Active cooling and gas protection device and method for magnesium alloy electric arc additive manufacturing

Abstract

The embodiment of the invention discloses an active cooling and gas protection device and method for magnesium alloy electric arc additive manufacturing. The device comprises a pipeline, wherein the pipeline is arranged in the side wall and the bottom of a groove structure and used for allowing heat dissipation fluid to pass through; a gap exists between the magnesium alloy component and the side wall of the cooling assembly; and the inert gas is filled into the gap and can take away heat on the magnesium alloy component. The rapid cooling effect is achieved through the side wall and the bottom of the cooling assembly, the base plate can be cooled through the side wall, in addition, the cavity is formed between the magnesium alloy component and the cooling assembly, gaps are formed in the two sides of the magnesium alloy component, after inert gas is filled, the inert gas flows through the gaps, and the cooling effect is achieved. The magnesium alloy component easy to oxidize is protected, oxidation of the component is avoided, the surface quality of the component is improved, oxide inclusions are reduced, and meanwhile cooling of the magnesium alloy component is accelerated.

Description

Technical Field

[0001] The present invention relates to the field of additive manufacturing, and in particular, to an active cooling and gas protection device for arc additive manufacturing of magnesium alloys. Background Art

[0002] In the fields of aerospace and transportation, lightweighting is a very important theme. Therefore, in these fields, more and more researchers have begun to focus on magnesium alloys. As the lightest structural metal, it has excellent specific strength. Especially when elements such as Gd, Y, Nd, and Zr are added to magnesium alloys, the performance of magnesium alloys will be greatly improved, such as WE43 alloy.

[0003] Arc additive manufacturing (WAAM), which uses an arc as the energy source and wire as the raw material, has the characteristics of low cost, high deposition efficiency, high material utilization rate, and the forming size is not limited by space. Therefore, currently WAAM is usually used to manufacture large and expensive components in advanced fields such as aerospace. In the WAAM manufacturing process, cold metal transfer (CMT) is currently the most promising. CMT realizes the transfer of molten droplets through short-circuit transfer and wire retraction, and has the advantages of low heat input, less spatter, and stable process. Therefore, CMT-WAAM is particularly suitable for manufacturing large magnesium alloy components.

[0004] Although it is currently possible to form magnesium alloy components through WAAM manufacturing technology, due to the heat input and layer-by-layer deposition strategy during the WAAM process, the components are greatly affected by heat during the deposition process, which will affect the microstructure and properties, especially for metals such as Mg-RE alloys that have an age hardening response. Its main strengthening mechanism is precipitation strengthening, and the type and density of precipitates are mainly related to the thermal history of the material. Therefore, it is necessary to optimize the microstructure and properties by managing the heat input and heat accumulation during the WAAM process. Currently, some researchers have proposed some methods for heat management during the WAAM manufacturing process, such as the method of immersing the substrate in liquid nitrogen, or the method of immersing the printed component in water, etc. However, since magnesium alloys react with water at high temperatures to generate flammable hydrogen gas, this method is not feasible for magnesium alloys. There is also an active cooling method of contacting the component with a heat-conducting copper plate. By passing water through the copper plate and directly contacting the deposited magnesium alloy component, a rapid cooling effect can be achieved. Although this method can improve the surface flatness of the component, due to the too-close distance between the copper block and the arc during the manufacturing process, the arc will shift towards the copper block, thus affecting the deposition effect. At the same time, the contact cooling method will also interfere with the welding torch during the manufacturing process and requires continuous adjustment during the manufacturing process, increasing the complexity of the operation. At the same time, due to the easy oxidation of magnesium alloys, atmosphere protection during the additive manufacturing process is also equally important. The protection of inert gas can prevent the surface of the component from being oxidized.

[0005] From the above research, it can be seen that active cooling technology can achieve thermal management during the deposition process, and thus optimize the structure and performance of magnesium alloy components manufactured by WAAM. However, there is still a lack of an effective, safe, low-cost and easy-to-operate active cooling device (ACT) to regulate the heat input during the magnesium alloy WAAM process, thereby optimizing its structure and performance. Summary of the invention

[0006] In a first aspect, an active cooling and gas protection device for magnesium alloy arc additive manufacturing includes a cooling component, wherein the cooling component is a groove structure with an opening at the top, the middle area of ​​the groove structure is a deposition area of ​​the magnesium alloy component to be manufactured, and a pipeline for passing a heat dissipation fluid is provided in the side wall and the bottom of the groove structure;

[0007] There is a gap between the magnesium alloy component and the side wall of the cooling assembly;

[0008] The invention also includes an inert gas which is filled into the gap and can take away the heat from the magnesium alloy component.

[0009] In an optional embodiment, the side wall includes a baffle assembly and a cooling plate, and the bottom is a substrate formed by the magnesium alloy component;

[0010] The baffle assembly is connected to the cooling plate and both are arranged on the base plate;

[0011] The partition assembly is provided with a vent hole, and the vent hole is used to fill the inert gas into the gap.

[0012] In an optional embodiment, the cooling plate includes a first cooling plate and a second cooling plate, and the long side directions of the first cooling plate and the second cooling plate are consistent with the direction of the fluid in the pipeline;

[0013] The first cooling plate and the second cooling plate are arranged relatively on the substrate, and the substrate, the first cooling plate and the second cooling plate are each provided with at least one pipeline, and at least one pipeline of the first cooling plate, at least one pipeline of the second cooling plate and at least one pipeline of the substrate form a cooling circuit.

[0014] In an optional embodiment, when the substrate, the first cooling plate and the second cooling plate are each provided with a plurality of the pipes, the plurality of pipes of the substrate, the plurality of pipes of the first cooling plate and the plurality of pipes of the second cooling plate are uniformly and longitudinally distributed in parallel.

[0015] In an optional embodiment, the baffle assembly includes a first baffle and a second baffle;

[0016] The first partition plate and the second partition plate are arranged opposite to each other on the substrate, the first partition plate and the second partition plate are connected to the cooling plate, and the substrate, the first partition plate, the second partition plate and the cooling plate together form the groove structure.

[0017] In an optional embodiment, the partition assembly is formed by bending a steel plate.

[0018] In an optional embodiment, the partition assembly is connected to the cooling plate by bolts.

[0019] In an optional embodiment, the substrate has a length of 370-390 mm, a width of 240-260 mm, and a height of 15-25 mm.

[0020] In an optional embodiment, the magnesium alloy component is deposited using a CMT deposition mode, adopting a single-pass multi-layer bidirectional deposition strategy.

[0021] In a second aspect, an active cooling and gas protection method for arc additive manufacturing of magnesium alloys is provided, using the above-mentioned device, the method comprising:

[0022] Passing heat dissipation fluid through the pipes on the side walls and bottom of the groove structure;

[0023] An inert gas is filled into a gap between the magnesium alloy component and the cooling assembly, and the heat of the magnesium alloy component is taken away by the inert gas.

[0024] The embodiments of the present application have the following beneficial effects:

[0025] The embodiment of the present application discloses an active cooling and gas protection device for magnesium alloy arc additive manufacturing, including a cooling component, the cooling component is a groove structure with an opening at the top, the middle area of ​​the groove structure is the deposition area of ​​the magnesium alloy component to be manufactured, and the side wall and the bottom of the groove structure are provided with a pipeline for passing a heat dissipation fluid; there is a gap between the magnesium alloy component and the side wall of the cooling component; and also includes an inert gas filled into the gap that can take away the heat on the magnesium alloy component. In the present application, the side wall and the bottom of the cooling component are used to achieve a rapid cooling effect, and the side wall can also dissipate heat for the substrate. In addition, the cavity formed between the magnesium alloy component and the cooling component has gaps on both sides of the magnesium alloy component. After the inert gas is filled, the inert gas will flow through the gap, forming a protective effect on the easily oxidized magnesium alloy component, avoiding the oxidation of the component, improving the surface quality of the component, reducing oxidation inclusions, and also accelerating the cooling of the magnesium alloy component. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] To more clearly illustrate the technical solution of the present invention, the accompanying drawings required in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as limiting the protection scope of the present invention. In each drawing, similar components are numbered similarly.

[0027] Figure 1 Shows a schematic diagram of a device for manufacturing a magnesium alloy component proposed in an embodiment of the present application;

[0028] Figure 2 Shows a front view of the overall appearance of an active cooling and gas protection device for magnesium alloy arc additive manufacturing proposed in an embodiment of the present application;

[0029] Figure 3 Shows an axonometric view of the active cooling and gas protection device for magnesium alloy arc additive manufacturing in an embodiment of the present application;

[0030] Figure 4 Shows a schematic diagram of substrate cooling of the active cooling and gas protection device for magnesium alloy arc additive manufacturing in an embodiment of the present application;

[0031] Figure 5 Shows a schematic diagram of bypass cooling of the active cooling and gas protection device for magnesium alloy arc additive manufacturing in an embodiment of the present application;

[0032] Figure 6 Is a comparison of the SEM (Scanning Electron Microscope) morphology of the WE43 component with or without the assistance of the active cooling and gas protection device for magnesium alloy arc additive manufacturing in an embodiment of the present application.

[0033] Figure 7 Is the TEM (Transmission Electron Microscope) morphology of the WE43 component manufactured with the assistance of the active cooling and gas protection device for magnesium alloy arc additive manufacturing in an embodiment of the present application.

[0034] Figure 8 Is the TEM morphology of the WE43 component manufactured without the assistance of the active cooling and gas protection device for magnesium alloy arc additive manufacturing in an embodiment of the present application.

[0035] Legend: 1. CMT welding torch; 2. First cooling plate; 3. Substrate; 4. First partition; 5. Water through hole; 6. Ventilation hole; 7. Second partition; 8. Second cooling plate. Detailed implementation manners

[0036] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0037] In order to more clearly show the implementation steps and advantages of the invention, the following describes the specific implementation manners in conjunction with the legends.

[0038] An embodiment of the present application provides an active cooling and gas protection device for magnesium alloy arc additive manufacturing, which is used to solve the heat accumulation during the CMT (Cold Metal Transfer) arc additive manufacturing process and the adverse effects of heat input on the microstructure and properties of magnesium alloys. While ensuring safety and easy operation, this device not only achieves a good cooling effect, can improve the microstructure uniformity and mechanical properties of magnesium alloy components, but also improves the surface quality of magnesium alloy components.

[0039] In the embodiment of the present invention as Figure 1 shown, the active cooling and gas protection device for magnesium alloy arc additive manufacturing includes a cooling component. The cooling component is a groove structure with an open top. The middle area of the groove structure is the deposition area of the magnesium alloy component to be manufactured. Heat dissipation fluid pipelines are provided inside the side walls and the bottom of the groove structure; there is a gap between the magnesium alloy component and the side walls of the cooling component; it also includes an inert gas filled into the gap that can take away the heat on the magnesium alloy component.

[0040] In this embodiment, the side walls of the cooling component include a partition component and a cooling plate, and the bottom is a substrate for the formation of the magnesium alloy component; the partition component is connected to the cooling plate and is both arranged on the substrate; the partition component is provided with ventilation holes for filling inert gas into the gap. In other words, the cooling component is composed of a substrate and side walls, and there is a gap between the manufactured magnesium alloy component and the side walls of the cooling component, that is, a cavity is formed.

[0041] In the process of manufacturing magnesium alloy components, the welding gun will be farther and farther away from the substrate. If cooling is only performed through the substrate of the cooling assembly, the effect of rapid cooling cannot be achieved. In this embodiment, in the early stage of manufacturing magnesium alloy components, the substrate will take away most of the heat. As the manufacturing process proceeds, the welding gun is farther and farther away from the substrate. Part of the heat of the magnesium alloy component will be transferred to the side wall of the cooling assembly, that is, the side wall of the groove structure, in the form of thermal radiation, and part of it will be transferred to the substrate of the cooling assembly through the magnesium alloy component, thereby achieving a rapid cooling effect; in addition, by filling the gap with inert gas, on the one hand, a protective atmosphere can be formed in the device to protect the easily oxidized magnesium alloy components, thereby avoiding oxidation of the magnesium alloy components, reducing oxidized inclusions, and protecting the magnesium alloy components. On the one hand, because of the protective effect of the cavity formed between the magnesium alloy component and the cooling assembly, there is a gap around the deposited magnesium alloy component. After being filled with inert gas, the inert gas will flow through the gap and take away the heat around the magnesium alloy component, which can further accelerate the reduction of the temperature of the magnesium alloy component on the basis of the heat dissipation of the cooling plate, and make up for the defect of reduced heat dissipation effect of the cooling plate caused by the gap. Therefore, under the premise of not affecting the deposition effect of the magnesium alloy component and ensuring the mechanical properties of the component, the surface quality of the magnesium alloy component is improved because of avoiding direct contact between the magnesium alloy component and the side wall and the protective effect of the inert gas.

[0042] It can be understood that the cooling assembly may include at least one cooling plate, each cooling plate is provided with at least one pipeline for passing the heat dissipation fluid, the partition assembly may include at least one partition, each partition is provided with a vent, multiple cooling plates can be connected to one partition, multiple cooling plates can be connected to multiple partitions, or one cooling plate can be connected to multiple partitions, and the cooling plates and partitions are both arranged on the substrate to form a groove structure.

[0043] like Figure 2 In the illustrated embodiment, the cooling plate comprises a first cooling plate (2) and a second cooling plate (8), the long side directions of the first cooling plate (2) and the second cooling plate (8) being consistent with the direction of the fluid in the pipeline; the first cooling plate (2) and the second cooling plate (8) are arranged on the substrate (3) relative to each other, the substrate (3), the first cooling plate (2) and the second cooling plate (8) are each provided with at least one pipeline, and at least one pipeline of the first cooling plate (2), at least one pipeline of the second cooling plate (8) and at least one pipeline of the substrate (3) form a cooling circuit.

[0044] like Figure 4As shown in the figure, at least one water through-hole (5) can be provided on the substrate (3). There is a pipeline for passing the heat dissipation flow in each water through-hole (5). When there are multiple pipelines, the multiple pipelines can be longitudinally parallel and evenly distributed, or the distribution can be adjusted according to the actual situation. The size of the above-mentioned substrate (3), the diameter of each water through-hole (5) on the substrate (3), and the adjacent hole spacing can all be set according to the actual situation. Among them, the size of the substrate (3) can be: the length is 370 - 390 mm, the width is 240 - 260 mm, and the height is 15 - 25 mm. Four water through-holes (5) can be provided on the short side of the substrate (3), the diameter of each water through-hole (5) is 15 mm, and the adjacent holes are spaced 20 mm apart.

[0045] The first cooling plate (2) and the second cooling plate (8) can be aluminum alloy plates. Aluminum alloy has better thermal conductivity. The cooling plates are placed on the substrate (3). Not only does it have a good heat dissipation effect itself, but it can also dissipate heat from the substrate (3). Among them, the size, the spacing distance, and the number of pipelines of the first cooling plate (2) and the second cooling plate (8) can all be set according to the actual situation.

[0046] For example, the sizes of the first cooling plate (2) and the second cooling plate (8) can both be 400 * 150 * 30 mm. The two cooling plates can be placed at intervals on both sides of the axis of the substrate (3), and the spacing distance between the first cooling plate (2) and the second cooling plate (8) can be 50 mm. Among them, fluids such as cooling water and rare gases can be passed through the pipelines.

[0047] When multiple pipelines are provided on the substrate, the first cooling plate, and the second cooling plate, the multiple pipelines in the substrate, the multiple pipelines in the first cooling plate, and the multiple pipelines in the second cooling plate are all longitudinally parallel and evenly distributed. Among them, the distribution of the multiple pipelines can also be set according to the actual situation. As Figure 3 shown, three water through-holes (5) can be provided on the short side of the first cooling plate (2), and the spacing between the three water through-holes (5) is the same. That is, when there are three pipelines in the first cooling plate (2), the three pipelines are all longitudinally parallel and evenly distributed. For example, the diameter of the water through-hole (5) on the first cooling plate (2) can be 20 mm, and the distance between each water through-hole (5) can be 30 mm. In this embodiment, at least one water through-hole (5) of the first cooling plate (2), at least one water through-hole (5) of the second cooling plate (8), and at least one water through-hole (5) of the substrate (3) can be connected through pipelines. In other words, at least one pipeline of the first cooling plate, at least one pipeline of the second cooling plate, and at least one pipeline of the substrate form a cooling loop.

[0048] During the manufacturing process, a heat dissipation fluid is continuously introduced into the pipeline, for example, cooling water is introduced into the pipeline by a water pump to reduce heat accumulation and heat input during the arc additive manufacturing process, thereby achieving cooling of the manufactured magnesium alloy component. The manufactured magnesium alloy component, that is, the manufactured thin-walled component, can have a length of 250 mm and a height of 80 mm.

[0049] In addition, the partition assembly includes a first partition (4) and a second partition (7), the first partition (4) and the second partition (7) are arranged on the substrate (3) relative to each other, the first partition (4) and the second partition (7) are connected to the cooling plate, and the substrate (3), the first partition (4), the second partition (7) and the cooling plate together form a groove structure.

[0050] like Figure 2 In the illustrated embodiment, the partition assembly comprises a first partition (4) and a second partition (7), the first partition (4) and the second partition (7) are arranged on the substrate (3) at intervals, the first partition (4) and the second partition (7) are each provided with at least one vent hole (6), one end of the first partition (4) is connected to one end of the second partition (7) through the first cooling plate (2), and the other end of the second partition (7) is connected to the other end of the first partition (4) through the second cooling plate (8). The first cooling plate (2), the second cooling plate (8), the first partition (4), the second partition (7) and the substrate (3) together form a groove structure. At least one vent hole (6) of the first partition (4) and at least one vent hole (6) of the second partition (7) are connected to an air pipe, which is used to introduce an inert gas that can take away the heat from the magnesium alloy component into the gap between the groove structure and the magnesium alloy component.

[0051] The first baffle (4) and the second baffle (7) can be formed by bending steel plates. The first baffle (4) and the second baffle (7) are connected to the first cooling plate (2) and the second cooling plate (8) by bolts, that is, the two baffles with vent holes (6) are fixedly connected to the two ends of the two cooling plates by bolts, and the gap between the first cooling plate (2), the second cooling plate (8), the first baffle (4) and the second baffle (7) forms a cavity. In other words, the substrate (3), the cooling plate and the baffle assembly form a groove structure, and the middle area of ​​the groove structure is a deposition area for thin-walled components, that is, a deposition area for magnesium alloy components. The inert gas can be argon gas, and the protective gas flow rate can be 20L / min, that is, the flow rate of the inert gas can be 20L / min.

[0052] It is understandable that when the magnesium alloy is constructed as WE43 alloy, the material of the substrate (3) can be AZ31 magnesium alloy, such as Figure 5As shown, the CMT welding torch (1) is correspondingly arranged above the formed groove structure. The material for depositing the magnesium alloy component in the CMT welding torch is WE43 magnesium alloy wire. The diameter of the WE43 magnesium alloy wire can be 1.2 mm, and the atomic percentage of the components is: Nd: 2.54%, Y: 5.92%, Zr: 0.46%, Gd: 1.60%, Mg: the balance. Among them, the wire feeding speed in the CMT welding torch (1) can be set to 8 m / min, the scanning speed is 10 mm / s, and the layer height is 2.5 mm.

[0053] Among them, the CMT deposition mode can be used for depositing the magnesium alloy component, and the single-pass multi-layer bidirectional deposition strategy is adopted, which can improve the surface roughness, forming efficiency and process stability of thin-walled parts. The CMT deposition mode and the single-pass multi-layer bidirectional deposition strategy are conventional technical means for those skilled in the art and will not be elaborated here.

[0054] This embodiment also provides an active cooling and gas protection method for magnesium alloy arc additive manufacturing. Using the above device, the method includes:

[0055] Passing a heat dissipation fluid through the pipelines on the side wall and bottom of the groove structure;

[0056] Filling an inert gas into the gap between the magnesium alloy component and the cooling component, and taking away the heat on the magnesium alloy component through the inert gas.

[0057] The implementation schemes and beneficial effects involved in the above embodiments are equally applicable in this embodiment and will not be elaborated here.

[0058] In the exemplary experiment, the arc additive manufacturing of the magnesium alloy component is carried out by using the aforementioned protection device and method. The specific process parameters of the CMT arc additive manufacturing are shown in Table 1. When the wire feeding speed is 8 m / min, the scanning speed is 10 mm / s, and the protective gas flow rate is 20 L / min, the length of the manufactured magnesium alloy component, that is, the thin-walled component, is about 250 mm, the height is 80 mm, 24 layers are deposited, and the interlayer waiting time is 30 s.

[0059]

[0060]

[0061] Table 1. CMT arc additive manufacturing parameters

[0062] The comparison diagram of the SEM morphology of the WE43 component assisted by the device of this embodiment and the SEM morphology of the WE43 component not assisted by the device of the embodiment is as Figure 6 shown, and the corresponding enlarged local view, Figure 6 b and Figure 6The eutectic phase (Eutectic phas) Mg3RE is distributed along the grain boundaries in e, and the particle phase (Particle phase) distributed in the grains is Zr single-element particles. From Figure 6 b and Figure 6 e comparison shows that the volume fraction of the eutectic phase in the WE43 alloy manufactured by using the active cooling and gas protection device of this embodiment is significantly reduced compared with that in the WE43 alloy manufactured without a cooling device. The grain size and the volume fraction of the eutectic phase of the component using the active cooling and gas protection device of this embodiment change less from the bottom to the top compared with the component without a cooling device, that is, the structure is more uniform. Among them, the brittle eutectic phase is prone to crack during the tensile process, which is not conducive to the plasticity of the material.

[0063] Figure 7 Figure Figure 7 shows the TEM results of the magnesium alloy component generated by using the device of this embodiment. From Figure 8 it can be seen that the precipitated phase in the magnesium alloy component manufactured by using the device of this embodiment is mainly the β1 phase (β1phase), and this β1 phase is the main strengthening phase of the WE43 alloy. As Figure 8 shown, the main phases in the magnesium alloy component manufactured without a cooling device are the β phase (β-Mg 12 RE) and the coarsened β1 phase (Coarsenβ1), and the β phase and the coarsened β1 phase are not conducive to the performance of the manufactured magnesium alloy component.

[0064] Through corresponding experiments, it can be known that the ultimate tensile strength (UTS), yield strength (YS) and elongation (EL) of the magnesium alloy component without cooling in the deposition direction (BD) are 239±2 MPa, 171±3 MPa and 6.5±1%, respectively. The UTS, YS and EL of the magnesium alloy component without cooling in the scanning direction (TD) of the welding torch are 234±2 MPa, 169±5 MPa and 5.5±1.2%, respectively. The UTS, YS and EL of the magnesium alloy component with cooling in the BD direction are 267±4 MPa, 180±6 MPa and 11.2±1%, respectively. The UTS, YS and EL of the magnesium alloy component with cooling in the TD direction are 263±2 MPa, 182±4 MPa and 9.5±1%, respectively. Therefore, the tensile properties and ductility of the cooled magnesium alloy component manufactured by using the active cooling and gas protection device for magnesium alloy arc additive manufacturing of this embodiment have been significantly improved.

[0065] In summary, part of the heat of the magnesium alloy component manufactured in this application is transferred to the side wall of the cooling component in the form of thermal radiation, and part is transferred to the substrate of the cooling component through the magnesium alloy component, thereby achieving a cooling effect. Moreover, the material of the side wall includes aluminum alloy with better thermal conductivity, which not only has a good heat dissipation effect itself but also can dissipate heat from the substrate. In addition, the cavity formed between the magnesium alloy component and the cooling component has gaps on both sides of the magnesium alloy component. After filling with inert gas, the inert gas will flow through the gaps, forming a protective effect on the easily oxidized magnesium alloy component, avoiding the oxidation of the component, improving the surface quality of the component, reducing oxidation inclusions, and at the same time accelerating the cooling of the magnesium alloy component.

[0066] Compared with the WE43 component manufactured without an active cooling device, the active cooling and gas protection device of this application makes the grains of the WE43 alloy thin-walled component finer, reduces the volume fraction of the hard and brittle eutectic phase, and the change in the grain size and the volume fraction of the eutectic phase from the bottom to the top of the component without a cooling device is smaller, that is, the structure is more uniform; at the same time, the active cooling and gas protection device of this application reduces the heat accumulation during the deposition process and the peak temperature in the thermal cycle. Therefore, the in-situ aging in the manufactured WE43 thin-walled component is weakened, inhibiting the coarsening of the β1 phase and the transformation of β1 to β phase, thereby improving the mechanical properties of the WE43 thin-walled component. In addition, the addition of gaps and inert gas also improves the surface quality of the workpiece.

[0067] The above is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention can easily think of changes or substitutions, which should all be covered within the protection scope of the present invention.

Claims

1. An active cooling and gas protection device for magnesium alloy arc additive manufacturing, comprising a cooling component, wherein the cooling component is a groove structure with a top opening, and the middle area of ​​the groove structure is a deposition area of ​​the magnesium alloy component to be manufactured, characterized in that : Pipes for passing heat dissipation fluid are provided in the side walls and bottom of the groove structure; There is a gap between the magnesium alloy component and the side wall of the cooling assembly; The invention also includes an inert gas which is filled into the gap and can take away the heat from the magnesium alloy component.

2. The active cooling and gas protection device for magnesium alloy arc additive manufacturing according to claim 1, characterized in that: The side wall includes a baffle assembly and a cooling plate, and the bottom is a base plate formed by the magnesium alloy component; The baffle assembly is connected to the cooling plate and both are arranged on the base plate; The partition assembly is provided with a vent hole, and the vent hole is used to fill the inert gas into the gap.

3. The active cooling and gas protection device for magnesium alloy arc additive manufacturing according to claim 2, characterized in that: The cooling plate comprises a first cooling plate and a second cooling plate, and the long side directions of the first cooling plate and the second cooling plate are consistent with the direction of the fluid in the pipeline; The first cooling plate and the second cooling plate are arranged relatively on the substrate, and the substrate, the first cooling plate and the second cooling plate are each provided with at least one pipeline, and at least one pipeline of the first cooling plate, at least one pipeline of the second cooling plate and at least one pipeline of the substrate form a cooling circuit.

4. The active cooling and gas protection device for magnesium alloy arc additive manufacturing according to claim 3, characterized in that: When the substrate, the first cooling plate and the second cooling plate are each provided with a plurality of the pipelines, the plurality of pipelines in the substrate, the plurality of pipelines in the first cooling plate and the plurality of pipelines in the second cooling plate are uniformly distributed in parallel in the longitudinal direction.

5. The active cooling and gas protection device for magnesium alloy arc additive manufacturing according to claim 2, characterized in that: The baffle assembly includes a first baffle and a second baffle; The first partition plate and the second partition plate are arranged opposite to each other on the substrate, the first partition plate and the second partition plate are connected to the cooling plate, and the substrate, the first partition plate, the second partition plate and the cooling plate together form the groove structure.

6. The active cooling and gas protection device for magnesium alloy arc additive manufacturing according to claim 2, characterized in that: The partition assembly is formed by bending a steel plate.

7. The active cooling and gas protection device for magnesium alloy arc additive manufacturing according to claim 2, characterized in that: The partition assembly is connected to the cooling plate by bolts.

8. The active cooling and gas protection device for magnesium alloy arc additive manufacturing according to claim 2, characterized in that: The substrate has a length of 370-390 mm, a width of 240-260 mm, and a height of 15-25 mm.

9. The active cooling and gas protection device for magnesium alloy arc additive manufacturing according to claim 1, characterized in that: The magnesium alloy component is deposited using a CMT deposition mode, with a single-pass multi-layer bidirectional deposition strategy.

10. An active cooling and gas protection method for arc additive manufacturing of magnesium alloys, using the device as claimed in any one of claims 1 to 9, characterized in that: The method comprises: Passing heat dissipation fluid through the pipes on the side walls and bottom of the groove structure; An inert gas is filled into a gap between the magnesium alloy component and the cooling assembly, and the heat of the magnesium alloy component is taken away by the inert gas.

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