An apparatus and method for active thermodynamic co-regulation of solid-state forming of metal wires

Abstract

This invention provides an active thermodynamic synergistic control device and method for solid-state forming of metal wires. The invention integrates a preheating module into the feeding path, forming a closed-loop temperature control system with a preheating coil group and a non-contact infrared thermometer. This system precisely heats the wire to a thermoplastic state before it enters the deposition zone, eliminating plasticization delay at the source. Simultaneously, a hollow stirring head with a central flow channel guides the preheated and softened material to be extruded and deposited in an orderly manner, completely eliminating the risk of material blockage. The monitoring and control module achieves signal interaction and linkage through a data acquisition and processing unit, forming a collaborative closed-loop architecture of sensing, control, and execution, thereby achieving active decoupling and collaborative control of heat input and mechanical parameters. On the one hand, this invention softens the material through preheating, significantly reducing dependence on spindle speed and axial pressure; on the other hand, the thermodynamic synergistic closed-loop control greatly improves process stability and fundamentally eliminates the risk of material blockage.

Description

Technical Field

[0001] This invention relates to the field of solid-state forming technology of metal materials, and in particular to a device and method for solid-state forming of metal wires with active thermodynamic synergistic control. Background Technology

[0002] Friction stir deposition additive manufacturing (FSD) is a solid-state additive manufacturing method developed based on the principle of friction stir welding. This technology generates heat through intense friction between a high-speed rotating stirring head and the supplied raw material, causing the material to plastically soften and deposit layer by layer under axial pressure to form a three-dimensional component. This technology features fine equiaxed recrystallized grains, and its mechanical properties approach or even exceed those of forgings. Therefore, it has broad application prospects in fields such as aerospace, defense, and transportation, where the quality and reliability of components are extremely important.

[0003] The raw materials for friction stir deposition additive manufacturing (FSD) mainly include particles, rods, and filaments. While particle raw materials allow for flexible composition adjustments, their large specific surface area, susceptibility to oxidation, poor flowability, and the need for complex pretreatment increase process complexity and cost. Rod raw materials, although offering stable delivery, are limited by fixed lengths, requiring frequent shutdowns for rod replacement during deposition. This disrupts process continuity and leads to uneven bonding quality due to interlayer temperature fluctuations. In contrast, filaments are standardized industrial raw materials with uniform diameter, stable composition, and easy availability and storage. Continuous filament feeding enables uninterrupted deposition, avoiding quality issues caused by frequent start-ups and shutdowns. Furthermore, the feed torque required for filaments is significantly lower than that for rods, facilitating equipment lightweighting and dynamic process control. Therefore, friction stir deposition technology based on filaments has become a current research hotspot.

[0004] Despite the numerous advantages of using filaments as raw materials, the heat input in traditional friction stir additive manufacturing relies entirely on frictional heat generation. In this mode, due to the limited efficiency of frictional heat generation and the time required for heat conduction, the material cannot reach a fully plasticized state immediately upon entering the stirring zone, leading to a series of interrelated technical problems:

[0005] First, delayed plasticization leads to poor flow and the risk of material blockage. When insufficiently softened filaments are continuously pushed into the mixing zone, their poor flowability makes them prone to accumulation and blockage inside the mixing head or under the shaft shoulder, causing interruptions in the deposition process. To compensate for insufficient frictional heat generation, existing processes are forced to use extremely high spindle speeds and enormous axial pressures. This not only places stringent requirements on equipment rigidity and spindle power but also subjectes the mixing tools to extremely high mechanical stress and thermal wear, significantly shortening their lifespan.

[0006] Second, existing research has attempted to employ a process monitoring and feedback strategy, which involves deploying sensors in the deposition zone to monitor the process status in real time and passively adjust process parameters. However, current control systems can only perform feedback adjustment of a single mechanical parameter and cannot independently control the heat input; thermal management and mechanical control are coupled and independent of each other, failing to form a synergistic closed loop.

[0007] In view of this, the inventors have specifically designed a device and method for active thermodynamic co-regulation of solid-state forming of metal wires, which leads to this invention. Summary of the Invention

[0008] To solve the above problems, the technical solution of the present invention is as follows: A device for active thermodynamic co-regulation of solid-state forming of metal wires, comprising: The feeding module forms a continuous wire conveying path inside; The preheating module receives the filament fed by the feeding module through the filament feeding tube, and includes a preheating coil group and a non-contact infrared thermometer. The preheating coil group is arranged around the outside of the filament feeding tube. The probe of the non-contact infrared thermometer is aimed at the surface of the filament at the outlet of the preheating coil group to heat the filament being fed and to detect the temperature of the filament in real time. The deposition module includes a hollow stirring head and a deposition process force sensor. The hollow stirring head has a through central channel inside, and the upper end of the central channel is connected to the wire feeding tube to guide the filament heated by the preheating module to be extruded and deposited. The deposition process force sensor is set on the clamping part of the hollow stirring head to detect the axial pressure and torque in real time during the deposition process. The monitoring and control module includes a temperature control unit, a mechanical state control unit, a motion control unit, and a data acquisition and processing unit; The temperature control unit is connected to the non-contact infrared thermometer and the preheating coil group respectively, and is used to receive the feedback signal from the non-contact infrared thermometer and perform closed-loop control of the heating power of the preheating coil group accordingly. The mechanical state control unit is connected to the force sensor signal of the deposition process and is used to perform closed-loop control of the deposition module's output pressure and Z-axis position adjustment commands during the deposition process based on the deviation between the axial pressure and torque feedback signals and the preset threshold. The motion control unit is signal-connected to the feeding module and the deposition module, and is used to coordinate the control of the wire feeding speed, the rotation speed of the hollow stirring head and the travel speed. The data acquisition and processing unit is connected to the signals of the non-contact infrared thermometer, the deposition process force sensor and the feeding module, respectively, and is used to collect wire temperature, axial pressure, torque and wire feeding speed signals in parallel for process monitoring and data recording. The temperature control unit, mechanical state control unit, and motion control unit are also connected to the data acquisition and processing unit for uploading their respective control state information to the data acquisition and processing unit and receiving the coordinated control instructions generated by the unit based on global information.

[0009] Preferably, the deposition module further includes a drive motor, a multi-axis motion mechanism, and a deposition substrate. The output shaft of the drive motor is mechanically connected to the clamping part of the hollow stirring head to drive the hollow stirring head to rotate. The multi-axis motion mechanism is fixedly connected to the mounting base of the hollow stirring head to drive the hollow stirring head to move in three-dimensional space. The deposition substrate is disposed below the hollow stirring head to support the deposition layer. The mechanical state control unit is electrically connected to the drive motor and the multi-axis motion mechanism.

[0010] Preferably, the deposition module further includes a stirring head temperature control unit, which includes a cooling sleeve fitted onto the handle of the hollow stirring head, with its cooling medium inlet and outlet connected to an external cooling system pipeline for cooling the hollow stirring head.

[0011] Preferably, the bottom of the hollow stirring head is provided with an upwardly recessed conical or spherical cavity, and the lower end of the central flow channel opens at the bottom center of the cavity. The preheated filament is transported to the center of the cavity through the central flow channel, and continuously extruded and directly deposited on the deposition substrate under the action of rotation and axial pressure.

[0012] Preferably, the deposition substrate integrates auxiliary heating elements and cooling channels, which are respectively connected to an external heating power supply and a cooling system pipeline.

[0013] Preferably, the monitoring and control module further includes a visual monitoring system, which is signal-connected to the data acquisition and processing unit and used to monitor the morphology of the sedimentation area in real time.

[0014] Preferably, the preheating module further includes a heat insulation cover, which wraps around the preheating coil assembly and the heated wire section and is mechanically fixed to the wire feeding tube.

[0015] This solution also provides a method for operating an active thermodynamically regulated solid-state forming device for metal wires, including the following steps: The preheating module and the feeding module are started. The continuously conveyed filament is heated and stabilized at the preset target preheating temperature through the closed-loop control of the temperature control unit. After the filament reaches the target preheating temperature, the deposition module is started, and the preheated filament is sent into the rotating hollow stirring head. The preheated and plasticized material is directly transported to the bottom through the central flow channel inside the hollow stirring head. Under the action of rotation and axial pressure, it is continuously extruded from the bottom center and directly deposited on the deposition substrate to form a dense deposition layer. During the deposition process, axial pressure and torque are monitored in real time using a deposition process force sensor; The monitoring and control module dynamically adjusts at least one parameter among the following: heating power of the preheating coil group, wire feeding speed, rotation speed of the hollow stirring head, downward pressure, or traveling speed, based on the acquired axial pressure and torque, thereby achieving proactive and coordinated control of the thermal state of the deposition process.

[0016] Preferably, the temperature control unit is used to receive the preset target preheating temperature and the real-time temperature fed back by the non-contact infrared thermometer, calculate the temperature deviation, and output a control signal through a PID control algorithm to dynamically adjust the heating power of the preheating coil group, thereby adjusting the temperature.

[0017] Preferably, the target preheating temperature is 0.4-0.9Tm, where Tm is the melting point temperature of the wire material.

[0018] The technical solution provided by this invention has the following beneficial effects: This invention integrates a preheating module into the material feeding path, forming a closed-loop temperature control system with a preheating coil assembly and a non-contact infrared thermometer. This system precisely heats the filament to a thermoplastic state before it enters the deposition zone, eliminating plasticization delay at the source. Simultaneously, a hollow stirring head with an internally connected central flow channel guides the preheated and softened material through orderly extrusion and deposition, completely eliminating the risk of material blockage. The monitoring and control module integrates a temperature control unit, a mechanical state control unit, and a motion control unit. Through a data acquisition and processing unit, these three units interact and coordinate, forming a collaborative closed-loop architecture of sensing, control, and execution. This achieves active decoupling and collaborative regulation of heat input and mechanical parameters. On the one hand, preheating softens the material, significantly reducing dependence on spindle speed and axial pressure. On the other hand, the thermo-mechanical collaborative closed-loop control greatly improves process stability and fundamentally eliminates the risk of material blockage, providing an efficient, stable, and reliable solution for solid-state additive manufacturing of high-performance metal components. Attached Figure Description

[0019] The accompanying drawings, which are provided to further illustrate the invention and constitute a part of this invention, are illustrative embodiments and descriptions of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention.

[0020] in: Figure 1 This is a schematic diagram of the overall structure of the present invention; Figure 2 This is a partial structural diagram of the stirring head temperature control unit device of the present invention; Figure 3 This is a schematic diagram of the flow channel structure and material flow path of the hollow stirring head in this invention; Figure 4This is a block diagram of the preheating closed-loop control principle of the present invention; Figure 5 This is a metallographic analysis diagram of Embodiment 1 of the present invention.

[0021] Label: 1. Feeding module; 11. Wire spool; 12. Multi-roller straightening mechanism; 13. Inert gas nozzle; 14. Wire feeder; 15. Wire feed tube; 2. Preheating module; 21. Non-contact infrared thermometer; 22. Preheating coil group; 23. Insulation cover; 3. Deposition module; 31. Drive motor; 32. Multi-axis motion mechanism; 33. Stirring head temperature control unit; 34. Hollow stirring head; 341. Cavity; 342. Shoulder; 35. Deposition substrate; 351. Cooling channel; 4. Monitoring and control module; 41. Deposition process force sensor; 42. Visual monitoring system; 43. Temperature control unit; 44. Mechanical state control unit; 45. Motion control unit; 46. Data acquisition and processing unit. Detailed Implementation

[0022] To make the technical problems, solutions, and beneficial effects of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of the invention.

[0023] The present invention provides an active thermodynamically synergistically controlled solid-state forming device for metal wires, comprising: The feeding module 1 forms a continuous wire conveying path. The feeding module 1 includes a wire spool 11, a multi-roller straightening mechanism 12, an inert gas nozzle 13, a wire feeder 14, and a wire feeding tube 15. The feeding module 1 draws the metal wire from the wire spool 11, straightens it through the multi-roller straightening mechanism 12, and then continuously conveys it to the preheating module 2 at a set speed via the wire feeder 14 and the wire feeding tube 15. The wire feeder 14 integrates an encoder for real-time measurement of the actual wire conveying speed. The motion control unit 45 receives this speed feedback signal and dynamically adjusts the servo motor speed of the wire feeder 14, thereby controlling the wire feeding speed fluctuation within ±5% of the set value to ensure smooth material conveying.

[0024] The preheating module 2 receives the filament fed by the feeding module 1 through the filament feeding tube 15. It includes a preheating coil group 22 and a non-contact infrared thermometer 21. The preheating coil group 22 is arranged around the outside of the filament feeding tube 15. The probe of the non-contact infrared thermometer 21 is aimed at the surface of the filament at the outlet of the preheating coil group 22 to heat the filament during transportation and detect the filament temperature in real time. In the preheating module 2, the induction heating coil arranged around the filament feeding tube 15 serves as the preheating coil group 22. The probe of the non-contact infrared thermometer 21 is aimed at the surface of the filament at the coil outlet. The temperature control unit 43 dynamically adjusts the heating power according to the deviation between the real-time temperature fed back by the thermometer and the preset target temperature, forming a closed-loop control so that the filament reaches the thermoplastic state before entering the deposition zone, avoiding defects such as material blockage and poor flow caused by this. The preheating coil group 22 is made of high-frequency induction coil or high-resistance electric heating alloy wire and is arranged tightly around the filament transportation path. Its power is independently and continuously adjusted by the temperature control unit 43, with an adjustment range typically from 0.5 kW to 5.0 kW. The non-contact infrared thermometer 21 is positioned directly opposite the surface of the wire at the outlet of the preheating coil group 22, and its temperature measurement band must match the material of the wire and the estimated temperature range.

[0025] The deposition module 3 includes a hollow stirring head 34 and a deposition process force sensor 41. The hollow stirring head 34 has a through-flow central channel, the upper end of which is connected to the wire feeding tube 15 to guide the extrusion and deposition of the filament heated by the preheating module 2. The deposition process force sensor 41 is mounted on the clamping part of the hollow stirring head 34 to detect the axial pressure and torque during the deposition process in real time. The deposition module 3 also includes a drive motor 31, a multi-axis motion mechanism 32, and a deposition substrate 35. The output shaft of the drive motor 31 is mechanically connected to the clamping part of the hollow stirring head 34 to drive the hollow stirring head 34 to rotate. The multi-axis motion mechanism 32 is connected to the hollow stirring head... The mounting base of 34 is fixedly connected and used to drive the hollow stirring head 34 to move in three-dimensional space. The deposition substrate 35 is set below the hollow stirring head 34 to support the deposition layer. The mechanical state control unit 44 is electrically connected to the drive motor 31 and the multi-axis motion mechanism 32. The thermoplastic filament is directly transported to the center through the through-center flow channel inside the hollow stirring head 34. Under the action of the rotation driven by the drive motor 31 and the axial pressure (measured at about 3-4 kN) applied by the multi-axis motion mechanism 32, it is continuously extruded from the bottom of the shoulder 342 and deposited on the deposition substrate 35. Since the material has been pre-softened, the required axial pressure is reduced by more than 40% compared with the traditional process, which significantly reduces tool wear. At the same time, the deposition process force sensor 41 set on the clamping part of the hollow stirring head 34 detects the axial pressure and torque in real time. The mechanical state control unit 44 outputs downward pressure and Z-axis position adjustment commands to the drive motor 31 and the multi-axis motion mechanism 32 according to the deviation between the detected value and the preset threshold. The hollow stirring head 34 is made of high-temperature wear-resistant materials, such as tungsten-based heavy alloys, nickel-based high-temperature alloys, polycrystalline cubic boron nitride composite materials, or tool steel with a wear-resistant coating. The diameter of its bottom shoulder 342 can be selected from 10 mm to 30 mm according to process requirements. The stirring head temperature control unit 33 includes a water-cooling jacket fitted onto the handle of the hollow stirring head 34. A cooling medium (such as water or a special coolant) circulates through the head at a pressure of 0.1-0.5 MPa and a flow rate of 5-20 L / min, which can control the operating temperature of the hollow stirring head 34 below 600°C, significantly extending its service life.

[0026] The monitoring and control module 4 includes a temperature control unit 43, a mechanical state control unit 44, a motion control unit 45, and a data acquisition and processing unit 46; The temperature control unit 43 is connected to the non-contact infrared thermometer 21 and the preheating coil group 22 respectively, and is used to receive the feedback signal of the non-contact infrared thermometer 21 and perform closed-loop control of the heating power of the preheating coil group 22 accordingly. The mechanical state control unit 44 is connected to the deposition process force sensor 41 and is used to perform closed-loop control of the deposition module 3 to output pressure and Z-axis position adjustment commands during the deposition process based on the deviation between the axial pressure and torque feedback signals and the preset threshold. The motion control unit 45 is signal-connected to the feeding module 1 and the deposition module 3, and is used to coordinate the control of the wire feeding speed, the rotation speed of the hollow stirring head 34 and the travel speed. The temperature control unit 43, the mechanical state control unit 44, and the motion control unit 45 form a collaborative closed loop through the data acquisition and processing unit 46, thereby realizing the active collaborative control of heat input and mechanical parameters.

[0027] The data acquisition and processing unit 46 acquires the wire temperature signal from the non-contact infrared thermometer 21, the axial pressure and torque signal from the deposition process force sensor 41, and the wire feeding speed signal from the feeding module 1, and transmits the acquired signals to the temperature control unit 43, the mechanical state control unit 44, and the motion control unit 45, respectively.

[0028] The deposition module 3 also includes a stirring head temperature control unit 33. The stirring head temperature control unit 33 includes a cooling sleeve fitted onto the handle of the hollow stirring head 34. Its cooling medium inlet and outlet are connected to an external cooling system pipeline for cooling the hollow stirring head 34. In this embodiment, a cooling medium (such as water or a special coolant) with a pressure of 0.1-0.5 MPa and a flow rate of 5-20 L / min is introduced into the cooling sleeve through an external cooling system. The circulating cooling medium continuously removes heat from the handle of the hollow stirring head 34, thereby controlling the working temperature of the stirring head below 600°C, effectively preventing tool performance degradation due to overheating. This stirring head temperature control unit 33 and the preheating module 2 form an active heat and cold coordinated management system: the preheating module 2 actively heats the filament from the source to soften it, reducing dependence on frictional heat generation from the stirring head; while the stirring head temperature control unit 33 actively cools the stirring head itself to prevent heat accumulation. With the combined effect of the two, the hollow stirring head 34 can operate stably for a long time under low mechanical load and suitable temperature environment. The actual service life of the tool is 2-3 times longer than that without cooling. At the same time, it avoids the coarsening or oxidation defects of the deposit layer caused by overheating of the stirring head, further improving the reliability and economy of the device of the present invention in large-scale continuous production.

[0029] The hollow stirring head 34 has an upwardly recessed conical or spherical cavity 341 at its bottom. The lower end of the central flow channel opens at the bottom center of the cavity 341. The preheated filament is transported to the center of the cavity 341 through the central flow channel and continuously extruded and directly deposited onto the deposition substrate 35 under the action of rotation and axial pressure. In specific operation, the filament heated to a thermoplastic state (e.g., 0.4-0.9Tm) by the preheating module 2 is directly transported to the bottom center of the cavity through the through central flow channel inside the hollow stirring head 34. With the high-speed rotation of the stirring head (e.g., 800-1000 rpm) and the axial pressure applied by the multi-axis motion mechanism 32, the thermoplastic material is constrained and guided by the conical or spherical cavity 341 and driven by the combined centrifugal force and axial extrusion force. It diffuses evenly outward along the inner wall of the cavity 341 and is continuously extruded downward, finally directly deposited onto the deposition substrate 35 below. The upwardly recessed cavity 341 structure serves as a flow guide, smoothly transitioning the vertically transported thermoplastic material from point to surface, preventing local accumulation or blockage of the material at the center of the bottom of the mixing head; on the other hand, the presence of cavity 341 increases the flow path and volume storage space of the material before deposition, allowing the material to be more fully mixed and compacted during the extrusion process, thereby significantly improving the metallurgical bonding strength and interlayer density between the deposited layer and the substrate.

[0030] The deposition substrate 35 integrates auxiliary heating elements and cooling channels 351, which are connected to an external heating power supply and cooling system piping, respectively. In practice, before deposition begins, the auxiliary heating elements are powered by an external heating power supply to actively preheat the deposition substrate 35 to a set temperature. This significantly reduces the temperature difference between the first layer of deposition material and the substrate, lowering thermal stress and enhancing the spreading ability and metallurgical bonding strength of the plasticizing material, thereby fundamentally preventing cracking or peeling of the first layer. During continuous deposition, the substrate preheating system maintains a constant temperature, ensuring that each deposition layer is stacked in a relatively stable thermal environment, reducing residual stress and deformation caused by interlayer temperature fluctuations. After a single layer deposition is completed or the entire component is manufactured, a cooling medium (such as water or compressed air) is introduced into the substrate through the cooling channels 351 to implement controlled-rate cooling of the component (e.g., 20-50°C / min). This prevents abnormal grain growth due to slow cooling, while also shortening process waiting time and improving production efficiency.

[0031] The monitoring and control module 4 also includes a visual monitoring system 42, which is signal-connected to the data acquisition and processing unit 46 for real-time monitoring of the deposition area morphology. Specifically, the visual monitoring system 42 uses an industrial CCD camera paired with a ring-shaped LED coaxial light source. The camera continuously acquires high-definition images of the deposition area at a frame rate of no less than 30 frames per second. The ring light source provides uniform, shadow-free illumination, ensuring that macroscopic morphological features such as deposition channel edges, surface gloss, flash, pits, and cracks can be clearly distinguished on different metal surfaces (such as aluminum alloys and magnesium alloys). The acquired image data is transmitted to the data acquisition and processing unit 46 in real time. Key features (such as deposition channel width, surface smoothness, and defect area) are extracted using image processing algorithms and compared with preset quality thresholds. When abnormalities such as the deposition channel width exceeding the allowable deviation, continuous pits on the surface, or excessive flash are detected, the data acquisition and processing unit 46 immediately sends an early warning signal to the mechanical state control unit 44 or the motion control unit 45. The latter then dynamically adjusts the downward pressure, travel speed, or Z-axis lifting amount of the hollow stirring head 34 to achieve online adaptive repair based on visual feedback.

[0032] The preheating module 2 also includes a heat insulation cover 23, which wraps around the preheating coil assembly 22 and the heated wire section, and is mechanically fixed to the wire feeding tube 15. In specific implementation, the heat insulation cover 23 is made of high-temperature resistant ceramic fiber felt or aerogel material, with a thermal conductivity not higher than 0.03 W / (m·K), completely wrapping the preheating coil assembly 22 and the heated wire section, and forming a firm mechanical fixing structure with the wire feeding tube 15 by high-temperature resistant tape or metal clamps.

[0033] This invention also provides a method for operating an active thermodynamic co-regulation metal wire solid-state forming device, comprising the following steps: Process preparation and parameter setting are carried out. The filament is installed on the filament reel 11 and passed sequentially through the multi-roller straightening mechanism 12, the filament feeder 14, and the preheating coil group 22 to the deposition zone. Key parameters such as the target preheating temperature, filament feeding speed, hollow stirring head 34 rotation speed, travel speed, and axial pressure threshold are set through the human-machine interface of the monitoring and control module 4.

[0034] The feeding module 1 and the preheating module 2 are started. The temperature control unit 43 drives the preheating coil group 22 to heat the filament. The non-contact infrared thermometer 21 monitors the temperature of the filament in real time and provides feedback, forming a closed-loop control, so that the temperature of the filament can quickly reach and stabilize in the preset thermoplastic temperature range.

[0035] After confirming that the filament preheating temperature has reached the set range, the monitoring and control module 4 issues a command to start the deposition module 3. The filament feeder 14 pushes the preheated filament below the high-speed rotating hollow stirring head 34. Since the yield strength of the thermoplastic material has been significantly reduced, it can undergo plastic rheology and be fully plasticized under a small axial pressure. It is then directly transported through the central flow channel inside the hollow stirring head 34 to the bottom center of the spherical cavity 341. Under the action of rotation and axial pressure, it is continuously extruded from the bottom center and directly deposited on the deposition substrate 35 to form a dense deposition layer.

[0036] During the deposition process, the process monitoring system operates synchronously. The deposition process force sensor 41 monitors axial pressure and torque, the visual monitoring system 42 observes the morphology of the deposition zone, and the data acquisition and processing unit 46 collects these data. Based on the axial pressure or torque signal fed back by the deposition process force sensor 41, it dynamically adjusts the downward pressure, rotation speed, or travel speed of the hollow stirring head 34 to ensure that the mechanical state remains stable within a preset threshold range. At the same time, it fine-tunes the Z-axis position of the multi-axis motion mechanism 32 or fine-tunes the preheating power based on temperature feedback, thereby achieving real-time or offline closed-loop feedback control of the process to maintain process stability and forming quality.

[0037] When the process is completed, the control system stops feeding first in a preset sequence, and then shuts down the preheating system, force feedback control system and cooling components according to the safety strategy.

[0038] The preheating target temperature The setting range is 0.4-0.9. ,in This is the melting point temperature of the material (unit: K). This temperature range can effectively soften the material, improve its plasticity, and prevent premature oxidation or phase transformation.

[0039] The preheating closed-loop control algorithm adopts an incremental PID algorithm, and its control quantity The calculation formula is as follows: = ,in, , , , These are the proportional, integral, and differential coefficients, respectively. This represents the temperature deviation at the previous sampling time. The temperature deviation at the sampling time two weeks prior is adjusted based on the thermal inertia of the preheating system.

[0040] Example 1: This embodiment uses high-strength aluminum alloy as the raw material to demonstrate the effectiveness of the present invention in solving the problem of delayed plasticization and improving the bonding quality of the first layer. The object to be deposited is an aerospace load-bearing support, the substrate is an annealed 2A10 aluminum alloy plate, and the deposition material is 2A10 aluminum alloy wire with a diameter of 2 mm. This material has high strength and poor room temperature plasticity. In traditional friction stir deposition, due to insufficient initial heat input, it is very easy to fail to plasticize instantaneously at the inlet of the stirring zone, resulting in poor bonding of the first layer and incomplete bonding defects within the layer.

[0041] Process preparation and parameter setting. The wire is mounted on the wire spool and sequentially threaded through the multi-roller straightening mechanism, intelligent feedback guide roller, and preheating coil assembly to the wire feeder. Key process parameters are set via the human-machine interface: target preheating temperature. The temperature was 420°C (approximately 0.71 times the absolute melting point of 2A10 aluminum alloy), the wire feeding speed was 150 mm / min, the hollow stirring head speed was 800 rpm, the deposition travel speed was 150 mm / min, the Z-axis layer pressure was 1.0 mm, and the upper limit of the axial pressure threshold was set to 8 kN as a reference for force closed-loop control.

[0042] Active preheating and closed-loop temperature control. The wire feeder and argon gas protection system are activated. The temperature control unit drives the preheating coil assembly to heat the wire. A non-contact infrared thermometer monitors the wire outlet temperature in real time. And feedback. The temperature control unit's built-in PID controller adjusts the response based on the deviation. The heating power is dynamically adjusted to raise the temperature of the filament to 420°C within 30 seconds and stabilize it within ±5°C, ensuring that it enters the deposition zone in a thermoplastic state.

[0043] Thermo-Mechanical Co-deposition and Process Monitoring. After preheating, the hollow stirring head is started to rotate and press down. The preheated and softened filament eliminates the plasticization delay caused by the low initial material temperature, and is continuously extruded from the bottom center of the hollow die core through the central flow channel and directly deposited. During the deposition process, force sensors monitor axial pressure and torque in real time. When the monitored values ​​approach the preset threshold, the control system dynamically adjusts the downward pressure or travel speed of the hollow stirring head to maintain a stable mechanical state. The entire process is smooth, with no signs of material blockage. Monitoring data shows that the spindle torque fluctuation is reduced compared to traditional processes without preheating.

[0044] Multi-parameter monitoring and closed-loop feedback control. A laser displacement sensor monitors layer height in real time, while a force sensor monitors axial pressure and torque during the deposition process. A visual monitoring system displays a smooth and uniform deposition channel surface. The mechanical state control unit and motion control unit fine-tune the multi-axis motion mechanism in real time based on layer height feedback, controlling single-layer height fluctuations within ±0.1 mm. Simultaneously, the force feedback signal participates in the dynamic optimization of process parameters, achieving coordinated control of the thermo-mechanical state.

[0045] Traditional preheating-free processes often require extremely high rotational speeds (>1200 rpm) and pressures to plasticize the material, yet still struggle to guarantee the quality of the first-layer bonding. With this invention, because the material is in a plastic state upon entry, plasticization delay is completely eliminated, achieving excellent forming quality at only 800 rpm and a stable axial pressure of 5-6 kN. Simultaneously, the stable preheating heat source ensures excellent consistency in process heat input, reducing spindle torque fluctuation by approximately 35%-45%, increasing the first-layer bonding strength by 20%-30%, significantly reducing tool wear, and extending the expected service life by 2-3 times. Metallographic analysis shows that the deposited layer is a uniform and fine equiaxed recrystallized structure with an average grain size of 3-4 μm, and no incomplete bonding defects.

[0046] Example 2: This embodiment uses AZ31 magnesium alloy, which has high activity and poor plasticity, as raw material to demonstrate the advantages of this invention in preventing oxidation, avoiding material blockage, and widening the process window. The component to be manufactured is a lightweight, thin-walled structure. The substrate is an AZ31 magnesium alloy rolled plate, and the deposition material is AZ31 magnesium alloy wire with a diameter of 2.5 mm. Traditional deposition of magnesium alloys faces two dilemmas: increasing the rotation speed can easily lead to overheating, oxidation, or even combustion; reducing the heat input results in insufficient plasticization, easy material blockage, and poor forming quality.

[0047] Process preparation and parameter setting. Wire clamping and path are the same as in Example 1. Preheating target temperature is set via the human-machine interface. The temperature was set at 340℃ (approximately 0.67 times the absolute melting point of AZ31 magnesium alloy), the wire feed speed was 100 mm / min, the hollow stirring head rotation speed was 1000 rpm, the deposition travel speed was 150 mm / min, and the upper limit of the axial pressure threshold was set to 4 KN. High-purity argon gas was used for protection, and the flow rate was increased to 15 L / min.

[0048] Precise preheating and temperature safety control. Start the medium-frequency induction preheating system and insulation cover. The temperature control unit uses a PID algorithm (parameters...) , , =0.5) Dynamically adjust the power to precisely stabilize the wire outlet temperature at (340±5)℃. This temperature ensures that the material is fully...

[0049] Plasticized and with a temperature far below its ignition point, it eliminates the risk of overheating and oxidation at the source.

[0050] Thermo-mechanical co-deposition and process monitoring. Deposition begins after preheating. The yield strength of the material is significantly reduced in the thermoplastic state, requiring only a small axial pressure (approximately 3-4 kN in practice) to achieve full plasticization. The peak temperature in the deposition zone is effectively controlled within a safe range below 380℃. Guided by a dedicated hollow stirring head, the plasticized material is continuously extruded from the bottom center through the central channel, resulting in a bright metallic luster on the formed surface, free of sparks or oxidation blackening. Force sensors monitor the deposition process in real time. When abnormal fluctuations occur in torque or axial pressure, the control system dynamically adjusts the travel speed or downward pressure to ensure process stability.

[0051] Real-time monitoring and adaptive control. Laser displacement sensors and a vision system monitor the entire process, while the motion controller enables adaptive Z-axis lifting to ensure dimensional accuracy. Stable vibration sensor signals confirm the absence of abnormal disturbances in the process. Force feedback data is synchronously used for real-time optimization of process parameters, forming a complete closed loop of thermo-mechanical synergy.

[0052] Traditional preheating processes often require rotational speeds exceeding 1800 rpm to achieve sufficient plasticity, yet still face issues of oxidation and inconsistent forming quality. This invention, however, achieves material pre-softening through precise thermal plasticization, realizing excellent plasticity and flowability at only 1000 rpm, reducing axial load by approximately 40%-50%, and eliminating any oxidation or combustion throughout the process. Preheating significantly improves material flowability, and combined with an anti-clogging material flow channel design, deposition rates can be increased by approximately 50% without clogging, significantly reducing tool wear. In summary, this invention expands the stable machinable process parameter range of AZ31 magnesium alloy by approximately two times, significantly improving process repeatability and manufacturing efficiency.

[0053] In summary, this invention integrates a preheating module into the material feeding path, forming a closed-loop temperature control system with a preheating coil assembly and a non-contact infrared thermometer. This system precisely heats the filament to a thermoplastic state before it enters the deposition zone, eliminating plasticization delay at the source. Simultaneously, a hollow stirring head with an internally connected central flow channel guides the preheated and softened material through orderly extrusion and deposition, completely eliminating the risk of material blockage. The monitoring and control module integrates a temperature control unit, a mechanical state control unit, and a motion control unit. Through a data acquisition and processing unit, these three units interact and coordinate, forming a collaborative closed-loop architecture of sensing, control, and execution. This achieves active decoupling and collaborative regulation of heat input and mechanical parameters. On the one hand, preheating softens the material, significantly reducing dependence on spindle speed and axial pressure. On the other hand, the thermo-mechanical collaborative closed-loop control greatly improves process stability and fundamentally eliminates the risk of material blockage, providing an efficient, stable, and reliable solution for solid-state additive manufacturing of high-performance metal components.

[0054] The present invention has been described above by way of example with reference to the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvements made using the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, are all within the protection scope of the present invention.

Claims

1. An active thermodynamic synergistically regulated wire forming apparatus, characterized in that, include: The feeding module forms a continuous wire conveying path inside; The preheating module receives the filament fed by the feeding module through the filament feeding tube, and includes a preheating coil group and a non-contact infrared thermometer. The preheating coil group is arranged around the outside of the filament feeding tube. The probe of the non-contact infrared thermometer is aimed at the surface of the filament at the outlet of the preheating coil group to heat the filament being fed and to detect the temperature of the filament in real time. The deposition module includes a hollow stirring head and a deposition process force sensor. The hollow stirring head has a through central channel inside, and the upper end of the central channel is connected to the wire feeding tube to guide the filament heated by the preheating module to be extruded and deposited. The deposition process force sensor is set on the clamping part of the hollow stirring head to detect the axial pressure and torque in real time during the deposition process. The monitoring and control module includes a temperature control unit, a mechanical state control unit, a motion control unit, and a data acquisition and processing unit; The temperature control unit is connected to the non-contact infrared thermometer and the preheating coil group respectively, and is used to receive the feedback signal from the non-contact infrared thermometer and perform closed-loop control of the heating power of the preheating coil group accordingly. The mechanical state control unit is connected to the force sensor signal of the deposition process and is used to perform closed-loop control of the deposition module's output pressure and Z-axis position adjustment commands during the deposition process based on the deviation between the axial pressure and torque feedback signals and the preset threshold. The motion control unit is signal-connected to the feeding module and the deposition module, and is used to coordinate the control of the wire feeding speed, the rotation speed of the hollow stirring head and the travel speed. The data acquisition and processing unit is connected to the signals of the non-contact infrared thermometer, the deposition process force sensor and the feeding module, respectively, and is used to collect wire temperature, axial pressure, torque and wire feeding speed signals in parallel for process monitoring and data recording. The temperature control unit, mechanical state control unit, and motion control unit are also connected to the data acquisition and processing unit for uploading their respective control state information to the data acquisition and processing unit and receiving the coordinated control instructions generated by the unit based on global information.

2. The wire forming apparatus according to claim 1, wherein The deposition module further includes a drive motor, a multi-axis motion mechanism, and a deposition substrate. The output shaft of the drive motor is mechanically connected to the clamping part of the hollow stirring head to drive the hollow stirring head to rotate. The multi-axis motion mechanism is fixedly connected to the mounting base of the hollow stirring head to drive the hollow stirring head to move in three-dimensional space. The deposition substrate is disposed below the hollow stirring head to support the deposition layer. The mechanical state control unit is electrically connected to the drive motor and the multi-axis motion mechanism.

3. The wire forming apparatus of claim 1, wherein the wire forming apparatus is a wire forming apparatus for active thermodynamic synergistic control. The deposition module also includes a stirring head temperature control unit, which includes a cooling sleeve fitted onto the handle of the hollow stirring head. The inlet and outlet of the cooling medium are respectively connected to the external cooling system pipeline for cooling the hollow stirring head.

4. The active thermodynamic synergistically controlled wire forming apparatus of claim 2, wherein The hollow stirring head has an upwardly recessed conical or spherical cavity at its bottom. The lower end of the central flow channel opens at the bottom center of the cavity. The preheated filament is transported to the center of the cavity through the central flow channel and continuously extruded and directly deposited onto the deposition substrate under the action of rotation and axial pressure.

5. The device for active thermodynamic co-regulation of solid-state forming of metal wire according to claim 2, characterized in that, The deposition substrate integrates auxiliary heating elements and cooling channels, which are connected to an external heating power supply and cooling system piping, respectively.

6. The device for active thermodynamic co-regulation of solid-state forming of metal wire according to claim 1, characterized in that, The monitoring and control module also includes a visual monitoring system, which is connected to the data acquisition and processing unit for real-time monitoring of the morphology of the sedimentation area.

7. The device for active thermodynamic co-regulation of solid-state forming of metal wire according to claim 1, characterized in that, The preheating module also includes a heat insulation cover, which is wrapped around the preheating coil group and the heated wire section and mechanically fixed to the wire feeding tube.

8. A method for operating an active thermodynamically regulated solid-state forming device for metal wires, applied to the active thermodynamically regulated solid-state forming device for metal wires as described in any one of claims 1-7, characterized in that, Includes the following steps: The preheating module and the feeding module are started. The continuously conveyed filament is heated and stabilized at the preset target preheating temperature through the closed-loop control of the temperature control unit. After the filament reaches the target preheating temperature, the deposition module is started, and the preheated filament is sent into the rotating hollow stirring head. The preheated and plasticized material is directly transported to the bottom through the central flow channel inside the hollow stirring head. Under the action of rotation and axial pressure, it is continuously extruded from the bottom center and directly deposited on the deposition substrate to form a dense deposition layer. During the deposition process, axial pressure and torque are monitored in real time using a deposition process force sensor; The monitoring and control module dynamically adjusts at least one parameter among the following: heating power of the preheating coil group, wire feeding speed, rotation speed of the hollow stirring head, downward pressure, or traveling speed, based on the acquired axial pressure and torque, thereby achieving proactive and coordinated control of the thermal state of the deposition process.

9. The working method of the active thermodynamic synergistic control device for solid-state forming of metal wire according to claim 8, characterized in that, The temperature control unit is used to receive the preset target preheating temperature and the real-time temperature fed back by the non-contact infrared thermometer, calculate the temperature deviation, and output a control signal through a PID control algorithm to dynamically adjust the heating power of the preheating coil group, thereby adjusting the temperature.

10. The working method of the active thermodynamic synergistic control metal wire solid-state forming device according to claim 8, characterized in that, The target preheating temperature is 0.4-0.9Tm, where Tm is the melting point temperature of the wire material.

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