Magnesium ingot 3D printing device based on metal magnesium liquid

Abstract

The invention discloses a magnesium ingot 3D printing device based on metal magnesium liquid. The magnesium ingot 3D printing device comprises a heat preservation cavity, a melting chamber, a printing chamber and a shielding gas system. The melting chamber is arranged in the heat preservation cavity; the printing chamber communicates with the melting chamber; the protective gas system is communicated with the melting chamber and the printing chamber; a magnesium steam collecting assembly is arranged in the printing chamber and comprises a magnesium steam collecting bin and a magnesium steam collecting pipe connected with the magnesium steam collecting bin. One end of the magnesium steam collecting bin is connected with a printing nozzle of the melting chamber, and the other end covers a printing platform in the printing chamber; and the free end of the magnesium vapor collecting pipe is connected with the magnesium vapor recovery and argon purification assembly. The device is simple in structure and reasonable in design, and the technical problems that in the prior art, magnesium liquid is prone to evaporation and oxidation and potential safety hazards exist when magnesium ingots are subjected to 3D printing based on metal magnesium liquid are effectively solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of 3D printing equipment development, and relates to a device for 3D printing magnesium ingots based on molten magnesium. Background Art

[0002] Magnesium and magnesium alloys have broad application prospects in the fields of rail transit lightweight, biomedical, aerospace, and national defense due to their excellent properties such as low density, high specific strength and specific stiffness, excellent biocompatibility, and degradability. However, in the actual production process, although the traditional die-casting method is widely used in the manufacture of ingots and large-sized components, it still faces many challenges. With the increase in product size, the control difficulty of casting defects increases significantly, such as problems like slow solidification rate of molten metal, uneven solidification, significant volume shrinkage, etc., resulting in defects such as coarse grain structure of the ingot, loose structure (including more porosity and shrinkage cavities), significant macrosegregation, and uneven distribution of composition and structure, making it difficult to meet the strict requirements for material quality in the high-end manufacturing field.

[0003] In recent years, as a subversive manufacturing method, 3D printing technology overcomes most of the disadvantages of traditional casting production methods in principle. The produced metal components have characteristics such as uniform composition, less segregation, finer grains, and fewer casting defects such as porosity and shrinkage cavities. Therefore, Wire Arc Additive Manufacture (WAAM) and Selective Laser Melting (SLM) provide new paths for the preparation of magnesium alloys. SLM selectively melts metal powder through a high-energy laser beam and stacks layer by layer to finally construct a three-dimensional solid part. Different from SLM which uses metal powder, WAAM uses metal wire as raw material. During the printing process, an electric arc is used as the heat source to melt the metal wire, and a three-dimensional solid part is constructed by layer-by-layer stacking. For SLM and WAAM, due to the high cost of the preparation process of magnesium wire or magnesium powder, and because magnesium wire or magnesium powder reacts quickly with oxygen and releases a large amount of heat, which may cause combustion or explosion, it brings additional challenges to the printing process. At the same time, due to the point-by-point or layer-by-layer melting printing method used in these two methods, their production efficiency is low, making it difficult to meet the demand for mass production of products such as large-sized magnesium ingots.

[0004] The liquid metal 3D printing technology is an innovative 3D printing method that uses molten metal as the printing medium. The liquid material is dropped or ejected to the specified position through a print head or a laser beam, and then the liquid material is quickly solidified by a curing mechanism to form a layered structure, and finally stacked into a complete object. Since this method directly uses liquid materials as the printing medium, but this technology is currently mostly used for printing low-melting-point metals below 300°C such as gallium-indium alloys. There are also currently prints using higher-melting-point metals such as aluminum. However, due to the high saturated vapor pressure and easy volatility of magnesium alloys, they are prone to volatilization in the liquid state. The magnesium vapor generated by volatilization will fill the entire chamber and crystallize on the inner wall of the chamber. When sampling by opening the chamber of the equipment, the crystallized magnesium particles or magnesium powder will burn and cause danger; in addition, magnesium alloys are prone to oxidation, so when magnesium is in a molten state and comes into contact with oxygen in the air, it is prone to a violent oxidation reaction and combustion; therefore, it limits the processing of large-sized magnesium alloy materials using liquid metal 3D printing technology. Summary of the Invention

[0005] Aiming at the problems existing in the prior art, the present invention provides a device for 3D printing magnesium ingots based on molten magnesium, so as to solve the technical problems of easy evaporation, easy oxidation and potential safety hazards of molten magnesium when 3D printing magnesium ingots based on molten magnesium in the prior art.

[0006] The present invention is realized through the following technical solutions: A device for 3D printing magnesium ingots based on molten magnesium includes a heat preservation chamber, a melting chamber, a printing chamber and a protective gas system; The melting chamber is arranged inside the heat preservation chamber; the printing chamber is communicated with the melting chamber; the protective gas system is communicated with both the melting chamber and the printing chamber; A magnesium vapor collection component is arranged in the printing chamber, and the magnesium vapor collection component includes a magnesium vapor collection bin and a magnesium vapor collection pipe connected to the magnesium vapor collection bin; One end of the magnesium vapor collection bin is connected to the printing nozzle of the melting chamber, and the other end covers the printing platform in the printing chamber; The free end of the magnesium vapor collection pipe is connected to a magnesium vapor treatment and argon recovery and purification component.

[0007] Preferably, the magnesium vapor collection bin includes a connecting section and a collection cover which are integrally arranged; the collection cover is in a horn structure, and a collection bin is also arranged in the printing chamber, and the cross-sectional area of the side of the collection cover close to the printing platform is larger than the cross-sectional area of the collection bin.

[0008] Preferably, the magnesium vapor collection pipe includes a first collection section, a second collection section and a transmission section; the first collection section is arranged around the inner wall of the connecting section, and the second collection section is arranged around the inner wall of the collection cover; One end of the transmission section is connected to both the first collection section and the second collection section, and the other end is connected to the magnesium vapor treatment and argon recovery and purification assembly; a plurality of through holes are provided on both the first collection section and the second collection section.

[0009] Preferably, the plurality of through holes are evenly spaced.

[0010] Preferably, the air outlet of the magnesium vapor treatment and argon recovery and purification assembly is connected to the protective gas system.

[0011] Preferably, the melting chamber includes a melting chamber body and a nozzle provided at the bottom of the melting chamber body; the diameter of the nozzle is 0.5 - 10 mm.

[0012] Preferably, the melting chamber body is threadedly connected to the nozzle; a baffle is provided below the nozzle.

[0013] Preferably, a filtering assembly is provided inside the melting chamber; the aperture of the filtering assembly is smaller than the inner diameter of the nozzle.

[0014] Preferably, a plurality of heating assemblies are provided in the heat preservation chamber, and the heating assemblies are arranged around the melting chamber body and the nozzle; first temperature sensing assemblies are provided near the melting chamber body and the nozzle.

[0015] Preferably, the side wall of the melting chamber body includes a vertically arranged section and an inclined section which are integrally formed, and the free end of the inclined section is connected to the nozzle.

[0016] Compared with the prior art, the present invention has the following beneficial technical effects: The present invention discloses a device for 3D printing magnesium ingots based on molten magnesium. The melting chamber is heated through the heat preservation chamber, so that the magnesium ingots stored inside the melting chamber are melted by heat. Under the action of the protective gas system, on the one hand, it realizes the anti-oxidation protection of the molten magnesium liquid inside the melting chamber, provides pressure, and enables the molten magnesium liquid to smoothly enter the printing chamber for printing. On the other hand, the protective gas system realizes the anti-oxidation protection of the magnesium liquid during the printing process and cools down the molten magnesium liquid during printing, realizing a smooth printing process. In addition, the magnesium vapor collection assembly provided by this device effectively recovers the magnesium vapor escaping from the printing chamber, avoiding the danger of magnesium powder explosion when the equipment opens the chamber for sampling. The device has a simple structure and reasonable design, and effectively solves the technical problems of easy evaporation, easy oxidation, and potential safety hazards of molten magnesium during 3D printing of magnesium ingots in the prior art.

[0017] Furthermore, the magnesium vapor collection chamber includes an integrally provided connection section and a collection hood; the collection hood is in a horn shape, and a collection chamber is also provided in the printing chamber. The cross-sectional area of the side of the collection hood close to the printing platform is larger than that of the collection chamber, which can ensure the full recovery of the magnesium vapor escaping from the printing chamber.

[0018] Furthermore, the magnesium vapor collection pipe includes a first collection section, a second collection section, and a transmission section; the first collection section is arranged around the inner wall of the connection section, and the second collection section is arranged around the inner wall of the collection hood; one end of the transmission section is connected to both the first collection section and the second collection section, and the other end is connected to the magnesium vapor treatment and argon recovery and purification assembly; a plurality of through holes are provided on both the first collection section and the second collection section, and the plurality of through holes are evenly spaced, so that the liquid ejected from the melting chamber is subjected to equal forces in all directions, preventing the liquid flow from deflecting and improving the quality of the printed part.

[0019] Furthermore, the gas outlet of the magnesium vapor treatment and argon recovery and purification assembly is connected to the protective gas system, effectively realizing the purification, recovery, and reuse of argon.

[0020] Furthermore, the melting chamber includes a melting cavity body and a nozzle provided at the bottom of the melting cavity body; the diameter of the nozzle is 0.5 - 10 mm, and a suitable nozzle diameter can be selected according to the printing size and precision.

[0021] Furthermore, the melting cavity body is threadedly connected to the nozzle for convenient replacement; a baffle is provided below the nozzle to prevent the magnesium melt from dripping prematurely during the melting and heat preservation process.

[0022] Furthermore, a filtering assembly is provided inside the melting chamber; the aperture of the filtering assembly is smaller than the inner diameter of the nozzle, effectively avoiding the blockage of the nozzle by oxidation inclusions and the impact on the quality of the printed part.

[0023] Furthermore, a number of heating components are provided in the heat preservation cavity, and the number of heating components is arranged around the melting cavity body and the nozzle; first temperature sensing components are provided near the melting cavity body and the nozzle, which can heat up separately at the nozzle to prevent the nozzle from being blocked and improve the quality of the printed part.

[0024] Furthermore, the side wall of the melting cavity body includes an integrally provided vertical section and an inclined section, and the free end of the inclined section is connected to the nozzle, which can enable the molten liquid in the melting cavity body to flow smoothly to the nozzle for printing.

[0025] Further, a heating table 311 is provided below the 3D printing collection crucible. The heating table 311 can be heated to 500 °C, which can provide supplementary heat and insulation for the collection crucible to ensure the spreading of the molten magnesium and improve the quality of the printed parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the drawings required for the embodiments. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can be obtained based on these drawings without creative efforts.

[0027] Figure 1 It is a schematic structural diagram of a device for 3D printing magnesium ingots based on molten magnesium in the present invention; Figure 2 It is a schematic structural diagram of the magnesium vapor collection chamber in the present invention; Figure 3 It is a bottom view of the magnesium vapor collection chamber in the present invention.

[0028] Wherein: 1. Heat preservation chamber, 11. Heating component, 12. First temperature sensing component, 2. Melting chamber, 21. Melting chamber body, 22. Nozzle, 23. Melting chamber sealing cover, 24. Filter component, 25. Stirring component, 3. Printing chamber, 31. Printing platform, 32. Collection chamber, 311. Heating table, 312. XY double-axis moving platform, 313. Z-axis moving platform, 33. Pressure indicating component, 34. Second temperature sensing component, 35. Water and oxygen indicating component, 4. Protection gas system, 41. Protection gas source, 42. First gas path, 421. First pressure control valve, 43. Second gas path, 431. Second pressure control valve, 45. Magnesium vapor recovery and argon purification component, 5. Magnesium vapor collection component, 51. Magnesium vapor collection chamber, 52. Magnesium vapor collection pipe, 521. First collection section, 522. Second collection section, 523. Transmission section, 524. Through hole, 53. Connection section, 54. Collection cover, 6. Control component, 7. Fixed chamber, 71. Chamber body, 72. Chamber sealing cover, 8. Baffle. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. Usually, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0030] Accordingly, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0031] It should be noted that like reference numerals and letters denote like items in the following drawings, and thus, once an item is defined in one drawing, it need not be further defined and explained in subsequent drawings.

[0032] In the description of the embodiments of the present invention, it should be noted that if terms such as "upper", "lower", "horizontal", "inner", etc. are used to indicate the orientation or positional relationship, it is based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the product of the invention is usually placed during use. This is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In addition, terms such as "first", "second", etc. are only used for distinguishing descriptions and cannot be understood as indicating or implying relative importance.

[0033] In addition, if the term "horizontal" appears, it does not mean that the component is required to be absolutely horizontal, but it can be slightly inclined. For example, "horizontal" only means that its direction is more horizontal relative to "vertical", and does not mean that the structure must be completely horizontal, but it can be slightly inclined.

[0034] In the description of the embodiments of the present invention, it should also be noted that unless otherwise clearly defined and limited, if terms such as "set", "installed", "connected", "coupled" are used, they should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0035] The present invention provides a rapid 3D printing device based on molten magnesium. This device uses liquid magnesium instead of costly magnesium powder or magnesium wire as raw materials, which can significantly reduce the raw material cost. At the same time, this solution abandons the processing method of point-by-point remelting, solving the problem of low production efficiency in traditional 3D printing technology. In addition, by using an inert protective gas protection and oxidation inclusion filtration device, this device can also effectively prevent the occurrence of oxidation problems and reduce the content of oxidation inclusions, thereby improving the surface quality and comprehensive performance of the printed parts. Therefore, the technical means in the present invention can effectively solve the shortcomings existing in the prior art in the field of magnesium alloy manufacturing, opening up a new path for the preparation and application of magnesium alloys.

[0036] Specifically, as Figure 1 shown, the present invention discloses a device for 3D printing magnesium ingots based on molten magnesium, including a heat preservation chamber 1, a melting chamber 2, a printing chamber 3, and a protective gas system 4; the melting chamber 2 is arranged inside the heat preservation chamber 1; the printing chamber 3 is communicated with the melting chamber 2; the protective gas system 4 is communicated with both the melting chamber 2 and the printing chamber 3; a magnesium vapor collection component 5 is arranged in the printing chamber 3, and the magnesium vapor collection component 5 includes a magnesium vapor collection bin 51 and a magnesium vapor collection pipe 52 arranged on the magnesium vapor collection bin 51; one end of the magnesium vapor collection bin 51 is connected to the printing nozzle of the melting chamber 2, and the other end covers the printing platform 31 in the printing chamber 3; the free end of the magnesium vapor collection pipe 52 is connected to a magnesium vapor treatment and argon recovery and purification component 45.

[0037] Specifically, for the device in the present invention, the melting chamber 2 includes a melting chamber body 21 and a melting chamber sealing cover 23, and a nozzle 22 is arranged at the bottom of the melting chamber body 21. The melting chamber here can be a crucible, which can withstand high temperatures. In a preferred solution, the side wall of the melting chamber body 21 includes an integrally arranged vertical section and an inclined section, and the free end of the inclined section is connected to the nozzle 22. This is convenient for the molten magnesium liquid to flow to the nozzle 22. The melting chamber body 21 is threadedly connected to the nozzle 22.

[0038] Further preferably, a filtration component 24 is arranged inside the melting chamber 2. The pore diameter of the filtration component 24 is smaller than the inner diameter of the nozzle 22, effectively realizing the filtration of oxidation inclusions and avoiding nozzle blockage. The filtration component 24 can be a porous filter plate. In addition, a stirring component 25 is also arranged inside the melting chamber 2.

[0039] A plurality of heating components 11 are provided in the heat preservation cavity 1, and the plurality of heating components are arranged around the molten cavity body 21 and the nozzle 22; first temperature sensing components 12 are provided near the molten cavity body 21 and the nozzle 22. The heating components 11 arranged around the molten cavity body 21 effectively realize the melting of the molten magnesium in the molten cavity body 21, and the heating components 11 arranged around the nozzle 22 effectively realize the maintenance of the melting of the molten magnesium flowing out of the molten cavity body 21, ensuring the stability of the printing process. At the same time, it also avoids the condensation of the molten magnesium caused by the temperature drop at the nozzle, blocking the nozzle. At the same time, the molten magnesium at the nozzle can also be at a higher temperature through the independent heating component 11.

[0040] The first temperature sensing components 12 provided at the molten cavity body 21 and the nozzle 22 effectively realize the monitoring of the temperature at the corresponding positions, realizing the controllable operation of the system. The above-mentioned heating component 11 can be an electric heating wire. The diameter of the nozzle 22 is preferably 0.5 - 10 mm. The first temperature sensing component 12 can be a thermocouple.

[0041] Further preferably, the device for 3D printing magnesium ingots based on molten magnesium also includes a fixed cavity 7, and the heat preservation cavity 1 is arranged inside the fixed cavity 7. Specifically, the fixed cavity 7 includes a cavity body 71 and a cavity sealing cover 72, and the cavity sealing cover 72 can be a flange cover.

[0042] More specifically, a printing platform 31 and a collection bin 32 arranged on the printing platform 31 are provided inside the printing chamber 3. The printing platform 31 sequentially includes a heating table 311, an XY biaxial moving platform 312, and a Z-axis moving platform 313 from top to bottom. Through the printing platform 31, the collection bin 32 can be adjusted arbitrarily in three dimensions. The heating table 311 can be heated to 500 °C, and the uniform spreading of the molten magnesium is realized through the heating table 311, improving the printing quality.

[0043] In addition, a pressure indicating component 33, a second temperature sensing component 34, and a water and oxygen indicating component 35 are also provided on the printing chamber 3, effectively realizing the effective monitoring of the internal pressure, temperature, and water and oxygen in the printing chamber 3. The pressure indicating component 33 here can be a pressure gauge, the second temperature sensing component 34 can be a thermocouple, and the water and oxygen indicating component 35 can be a water and oxygen probe.

[0044] The protective gas system 4 here includes a protective gas source 41, a first gas path 42 and a second gas path 43 which are both connected to the protective gas source 41; the free end of the first gas path 42 is communicated with the melting chamber 2, and protective gas is introduced into the melting chamber 2 through the first gas path 42. On the one hand, the protective gas here protects the molten magnesium liquid from oxidation, and at the same time provides pressure to enable the molten magnesium liquid to be smoothly ejected from the nozzle for printing. That is, the present invention uses gas pressure control to generate droplets. The free end of the second gas path 43 extends to the inside of the magnesium vapor collection bin 51. On the one hand, the second gas path 43 protects the molten magnesium liquid during the printing process to avoid its oxidation, and at the same time realizes the cooling and condensation printing of the molten magnesium liquid. The protective gas here can be argon.

[0045] In order to facilitate the control of the flow rate of the protective gas introduced into the magnesium vapor collection bin 51, a second pressure control valve 431 is provided on the second gas path 43. In order to facilitate the control of the pressure of the protective gas entering the inside of the melting chamber 2, a first pressure control valve 421 is provided on the first gas path 42. In addition, an argon cooling device 44 is provided at the outlet of the protective gas source 41. Specifically, the cooling of argon is realized through a water chiller.

[0046] At the same time, the protective gas system 4 further includes a magnesium vapor treatment and argon recovery and purification component 45, and the gas outlet of the magnesium vapor treatment and argon recovery and purification component 45 is connected to the protective gas system 4. The specific purification process is that argon containing magnesium vapor enters the magnesium vapor treatment and argon recovery and purification component 45, and after passing through the magnesium vapor treatment and argon recovery and purification component 45, the purified argon is directly connected to the protective gas system 4 to realize the effective recycling of argon.

[0047] As Figure 2 、 3 shown, in a preferred solution, the magnesium vapor collection bin 51 includes an integrally provided connection section 53 and a collection hood 54; the collection hood 54 is of a horn structure, and the cross-sectional area of the collection hood 54 on the side close to the printing platform 31 is larger than the cross-sectional area of the collection bin 32, effectively realizing the recovery of magnesium vapor and avoiding the explosion of the small crystalline magnesium particles remaining inside the printing chamber during furnace opening.

[0048] In a preferred solution, the magnesium vapor collection pipe 52 includes a first collection section 521, a second collection section 522 and a transmission section 523; the first collection section 521 is arranged around the inner wall of the connection section 53, and the second collection section 522 is arranged around the inner wall of the collection hood 54; one end of the transmission section 523 is communicated with both the first collection section 521 and the second collection section 522, and the other end is connected to the magnesium vapor treatment and argon recovery and purification component 45; a plurality of through holes 524 are provided on both the first collection section 521 and the second collection section 522. The plurality of through holes 524 are arranged at equal intervals.

[0049] That is, the magnesium vapor collection bin 51 is provided with double extraction pipes up and down. The upper extraction pipe, that is, the first collection section 521, mainly collects the magnesium vapor evaporated from the upper liquid flow. The lower extraction pipe, that is, the second collection section 522, mainly collects the magnesium vapor evaporated from the surface of the printed part.

[0050] In addition, as Figure 1 shown, the device of the present invention further includes a control component 6. The control component 6 communicates with the control switch of the heating component 11, the first temperature sensing component 12, the control component of the printing platform 31, the pressure indicating component 33, the second temperature sensing component 34, the water and oxygen indicating component 35, the second pressure control valve 431, and the first pressure control valve 421 to realize the intelligent control of the printing device.

[0051] The usage method of the above-mentioned 3D printing magnesium ingot device based on molten magnesium includes the following steps: 1. Loading When loading, open the chamber sealing cover 72, disconnect the pipeline connection of the protective gas system 4, lift out the melting chamber 2 and open the melting chamber sealing cover 23 for loading. After loading is completed, close the melting chamber sealing cover 23, put the melting chamber 2 back into the heat preservation chamber 1, reconnect the pipeline of the protective gas system 4, and tightly close the chamber sealing cover 72.

[0052] 2. Melting and storing molten magnesium Use argon for gas washing treatment to ensure that the molten magnesium is smelted under the protection of argon. Raise the temperature to between 650 and 800 °C and keep it warm for 1 to 2 hours to ensure that the melt is completely melted and the temperature is uniform. Use the first temperature sensing component 12 to detect the temperature of different parts of the melt in real time to ensure the accuracy of temperature control. At the same time, use the filtering component 24 to intercept oxidation inclusions and improve the purity of the melt. To prevent the nozzle 22 from being blocked, a resistance wire, that is, an electric heating wire, is separately arranged at the nozzle 22 to increase the temperature at the nozzle 22. And, in order to prevent the molten magnesium from flowing down under the action of gravity, a baffle 8 is added in front of the nozzle 22 and is opened during use. If printing of magnesium alloy is to be carried out, the stirring component 25 can be opened to make the composition more uniform.

[0053] 3. Printing When the crystalline magnesium block or commercial magnesium ingot is completely melted, adjust the pressure in the melting chamber 2 to ensure that the molten magnesium can drip or flow out evenly. In order to adjust the size and speed of the droplets as needed, nozzles of different sizes can be replaced, and the pressure above the melt in the melting chamber 2 can be precisely controlled by the solenoid valve. During the dripping process of the droplets, in cooperation with the XY double-axis moving platform 312, single-layer printing of molten magnesium can be achieved. At the same time, through the precise control of the Z-axis moving platform 313, layer-by-layer printing of magnesium ingots can also be achieved, thereby constructing large-sized magnesium ingots.

[0054] 4 Cooling and Solidification After the magnesium melt drops, the second gas path 43 is used to achieve gas cooling, and the water-cooled disk located at the bottom of the collection bin 32 is used to achieve lower water cooling, or one of gas cooling and water cooling is used for cooling to ensure that the magnesium melt can solidify rapidly. Since the goal of this equipment is to print large-sized magnesium ingots, the size of the nozzle and the speed and size of the melt droplet dripping do not need to be controlled too precisely, which greatly reduces the probability of nozzle clogging and the difficulty of controlling uniform droplets.

[0055] 5 Atmosphere Control In addition, since magnesium is extremely easy to oxidize and will burn in the atmosphere, the entire printing chamber is filled with argon to isolate the air. At the same time, the water and oxygen content in the printing chamber is strictly controlled to ensure that it is not higher than 10 ppm, thereby effectively preventing the oxidation and combustion of the magnesium melt. Moreover, the exhausted argon is purified, dried, cooled and recycled to improve the utilization rate of argon.

[0056] Specifically, in view of the problem that magnesium has a low saturated vapor pressure and is easy to volatilize, a magnesium vapor collection component 5 is added. The distance between the lower edge of the magnesium vapor collection component 5 and the upper surface of the printing part is 10-20 mm. During the printing process, the position of the collection bin 32 in the vertical direction is adjusted by the Z-axis moving platform 313, so that the upper surface of the printing part and the lower edge of the magnesium vapor collection component 5 always maintain a constant distance. And the magnesium vapor collection bin 51 promotes the condensation of magnesium vapor, thus effectively solving the problem of magnesium vapor during the printing process.

[0057] In traditional casting technology, magnesium alloys are prone to form an oxide layer in the atmospheric environment. However, this technology is carried out under inert gas protection, significantly reducing the generation of oxide inclusions, effectively curbing the oxidation phenomenon, and thus significantly improving the surface quality and comprehensive mechanical properties of the printed parts. In addition, compared with the large molten pool and slow cooling rate of traditional casting, the rapid 3D printing technology of magnesium liquid, with its small molten pool and rapid condensation characteristics, shows significant advantages in refining grains, so it can significantly enhance the mechanical properties such as strength and hardness of magnesium alloys. Additionally, aiming at the problem that magnesium alloys in traditional casting technology are prone to form an oxide layer in the atmospheric environment, which damages the material properties, this application adopts an inert protective gas environment for the rapid 3D printing of magnesium liquid. This design effectively curbs the occurrence of the oxidation phenomenon. By reducing the generation of oxide inclusions, the surface finish and comprehensive mechanical properties of the printed parts are significantly improved. Compared with 3D printing technologies based on powder and wire, this application shows significant advantages in terms of cost-effectiveness, safety, and preparation efficiency. From a cost perspective, the rapid 3D printing technology of molten metal magnesium directly uses relatively inexpensive pure magnesium ingots as raw materials, showing an obvious cost advantage compared with high-priced magnesium powder or magnesium wire. At the same time, this technology also avoids the explosion risk that may be caused by magnesium alloy powder during the manufacturing process, improving the safety of production. In addition, by equipping with an oxide inclusion filtration device, this technology further reduces the content of oxide inclusions, and can effectively improve the quality of the printed parts. Moreover, for the existing droplet deposition additive manufacturing and liquid metal 3D printing technologies, this application has the ability to print magnesium alloys and can efficiently produce high-quality intermediate products in large quantities. Currently, the existing droplet deposition additive manufacturing and liquid metal 3D printing technologies are basically for other metals except magnesium, and there is little for magnesium printing. Even when printing magnesium, it is small-sized precision printing. However, this patented technology can achieve the high-efficiency and low-cost rapid printing of large-sized high-quality magnesium alloy components. This characteristic makes this technology have broad application prospects and huge market potential in the industrial production field.

[0058] In summary, the rapid 3D printing technology of molten metal magnesium proposed in this application, through a series of innovative designs, is expected to solve the shortcomings of the existing technology and demonstrate its unique advantages and significant beneficial effects. The emergence of this technology will undoubtedly bring about a profound change in the field of magnesium alloy processing and manufacturing.

[0059] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A device for 3D printing magnesium ingots based on magnesium liquid, characterized in that: It comprises a heat preservation chamber (1), a melting chamber (2), a printing chamber (3) and a protective gas system (4); The melting chamber (2) is arranged inside the heat preservation chamber (1); the printing chamber (3) is arranged in communication with the melting chamber (2); the protective gas system (4) is arranged in communication with both the melting chamber (2) and the printing chamber (3); A magnesium vapor collection component (5) is provided in the printing chamber (3), and the magnesium vapor collection component (5) comprises a magnesium vapor collection bin (51) and a magnesium vapor collection pipe (52) connected to the magnesium vapor collection bin (51); One end of the magnesium vapor collection chamber (51) is connected to the printing nozzle of the melting chamber (2), and the other end covers the printing platform (31) in the printing chamber (3); The free end of the magnesium vapor collection tube (52) is connected to the magnesium vapor processing and argon gas recovery and purification component (45).

2. The device for 3D printing magnesium ingots based on magnesium liquid according to claim 1, characterized in that: The magnesium vapor collection bin (51) comprises an integrally arranged connection section (53) and a collection cover (54); the collection cover (54) is a trumpet structure, and a collection bin (32) is further provided in the printing chamber (3); the cross-sectional area of ​​the side of the collection cover (54) close to the printing platform (31) is larger than the cross-sectional area of ​​the collection bin (32).

3. The device for 3D printing magnesium ingots based on metallic magnesium liquid according to claim 2, characterized in that: The magnesium vapor collection pipe (52) comprises a first collection section (521), a second collection section (522) and a transmission section (523); the first collection section (521) is arranged around the inner wall of the connecting section (53), and the second collection section (522) is arranged around the inner wall of the collection cover (54); One end of the transmission section (523) is connected to the first collection section (521) and the second collection section (522), and the other end is connected to the magnesium vapor processing and argon gas recovery and purification component (45); the first collection section (521) and the second collection section (522) are both provided with a plurality of through holes (524).

4. The device for 3D printing magnesium ingots based on metallic magnesium liquid according to claim 3, characterized in that: The plurality of through holes (524) are evenly spaced.

5. The device for 3D printing magnesium ingots based on magnesium liquid according to claim 1, characterized in that: The gas outlet of the magnesium vapor treatment and argon gas recovery and purification component (45) is connected to the protective gas system (4).

6. The device for 3D printing magnesium ingots based on magnesium liquid according to claim 1, characterized in that: The melting chamber (2) comprises a melting chamber body (21) and a nozzle (22) arranged at the bottom of the melting chamber body (21); the diameter of the nozzle (22) is 0.5-10 mm.

7. The device for 3D printing magnesium ingots based on magnesium liquid according to claim 6, characterized in that: The melting chamber body (21) is threadably connected to the nozzle (22); a baffle (8) is provided below the nozzle (22).

8. The device for 3D printing magnesium ingots based on magnesium liquid according to claim 6, characterized in that: A filter assembly (24) is provided inside the melting chamber (2); the aperture of the filter assembly (24) is smaller than the inner diameter of the nozzle (22).

9. The device for 3D printing magnesium ingots based on magnesium liquid according to claim 6, characterized in that: A plurality of heating components are provided in the heat preservation chamber (1), and the heating components are arranged around the melting chamber body (21) and the nozzle (22); and a first temperature sensing component (12) is provided near the melting chamber body (21) and the nozzle (22).

10. The device for 3D printing magnesium ingots based on magnesium liquid according to claim 6, characterized in that: The side wall of the melting chamber body (21) comprises a vertical section and an inclined section which are integrally arranged, and a free end of the inclined section is connected to the nozzle (22).

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