Aluminum melting, casting and extrusion integrated system and method

Abstract

The application relates to the technical field of aluminum processing, and provides an aluminum melting, casting and extruding integrated system and method.The system comprises an aluminum liquid melting furnace, an extruding machine, a cooling assembly and a mechanical pushing mechanism.The aluminum liquid melting furnace is used for smelting liquid aluminum or semi-solid aluminum, the discharge end of the aluminum liquid melting furnace is communicated with the feeding end of the extruding machine, the liquid aluminum or semi-solid aluminum is directly fed into the extruding machine, the cooling assembly is used for cooling the extruding process of the liquid aluminum or semi-solid aluminum and is arranged around the extruding forming station of the extruding machine, and the mechanical pushing mechanism is used for extruding power source and reciprocating in the extruding cavity to push the aluminum into the extruding die for extruding forming.The liquid / semi-solid aluminum is directly fed into the extruding machine, the process is compact and continuous, the cooling unit is used for real-time cooling and setting, the forming speed can be effectively improved and the overall production cycle can be shortened, the production efficiency is improved, and continuous production is realized.

Description

Technical Field

[0001] This invention relates to the field of aluminum processing technology, and more specifically, to an integrated system and method for aluminum melting, casting, extrusion molding. Background Technology

[0002] Traditional aluminum profile extrusion molding processes generally adopt a production mode of preheating solid aluminum round bars before extrusion. Specifically, the raw materials are first processed into solid aluminum round bars, and then the aluminum bars are heated separately by special heating equipment. After being transferred, they are sent into the extruder, and the profile extrusion molding is completed by relying on the matching hydraulic extrusion system.

[0003] Traditional aluminum profile extrusion processes involve numerous steps, requiring multiple sets of equipment for ingot casting, ingot heating, material transfer, and hydraulic extrusion. This results in large production lines with high equipment costs and significant energy losses and time consumption during solid aluminum ingot preparation, secondary heating, and intermediate transfer. Consequently, production continuity is poor and forming efficiency is low. In short, these processes hinder the overall efficiency of aluminum profile extrusion production, necessitating optimization and improvement of existing processes and equipment. Summary of the Invention

[0004] Based on this, in order to improve production efficiency and achieve continuous production, the present invention provides an integrated system and method for aluminum melting, casting, and extrusion molding, the specific technical solution of which is as follows: An integrated aluminum melting, casting, and extrusion molding system includes an aluminum molten furnace, an extruder, a cooling assembly, and a mechanical pushing mechanism. The aluminum molten furnace is used to melt and generate liquid or semi-solid aluminum molten material and is positioned above the extruder. The discharge end of the aluminum molten furnace is connected to the feed end of the extruder, allowing the liquid or semi-solid aluminum molten material to be directly fed into the extruder. The cooling assembly is used to cool and reduce the temperature of the liquid or semi-solid aluminum molten material during the extrusion molding process and is arranged around the forming station of the extruder. The mechanical pushing mechanism is used to power the extrusion and reciprocates within the extrusion working chamber to push the aluminum molten material into the extrusion die for extrusion molding.

[0005] The integrated aluminum melting, casting, and extrusion system directly feeds liquid / semi-solid aluminum liquid into the extruder. Its processes are tightly and continuously connected. With the help of a cooling unit for real-time cooling and shaping, the forming speed can be effectively improved and the overall production cycle can be shortened, thereby improving production efficiency and realizing continuous production. In addition, since the aluminum melting furnace is placed directly above the extruder, the traditional hydraulic extrusion system is eliminated, and intermediate processes such as solid aluminum bar preparation, separate heating of bars, and material transfer are eliminated, which greatly reduces the number of supporting equipment. It can realize the integration of melting, casting, liquid supply, cooling, and extrusion, and reduce equipment procurement, installation, and site usage costs.

[0006] Preferably, the cooling assembly includes: A cooling unit for the feeding transition section is located in the aluminum liquid feeding transition zone between the discharge end of the aluminum melt furnace and the feed end of the extruder. The extrusion working area cooling unit is located in the extrusion working area of ​​the extruder; The cooling unit for the mold cavity forming area is located in the mold forming area; The cooling unit for the discharge and shaping area is located in the discharge and shaping area.

[0007] Preferably, the cooling unit of the feeding transition section includes an axial flow fan, which cools the aluminum liquid in the aluminum feeding transition zone by means of air cooling.

[0008] Preferably, the cooling unit of the extrusion working area includes a cooling water jacket, which has a spiral cooling channel inside and surrounds the outer wall of the extrusion working chamber of the extruder.

[0009] Preferably, the cooling unit of the mold cavity forming area includes a cooling water jacket, which has a spiral cooling channel inside and wraps around the outer wall of the mold cavity.

[0010] Preferably, the cooling unit of the discharge shaping zone includes a mist nozzle, which is arranged around the discharge port.

[0011] Preferably, the mechanical pushing mechanism includes a drive unit and a spiral body. The drive unit is connected to the spiral body and is used to drive the spiral body to move. The spiral body includes a spiral shaft core as a rotation support base and spiral blades mounted on the spiral shaft core.

[0012] An integrated method for aluminum melting, casting, and extrusion molding, applied to the aforementioned integrated aluminum melting, casting, and extrusion molding system, includes the following steps: An aluminum melt furnace is integrated into the extruder to prepare liquid or semi-solid aluminum melt through smelting in the aluminum melt furnace. Connect the discharge end of the aluminum molten furnace to the feed end of the extruder, and directly transport the molten or semi-solid aluminum molten material prepared by smelting to the inside of the extruder. During the extrusion molding process, the liquid or semi-solid aluminum liquid is cooled down by a cooling component. The molten aluminum is pushed into the extrusion die by a mechanical pushing mechanism that reciprocates within the extrusion working chamber, thus achieving integrated continuous production of melting, casting and extrusion.

[0013] Preferably, the integrated aluminum melting, casting, extrusion molding method further includes the following steps: Obtain the apparent viscosity and helix angular velocity of the molten aluminum, and then obtain the shear resistance torque based on the apparent viscosity and helix angular velocity of the molten aluminum. Obtain the average back pressure of the mold cavity, and obtain the mold back pressure resistance torque based on the average back pressure of the mold cavity; The minimum input torque required for the mechanical pushing mechanism to drive the molten aluminum is obtained based on the shear resistance torque and the die back pressure resistance torque. The mechanical pushing mechanism is a spiral pushing mechanism.

[0014] Preferably, the integrated aluminum melting, casting, extrusion molding method further includes the following steps: Obtain the effective cross-sectional area of ​​the aluminum liquid flow and the radial average lever arm, and obtain the comprehensive coefficient of back pressure resistance based on the effective cross-sectional area of ​​the aluminum liquid flow and the radial average lever arm; Specifically, the method of obtaining the mold back pressure resistance torque based on the average back pressure of the mold cavity is as follows: the mold back pressure resistance torque is obtained by multiplying the average back pressure of the mold cavity and the comprehensive coefficient of back pressure resistance. Attached Figure Description

[0015] The invention will be further understood from the following description taken in conjunction with the accompanying drawings. The components in the drawings are not necessarily drawn to scale, but rather the emphasis is on illustrating the principles of the embodiments. In different views, the same reference numerals designate corresponding parts.

[0016] Figure 1 This is a schematic diagram of the overall structure of an integrated aluminum melting, casting, extrusion molding system according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the unit structure of a cooling component in one embodiment of the present invention; Figure 3 This is a schematic diagram of the overall structure of an integrated aluminum melting, casting, extrusion molding method according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the overall structure of an integrated aluminum melting, casting, extrusion molding method according to another embodiment of the present invention.

[0017] Explanation of reference numerals in the attached drawings: 1. Aluminum molten metal furnace; 10. Extrusion press; 3. Cooling assembly; 4. Mechanical pushing mechanism. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to its embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and do not limit the scope of protection of the invention.

[0019] It should be noted that when an element is referred to as being "fixed to" another element, it can be directly attached to the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0020] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0021] In this invention, "first" and "second" do not represent a specific quantity or order, but are merely used to distinguish names.

[0022] like Figure 1 As shown, an embodiment of the present invention provides an integrated aluminum melting, casting, extrusion, and forming system, including an aluminum molten furnace 1, an extruder 2, a cooling assembly 3, and a mechanical pushing mechanism 4. The aluminum molten furnace is used to melt and generate liquid or semi-solid aluminum molten material and is located above the extruder. The discharge end of the aluminum molten furnace is connected to the feed end of the extruder, so that the liquid or semi-solid aluminum molten material is directly fed into the extruder. The cooling assembly is used to cool and reduce the temperature of the liquid or semi-solid aluminum molten material during the extrusion forming process and is arranged around the forming station of the extruder. The mechanical pushing mechanism is used to extrude the power source and reciprocates within the extrusion working chamber to push the aluminum molten material into the extrusion die for extrusion forming.

[0023] As a preferred technical solution, such as Figure 2 As shown, the cooling assembly includes a feeding transition section cooling unit, an extrusion working area cooling unit, a mold cavity forming area cooling unit, and an outlet shaping area cooling unit.

[0024] The feeding transition section cooling unit is located in the aluminum molten metal feeding transition zone between the discharge end of the aluminum molten metal furnace and the feeding end of the extruder; the extrusion working zone cooling unit is located in the extrusion working zone of the extruder; the die cavity forming zone cooling unit is located in the die forming zone; and the discharge shaping zone cooling unit is located in the discharge shaping zone.

[0025] The cooling components are laid out based on the aluminum liquid conveying path, extrusion process and profile forming stage. They are arranged in four sections along the four forming stations of the extruder: feeding transition section, extrusion working section, die cavity forming section and discharge shaping section. They are set in the extruder cavity, the outer wall of the die and the periphery of the flow channel, without intruding into the aluminum liquid flow and extrusion operation space, ensuring that the extrusion action is not interfered with, and realizing synchronous cooling throughout the entire process.

[0026] Specifically, considering the high-temperature characteristics of molten aluminum, the forming rate, and the requirements for temperature control accuracy, the cooling component can adopt a composite cooling system that primarily uses water cooling, supplemented by air mist cooling, and uses air cooling for temperature compensation and adjustment.

[0027] The feeding transition section cooling unit includes an axial flow fan, which cools the molten aluminum in the feeding transition zone using air cooling to achieve small-scale temperature control, offset local residual heat, and prevent the molten aluminum from becoming too hot and difficult to shape. The extrusion working area cooling unit includes a cooling water jacket with a spiral cooling channel inside and wrapping the outer wall of the extrusion working cavity of the extruder. The die cavity forming area cooling unit includes a cooling water jacket with a spiral cooling channel inside and wrapping the outer wall of the die cavity, thereby enhancing the cooling capacity and heat exchange efficiency of high-load cooling areas such as the extrusion working area and the die cavity forming area. The discharge and shaping area cooling unit includes a mist nozzle, which is arranged around the discharge port to ensure uniform and gradual cooling, avoiding defects such as deformation and cracks caused by sudden cooling of the profile.

[0028] The mechanical pushing mechanism includes a drive unit and a spiral body. The drive unit is pulsatorically connected to the spiral body and is used to drive the spiral body to move. The spiral body includes a spiral shaft as a rotational support base and spiral blades mounted on the spiral shaft. Here, both the spiral shaft and the spiral blades of the spiral body are made of high-temperature resistant materials such as carbon steel.

[0029] The mechanical pushing mechanism can also be a drive motor and a reducer that drive the push rod and the extrusion push head to reciprocate in the extrusion working area to achieve the extrusion forming of aluminum liquid.

[0030] When the aluminum furnace feeds the molten liquid / semi-solid aluminum into the feed end of the extruder, and the mechanical pushing mechanism begins to move forward and apply extrusion pressure to the aluminum, all cooling units are simultaneously powered on and started. The cooling medium of each cooling unit is supplied according to the preset initial parameters, and the cooling operation is connected to the extrusion operation with zero time difference.

[0031] After the high-temperature molten aluminum enters the extrusion chamber from the furnace, it first passes through the feeding transition zone. At this time, forced air cooling is used for preliminary temperature control to stabilize the temperature of the molten aluminum within the process setting range: the liquid aluminum is controlled above the critical temperature for casting, and the semi-solid aluminum maintains a uniform coexistence of solid and liquid phases. This avoids uneven local temperature drops in the molten aluminum due to heat dissipation from the chamber, and also prevents excessively high temperatures from causing excessive fluidity and making it impossible to complete the shaping and extrusion.

[0032] Once the molten aluminum enters the core extrusion stroke area, the mechanical pushing mechanism applies mechanical extrusion force. Since this stage is crucial for profile forming, the cooling water jacket and built-in spiral cooling channels need to be activated. The circulating cooling water continuously removes the frictional heat generated during extrusion and the latent heat of the molten aluminum, uniformly lowering its temperature. This allows the molten aluminum to gradually transform from a fully liquid state to a semi-solid and then a plastically solid state during extrusion. Here, a uniform cooling mode can be used, ensuring the aluminum material has sufficient plasticity to complete the extrusion shaping while avoiding excessive temperature that could lead to material collapse and deformation. This replaces the room-temperature extrusion conditions of traditional aluminum rod processes.

[0033] After the molten aluminum is squeezed into the mold cavity of the profile mold, the water cooling system on the outer wall of the mold cavity runs continuously to stabilize the temperature of the mold cavity and the aluminum material inside within the optimal temperature range for profile shaping. This ensures that the aluminum material is fully filled and properly shaped in the mold cavity, and prevents problems such as uneven profile wall thickness, surface defects, and dimensional deviations caused by temperature fluctuations.

[0034] After the profile is extruded from the die, the aerosol nozzles of the cooling unit in the discharge and shaping zone are activated to uniformly cool the outer surface of the profile, gradually completing the solidification and shaping process. Aerosol cooling avoids the problems of localized rapid cooling and excessive internal and external temperature differences caused by direct cooling with pure water, ensuring that the internal structure of the profile is dense and the mechanical properties are uniform.

[0035] When a single batch of extrusion ends and the mechanical pushing mechanism resets and retracts, each cooling unit is shut down synchronously and sequentially along with the extrusion action. Specifically, the air mist cooling in the discharge area can be shut down first, followed by the water cooling in the die cavity and extrusion area, and finally the air cooling in the feeding area, completing a single synchronous cooling process and waiting for the next round of aluminum liquid feeding and extrusion operation.

[0036] High-temperature thermocouples can be installed in each cooling zone of the extruder, on the inner wall of the aluminum liquid flow channel, and inside the mold cavity to collect the temperature of the aluminum liquid body, the cavity wall temperature, and the mold temperature in real time. The real-time temperature measurement data of the high-temperature thermocouples is compared with the process setting value to calculate the temperature difference and temperature change rate. The cooling parameters of each area, such as the flow rate and pressure of the cooling medium and the speed of the axial flow fan, are automatically adjusted according to the temperature difference.

[0037] Generally speaking, for fully liquid aluminum, since the initial temperature of liquid aluminum is high and its fluidity is strong, the overall strategy can be to first cool quickly and then cool slowly. That is, the cooling intensity is increased in the feeding transition section to quickly reduce the high temperature of the aluminum liquid to the plastic forming temperature range, and the cooling rate is slowed down in the forming and unloading stages to ensure the quality of profile forming. The overall temperature drop is strictly controlled throughout the process to avoid the aluminum liquid from solidifying quickly and blocking the flow channel.

[0038] For semi-solid aluminum liquid, since semi-solid aluminum is in a solid-liquid equilibrium state, its fluidity and plasticity are better matched. Therefore, a strategy of constant temperature as the main method and slow cooling in small increments can be adopted. That is, the cooling intensity is reduced throughout the process, the focus is on maintaining a stable solid-liquid ratio, and only a small amount of cooling is used to offset the extrusion friction heat, to prevent the semi-solid aluminum from completely solidifying and losing its extrusion plasticity, while avoiding the formation failure caused by an excessively high liquid phase ratio.

[0039] The feed channel between the aluminum molten furnace discharge end and the extruder feed end can be treated with high temperature and wear resistance. The molten aluminum, after being melted, does not go through a transfer or become solid aluminum rods. It flows directly from the furnace discharge end into the extruder feed end. With the help of the micro-positive pressure in the furnace and the synergistic effect of the mechanical pushing structure, the molten aluminum is transported forward smoothly.

[0040] When the mechanical pushing mechanism is activated, it applies mechanical thrust to the molten aluminum flowing into the flow channel. Due to the good fluidity of the liquid / semi-solid molten aluminum, the thrust is quickly converted into internal fluid pressure, replacing the extrusion pressure of the traditional hydraulic system, causing the molten aluminum to move towards the die. Under the combined action of the flow channel pressure and the mechanical pushing force, the molten aluminum continuously flows into the extrusion die cavity. Relying on the rheological properties of the molten aluminum itself, it can naturally fill the contours of the die cavity, completing the initial shaping. For semi-solid molten aluminum, its internal solid particles can rearrange under pressure, combining fluidity and structural strength, thus preventing profile collapse and deformation, and achieving complete filling without the need for large-tonnage hydraulic power.

[0041] Pressure and temperature sensors can be installed in the feed channel, extrusion working area, die cavity, and discharge port to collect parameters such as internal pressure of molten aluminum, material temperature, and pushing resistance in real time. If the channel pressure is insufficient or the molten aluminum is not filled enough, the pushing speed can be appropriately increased. If the local temperature is abnormal and the molten aluminum solidifies prematurely, the cooling intensity of the corresponding cooling unit can be appropriately reduced.

[0042] In summary, the integrated aluminum melting, casting, and extrusion system directly feeds liquid / semi-solid aluminum liquid into the extruder. Its processes are tightly and continuously connected. With the real-time cooling unit for cooling and shaping, the forming speed can be effectively improved and the overall production cycle can be shortened, thereby improving production efficiency and achieving continuous production. In addition, since the aluminum melting furnace is placed directly above the extruder, the traditional hydraulic extrusion system is eliminated, and intermediate processes such as solid aluminum bar preparation, separate heating of bars, and material transfer are eliminated, significantly reducing the number of supporting equipment. It can realize the integrated integration of melting, casting, liquid supply, cooling, and extrusion, reducing equipment procurement, installation, and site usage costs.

[0043] An embodiment of the present invention also provides an integrated method for aluminum melting, casting, and extrusion molding, applied to the aforementioned integrated aluminum melting, casting, and extrusion molding system, such as... Figure 3 As shown, it includes the following steps: S1, an aluminum molten furnace is integrated on the extruder to prepare liquid aluminum liquid or semi-solid aluminum liquid by melting in the aluminum molten furnace.

[0044] S2 connects the discharge end of the aluminum molten furnace with the feed end of the extruder, directly conveying the molten or semi-solid aluminum molten material prepared by smelting to the inside of the extruder.

[0045] S3, during the extrusion molding process, the liquid aluminum liquid or semi-solid aluminum liquid is cooled and cooled by a cooling component.

[0046] S4, through the reciprocating motion of the mechanical pushing mechanism in the extrusion working chamber, pushes the molten aluminum into the extrusion mold for extrusion molding, realizing integrated continuous production of melting and casting and extrusion.

[0047] Specifically, the integrated aluminum melting furnace continuously melts, heats, and tempers the aluminum material, stably producing liquid or semi-solid aluminum that meets process requirements. The furnace maintains a slightly positive pressure, providing the basic power for the gravity-flow transport of the aluminum. The molten aluminum flows directly into the extruder feed channel from the furnace outlet without being transferred or formed into solid aluminum rods. Through the combined action of the slightly positive pressure within the furnace and the mechanical pushing mechanism, the aluminum is smoothly transported forward, maintaining its initial flow state. Throughout the extrusion process, the cooling unit starts and operates synchronously with the pushing mechanism, and temperature control is performed on the aluminum and profiles in designated areas. For the feed channel area, mild cooling can be used to offset the residual heat generated during the conveying process, stabilize the temperature of the molten aluminum within the preset range, and prevent the molten aluminum from being too fluid and the semi-solid aluminum from having an unbalanced solid-liquid ratio. For the core area of ​​the die cavity extrusion, the cooling intensity can be increased to gradually reduce the temperature of the molten aluminum, so that the molten aluminum gradually transitions from a highly fluid dynamic state to a plastic solid state while being extruded and filled. This improves the structural strength of the profile by relying on temperature changes, allowing the profile to have the ability to maintain its shape before demolding, and making up for the problem of insufficient structural support caused by the lack of hydraulic pressure.

[0048] The integrated aluminum melting, casting, and extrusion molding method relies on the high fluidity and solid-liquid coexistence plasticity of liquid / semi-solid aluminum liquid. It abandons the traditional hydraulic main drive structure and completes continuous extrusion molding by combining mechanical pushing, aluminum liquid flow pressure, and synchronous cooling and shaping. The entire process is matched with an integrated aluminum liquid melting furnace and zoned cooling units, which can realize continuous operation of the entire process of melting, casting, feeding, extrusion, and shaping.

[0049] In summary, the integrated aluminum melting, casting, and extrusion molding method directly feeds liquid / semi-solid aluminum liquid into the extruder. Its processes are tightly and continuously linked, and with the real-time cooling unit for temperature reduction and shaping, the molding speed can be effectively increased and the overall production cycle shortened, thereby improving production efficiency and achieving continuous production. Furthermore, since the aluminum melting furnace is directly placed above the extruder, the traditional hydraulic extrusion system is eliminated, and intermediate processes such as solid aluminum bar preparation, separate bar heating, and material transfer are omitted, significantly reducing the number of supporting equipment. This allows for the integrated processing of melting, casting, liquid supply, cooling, and extrusion, reducing equipment procurement, installation, and site usage costs.

[0050] In one embodiment, such as Figure 4 As shown, the integrated aluminum melting, casting, extrusion molding method further includes the following steps: S5, obtain the apparent viscosity of the molten aluminum and the helical angular velocity, and obtain the shear resistance torque based on the apparent viscosity of the molten aluminum and the helical angular velocity.

[0051] The shear resistance torque factor can be obtained by multiplying the apparent viscosity of the molten aluminum and the spiral angular velocity. At the same time, the equal-depth spiral groove, spiral root radius, and spiral blade outer diameter of the spiral pushing mechanism are obtained. Based on the equal-depth spiral groove, spiral root radius r, and spiral blade outer diameter R, the comprehensive shear resistance coefficient is obtained. The shear resistance torque is obtained by multiplying the comprehensive shear resistance coefficient and the shear resistance torque factor.

[0052] The helical root radius, i.e., the outer radius of the helical shaft, is the minimum radial position of the helical groove; the outer diameter of the helical blade, the radius of the tip of the helical blade, is the maximum radial position of the helical groove. The non-Newtonian apparent viscosity of molten aluminum at a specific temperature T and solid fraction fs. Viscosity directly determines the magnitude of shear stress. When the cooling unit increases the solid fraction fs, the apparent viscosity of the molten aluminum increases sharply, and the required torque increases exponentially.

[0053] For example, the overall shear resistance coefficient = first adjustment factor × 2πL × average radius 3 / Equal depth of the spiral groove. It can be understood that the shear resistance torque is the product of the shear force and the shear arm. The shear force equals the shear stress multiplied by the shear area. Shear stress = apparent viscosity × shear rate = apparent viscosity × spiral angular velocity × average radius / equal depth of the spiral groove. The shear area = 2πL × average radius. Therefore, it can be deduced that the final shear resistance torque = first adjustment factor × apparent viscosity × spiral angular velocity × 2πL × average radius. 3 / Equal depth of the spiral groove. The purpose of setting the first adjustment factor is to ensure that the final shear resistance torque model is applicable to different equipment and operating conditions.

[0054] Apparent viscosity of molten aluminum = Reference viscosity × exp(Flow activation energy / (Gas constant × Absolute temperature of molten aluminum T)) × (1 - Solid fraction fs / Critical solid fraction) k The critical solid fraction is generally taken as 0.6-0.8, and k is the solid-state strengthening index, a fitting constant, generally ranging from 2 to 5; the reference viscosity of pure aluminum / common aluminum alloys is generally around 10. -4 -10 -3 Between Pa·s. L is the effective axial contact length of the helix, that is, the length of the axial section within the helical groove filled with molten aluminum and generating relative motion. Generally speaking, the larger L is, the larger the contact area between the molten aluminum and the helix, the greater the shear resistance, and the greater the required shear torque.

[0055] Since semi-solid molten aluminum is a non-Newtonian shear-thinning fluid, its apparent viscosity is simultaneously affected by temperature T, solid fraction fs, and shear rate γ. Therefore, in actual operating conditions, the higher the screw speed and the stronger the shear, the significantly lower the viscosity of the molten aluminum. To address this, the rheological effect of the shear rate can be introduced. The apparent viscosity of molten aluminum is then calculated as: Apparent viscosity of molten aluminum = Reference viscosity × exp(Flow activation energy / (Gas constant × Temperature T)) × (1 - Solid fraction fs / Critical solid fraction) k ×Shear rate n n represents the shear thinning index, typically 0.2-0.5 for semi-solid molten aluminum and 0.1-0.3 for liquid molten aluminum, and is dimensionless; the shear rate is expressed as helical angular velocity × average radius / equal-depth helical groove depth, where the average radius is the average of the helical root radius r and the outer diameter R of the helical blade.

[0056] Specifically, the shear rate can be understood as the equivalent average shear deformation rate of the molten aluminum relative to the spiral blades and the inner wall of the cavity across the entire radial cross-section of the spiral channel. It characterizes the intensity of the agitation and shearing of the molten aluminum. exp(flow activation energy / (gas constant × temperature T)) can be understood as the temperature-activated viscosity term, which describes the exponential effect of temperature on melt viscosity and is a common thermal activation model for high-temperature metal melts; the solid fraction viscosity-increasing term (1 - solid fraction fs / critical solid fraction) kIt is understandable that semi-solid aluminum liquid is a two-phase suspension system consisting of a liquid aluminum matrix and solid aluminum grains. The solid grains lack fluidity and will rub against each other and overlap to form a solid network, significantly increasing the overall flow resistance. For pure liquid aluminum, the solid fraction fs≈0, and the viscosity-increasing term of the solid fraction≈1, which is ineffective, and the viscosity is no longer affected by the solid phase. In the semi-solid range, 0<solid fraction<critical solid fraction, and the apparent viscosity of the aluminum liquid will increase accordingly.

[0057] As the most sensitive influencing factor on the viscosity of semi-solid aluminum liquid, the viscosity-increasing term of solid fraction is used to achieve the process control objective, namely, strictly controlling the solid fraction to be less than the critical solid fraction, while maintaining the solid fraction in the optimal semi-solid range.

[0058] Because liquid / semi-solid aluminum is a shear-thinning non-Newtonian fluid, the rotation of the helical blades and the relative motion of the aluminum within the helical channel generate shear forces, which break up the solid-phase grain network within the semi-solid aluminum and weaken intermolecular forces. The stronger the shear, the lower the flow resistance and viscosity. Shear rate n It is mainly used to connect to the spiral feeding mechanism and control its speed. Specifically, the shear rate is positively correlated with the spiral angular velocity; the higher the spiral speed, the greater the shear rate and the lower the viscosity of the molten aluminum. When excessive cooling, low temperature, or high solids fraction lead to a viscosity spike or torque overload, the PLC can actively increase the spiral speed to reduce viscosity and decrease the drive load by utilizing the shear thinning effect, thus achieving self-compensation. In summary, this apparent viscosity model for molten aluminum integrates three major physical effects: thermally activated viscosity, thickening due to solid particles, and thinning due to non-Newtonian shear. It can be used to quantitatively describe the variation of apparent viscosity of molten aluminum with three major process parameters: temperature, solid fraction, and shear rate.

[0059] S6, obtain the average back pressure of the mold cavity, and obtain the mold back pressure resistance torque based on the average back pressure of the mold cavity.

[0060] The average back pressure of the die cavity is the comprehensive average pressure exerted on the molten aluminum at the die inlet section, macroscopically representing the overall resistance on the die side. The die back pressure resistance torque is the additional torque required by the helical rotation shaft, which is used to balance all axial resistance generated by the die, die cavity, and die opening during the molten aluminum extrusion molding process.

[0061] As a preferred technical solution, the integrated aluminum melting, casting, extrusion molding method further includes the following steps: obtaining the effective cross-sectional area of ​​the aluminum liquid flow and the radial average lever arm, and obtaining the back pressure resistance comprehensive coefficient based on the effective cross-sectional area of ​​the aluminum liquid flow and the radial average lever arm; wherein, obtaining the mold back pressure resistance torque based on the average back pressure of the mold cavity specifically involves obtaining the mold back pressure resistance torque based on the product between the average back pressure of the mold cavity and the back pressure resistance comprehensive coefficient.

[0062] For example, the back pressure resistance coefficient = second adjustment factor × effective cross-sectional area of ​​molten aluminum flow × radial average lever arm. The effective cross-sectional area of ​​molten aluminum flow is the effective flow area of ​​the extrusion chamber. The radial average lever arm can be understood as the equivalent radial lever arm of the flow section. The average back pressure of the die cavity is the axial resistance pressure generated by the extrusion of molten aluminum into the die cavity. It can be understood that the product of the average back pressure of the die cavity and the effective cross-sectional area of ​​molten aluminum flow is the total axial back pressure, that is, the total axial resistance that hinders the forward extrusion of molten aluminum; the result of the total axial back pressure and the radial average lever arm is the die back pressure resistance torque. The main purpose of setting the second adjustment factor is to allow the die back pressure resistance torque model to be used under different equipment operating conditions.

[0063] S7. Obtain the minimum input torque required for the mechanical pushing mechanism to drive the molten aluminum based on the shear resistance torque and the mold back pressure resistance torque; wherein, the mechanical pushing mechanism is a spiral pushing mechanism.

[0064] Ultimately, the minimum input torque required for the mechanical pushing mechanism to drive the molten aluminum is the sum of the shear resistance torque and the die back pressure resistance torque. The power of the driving mechanism can be expressed as the product of the input torque and the angular velocity.

[0065] For the first and second adjustment factors, multiple sets of experiments can be conducted. Under the condition that the effective cross-sectional area of ​​the aluminum liquid flow, the radial average lever arm, the depth of the equal-depth spiral groove, and the apparent viscosity of the aluminum liquid are determined, the power and angular velocity of the mechanical pushing mechanism are measured. The first and second adjustment factors corresponding to each set of experiments are derived by function fitting. Then, the average value of the first adjustment factor of multiple sets of experiments is taken as the final value of the first adjustment factor, and the average value of the second adjustment factor is taken as the final value of the second adjustment factor.

[0066] Thus, by calculating the minimum input torque required for the mechanical pushing mechanism to drive the molten aluminum, the selection and design of the rated torque, speed range, and screw groove geometric parameters of the screw mechanism can be determined, ensuring that the conveying, pressure building, and extrusion molding of molten aluminum can be completed solely by rotary shearing without external hydraulic thrust.

[0067] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0068] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. An integrated aluminum melting, casting, and extrusion forming system, comprising an aluminum molten furnace, an extruder, a cooling assembly, and a mechanical pushing mechanism, characterized in that, The aluminum melting furnace is used to melt and generate liquid or semi-solid aluminum liquid and is located above the extruder. The discharge end of the aluminum melting furnace is connected to the feed end of the extruder, so that the liquid or semi-solid aluminum liquid is directly fed into the extruder. The cooling component is used to cool and reduce the temperature of the liquid or semi-solid aluminum liquid during the extrusion forming process and is arranged around the forming station of the extruder. The mechanical pushing mechanism is used as the extrusion power source and reciprocates in the extrusion working chamber to push the aluminum liquid into the extrusion die for extrusion forming.

2. The integrated aluminum melting, casting, and extrusion molding system as described in claim 1, characterized in that, The cooling assembly includes: A cooling unit for the feeding transition section is located in the aluminum liquid feeding transition zone between the discharge end of the aluminum melt furnace and the feed end of the extruder. The extrusion working area cooling unit is located in the extrusion working area of ​​the extruder; The cooling unit for the mold cavity forming area is located in the mold forming area; The cooling unit for the discharge and shaping area is located in the discharge and shaping area.

3. The integrated aluminum melting, casting, and extrusion molding system as described in claim 2, characterized in that, The cooling unit of the feeding transition section includes an axial flow fan, which cools and lowers the temperature of the aluminum liquid in the aluminum feeding transition zone by means of air cooling.

4. The integrated aluminum melting, casting, and extrusion molding system as described in claim 2, characterized in that, The cooling unit for the extrusion working area includes a cooling water jacket, which has a spiral cooling channel inside and surrounds the outer wall of the extrusion working chamber of the extruder.

5. The integrated aluminum melting, casting, and extrusion molding system as described in claim 2, characterized in that, The cooling unit for the mold cavity forming area includes a cooling water jacket, which has a spiral cooling channel inside and wraps around the outer wall of the mold cavity.

6. The integrated aluminum melting, casting, and extrusion molding system as described in claim 2, characterized in that, The cooling unit of the discharge shaping zone includes a mist nozzle, which is arranged around the discharge port.

7. The integrated aluminum melting, casting, and extrusion molding system as described in claim 1, characterized in that, The mechanical pushing mechanism includes a drive unit and a spiral body. The drive unit is connected to the spiral body and is used to drive the spiral body to move. The spiral body includes a spiral shaft core as a rotation support base and spiral blades mounted on the spiral shaft core.

8. An integrated method for aluminum melting, casting, and extrusion molding, applied to the integrated aluminum melting, casting, and extrusion molding system as described in any one of claims 1-7, characterized in that, Includes the following steps: An aluminum melt furnace is integrated into the extruder to prepare liquid or semi-solid aluminum melt through smelting in the aluminum melt furnace. Connect the discharge end of the aluminum molten furnace to the feed end of the extruder, and directly transport the molten or semi-solid aluminum molten material prepared by smelting to the inside of the extruder. During the extrusion molding process, the liquid or semi-solid aluminum liquid is cooled down by a cooling component. The molten aluminum is pushed into the extrusion die by a mechanical pushing mechanism that reciprocates within the extrusion working chamber, thus achieving integrated continuous production of melting, casting and extrusion.

9. The integrated aluminum melting, casting, and extrusion molding method as described in claim 8, characterized in that, It also includes the following steps: Obtain the apparent viscosity and helix angular velocity of the molten aluminum, and then obtain the shear resistance torque based on the apparent viscosity and helix angular velocity of the molten aluminum. Obtain the average back pressure of the mold cavity, and obtain the mold back pressure resistance torque based on the average back pressure of the mold cavity; The minimum input torque required for the mechanical pushing mechanism to drive the molten aluminum is obtained based on the shear resistance torque and the die back pressure resistance torque. The mechanical pushing mechanism is a spiral pushing mechanism.

10. The integrated aluminum melting, casting, and extrusion molding method as described in claim 9, characterized in that, It also includes the following steps: Obtain the effective cross-sectional area of ​​the aluminum liquid flow and the radial average lever arm, and obtain the comprehensive coefficient of back pressure resistance based on the effective cross-sectional area of ​​the aluminum liquid flow and the radial average lever arm; Specifically, the method of obtaining the mold back pressure resistance torque based on the average back pressure of the mold cavity is as follows: the mold back pressure resistance torque is obtained by multiplying the average back pressure of the mold cavity and the comprehensive coefficient of back pressure resistance.

Images