Component forming method based on electric arc additive and pressing die compounding

Abstract

The invention relates to a part forming method based on electric arc material increase and pressing die combination. The part forming method comprises the following steps that a cavity and a core are machined through the electric arc material increase technology; the cavity and the core are installed on a die-casting machine, and a part is machined and formed in the cavity and the core through a high-pressure die pressing technology; and the cavity and the core are pushed out of the die casting machine, and the part is demolded from the cavity and the core. The cavity and the core are machined through the electric arc additive process, the cavity and the core are formed at a time, the situation that the manufacturing period is long due to the fact that multiple sets of molds are designed is avoided, the part is machined and formed in the cavity and the core through the high-pressure mold pressing process, the part is integrally formed, and the situation that the reliability of the overall strength is reduced due to the welding process is avoided. The problem that in the prior art, when an existing casting process is used for manufacturing a complex topological structure, the requirements for high strength and rapid forming cannot be met at the same time is solved.

Description

Technical Field

[0001] This application relates to the field of mold preparation, specifically to a component forming method based on a combination of electric arc additive manufacturing and compression molding. Background Technology

[0002] Currently, in the automotive and transportation equipment sector, large, complex, thin-walled load-bearing structural components have long faced severe challenges. To meet increasingly stringent requirements for energy conservation, emission reduction, and performance improvement, structures are developing towards lightweighting. Based on the stress conditions, these components can form complex shapes with thin walls and multiple ribs through topology optimization.

[0003] In related technologies, existing casting processes have bottlenecks when manufacturing complex topological structures. These structures require the manufacture of many components, and the mold design and manufacturing cycle for each component is long. They also rely on high-precision machining, resulting in long manufacturing cycles and high costs. Furthermore, after the components are cast, they need to be welded and assembled, and the welds are prone to cracking, which reduces the reliability of the overall strength. It is difficult to meet the requirements of both high strength and rapid prototyping.

[0004] Therefore, it is necessary to design a component forming method based on electric arc additive manufacturing and compression molding to overcome the above problems. Summary of the Invention

[0005] This application provides a component forming method based on a combination of electric arc additive manufacturing and compression molding, which can solve the technical problem in the existing casting process of related technologies that it is difficult to meet the requirements of high strength and rapid prototyping when manufacturing complex topological structures.

[0006] In a first aspect, embodiments of this application provide a component forming method based on a combination of electric arc additive manufacturing and compression molding, which includes the following steps: Using electric arc additive manufacturing process to process cavities and cores; The cavity and core are installed in the die-casting machine, and the parts are formed by high-pressure molding process in the cavity and core; The cavity and core are pushed out of the die-casting machine, and the part is demolded from the cavity and core.

[0007] In conjunction with the first aspect, in one embodiment, the machining of the cavity and core using the electric arc additive manufacturing process includes: Design the structural models of the cavity and core based on the three-dimensional model of the component; Based on the structural models of the cavity and core, a robot equipped with an arc welding head is used to deposit welding material layer by layer to form the cavity and core. In conjunction with the first aspect, in one embodiment, the step of depositing welding material layer by layer using a robot equipped with an arc welding head to form the cavity and core, based on the structural model of the cavity and core, includes: First, the solid areas of the cavity and core are welded, and then the rib grooves of the cavity and core are gradually filled. The cavity is heated as a whole to relieve stress after each deposition of a preset thickness.

[0008] In conjunction with the first aspect, in one embodiment, after the layer-by-layer deposition of weld overlay material using a robot equipped with an arc welding head to form a cavity and a core, the method includes: Mill the surface of the cavity to the designed dimensions of the cavity.

[0009] In conjunction with the first aspect, in one embodiment, the process of forming a component in a cavity and a core using a high-pressure molding process includes: The cavity and core are heated to a first set temperature, while the molten alloy is maintained at a second set temperature; The alloy is hydraulically injected between the cavity and the core, and the cavity and core are filled and pressure is maintained to obtain the part.

[0010] In conjunction with the first aspect, in one embodiment, the step of hydraulically injecting the alloy fluid between the cavity and the core, filling the cavity and the core, and holding pressure to obtain the component includes: The molten alloy is pushed into the gate at the first injection velocity; The alloy liquid is injected between the cavity and the core at a second injection speed, and the pressure is maintained to obtain the part.

[0011] In conjunction with the first aspect, in one embodiment, the alloy liquid is configured as an aluminum alloy.

[0012] In conjunction with the first aspect, in one embodiment, the machining of the cavity and core using the electric arc additive manufacturing process further includes: Additional welding or geometric adjustments are made to specific areas of the cavity and core to obtain a structurally adjusted cavity and core. The restructured cavity and core are installed on a die-casting machine, and a correction component is formed in the cavity and core using a high-pressure die-casting process. The correction component is lighter than the main component.

[0013] In conjunction with the first aspect, in one embodiment, the cavity is provided with a plurality of protrusions spaced apart, and the core is provided with a plurality of bent plates spaced apart, each of the bent plates being used to insert into the gap between two adjacent protrusions, and the shape of the bent plate being consistent with the shape of the gap between two adjacent protrusions.

[0014] In conjunction with the first aspect, in one embodiment, the tip of the cavity and the tip of the core are both configured as arc-shaped.

[0015] The beneficial effects of the technical solutions provided in this application include: By utilizing arc additive manufacturing technology to process cavities and cores, which are formed in one step, the long manufacturing cycle caused by designing multiple sets of molds is avoided. By using high-pressure molding technology to process components in cavities and cores, the components are formed as a single piece, avoiding the reduction in overall strength and reliability caused by welding processes. This solves the problem that existing casting processes in related technologies are difficult to meet the requirements of high strength and rapid prototyping when manufacturing complex topological structures. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A flowchart illustrating a component forming method based on arc additive manufacturing and compression molding, provided for embodiments of this application; Figure 2 A schematic diagram illustrating the assembly of the cavity, core, and components provided in the embodiments of this application; Figure 3 This is a schematic diagram of the cavity structure provided in an embodiment of this application; Figure 4 This is a schematic diagram of the core structure provided in the embodiments of this application; Figure 5 This is a schematic diagram of the structure of the component provided in the embodiments of this application; Figure 6 An exploded view of the die-casting machine provided in an embodiment of this application.

[0018] In the diagram: 1. Cavity; 11. Protrusion; 2. Core; 21. Bending plate; 3. Component; 4. Die casting machine; 41. Moving mold base plate; 42. Push plate; 43. Support plate; 44. Pad plate; 45. Fixed mold base plate. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0020] This application provides a component forming method based on a combination of electric arc additive manufacturing and compression molding, which can solve the technical problem that existing casting processes are unable to simultaneously meet the requirements of high strength and rapid prototyping when manufacturing complex topological structures.

[0021] See Figure 1 As shown in the figure, this application provides a component forming method based on arc additive manufacturing and compression molding, which includes the following steps: S1: Cavity 1 and core 2 are fabricated using electric arc additive manufacturing process.

[0022] S2: Install cavity 1 and core 2 on die casting machine 4, and use high pressure molding process to process component 3 in cavity 1 and core 2.

[0023] S3: Push cavity 1 and core 2 out of die casting machine 4, and demold part 3 from cavity 1 and core 2.

[0024] In this embodiment, the cavity 1 and the core 2 are rapidly prepared using an electric arc additive manufacturing process. The cavity 1 and the core 2 are formed in one step, avoiding the need for designing multiple molds that would result in a long manufacturing cycle and significantly shortening the mold manufacturing cycle. The cavity 1 and the core 2 are installed on the die-casting machine 4, and the component 3 is formed in the cavity 1 and the core 2 using a high-pressure molding process. The cavity 1 and the core 2 are then ejected from the die-casting machine 4, and the component 3 is demolded from the cavity 1 and the core 2. The component 3 has complex ribs and hollow structures. The component 3 is integrally formed, avoiding the need for segmented connection of the component 3 during processing and avoiding the reduction in overall strength reliability caused by welding processes. This ensures the strength of the complex topology while achieving rapid prototyping of the complex topology. The formed component 3 can be directly integrated into the vehicle chassis without welding assembly. Furthermore, the component 3 has high precision, good integrity, and high assembly coordination, meeting the tolerance requirements of vehicle manufacturing and greatly improving the efficiency of product iteration and customization.

[0025] The die-casting machine 4 includes a moving mold base plate 41, such as Figure 6 As shown, a push plate 42 is slidably mounted on the moving mold base plate 41. Support plates 43 are provided on both sides of the push plate 42. The support plates 43 are used to limit the cavity 1 and the core 2. Two spaced pads 44 are provided on the push plate 42. A fixed mold base plate 45 is provided on the pads 44. The cavity 1 and the core 2 are used to clamp between the two pads 44.

[0026] This embodiment utilizes an electric arc additive manufacturing process to process the cavity 1 and the core 2, wherein the cavity 1 and the core 2 are formed in one step, avoiding the need for designing multiple sets of molds that would result in a long manufacturing cycle. The component 3 is formed by processing the cavity 1 and the core 2 using a high-pressure molding process, wherein the component 3 is integrally formed, avoiding the reduction in overall strength reliability caused by welding processes. This solves the problem that existing casting processes in related technologies are difficult to simultaneously meet the requirements of high strength and rapid prototyping when manufacturing complex topological structures.

[0027] Further, see Figure 2-4 As shown, in some embodiments, the machining of the cavity 1 and the core 2 using the electric arc additive manufacturing process includes: S11: Design the structural models of cavity 1 and core 2 based on the three-dimensional model of component 3.

[0028] S12: Based on the structural models of cavity 1 and core 2, a robot equipped with an arc welding head is used to deposit welding material layer by layer to form cavity 1 and core 2.

[0029] In this embodiment, exemplary, component 3 is configured as a large load-bearing frame. The front of component 3 is used to install an electrical box, the middle of component 3 is used to carry a battery driver, and the rear of component 3 is used to support heavy-duty cargo. Component 3 requires the removal of redundant material while meeting the requirements for front stiffness and rear heavy-duty load-bearing capacity. Intersecting ribs are formed longitudinally and laterally inside component 3, and solid reinforcement zones are provided in local high-stress areas. The height of component 3 is set to 105~110 mm, the wall thickness of the frame of component 3 is set to 10~30 mm, the thickness of the ribs is set to 4~6 mm, and component 3 is made of aluminum alloy. For example, high-strength die-cast aluminum alloy, high-ductility die-cast aluminum alloy, or A356 aluminum alloy. The cavity 1 and the core 2 are made of steel, and the welding material is H13 mold steel or 18Ni maraging steel. The arc additive manufacturing trajectory of the robot is obtained according to the structural model of the cavity 1 and the core 2. The six-axis robot performs arc additive manufacturing along the arc additive manufacturing trajectory. The protective gas is argon and 5% carbon dioxide. The welding current is set to 300A and the welding voltage is set to 32V. The cavity 1 and the core 2 form a pressing mold. The forming method of the pressing mold adapted to the component 3 is also applicable to products of other shapes, which will not be described in detail here.

[0030] Further, see Figure 2-4 As shown, in some embodiments, the step of depositing welding material layer by layer using a robot equipped with an arc welding head to form the cavity 1 and the core 2 according to the structural models of the cavity 1 and the core 2 includes: First, the solid areas of cavity 1 and core 2 are welded together, and then the rib grooves of cavity 1 and core 2 are gradually filled. Cavity 1 is heated as a whole to relieve stress after each deposition of a preset thickness.

[0031] In this embodiment, the solid areas of the cavity 1 and the core 2 are first welded together, and then the grooves of the cavity 1 and the core 2 are gradually filled to avoid the collapse of the cavity 1 and the core 2 during the arc additive manufacturing process. For example, the height of the blank cavity 1 is about 150 mm. The cavity 1 is heated to relieve stress every 50 mm of deposition to reduce the residual stress in the cavity 1 and prevent cracking. The set heating temperature is 600°C.

[0032] Further, see Figure 3 and Figure 4 As shown, in some embodiments, after the robot equipped with an arc welding head deposits welding material layer by layer to form cavity 1 and core 2, the process includes: S13: Mill the surface of cavity 1 to the designed dimensions of cavity 1.

[0033] In this embodiment, before milling the surface of the cavity 1, a machining allowance of 0.2~0.4 mm is left in the cavity 1. Precision machining, such as milling, grinding or polishing, is performed on the key surfaces of the cavity 1 to remove the gate and flash of the blank cavity 1. The inner surface of the cavity 1 is then milled to obtain the cavity 1 of the designed size, ensuring the dimensional accuracy and surface roughness of the cavity 1. Both the cavity 1 and the core 2 are subjected to quenching and tempering treatment to improve the thermal fatigue performance of the cavity 1 and the core 2. After quenching and tempering, the hardness of the cavity 1 and the core 2 is about 45 HRC.

[0034] Further, see Figure 2-5 As shown, in some embodiments, the process of forming component 3 in cavity 1 and core 2 using high-pressure molding includes: S21: Heat the cavity 1 and the core 2 to the first set temperature, and keep the molten alloy at the second set temperature.

[0035] S22: The alloy is hydraulically injected between cavity 1 and core 2, and the cavity 1 and core 2 are filled and pressure is maintained to obtain part 3.

[0036] In this embodiment, exemplary, before die casting the component 3 in the cavity 1 and the core 2, the cavity 1 and the core 2 are preheated to 200°C to 300°C to reduce the thermal shock during alloy liquid filling, and the alloy liquid is maintained at 680°C to 720°C. The alloy liquid is then injected into the cavity 1 and the core 2 in the die casting machine 4, and the mold is filled between the cavity 1 and the core 2. The component 3 is obtained by holding the pressure.

[0037] Furthermore, in some embodiments, the step of hydraulically injecting the alloy fluid between the cavity 1 and the core 2, filling the cavity 1 and the core 2, and holding the pressure to obtain the component 3 includes: S221: Push the molten alloy into the gate at the first injection speed.

[0038] S222: The alloy liquid is injected between the cavity 1 and the core 2 at the second injection speed, and the pressure is maintained to obtain the component 3.

[0039] In this embodiment, the vacuum system is turned on. In the first stage of the injection process, the alloy liquid is pushed into the gate at a low injection speed of 0.2 m / s, and the vacuum degree is maintained at -0.05 MPa. In the second stage of the injection process, the alloy liquid is injected into the space between the cavity 1 and the core 2 at a high injection speed of 5 m / s to achieve rapid filling. The injection specific pressure is maintained at 100 MPa. During the solidification stage of the alloy liquid, the pressure is maintained at 80 MPa. Vacuum assistance during the die casting process can reduce the generation of porosity. At the same time, the alloy liquid smoothly fills the ribs under vacuum assistance, and no under-casting phenomenon occurs. The key parts of the component 3 are inspected, such as the transition of the frame and the intersection of the ribs. No obvious shrinkage cavities or cracks are found. Finally, the cavity 1 and the core 2 are opened, the component 3 is taken out, the burrs and gate of the component 3 are removed, and the component 3 is subjected to weak aging treatment to stabilize the microstructure of the component, thus obtaining the final component 3.

[0040] Furthermore, in some embodiments, the molten alloy is an aluminum alloy.

[0041] In this embodiment, the alloy liquid is made of aluminum alloy, which ensures the structural strength of the component 3 while achieving lightweight. Exemplarily, the aluminum alloy is made of Al-10Si-Mg alloy, so that the yield strength of the component 3 is greater than or equal to 300MPa and the elongation of the component 3 is about 8%.

[0042] Furthermore, in some embodiments, the process of machining the cavity 1 and the core 2 using the electric arc additive manufacturing process further includes: S23: Perform additional welding or geometric adjustments on local parts of cavity 1 and core 2 to obtain cavity 1 and core 2 after structural adjustment; S24: The adjusted cavity 1 and core 2 are installed on the die-casting machine 4, and a correction component is formed in the cavity 1 and core 2 using a high-pressure die-casting process, wherein the correction component is lighter than component 3.

[0043] In this embodiment, in the initial stage, the cavity 1 and the core 2 are processed using an electric arc additive manufacturing process, and the component 3 is formed in the cavity 1 and the core 2 using a high-pressure molding process. The structural strength, stiffness, assembly accuracy, and fatigue performance of the component 3 are initially verified to ensure the overall reliability of the component 3 and verify the feasibility of the processing technology. During the iteration process, the electric arc additive manufacturing process is used to supplement the welding or geometric adjustment of the existing cavity 1 and core 2 locally, gradually reducing redundant material. After each additive correction and post-processing is completed, the molding process is re-produced, and the results are verified by 3D scanning and industrial CNC machining. T-tests and mechanical tests were used to verify the modified component, resulting in the final component 3 that approached the limit of lightweight design. This approach gradually converged from a conservative and safe setting to the optimal lightweight setting, avoiding the traditional mold-making process of completely remaking the mold, prototyping, and remaking the mold. This reduced the mold-making cost and shortened the mold-making cycle. Finite element analysis showed that the overall stiffness of component 3 met the design target. At the same time, component 3 reduced the weight by about 20% compared to the existing welded steel structure. Test results showed that component 3 exhibited excellent strength and durability under key load conditions (bending or fatigue), achieving the dual goals of structural weight reduction and performance improvement.

[0044] Further, see Figure 2-5 As shown, in some embodiments, the cavity 1 is provided with a plurality of protrusions 11 spaced apart, and the core 2 is provided with a plurality of bent plates 21 spaced apart. Each bent plate 21 is used to insert into the gap between two adjacent protrusions 11, and the shape of the bent plate 21 is consistent with the shape of the gap between two adjacent protrusions 11.

[0045] In this embodiment, the cross-section of the protrusion 11 can be set as triangular, rectangular or arc-shaped. The cavity 1 and the core 2 form a processing cavity for the component 3. The protrusion 11 corresponds to the groove of the component 3. The bent plate 21 corresponds to the hollow structure of the component 3. The curvature of the bent plate 21 is equal to the curvature of the corresponding protrusion 11. The frame and ribs of the component 3 are connected to each other. During the filling process, the casting parts of the component 3 are connected to form internal flow channels and cooling channels, which improves the temperature control efficiency of the high-pressure molding process, reduces the air entrapment generated by the collision of the alloy liquid front, and improves the filling quality of the component 3.

[0046] Further, see Figure 2-5 As shown, in some embodiments, the tip of the cavity 1 and the tip of the core 2 are both set to be arc-shaped.

[0047] In this embodiment, the cross-section of some of the protrusions 11 is set as a variable cross-section, and the inner wall of the cavity 1 and the outer wall of the core 2 are provided with draft angles along the demolding direction, so that the inner sidewalls corresponding to the grooves of the component 3 and the corners are smoothly transitioned, thereby reducing the sticking resistance and frictional resistance, reducing the risk of demolding defects, and ensuring that the component 3 can be reliably demolded from the cavity 1 and the core 2 while maintaining structural integrity.

[0048] In the description of this application, it should be noted that the terms "upper," "lower," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Unless otherwise expressly specified and limited, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication between two elements. For those skilled in the art, the specific meaning of the above terms in this application can be understood according to the specific circumstances.

[0049] It should be noted that in this application, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0050] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A method for forming a part based on a combination of electric arc additive and die molding, characterized by, It comprises the following steps: Processing the cavity (1) and the core (2) by using the electric arc additive process; Installing the cavity (1) and the core (2) on the die casting machine (4), and processing the component (3) in the cavity (1) and the core (2) by using the high-pressure die casting process; Pushing the cavity (1) and the core (2) out of the die casting machine (4), and demolding the component (3) from the cavity (1) and the core (2).

2. The method of claim 1, wherein, The processing of the cavity (1) and the core (2) by using the electric arc additive process comprises: Designing a structure model of the cavity (1) and the core (2) according to a three-dimensional model of the component (3); Depositing a surfacing material layer by layer by using a robot carrying an electric arc welding head according to the structure model of the cavity (1) and the core (2) to form the cavity (1) and the core (2).

3. The method of claim 2, wherein, The depositing of the surfacing material layer by layer by using the robot carrying the electric arc welding head according to the structure model of the cavity (1) and the core (2) to form the cavity (1) and the core (2) comprises: Surfacing the solid area of the cavity (1) and the core (2) first, and then gradually filling the rib groove of the cavity (1) and the core (2), and the cavity (1) is heated as a whole to relieve stress after being deposited by a preset thickness.

4. The method of claim 2, wherein, After the depositing of the surfacing material layer by layer by using the robot carrying the electric arc welding head to form the cavity (1) and the core (2), it comprises: Milling the surface of the cavity (1) to the designed size of the cavity (1).

5. The method of claim 1, wherein, The processing of the component (3) in the cavity (1) and the core (2) by using the high-pressure die casting process comprises: Heating the cavity (1) and the core (2) to a first set temperature, and keeping the alloy liquid at a second set temperature; Pressing the alloy liquid into the cavity (1) and the core (2), and filling the cavity (1) and the core (2) to obtain the component (3).

6. The method of claim 5, wherein the method further comprises, The pressing of the alloy liquid into the cavity (1) and the core (2), and the filling of the cavity (1) and the core (2) to obtain the component (3) comprises: Pushing the alloy liquid into the sprue at a first pressing speed; Injecting the alloy liquid into the cavity (1) and the core (2) at a second pressing speed, and keeping pressure to obtain the component (3).

7. The method of claim 5, wherein the method further comprises, The alloy liquid is set as an aluminum alloy.

8. The method of claim 1, wherein, The processing of the cavity (1) and the core (2) by using the electric arc additive process further comprises: Supplementarily surfacing or geometrically adjusting the cavity (1) and the core (2) at a local part to obtain the cavity (1) and the core (2) after structure adjustment; Installing the cavity (1) and the core (2) after structure adjustment on the die casting machine (4), and processing a modified component in the cavity (1) and the core (2) by using the high-pressure die casting process, wherein the modified component is lighter than the component (3).

9. The component forming method based on the combination of electric arc additive and die casting according to claim 1, wherein A plurality of protrusions (11) are arranged at intervals in the cavity (1), and a plurality of bent plates (21) are arranged at intervals in the core (2), each of the bent plates (21) is used for being inserted into the gap between two adjacent protrusions (11), and the shape of the bent plate (21) is consistent with the shape of the gap between the two adjacent protrusions (11).

10. The method of claim 1, wherein, The tip of the cavity (1) and the tip of the core (2) are both arranged in an arc shape.

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