 11, a main shaft 13 for driving the screw 12 to rotate, and a hopper 5 connected to the shoulder 11.

[0046] Cooling assembly 2 is mounted on shoulder 11 and is used to circulate coolant into shoulder 11 in a circumferential manner.

[0047] The overall temperature monitoring mechanism 3 includes three thermistors 31 and a microcontroller 32. The three thermistors 31 are respectively embedded in the top, middle, and bottom of the stirring section of the screw 12. From top to bottom, the three thermistors 31 are used to monitor the particle migration temperature, metallurgical bonding temperature, and plasticizing flow temperature in real time, enabling monitoring of the entire stirring zone temperature. Specifically, the stirring section of the screw 12 has three hollow structures with dimensions of 1.0mm × 1.0mm × 1.0mm. The thermistors 31, after encapsulation, have dimensions of 1.0mm × 0.8mm × 0.8mm and are embedded in the hollow structures. The microcontroller 32 is mounted on the main shaft 13 and is connected to the three thermistors 31. The microcontroller 32 is used to acquire the particle migration temperature, metallurgical bonding temperature, and plasticizing flow temperature monitored by the three thermistors 31 in real time. Specifically, the microcontroller 32 is positioned between the main shaft 13 and the screw 12 and is electrically connected to the three thermistors 31.

[0048] The thermistor 31 is combined with a fixed resistor to form a voltage divider circuit. The voltage signal is acquired by the data receiving module 321 of the microcontroller 32, and converted into a resistance value by the analog-to-digital converter module 322. The temperature calculation module 323 calculates the corresponding temperature and records it by the value storage module 324, and then transmits it to the receiving end by the wireless communication module 325.

[0049] The microcontroller 32 outputs voltage U out Find the resistance value of thermistor 31. R t The formula is as follows:

[0050] ;

[0051] in, U out This is the voltage signal transmitted to the microcontroller 32; U in This refers to the power supply voltage. R t The resistance value of the thermistor 31; R y The fixed resistor has a known resistance.

[0052] The microcontroller 32 uses a B-parameter equation to calculate the resistance value of the thermistor 31. R t Calculate temperature T k The B-parameter equation is as follows:

[0053] ;

[0054] in, T k The actual temperature (K) obtained from the calculation; T 0 Reference temperature (K); R 0 represents the resistance value at the reference temperature; B It is a constant, and each thermistor 31 has a specific B value.

[0055] Kelvin temperature T k Convert to Celsius T (°C), the formula is as follows:

[0056] ;

[0057] Based on the temperature calculation method described above, code was written to automatically obtain the temperatures during the particle migration stage, the metallurgical bonding stage, and the plasticizing flow stage.

[0058] The shape control system 4 is connected to the microcontroller 32 and is used to receive the particle migration temperature, metallurgical bonding temperature and plasticizing flow temperature acquired by the microcontroller 32 in real time. It also controls the rotational speed, forward speed, axial pressure and axial displacement of the spindle 13, as well as the coolant flow rate and coolant temperature of the cooling component 2 in real time based on the particle migration temperature, metallurgical bonding temperature and plasticizing flow temperature.

[0059] As an alternative embodiment, the shape control system 4 includes:

[0060] Spindle control module 42 is used to regulate the speed of spindle 13;

[0061] Cooling control module 43 is used to regulate the flow rate of coolant in cooling component 2;

[0062] Temperature control module 41 is connected to spindle control module 42, cooling control module 43 and microcontroller 32. Target temperature value is preset in temperature control module 41. Where y = 1, 2, or 3, the temperature control module 41 is used to receive the temperature data collected in real time by the microcontroller 32. T x Where x = 1, 2, or 3, and after identifying and processing abnormal temperature values, compare them with a pre-set target temperature value. The deviation values ​​at each temperature point were compared and obtained. e x ( t The three deviation signals are then weighted and summed to obtain the overall temperature deviation. e ( t Then, the control quantity is calculated through PID control. u ( t ), control quantity u ( t ) converted into spindle speed adjustment amount Δ N and coolant flow rate adjustment Δ V and Δ N and Δ V The signals are sent in real time to the spindle control module 42 and the cooling control module 43 to adjust the spindle speed 13 and the coolant flow rate of the cooling component 2.

[0063] Specifically, the temperature control module 41 will collect real-time data on particle migration, metallurgical bonding, and plasticizing temperatures. T x (°C) and preset target temperature (Based on material type) Compare and calculate the deviation value at the temperature point. e x ( t (where x = 1, 2, or 3), and then the three deviation signals are weighted and summed to obtain the comprehensive temperature deviation. e ( t ):

[0064] ;

[0065] ;

[0066] in, w 1. w 2 and w 3 represents the weights for particle migration, metallurgical bonding, and plasticizing temperature, which are allocated based on the importance of the material and its corresponding process stage.

[0067] Temperature control module 41 based on comprehensive deviation value e ( t The control quantity u(t) is calculated using the following formula:

[0068] ;

[0069] in, K p , K i , K d These are the proportional coefficient, integral coefficient, and differential coefficient, respectively, and their values ​​are pre-calibrated based on material properties and process requirements.

[0070] Temperature control module 41 according to the control quantity u ( t Calculate the spindle speed adjustment Δ. N and the flow rate regulation amount Δ of cooling component 2 V :

[0071] ;

[0072] in, α This is the speed adjustment gain coefficient (range: 0 rpm / ℃ ~ 10 rpm / ℃). If the temperature is higher than the target temperature, reduce the speed to reduce frictional heat; conversely, increase the speed if the temperature is lower. β This is the flow rate adjustment gain coefficient (range: 0.5 L / min / ℃~5 L / min / ℃). If the temperature is too high, increase the flow rate to enhance heat dissipation; conversely, decrease the flow rate.

[0073] As an alternative embodiment, the spindle control module 42 controls the spindle 13 to rotate at a speed range of 0 rpm to 2000 rpm, to advance at a speed range of 0 mm / min to 1000 mm / min, to exert axial pressure at a speed range of 0 kN to 60 kN, and to exert axial displacement at a speed range of 0 mm to 5 mm.

[0074] As an alternative embodiment, the bottom end of the screw 12 is provided with one to four stirring pins 121, each stirring pin 121 being boss-shaped, and the dimensions of the boss-shaped stirring pin 121 are as follows: Ф 2.5 mm (top diameter) × Ф 4 mm (bottom diameter) × 2 mm (height); the rotating friction of the stirring needle 121 causes the thermoplastic material to undergo severe plastic deformation, achieving secondary plasticization and further enhancing the bonding between the additive body and the substrate or the additive body.

[0075] As an alternative embodiment, the cooling assembly 2 includes a cooling ring and a cooler (refrigerated water bath). The cooling ring is fitted onto the shoulder 11, and the cooler is connected to the cooling ring. The coolant flow rate of the cooling assembly 2 is 0 m / s to 3 m / s, the coolant temperature is -40℃ to 30℃, the cooling rate is 0℃ / min to 400℃ / min, and the pressure is 0MPa to 5MPa. The coolant of the cooling assembly 2 can be oxygen-free pentane, liquid carbon dioxide, liquid nitrogen, water, or alcohol. The cooling assembly 2 can not only cool the additive material but also significantly extend the tool's service life and ensure long-term stable operation of the equipment. The cooling assembly 2 supports various cooling media such as oxygen-free pentane and liquid nitrogen (flow rate 0 m / s to 3 m / s, temperature -40℃ to 30℃), avoiding material adhesion, wear, or deformation of the stirring pin 121 and screw 12 due to local overheating or overcooling, reducing material adhesion and tool wear, extending tool life, reducing equipment maintenance costs, and making the equipment operation more stable, significantly increasing the single continuous additive time.

[0076] As an alternative embodiment, the screw 12 is a single helical conical shape with a thread pitch of 10 mm. The material is quenched and tempered H13 steel, tungsten rhenium alloy, and hard alloy. The lower end face of the screw 12 is concave or asymptotic to enhance the fluidity of the material.

[0077] As an alternative embodiment, the additive manufacturing mechanism 1 also includes a limiting part 14, on which the screw 12 is rotatably connected, and the shoulder 11 is bolted to the bottom of the limiting part 14; and various shims of different specifications can be added between the shoulder 11 and the limiting part 14, which can change the gap between the screw 12 and the stationary shoulder 11 and the length of the stirring needle 121 extending out of the stationary shoulder 11, thereby adapting to the additive manufacturing of particles of different diameters.

[0078] This invention also provides a smart manufacturing method for global temperature-controlled stir triboelectric deposition additive manufacturing, comprising the following steps:

[0079] S1: Particle raw materials are continuously added into the cavity formed by the shoulder 11 and the screw 12. Under the action of the main shaft 13 driving the screw 12 to rotate, the particle raw materials undergo particle migration, metallurgical bonding and plastic flow, and are extruded into the cavity under the axial pressure of the screw 12. At the same time, the thermoplastic material undergoes violent plastic deformation under the rotational friction of the stirring needle 121, realizing secondary plasticization, and finally completing additive manufacturing.

[0080] S2: The microcontroller 32 collects the particle migration temperature T1, metallurgical bonding temperature T2 and plasticizing flow T3 through three thermistors 31, and sends the collected temperature data T1, T2 and T3 to the temperature control module 41, which determines the additive forming and microstructure quality.

[0081] S3: The temperature control module 41 has pre-set target temperatures T1, T2, and T3. Where y = 1, 2, or 3, the temperature control module 41, after identifying and processing abnormal temperature values, compares them with the preset target temperature value. The deviation values ​​at each temperature point were compared and obtained. e x ( t Where x = 1, 2, or 3, the three deviation signals are then weighted and summed to obtain the comprehensive temperature deviation. e ( t Then, the control quantity is calculated through PID control. u ( t ), control quantity u ( t ) converted into spindle speed adjustment amount Δ N and coolant flow rate adjustment Δ V and Δ N and Δ V The data are sent in real time to the spindle control module 42 and the cooling control module 43 to regulate the spindle speed 13 and the coolant flow rate of the cooling component 2, so that the temperature of the additive manufacturing area is maintained at the target temperature, thereby ensuring the quality of additive forming and microstructure properties.

[0082] As an alternative embodiment, in step S1, the particulate raw materials include single particulate raw materials and mixed particulate raw materials. The single particulate raw materials include aluminum alloys, magnesium alloys, copper alloys, and titanium alloys. The mixed particulate raw materials include metal-based composite material particles, dissimilar pure metal particles, and mixed metal and non-metal particles. The particle size range of the single and mixed particulate raw materials is 0.5 mm to 4 mm, and the feeding speed is 20 g / min to 70 g / min, thus allowing application to additive manufacturing of various materials.

[0083] As an alternative embodiment, in step S3, T set1 The range is 0T m ~0.2T m T set2 The range is 0.2T m ~0.6T m T set3 The range is 0.5T m ~0.8T m T m This is the melting point temperature of the material.

[0084] As an alternative embodiment, in step S3, the method for identifying abnormal temperature values ​​is the physical limit check method, that is, values ​​that exceed or fall below 100% of the previous or next temperature values ​​are marked as abnormal and directly deleted. That is, at this temperature value, the temperature control module 41 does not perform calculations on particle migration, metallurgical bonding and plasticizing temperature deviations, control quantities, and adjustment quantities, and suspends the sending of control commands to avoid process fluctuations caused by misoperation. At the same time, temperature data feedback adjustment avoids abnormal values ​​from interfering with the control logic, thereby enhancing system stability and process reliability.

[0085] As an alternative embodiment, the temperature control module 41 sends instructions to the spindle control module 42 first, and then sends instructions to the cooling control module 43 to prioritize the control of the spindle speed 13 and then adjust the coolant flow rate of the cooling component 2. This design prioritizes the control of the spindle speed 13, which enables the overall system to respond faster to temperature control and thus ensures the quality of additive manufacturing.

[0086] This invention discloses a full-domain temperature-controlled friction stir additive manufacturing device and intelligent manufacturing method, solving the problems of poor additive quality caused by single temperature measurement, temperature control lag, and the inability to dynamically optimize and control process parameters in existing technologies. Based on real-time and accurate monitoring of the three stages of temperature—particle migration (T1), metallurgical bonding (T2), and plasticizing flow (T3)—using an embedded thermistor, and combined with a PID algorithm in the temperature control module, full-domain closed-loop temperature control of the additive process is achieved. This not only significantly improves the forming quality and mechanical properties of the microstructure, and extends tool life, but also supports the flexible forming of various materials such as aluminum, magnesium, titanium alloys, and dissimilar metal composites, providing a reliable technical guarantee for high-quality and high-efficiency additive manufacturing of complex components in aerospace and other fields.

[0087] The above embodiments are merely specific implementations of the present invention, used to illustrate the technical solutions of the present invention, and not to limit them. The protection scope of the present invention is not limited thereto. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments within the technical scope disclosed in the present invention, or make equivalent substitutions for some of the technical features; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions implemented in the present invention, and should all be covered within the protection scope of the present invention.

Claims

1. A temperature-controlled stirring triboelectric additive manufacturing apparatus, characterized in that, include: The additive manufacturing mechanism (1) includes a shoulder (11), a screw (12) disposed in the shoulder (11), and a main shaft (13) for driving the screw (12) to rotate. Cooling assembly (2) is provided on the shoulder (11) for circulating coolant into the shoulder (11) circumferentially; The full-range temperature monitoring mechanism (3) includes three thermistors (31) and a microcontroller (32). The three thermistors (31) are respectively embedded in the top, middle and bottom of the stirring part of the screw (12). The three thermistors (31) are used to monitor the particle migration temperature, metallurgical bonding temperature and plasticizing flow temperature in real time from top to bottom. The microcontroller (32) is set on the main shaft (13) and connected to the three thermistors (31) to acquire the particle migration temperature, metallurgical bonding temperature and plasticizing flow temperature monitored by the three thermistors (31) in real time. The shape control system (4) is connected to the microcontroller (32) for receiving the particle migration temperature, metallurgical bonding temperature and plasticizing flow temperature obtained by the microcontroller (32) in real time, and adjusting the rotation speed of the spindle (13) and the flow rate of the coolant in the cooling assembly (2) in real time according to the particle migration temperature, metallurgical bonding temperature and plasticizing flow temperature. The shape control system (4) includes: The spindle control module (42) is used to regulate the spindle (13) speed; Cooling control module (43) is used to regulate the flow rate of coolant in cooling component (2); The temperature control module (41) is connected to the spindle control module (42), the cooling control module (43), and the microcontroller (32). The temperature control module (41) has a target temperature value preset in it. Where y = 1, 2 or 3, is used to receive temperature data collected in real time by the microcontroller (32). T x Where x = 1, 2, or 3, and after identifying and processing abnormal temperature values, compare them with the preset target temperature value. The deviation values ​​at each temperature point were compared and obtained. e x ( t (where x = 1, 2, or 3), and then the three deviation signals are weighted and summed to obtain the comprehensive temperature deviation. e ( t Then, the control quantity is calculated through PID control. u ( t ), control quantity u ( t ) converted into spindle speed adjustment amount Δ N and coolant flow rate adjustment amount Δ V and the Δ N and Δ V The signals are sent in real time to the spindle control module (42) and the cooling control module (43) respectively to adjust the spindle (13) speed and the coolant flow rate of the cooling assembly (2).

2. The temperature-controlled stirring triboelectric additive manufacturing apparatus as described in claim 1, characterized in that, The bottom end of the screw (12) is provided with one to four stirring needles (121), and each stirring needle (121) is a boss-shaped structure.

3. The global temperature-controlled stirring triboelectric additive manufacturing apparatus as described in claim 1, characterized in that, The cooling assembly (2) includes a cooling ring and a cooling machine. The cooling ring is fitted on the shoulder (11), and the cooling machine is connected to the cooling ring. The coolant flow rate of the cooling assembly (2) is 0 m / s to 3 m / s, the coolant temperature is -40℃ to 30℃, and the cooling rate is 0℃ / min to 400℃ / min.

4. The global temperature-controlled stir-friction deposition additive manufacturing apparatus as described in claim 1, characterized in that, The additive manufacturing mechanism (1) also includes a limiting part (14), the screw (12) is rotatably connected to the limiting part (14), and the shoulder (11) is bolted to the bottom of the limiting part (14).

5. A global temperature-controlled stir triboelectric additive manufacturing method, based on the global temperature-controlled stir triboelectric additive manufacturing apparatus according to claim 1, characterized in that, Includes the following steps: S1: Particle raw materials are continuously added into the cavity formed by the shoulder (11) and the screw (12). Under the action of the main shaft (13) driving the screw (12) to rotate, the particle raw materials undergo particle migration, metallurgical bonding and plastic flow, and are extruded into the cavity under the axial pressure of the screw (12). S2: The microcontroller (32) collects the particle migration temperature T1, metallurgical bonding temperature T2 and plasticizing flow temperature T3 through the three thermistors (31), and sends the collected temperature data T1, T2 and T3 to the temperature control module (41). S3: The temperature control module (41) has pre-set target temperatures T1, T2 and T3. Where y = 1, 2 or 3, the temperature control module (41) identifies and processes abnormal temperature values ​​and compares them with the preset target temperature value. The deviation values ​​at each temperature point were compared and obtained. e x ( t Where x = 1, 2, or 3, the three deviation signals are then weighted and summed to obtain the comprehensive temperature deviation. e ( t Then, the control quantity is calculated through PID control. u ( t The control quantity u(t) is converted into the spindle speed adjustment quantity Δ. N and coolant flow rate adjustment amount Δ V and Δ N and Δ V The signals are sent in real time to the spindle control module (42) and the cooling control module (43) to adjust the spindle (13) speed and the coolant flow rate of the cooling assembly (2) so that the temperature of the additive manufacturing area is maintained at the target temperature.

6. The intelligent manufacturing method for global temperature-controlled stir-friction deposition additive manufacturing as described in claim 5, characterized in that, In step S1, the particulate raw material includes: single particulate raw material and mixed particulate raw material. The single particulate raw material includes aluminum alloy, magnesium alloy, copper alloy and titanium alloy. The mixed particulate raw material includes metal matrix composite particles, dissimilar pure metal particles and metal and non-metal mixed particles. The particle size range of the single particulate raw material and the mixed particulate raw material is 0.5 mm to 4 mm, and the feeding speed is 20 g / min to 70 g / min.

7. The intelligent manufacturing method for global temperature-controlled stir-friction deposition additive manufacturing as described in claim 5, characterized in that, In step S3, T set1 The range is 0T m ~0.2T m T set2 The range is 0.2T m ~0.6T m T set3 The range is 0.5T m ~0.8T m T m This is the melting point temperature of the material.

8. The intelligent manufacturing method for global temperature-controlled stir-friction deposition additive manufacturing as described in claim 5, characterized in that, In step S3, the method for identifying abnormal temperature values ​​is the physical limit check method, which marks values ​​that exceed or fall below 100% of the preceding or following temperature values ​​as abnormal and deletes them directly.

9. The intelligent manufacturing method for global temperature-controlled stir-friction deposition additive manufacturing as described in claim 5, characterized in that, In step S3, the temperature control module (41) first sends an instruction to the spindle control module (42) and then sends an instruction to the cooling control module (43) to achieve priority control of the spindle (13) speed and then adjustment of the coolant flow rate of the cooling component (2).

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