Aluminum alloy deposition additive forming method and system based on metal extrusion

Abstract

The invention discloses an aluminum alloy deposition additive forming method and system based on metal extrusion, and belongs to the technical field of metal additive forming. According to the method, an aluminum ingot is adopted as a raw material and pushed into a threaded pipe which is heated to 5 DEG C above the melting point through an extrusion rod, and after melting, components are made to be uniform through rotary stirring; and the nozzle moves in an XY plane according to a preset path, molten metal is extruded and deposited on the preheated substrate, and after each layer of deposition, the substrate descends by one layer of height to be formed layer by layer. The extrusion technology and the fused deposition principle are combined, limitation of traditional FDM materials is broken through, aluminum ingots are directly used for replacing wires, and energy consumption is reduced; a nozzle lifting and temperature control system is replaced by substrate preheating and Z-direction substrate moving, workpiece deformation is reduced, and the surface quality and density are improved. The method has the advantages of high efficiency, low cost, environmental protection and suitability for mass production.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of metal additive forming, and particularly relates to an aluminum alloy deposition additive forming method and system based on metal extrusion. BACKGROUND

[0002] Fused deposition modeling technology (FDM) is an additive manufacturing process that heats a filament of thermoplastic material to a molten state and extrudes it layer by layer according to the CAD layering path to accumulate and form. Because of its simple operation, low cost, high material utilization rate and small environmental pollution, it is widely used in aerospace, automotive parts and biomedical fields. However, this technology has the following significant defects: Material limitations: the upper limit of heating temperature of traditional FDM equipment is only 280-310℃, which can only process plastics and low-melting-point metals, and cannot be applied to high-melting-point metals (such as aluminum alloy).

[0003] Cost and efficiency problems: the raw material needs to be made into a filament in advance, which has high energy consumption and low efficiency, greatly increasing the production cost.

[0004] Small batch production limitations: limited material selection makes it only suitable for small-scale prototype manufacturing, making it difficult to meet the needs of industrial mass production.

[0005] In order to break through the bottleneck of metal additive manufacturing, electric arc additive manufacturing technology has been introduced into the field of aluminum alloy. However, it has the problems of complex process parameters, unstable welding quality, splashing of molten droplets leading to rough surface, expensive equipment and low efficiency, which also makes it difficult to adapt to the needs of industrial scale production. SUMMARY

[0006] The purpose of the embodiments of the present application is to provide an aluminum alloy deposition additive forming method and system based on metal extrusion, which innovatively combines metal extrusion process and fused deposition principle, proposes a deposition additive forming method using aluminum ingot as a direct raw material, and for the first time introduces extrusion process into the fused deposition system, providing an industrialized feasible path for high-melting-point metal additive manufacturing, thereby solving at least one of the technical problems involved in the background art.

[0007] In order to solve the above technical problems, the present application is implemented as follows: The embodiments of the present application provide an aluminum alloy deposition additive forming method based on metal extrusion, comprising the following steps: Step S1, constructing a target model through a CAD software, importing a motion planning software to generate a deposition path and simulate and verify; Step S2, preheating the threaded pipe and the base plate, and feeding the aluminum ingot into the extrusion cylinder; Step S3, controlling the extrusion rod to push the aluminum ingot at a set speed and pressure, so that it is heated to 5℃ above the melting point in the extrusion cylinder, and then the molten metal enters the threaded pipe. Step S4, control the threaded tube to rotate to stir the molten metal, and ensure uniformity of the components; Step S5, control the nozzle to move in the XY plane according to a path, extrude the molten metal to deposit on the substrate (7), and cool to form a layer of cross-sectional profile; Step S6, drive the support by the servo motor to lower the substrate by the height of a layer of cross-sectional profile, and then use the molten metal extruded by the nozzle to deposit a new layer of cross-sectional profile on the cross-sectional profile; Step S8, repeat steps S5-S6 until the aluminum alloy structural part is completed.

[0008] Optionally, in step S1, the motion planning software is SprutCAM X17; and the simulation inspection is used to inspect whether there is collision, singularity and overstroke.

[0009] Optionally, in step S2, the preheating temperature of the substrate is close to and lower than the melting point of the aluminum alloy, and an aluminum silicate ceramic fiber heat insulation layer is arranged between the substrate and the motor.

[0010] Optionally, in step S3, a three-stage temperature control system is used to control respectively: extrusion barrel temperature: maintain the plasticity of the aluminum alloy in solid state; threaded tube temperature: 5℃ higher than the melting point; nozzle outlet temperature: 1℃ higher than the solidification point.

[0011] Optionally, in step S5, the nozzle is fixed in the Z direction, and the layer height adjustment is realized by the Z direction movement of the substrate.

[0012] The application further provides a metal extrusion-based aluminum alloy deposition additive forming system for implementing the method, comprising: an extrusion feeding module, comprising an extrusion rod, an extrusion pad arranged at the bottom end of the extrusion rod, and an extrusion barrel matched with the extrusion pad, and used for continuous conveying of aluminum ingots; a molten homogenization module, comprising a threaded tube with a rotating function and a built-in temperature control device; a motion control module, comprising a nozzle moving in the XY plane, a workbench lifting in the Z direction, a support supporting the workbench, a substrate fixed on the workbench, and a servo motor driving the workbench to lift on the support; a temperature control system, used for independently regulating and controlling the temperatures of the extrusion barrel, the threaded tube, the nozzle and the substrate; a control end, used for executing path planning and coordinating actions of the modules.

[0013] Optionally, the threaded tube is directly connected with the nozzle, and the rotating speed of the threaded tube is adjustable to realize homogenization of the components of the molten metal.

[0014] Optionally, a heat insulation layer is arranged between the substrate and the servo motor, and the material of the heat insulation layer is aluminum silicate ceramic fiber.

[0015] Optionally, the temperature control system comprises four independent closed-loop temperature control units corresponding to the extrusion cylinder, the threaded pipe, the nozzle outlet and the substrate, respectively.

[0016] Compared with the prior art, the present application has the following beneficial effects: 1. The present application directly uses aluminum ingots (non-wire materials) as raw materials, eliminating the energy-consuming wire preparation process in traditional fused deposition (FDM), reducing raw material costs by 15%-30%, and solving the problem of high melting point metals that cannot be processed due to heating temperature limitations (≤310℃) in FDM technology.

[0017] 2. The present application provides stable driving force through the extrusion process, combined with a precise temperature control system (melting temperature +5℃), to ensure continuous melting and extrusion of high melting point aluminum alloys, providing a new path for metal additive manufacturing.

[0018] 3. Compared with electric arc additive manufacturing (surface roughness, easy spatter), the present method ensures uniformity of the composition by rotating and stirring the molten metal through the threaded pipe, and extrudes a molten liquid flow with uniform thickness, making the surface of the deposited layer smooth and the internal dense (porosity reduction >40%).

[0019] 4. The deposited layer thickness of the present application is significantly increased, and the single-layer forming speed is improved by more than 50%; the substrate Z-axis lifting replaces the nozzle movement, avoiding the mechanical braking problem during high-speed scanning, and improving the positioning accuracy by 30%; supporting mass production, suitable for industrial manufacturing scenarios.

[0020] 5. The present application eliminates the wire preparation link, reduces the comprehensive energy consumption by more than 20%; the temperature control system accurately controls the temperature (melting temperature +5℃, solidification point +1℃), avoiding energy waste; the substrate preheating (close to but lower than the melting point) and the heat insulation design (aluminum silicate ceramic fiber) further reduce heat loss.

[0021] 6. The present application combines mature extrusion technology with the fused deposition framework, simplifies the equipment structure, and has lower maintenance cost than electric arc additive systems.

[0022] 7. The present application's substrate continuous preheating and layer-by-layer deposition strategy effectively reduces the temperature difference between the top and bottom of the workpiece, and suppresses internal stress deformation (thermal deformation reduction by 35%).

[0023] 8. The present application sets an aluminum silicate ceramic fiber heat insulation layer between the substrate and the motor, blocking heat conduction to the driving components, ensuring long-term stable operation of the equipment.

[0024] 9. The present application's nozzle is fixed on the XY plane, and the substrate moves in the Z direction, eliminating the mechanical errors of traditional nozzle lifting and improving the forming precision.

[0025] In general, the present application effectively reduces the aluminum alloy liquid cracking phenomenon by the combination process of extrusion driving + fused deposition + structure innovation, significantly improves the toughness of the aluminum alloy material, and is beneficial to break through the limitation of fused deposition manufacturing materials and realize the application in the metal field. BRIEF DESCRIPTION OF DRAWINGS

[0026] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor on the premise of the drawings. Figure 1 The present application provides an overall structure schematic diagram of an aluminum alloy deposition additive forming system based on metal extrusion for the embodiments of the present application. Figure 2 The present application provides a flow chart of an aluminum alloy deposition additive forming method based on metal extrusion for the embodiments of the present application. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be described clearly and completely in combination with the drawings of the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0028] The terms "first", "second", and the like in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally a class, not limited to the number of objects, for example, the first object can be one or more. In addition, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / ", generally indicates that the front and rear associated objects are in an "or" relationship.

[0029] Please refer to Figure 1 The present application also provides an aluminum alloy deposition additive forming system based on metal extrusion, which comprises an extrusion feeding module, a melting homogenization module, a motion control module, a temperature control system 5, and a control end 11.

[0030] The extrusion feeding module comprises an extrusion rod 2, an extrusion gasket 21 mounted at the bottom end of the extrusion rod 2, and an extrusion cylinder 3 matched with the extrusion gasket 21, which is used for continuous conveying of the aluminum ingot 1.

[0031] The melting homogenization module includes a threaded pipe 4 with rotation function, and a temperature control device is built-in.

[0032] The motion control module includes a nozzle 6 moving in XY plane, a workbench 8 lifting in Z direction, a support 10 supporting the workbench 8, a substrate 7 fixed on the workbench, and a servo motor 9 driving the workbench 8 to lift on the support 10.

[0033] Specifically, the threaded pipe 4 is directly connected with the nozzle 6, and the rotation speed of the threaded pipe 4 can be adjusted to realize the homogenization of the melted metal composition.

[0034] The temperature control system 5 is used for independently adjusting the temperature of the extrusion cylinder 3, the threaded pipe 4, the nozzle 6 and the substrate 7. Specifically, the temperature control system 5 includes four independent closed-loop temperature control units corresponding to the extrusion cylinder 3, the threaded pipe 4, the nozzle 6 outlet and the substrate 7 respectively.

[0035] The control end 11 is used for executing path planning and coordinating the actions of each module.

[0036] A heat insulation layer is arranged between the substrate 7 and the servo motor 9, and the material is aluminum silicate ceramic fiber, so that the temperature of the motor cannot be too high to work when the substrate 7 is heated.

[0037] In combination Figure 2 The embodiment of the present application provides an aluminum alloy deposition additive forming method based on metal extrusion, which comprises the following steps: Step S1, a target model is constructed through a CAD software, a deposition path is generated and simulated by importing a motion planning software, and simulation inspection is performed; Step S2, the threaded pipe 4 and the substrate 7 are preheated, and the aluminum ingot 1 is sent into the extrusion cylinder 3; Step S3, the extrusion rod 2 is controlled to push the aluminum ingot 1 at a set speed and pressure, so that the aluminum ingot 1 is heated to be above the melting point by 5℃ in the extrusion cylinder 3, and then the melted metal enters the threaded pipe 4; Step S4, the threaded pipe 4 is controlled to rotate and stir the melted metal to ensure uniform composition; Step S5, the nozzle 6 is controlled to move in XY plane according to the path, and the melted metal is extruded to be deposited on the substrate 7 to form a layer of cross section profile 12; Step S6, the servo motor 9 drives the support 8 to make the substrate 7 descend by the height of a layer of cross section profile 12, and then the melted metal extruded by the nozzle 6 is used to deposit a new layer of cross section profile on the cross section profile; Step S8, steps S5-S6 are repeated until the aluminum alloy structure is completed.

[0038] In step S1, the motion planning software is SprutCAM X17; and the simulation inspection is used for checking whether there is collision, singular point and overstroke.

[0039] In fact, it needs to be further explained that after the re-simulation test is completed, the executable file is sent to the molding workstation through the control end 11, the nozzle 6 is tested on the actual substrate, and the planned path is saved after no problem is found to prepare for starting processing.

[0040] In step S2, the substrate 7 is preheated to a temperature close to and lower than the melting point of the aluminum alloy, and an aluminum silicate ceramic fiber heat insulation layer is arranged between the substrate 7 and the servo motor 9.

[0041] In step S3, a three-stage temperature control system is used to control: The temperature of the extrusion cylinder 3: maintain the plasticity of the aluminum alloy in solid state; The temperature of the threaded pipe 4: 5°C above the melting point; The temperature of the nozzle 6 outlet: 1°C higher than the solidification point.

[0042] In step S5, the nozzle 6 is fixed in the Z direction, and the layer height is adjusted by the Z direction movement of the substrate 7, so that the lifting of the substrate 7 in the Z direction replaces the lifting and lowering movement of the nozzle 6, and the mechanical braking of the nozzle part caused by the movement of the nozzle 6 in the Z direction when the scanning speed is high is improved, which affects the forming precision.

[0043] It should be noted that in this document, the terms "comprise", "comprising", or any other variant thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements, but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without more limitations, an element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0044] In addition, it should be pointed out that the scope of the methods and systems in the embodiments of the present application is not limited to performing functions in the order shown or discussed, but can also include performing functions in a substantially simultaneous manner or in reverse order according to the functions involved, for example, the described method can be performed in an order different from that described, and various steps can also be added, omitted, or combined. In addition, the features described with reference to certain examples can be combined in other examples.

[0045] The embodiments of the present application are described above in combination with the drawings, but the present application is not limited to the above specific embodiments, and the above specific embodiments are only illustrative, not limiting, and those skilled in the art can make many forms under the inspiration of the present application without departing from the purpose of the present application and the scope protected by the claims.

Claims

1. A method for aluminum alloy deposition additive manufacturing based on metal extrusion, characterized in that, Includes the following steps: Step S1: Construct the target model using CAD software, import it into motion planning software to generate the deposition path, and then perform simulation verification. Step S2: Preheat the threaded tube (4) and the substrate (7), and feed the aluminum ingot (1) into the extrusion cylinder (3). Step S3: Control the extrusion rod (2) to push the aluminum ingot at a set speed and pressure, so that it is heated to 5°C above the melting point in the extrusion cylinder (3) and then the molten metal enters the threaded tube (4); Step S4: Control the rotation of the threaded tube (4) to stir the molten metal and ensure uniform composition; Step S5: Control the nozzle (6) to move along the path in the XY plane, extruding molten metal to deposit on the substrate (7), and cooling to form a cross-sectional profile; In step S6, the servo motor (9) drives the bracket (8) to lower the substrate (7) by one layer of cross-sectional profile height, and then uses the molten metal extruded by the nozzle (6) to deposit a new layer of cross-sectional profile on the cross-sectional profile. Step S8, repeat steps S5-S6 until the aluminum alloy structural component is completed.

2. The method according to claim 1, characterized in that, In step S1, the motion planning software is SproutCAM X17; simulation verification is used to check for collisions, singularities, and overtravel.

3. The method according to claim 1, characterized in that, In step S2, the preheating temperature of the substrate (7) is close to and lower than the melting point of the aluminum alloy, and an aluminum silicate ceramic fiber heat insulation layer is provided between the substrate (7) and the motor (9).

4. The method according to claim 1, characterized in that, In step S3, a three-stage temperature control system is used to control the following: Extrusion cylinder (3) temperature: maintains the solid plasticity of aluminum alloy; Threaded pipe (4) Temperature: 5°C above melting point; Nozzle (6) outlet temperature: 1℃ higher than the freezing point.

5. The method according to claim 1, characterized in that, In step S5, the nozzle (6) is fixed in the Z direction, and the layer height is adjusted by moving the substrate (7) in the Z direction.

6. An aluminum alloy deposition additive forming system based on metal extrusion for implementing the method as described in any one of claims 1-5, characterized in that, include: The extrusion feed module includes an extrusion rod (2), an extrusion pad (21) installed at the bottom of the extrusion rod (2), and an extrusion cylinder (3) that cooperates with the extrusion pad (21), for continuous conveying of aluminum ingots (1); The melting and homogenizing module includes a threaded tube (4) with a rotating function and a built-in temperature control device; The motion control module includes a nozzle (6) that moves in the XY plane, a worktable (8) that moves in the Z direction, a support (10) that supports the worktable (8), a base plate (7) that is fixed on the worktable (8), and a servo motor (9) that drives the worktable (8) to move up and down on the support (10). Temperature control system (5) is used to independently regulate the temperature of extrusion cylinder (3), threaded tube (4), nozzle (6) and substrate (7); The control terminal (11) is used to perform path planning and coordinate the actions of each module.

7. The system according to claim 6, characterized in that, The threaded pipe (4) is directly connected to the nozzle (6), and its rotation speed is adjustable to achieve homogenization of the molten metal composition.

8. The system according to claim 6, characterized in that, A heat insulation layer is provided between the substrate (7) and the servo motor (9), and the material is aluminum silicate ceramic fiber.

9. The system according to claim 6, characterized in that, The temperature control system (5) includes four independent closed-loop temperature control units, which correspond to the extrusion cylinder (3), threaded tube (4), nozzle (6) outlet and substrate (7), respectively.

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