Aluminum profile high-speed extrusion forming process based on dynamic temperature control

Abstract

The invention discloses an aluminum profile high-speed extrusion forming process based on dynamic temperature control, and relates to the technical field of aluminum profile machining, the extrusion forming process comprises the following steps: dividing a to-be-extruded aluminum alloy blank into at least three axial continuous temperature control sections along the extrusion direction; independent and adjustable heating or cooling effects are applied to the three axially continuous temperature control sections; and in the extrusion process, the axial temperature distribution is maintained to synchronously move forwards along with the extrusion process, so that the material blank entering the pressurizing die hole is always in a preset temperature interval in different extrusion stages. According to the method, through axial segmentation dynamic thermal field construction and forward movement scheduling, it is guaranteed that different axial positions of a material blank are located in a preset temperature window when the material blank enters a die hole, the defects of inlet temperature sudden change caused by overall constant temperature, insufficient inlet plasticity or thrust fluctuation, surface cracks and the like caused by tail end shock cooling are overcome, axial stress-strain distribution is balanced, and the stability of the material blank is improved. And meanwhile, the section size stability is improved.

Description

Technical Field

[0001] This invention relates to the field of aluminum profile processing technology, specifically to a high-speed extrusion molding process for aluminum profiles based on dynamic temperature control. Background Technology

[0002] Traditional aluminum profile extrusion typically employs overall constant-temperature preheating of the billet and static die temperature control, suitable for low-to-medium speed or conventional extrusion conditions. However, when increasing extrusion speed or processing high-strength / complex cross-section alloys, common problems include: surface cracks caused by a surge in shear and friction at the die entrance; uneven wall thickness or delamination due to inconsistent metal flow inside and outside the cross-section; thermal fatigue caused by localized die overheating; and residual stress and warping due to improper cooling. Traditional single constant-temperature strategies lack precise control over the axial and radial temperature fields and rapid response to transient conditions, making it difficult to significantly increase production capacity or process complex cross-section materials while ensuring quality. Therefore, a high-speed extrusion process is needed that can dynamically construct the thermal field, coordinate die and billet processes, and possess real-time closed-loop scheduling.

[0003] Patent CN113020682B discloses an aluminum profile extrusion molding process, which enables automatic cleaning of the cutting blade.

[0004] The aforementioned patent removes residual material from the extrusion device; this aluminum profile extrusion molding process is not only simple to operate, but also enables automatic cleaning of the cutter. However, it lacks precise control over the axial and radial temperature fields and rapid response to transient conditions, making it difficult to significantly increase production capacity or process complex cross-section materials while ensuring quality.

[0005] Therefore, this application proposes a high-speed extrusion forming process for aluminum profiles based on dynamic temperature control, which can ensure that the blank is at different axial positions within a preset temperature window when entering the die orifice. Summary of the Invention

[0006] The purpose of this invention is to provide a high-speed extrusion molding process for aluminum profiles based on dynamic temperature control, so as to solve the problems of traditional single isothermal strategies in the background art lacking fine control of axial and radial temperature fields and rapid response to transient conditions.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a high-speed extrusion molding process for aluminum profiles based on dynamic temperature control, wherein the extrusion molding process includes the following steps:

[0008] The aluminum alloy billet to be extruded is divided into at least three axially continuous temperature control sections along the extrusion direction, namely the front preheating zone, the middle stabilization zone, and the rear buffer zone.

[0009] The preheating zone, stabilization zone and buffer zone are each subjected to independent and adjustable heating or cooling, so that each segment forms an axial temperature distribution that varies in a stepped or gradient manner along the extrusion direction before entering the extrusion die.

[0010] During the extrusion process, the axial temperature distribution is maintained to move forward synchronously with the extrusion process, so that the billet entering the pressure die hole is always in the preset temperature range at different extrusion stages. Thus, by dynamically constructing and scheduling the axial temperature field of the billet, the flow stress distribution of the billet during the extrusion molding process is controlled.

[0011] Preferably, in the axially continuous temperature control segmentation, the front preheating zone corresponds to the end of the billet that first enters the extrusion die, the middle stabilization zone corresponds to the main body of the billet that mainly bears plastic deformation during the extrusion process, and the rear buffer zone corresponds to the tail of the billet near the extrusion rod, so as to reduce the temperature change when the tail section of the billet enters the die.

[0012] Preferably, the target temperature of the front preheating zone is higher than the target temperature of the middle stabilization zone, and the target temperature of the middle stabilization zone is higher than the target temperature of the rear buffer zone, so as to form a cooling axial temperature gradient from front to back when the billet enters the extrusion die, thereby reducing the risk of surface cracking of the billet under high-speed extrusion conditions.

[0013] Preferably, before the billet enters the extrusion die, the radial temperature distribution of the billet is further controlled to form a preset radial temperature difference between the surface temperature and the core temperature of the billet, thereby making the radial flow rate of the billet in the die hole more uniform and reducing uneven cross-sectional deformation.

[0014] Preferably, the radial temperature difference is formed by locally cooling the outer surface of the billet or by strengthening the heating of the billet core, so that the billet forms a differential thermal state between the surface and the core before entering the extrusion die, thereby suppressing the surface overflow and core retention phenomenon under high-speed extrusion.

[0015] Preferably, during the extrusion molding process, at least one mold temperature control zone is provided for the extrusion mold, and heating or cooling is applied to the extrusion mold temperature control zone to match the mold temperature distribution in the circumferential and axial directions of the mold hole with the axial temperature distribution of the blank, so as to reduce the transient temperature difference between the blank and the mold hole.

[0016] Preferably, the mold temperature control zone includes a first mold temperature control zone located in the mold hole inlet area and a second mold temperature control zone located in the mold hole outlet area, wherein the temperature of the first mold temperature control zone is higher than the temperature of the second mold temperature control zone, so as to form a controlled thermo-mechanical coupling deformation environment when the blank passes through the mold hole.

[0017] Preferably, during the extrusion process, the temperature settings of the preheating zone, the stabilization zone, and the buffer zone are adjusted synchronously according to the changes in the extrusion speed, so that the billet remains within the preset forming temperature window when it enters the die at different extrusion speeds.

[0018] Preferably, during the extrusion process:

[0019] When the extrusion speed is increased, the temperature setpoints of the preheating zone and the stabilization zone in the middle section are increased, and the length of the temperature transition zone between each temperature control section is shortened.

[0020] When the extrusion speed is reduced, the temperature settings of the preheating zone and the stabilization zone in the middle section are reduced, and the length of the temperature transition zone is extended.

[0021] Preferably, after the aluminum profile is demolded, the extruded profile is subjected to segmented cooling treatment that matches the axial temperature distribution, so that the extruded profile forms a controlled cooling rate distribution along the extrusion direction, thereby reducing residual stress and stabilizing the final cross-sectional dimensions and mechanical properties.

[0022] Compared with the prior art, the beneficial effects of the present invention are:

[0023] 1. This invention constructs and advances a segmented dynamic thermal field in the axial direction to ensure that the billet is in a preset temperature window at different axial positions when entering the die hole. This overcomes defects such as sudden temperature changes at the inlet caused by overall constant temperature, insufficient plasticity at the inlet, or thrust fluctuations and surface cracks caused by sudden cooling at the tail end. It balances the axial stress-strain distribution, reduces the risk of inlet shear cracking, allows for stable forming at higher linear speeds and increases production capacity, while also improving the stability of cross-sectional dimensions.

[0024] 2. This invention uses radial temperature difference control to adjust the flow matching between the surface and the core, so that the surface and the core exhibit the desired viscoplasticity difference when entering the die cavity. This solves the problems of excessive surface flow, wall thickness reduction, or uneven local deformation of thin-walled or hollow sections during high-speed extrusion, improves wall thickness consistency and cross-sectional geometric accuracy, reduces subsequent processing or rework rate, and can significantly improve the finished product qualification rate for complex cross-sections.

[0025] 3. This invention enables the mold temperature field to be independently adjusted and responded to quickly in both axial and circumferential directions through active thermal management of the mold zone. This reduces the transient temperature difference between the mold hole and the blank, alleviates the high shear and friction concentration at the mold hole inlet, reduces thermal fatigue caused by mold thermal cycling, improves the deformation conditions and metal shaping process in the mold hole, improves the surface quality and microstructure uniformity of the output material, and extends the service life of the mold and reduces maintenance costs.

[0026] 4. This invention uses multi-sensor fusion, thermo-mechanical coupling prediction, and online model predictive control to adjust control parameters such as heating power, cooling flow rate, lubrication, and extrusion speed in real time. This solves the problems of blind spots and slow manual response under transient conditions, thereby avoiding defect amplification or mold damage caused by delayed adjustment, realizing automatic process self-adaptation, and ensuring batch-to-batch consistency and long-term stable operation. Detailed Implementation

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the 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.

[0028] Example 1

[0029] One embodiment of the present invention provides: a high-speed extrusion forming process for aluminum profiles based on dynamic temperature control, implemented using conventional high-speed extrusion of aluminum alloys based on axial three-segment dynamic temperature control.

[0030] This embodiment is applicable to high-speed extrusion molding of 6xxx series aluminum alloys with medium complex cross sections;

[0031] During the implementation process, the cylindrical aluminum alloy billet is first divided into three continuous axial temperature control sections along the extrusion direction, namely the front preheating zone, the middle stabilization zone, and the rear buffer zone, with the length ratio of the three sections being approximately 3:4:3.

[0032] Before extrusion begins, each segment is temperature-controlled using a zoned induction heating device:

[0033] The preheating zone is heated to 460-480℃; the stabilization zone is heated to 440-460℃; and the buffer zone is heated to 410-430℃.

[0034] The above temperature setting creates a stepped temperature distribution in the axial direction of the billet, which gradually decreases from front to back. During the extrusion process, as the billet moves towards the die, the temperature control zones of each segment move forward synchronously, so that the front end of the billet entering the die hole always maintains a high plasticity, while the temperature of the billet at the tail end changes slowly, thereby effectively reducing the fluctuation of inlet flow resistance under high-speed extrusion conditions.

[0035] With this axial dynamic temperature control method, the flow stress distribution of the billet in the die hole is more uniform, avoiding the surface cracking and sudden increase in extrusion thrust problems that are prone to occur in traditional integral constant temperature billets during high-speed extrusion.

[0036] Equipment and parameters:

[0037] The billet diameter is 150mm; axial segmentation: front section length 300mm, middle section length 400mm, rear section length 300mm; preheating method: segmented control of induction heaters; heating power can be independently adjusted; target temperature: front section 460-480℃, middle section 440-460℃, rear section 410-430℃, temperature tolerance ±10℃; target initial linear speed of extrusion 60m / min; sensors: at least one thermocouple is set in each segment for closed-loop temperature calibration; infrared temperature measuring points are arranged at the die opening to monitor the temperature entering the die.

[0038] Process steps:

[0039] The billet is heated to the target temperature in three axial sections in the preheating furnace, so that the billet forms a stepped temperature field along the axial direction.

[0040] The billet is fed into the receiving cylinder by the feeding mechanism and begins to advance, and the extruder extrudes it at a predetermined speed;

[0041] As the billet is advanced, the temperature control position of the preheating zone moves forward synchronously with the heating output (that is, the segmented heating die holes keep the thermal field in a relative position according to the movement of the billet), ensuring that the material end entering the die hole is always in the preset high temperature range.

[0042] The actual temperature of the material entering the mold hole is monitored by infrared temperature measurement and thermocouple, and the segmented heating power is adjusted manually or automatically to maintain the target temperature zone.

[0043] After the billet is produced, the profile is subjected to conventional cooling and downstream processing.

[0044] By employing an axial segmented high-temperature forward-moving strategy, the material entering the die hole is ensured to have higher plasticity and more stable flow stress, significantly reducing surface tearing and thrust fluctuations.

[0045] Example 2

[0046] One embodiment of the present invention: a high-speed extrusion forming process for aluminum profiles based on dynamic temperature control, implementing high-speed extrusion with coordinated control of axial segmentation and radial temperature difference:

[0047] Based on Example 1, this example further introduces radial temperature difference control, which is applicable to thin-walled or hollow profiles.

[0048] After the axial three-segment temperature control of the billet is completed, the radial temperature field of the billet is adjusted:

[0049] By setting an annular cooling air duct around the outer periphery of the billet, the surface of the billet is lightly cooled; at the same time, the original heating power is maintained in the core of the billet.

[0050] This creates a radial temperature difference structure where the surface temperature is 10-25°C lower than the core temperature before the billet enters the die hole. This radial temperature difference causes the flow rate of the billet surface layer in the die hole to be slightly lower than the flow rate of the core layer, thereby suppressing excessive flow of surface metal.

[0051] Under high-speed extrusion conditions, this radial-axial synergistic temperature control method significantly improves the consistency of cross-sectional metal flow and effectively reduces local thinning, warping, and dimensional deviations in thin-walled areas.

[0052] Equipment and parameters:

[0053] The billet diameter is 120-180mm; the axial segmentation is the same as in Example 1; the radial temperature difference target is that the surface temperature of the billet is 10-25℃ lower than the core temperature; the surface cooling method is: outer ring air cooling (annular air duct), with an adjustable air speed of 2-8m / s; or annular spray is used to achieve stronger cooling; the core heating is: maintaining the induction heating power to ensure that the core maintains the target temperature of the middle section;

[0054] Process steps:

[0055] According to the embodiment, a pair of axial three-section heating;

[0056] An annular cooling device is arranged at the end of the billet entering the receiving cylinder or inside the receiving cylinder, and a quantitative cooling is applied to the outer peripheral surface to establish a radial temperature difference.

[0057] The surface temperature and core temperature are calibrated by thermocouple arrays or surface infrared point measurement to ensure that the radial temperature difference is within the set range.

[0058] After entering the die cavity, the radial temperature difference guides the flow velocity of the surface layer and the core within the die cavity to match, thereby controlling the wall thickness distribution;

[0059] After billet is removed, it is further processed according to the segmented cooling strategy in Example 5 to stabilize the cross-section.

[0060] The radial-axial linkage thermal field significantly suppresses excessive flow on the surface of thin-walled / hollow sections, improves wall thickness consistency and surface quality, and reduces the scrap rate in subsequent processing.

[0061] Example 3

[0062] One embodiment of the present invention provides a high-speed extrusion molding process for aluminum profiles based on dynamic temperature control, wherein dynamic hot field extrusion is implemented with coordinated temperature control of the die zones:

[0063] This embodiment is designed for high-strength aluminum alloys or complex irregular cross-sections, and further extends dynamic temperature control from the billet side to the mold side.

[0064] Two temperature control zones are set on the extrusion die along the axial direction of the die hole:

[0065] The first mold temperature control zone is located at the mold hole inlet; the second mold temperature control zone is located at the mold hole outlet.

[0066] By embedding heating rods and cooling channels within the mold, the temperature of the first mold temperature control zone is maintained at 320-350℃, and the temperature of the second mold temperature control zone is maintained at 280-300℃.

[0067] During extrusion, the axial temperature gradient of the billet aligns with the axial temperature gradient of the die, placing the metal in a high-plasticity, low-friction state upon entering the die orifice, while gradually cooling and solidifying in the exit region. This die-billet synergistic thermal field structure effectively reduces shear stress concentration at the die orifice inlet and improves microstructural stability at the exit.

[0068] Equipment and parameters:

[0069] Mold axial partitioning: First mold temperature control zone (mold hole inlet, length 20-50mm), second mold temperature control zone (mold hole outlet, length 20-50mm); target temperature of the first mold temperature control zone: 320-350℃; target temperature of the second mold temperature control zone: 280-300℃; mold temperature control methods: induction heating coil embedded in the mold core and thin-walled cooling channel in the mold sleeve; the mold temperature control unit has the ability to quickly adjust power and pulse cooling; sensors: thermocouples are arranged at the mold core and infrared measuring points are arranged on the mold surface; real-time monitoring of mold circulating cooling water flow rate and inlet temperature.

[0070] Process steps:

[0071] The billet is preheated axially and radially according to Example 1 or 2;

[0072] Before startup, the temperature control zones of the first and second molds are adjusted to the target temperature and enter a steady state.

[0073] During extrusion, the first zone of the die core is kept at a high temperature to reduce friction and inlet shear, while the outlet zone is moderately cooled to help the metal take shape and control grain evolution.

[0074] During the extrusion process, the temperature-controlled die orifice can be rapidly pulsed heated or pulsed cooled to cope with local transient temperature fluctuations;

[0075] Die temperature, thrust, and billet temperature are monitored and recorded in real time, and die temperature control or extrusion speed is adjusted when necessary.

[0076] The mold and blank work together to create an axial thermal gradient, which effectively reduces the strong shear and friction at the mold inlet, improves the microstructure and dimensional stability at the outlet, and reduces thermal fatigue damage by limiting the temperature difference during mold cycles, thereby extending the mold life.

[0077] Example 4

[0078] One embodiment of the present invention provides a high-speed extrusion forming process for aluminum profiles based on dynamic temperature control, with adaptive dynamic temperature control for changes in high-speed extrusion speed.

[0079] This embodiment is applicable to production line conditions where the extrusion speed changes frequently;

[0080] During the extrusion process, as the extrusion speed gradually increases from a low speed stage (e.g., 30 m / min) to a high speed stage (e.g., 60-70 m / min), the following temperature control adjustment strategy is executed simultaneously;

[0081] Increase the temperature of the preheating zone by 10-20℃; increase the temperature of the stabilization zone by 5-15℃; and shorten the length of the temperature transition zone between each section.

[0082] When the extrusion speed decreases or approaches the shutdown state, the above parameters are adjusted in reverse to gradually reduce the temperature of the billet and avoid overheating of the mold due to inertial heat accumulation.

[0083] This implementation method ensures that the billet always enters the effective forming temperature window of the die cavity under different speed conditions, thus guaranteeing the stability and continuity of the high-speed extrusion process.

[0084] Equipment and parameters:

[0085] The extrusion speed range is 30-70 m / min; the speed change trigger logic is: when the speed increases or decreases by ≥10%, the temperature control is adaptively triggered; the adaptive adjustment strategy is: when the speed increases, the front temperature increases by 10-20℃; the middle temperature increases by 5-15℃; the length of the temperature transition zone is shortened by 10-30%; the opposite adjustment is made when the speed decreases.

[0086] Process steps:

[0087] The controller monitors the extrusion speed and compares it with a preset speed curve;

[0088] When a speed change is detected, the controller automatically calculates and issues new segmented temperature setpoints and heating power according to the mapping table or online model;

[0089] The heating and cooling units adjust their output within the allowed response time to achieve a new thermal field;

[0090] During the adjustment process, the temperature at the mold inlet and the change in thrust are monitored. If any abnormality occurs (sudden increase in thrust, surface temperature exceeding the upper or lower limit), the controller will trigger speed limiting or short-term deceleration protection.

[0091] Once the speed returns to a steady state, the controller enters steady-state tracking mode and records parameters for subsequent optimization.

[0092] Real-time speed-temperature linkage significantly increases process robustness, ensuring consistency of finished products when production cycle changes or when switching between different material batches.

[0093] Example 5

[0094] One embodiment of the present invention provides a high-speed extrusion molding process for aluminum profiles based on dynamic temperature control, and a complete process implementation involving segmented demolding and coordinated cooling during high-speed extrusion:

[0095] Based on Example 3 or 4, this example further implements segmented cooling control on the profile after demolding.

[0096] After the profile is demolded, it passes through the following parts in the extrusion direction:

[0097] First slow cooling zone: Low air volume air cooling is used, with the cooling rate controlled at 5-10℃ / s;

[0098] Second enhanced cooling zone: Adjustable spray or forced air cooling is used, with the cooling rate controlled at 20-40℃ / s;

[0099] Third stable zone: naturally cooled to ambient temperature.

[0100] The above-mentioned segmented cooling method matches the axial temperature distribution of the billet, so that the residual stress inside the profile is released step by step, avoiding warping or microcracks in the cross section caused by sudden cooling.

[0101] Equipment and parameters:

[0102] Demolding sections: First slow cooling zone (length 1-3m), second enhanced cooling zone (length 1-3m), third stabilizing zone (length depends on production line layout);

[0103] The first slow cooling zone uses low-volume air cooling or natural cooling, with a cooling rate of 5-10℃ / s.

[0104] The second enhanced cooling zone uses adjustable spray or forced air cooling, with a cooling rate of 20-40℃ / s.

[0105] Third stable zone: belt traction and natural cooling to ambient temperature;

[0106] Cooling control: Based on the temperature distribution along the axial direction during demolding, dynamically adjust the cooling intensity and belt speed of each zone.

[0107] Process steps:

[0108] After the profile is demolded, it first enters the first slow cooling zone to gradually reduce the temperature difference between the surface and the core to avoid thermal stress concentration.

[0109] Subsequently, it enters the second enhanced cooling zone for rapid cooling to fix the cross-sectional dimensions and promote the formation of the desired tissue.

[0110] Finally, the process of returning to the environment is completed at a constant band speed in the third stable region;

[0111] The entire demolding cooling curve is matched with the axial temperature control setting of the extrusion section (i.e., the demolding cooling strategy is designed based on the axial temperature field of the extrusion section), and is controlled by the PLC controller.

[0112] The segmented cooling and axial temperature control of the extrusion section form a closed-loop process chain, which effectively reduces residual stress, improves straightness and dimensional stability, and is conducive to the consistency of mechanical properties.

[0113] Example 6

[0114] One embodiment of this invention: a high-speed extrusion forming process for aluminum profiles based on dynamic temperature control, providing a comprehensive approach for high-consistency quality control of complex cross-sections.

[0115] This embodiment is applicable to aluminum profiles with multi-cavity hollow structures, variable wall thickness, or high dimensional accuracy requirements.

[0116] In actual production, the following comprehensive measures are adopted: axial three-segment dynamic temperature control; radial temperature difference regulation; mold inlet and outlet zone temperature control; extrusion speed-temperature linkage adjustment; and demolding segmented cooling.

[0117] By jointly setting the above process parameters, the metal is kept in a controlled thermo-mechanical state throughout the entire extrusion-forming-cooling process. The resulting profiles are significantly superior to those obtained through traditional isothermal extrusion processes in terms of cross-sectional dimensional consistency, surface quality, and microstructure uniformity, making them particularly suitable for the mass production of high-end structural components or precision industrial profiles.

[0118] Main strategies:

[0119] Axial three-section preheating is adopted;

[0120] Radial temperature difference control is implemented based on this.

[0121] The mold adopts inlet and outlet zoned temperature control and has rapid pulse heating and cooling capabilities;

[0122] The controller implements adaptive temperature linkage based on the extrusion speed and online detection results;

[0123] A segmented cooling strategy is adopted after demolding;

[0124] The entire process utilizes multiple sensors for online detection (surface infrared thermal imaging, thermocouple array, online ultrasonic / acoustic emission, thrust / torque sensing) and performs real-time recording and process backtracking.

[0125] Key parameters:

[0126] Extrusion speed: 40-65 m / min; Target radial temperature difference between surface and core: 8-20℃ lower for surface; Target temperature of mold inlet / outlet zone: 330-350℃ for inlet and 280-300℃ for outlet; Segmented cooling rate after demolding: 5-10℃ / s for the first segment and 25-35℃ / s for the second segment.

[0127] Implementation steps:

[0128] Initial axial / radial temperature and velocity profiles are generated based on specific profiles and materials, and with reference to the process database.

[0129] The billet is heated in sections according to the generation curve and radial cooling is applied to form a surface-core temperature difference;

[0130] The mold is preheated to the target zone and enters a steady state;

[0131] Initiate extrusion and execute speed-temperature linkage under the controller, collect data in real time, and fine-tune based on rules or models;

[0132] After demolding, the material is processed according to the segmented cooling curve and subjected to online and offline quality inspections (sampling inspection of dimensions, hardness, and microstructure).

[0133] The test results are used as process feedback for periodic or online updates to the process database and controller parameters.

[0134] The comprehensive strategy can significantly improve cross-sectional consistency and surface quality, reduce defect rate and ensure batch consistency in high-difficulty profile forming, making it suitable for high-end applications and mass industrial production.

[0135] Test results

[0136] Working principle:

[0137] Before extrusion, the billet is preheated in sections: the billet is divided into front, middle, and rear sections along the extrusion direction, and a stepped or continuous gradient temperature distribution is formed in the axial direction; at the same time, a surface-to-core temperature difference is formed in the radial direction according to the profile cross-section requirements. This step is achieved through independently controllable induction heating, resistance heating, and outer ring air cooling and spray cooling. The purpose is to pre-distribute the plasticity and flow resistance of the material in the axial and radial directions before the billet enters the die cavity, creating a favorable thermo-mechanical initial field for subsequent high-speed forming.

[0138] After the billet enters the die cavity, the local forming behavior is jointly determined by the billet's thermal field and the die's temperature field. The die body is temperature-controlled in axial and circumferential zones to form a die cavity temperature field that matches the axial gradient of the billet. Online sensors collect data in real time on the entry temperature, thrust fluctuations, and signs of internal defects. The controller, based on a thermo-mechanical coupling prediction model and a model predictive control strategy, adjusts the heating power, cooling flow rate, lubrication input, and extrusion speed in real time to maintain optimal rheological conditions and suppress surface cracks, delamination, and dimensional drift under high-speed conditions.

[0139] After the profile is demolded, it undergoes programmable cooling in axial segments: first, slow cooling to reduce the temperature difference between the surface and the core and release thermal stress; then, intensified cooling to fix the cross-sectional dimensions and microstructure; and finally, stable temperature recovery to ambient temperature. Online and offline quality inspection results after demolding are recorded and fed back to the process database for periodic or online updates of model control parameters, achieving adaptive optimization of the process and improved batch-to-batch consistency.

[0140] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and non-limiting, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No markings in the claims should be construed as limiting the scope of the claims.

Claims

1. A high-speed extrusion forming process for aluminum profiles based on dynamic temperature control, characterized in that: The extrusion molding process includes the following steps: The aluminum alloy billet to be extruded is divided into at least three axially continuous temperature control sections along the extrusion direction, namely the front preheating zone, the middle stabilization zone, and the rear buffer zone. The preheating zone, stabilization zone and buffer zone are each subjected to independent and adjustable heating or cooling, so that each segment forms an axial temperature distribution that varies in a stepped or gradient manner along the extrusion direction before entering the extrusion die. During the extrusion process, the axial temperature distribution is maintained to move forward synchronously with the extrusion process, so that the billet entering the pressure die hole is always in the preset temperature range at different extrusion stages. Thus, by dynamically constructing and scheduling the axial temperature field of the billet, the flow stress distribution of the billet during the extrusion molding process is controlled.

2. The high-speed extrusion forming process for aluminum profiles based on dynamic temperature control according to claim 1, characterized in that: When dividing the axially continuous temperature control segments, the front preheating zone corresponds to the end of the billet that first enters the extrusion die, the middle stabilization zone corresponds to the main body of the billet that mainly bears plastic deformation during the extrusion process, and the rear buffer zone corresponds to the tail of the billet near the extrusion rod, in order to reduce the temperature change when the tail section of the billet enters the die.

3. The high-speed extrusion molding process for aluminum profiles based on dynamic temperature control according to claim 1, characterized in that: The target temperature of the front preheating zone is higher than that of the middle stabilization zone, and the target temperature of the middle stabilization zone is higher than that of the rear buffer zone, so as to form a cooling axial temperature gradient from front to back when the billet enters the extrusion die, thereby reducing the risk of surface cracking of the billet under high-speed extrusion conditions.

4. The high-speed extrusion forming process for aluminum profiles based on dynamic temperature control according to claim 1, characterized in that: Before the billet enters the extrusion die, the radial temperature distribution of the billet is further controlled to form a preset radial temperature difference between the surface temperature and the core temperature of the billet. This makes the radial flow rate of the billet in the die hole more uniform and reduces uneven cross-sectional deformation.

5. The high-speed extrusion molding process for aluminum profiles based on dynamic temperature control according to claim 4, characterized in that: The radial temperature difference is achieved by locally cooling the outer surface of the billet or by strengthening the heating of the billet core, so that the billet forms a differential thermal state between the surface and the core before entering the extrusion die, thereby suppressing the surface overflow and core retention phenomenon under high-speed extrusion.

6. The high-speed extrusion forming process for aluminum profiles based on dynamic temperature control according to claim 1, characterized in that: During the extrusion molding process, at least one temperature control zone is set for the extrusion die, and heating or cooling is applied to the temperature control zone of the extrusion die to match the temperature distribution of the die hole in the circumferential and axial directions with the temperature distribution of the blank in the axial direction, so as to reduce the transient temperature difference between the blank and the die hole.

7. The high-speed extrusion forming process for aluminum profiles based on dynamic temperature control according to claim 6, characterized in that: The mold temperature control zone includes a first mold temperature control zone located in the mold hole inlet area and a second mold temperature control zone located in the mold hole outlet area, wherein the temperature of the first mold temperature control zone is higher than the temperature of the second mold temperature control zone, so as to form a controlled thermo-mechanical coupling deformation environment when the blank passes through the mold hole.

8. The high-speed extrusion forming process for aluminum profiles based on dynamic temperature control according to claim 6, characterized in that: During the extrusion process, the temperature settings of the front preheating zone, the middle stabilization zone, and the rear buffer zone are adjusted synchronously according to the changes in the extrusion speed, so that the billet remains within the preset forming temperature window when it enters the die at different extrusion speeds.

9. The high-speed extrusion forming process for aluminum profiles based on dynamic temperature control according to claim 8, characterized in that: During the extrusion process: When the extrusion speed is increased, the temperature setpoints of the preheating zone and the stabilization zone in the middle section are increased, and the length of the temperature transition zone between each temperature control section is shortened. When the extrusion speed is reduced, the temperature settings of the front preheating zone and the middle stabilization zone are reduced, and the length of the temperature transition zone is extended.

10. The high-speed extrusion forming process for aluminum profiles based on dynamic temperature control according to claim 1, characterized in that: After the aluminum profile is demolded, the extruded profile is subjected to segmented cooling treatment that matches the axial temperature distribution, so that the extruded profile forms a controlled cooling rate distribution along the extrusion direction, thereby reducing residual stress and stabilizing the final cross-sectional dimensions and mechanical properties.