Vacuum stirring casting preparation equipment and method for yttrium-containing aviation magnesium alloy

Abstract

The invention relates to the technical field of yttrium-containing aviation magnesium alloys, in particular to vacuum stirring casting preparation equipment and method for a yttrium-containing aviation magnesium alloy. The vacuum stirring casting preparation equipment for the yttrium-containing aviation magnesium alloy comprises a furnace body, and a charging double-bin, an induction heating smelting device, a stirring homogenizing device and a water-cooling pouring tire film which are arranged in the furnace body, the double charging bins comprise an automatic charging bin and a secondary charging bin, a plurality of material chambers are arranged in the bins, a grid is arranged below each material chamber, and after the grids are opened, the materials are filled under the action of gravity; the stirring homogenization device comprises a control motor, a magnetic coupler, a stepless speed regulation stirring blade and a detachable crucible, and realizes homogenization of components with different densities through positive and negative rotation; the induction heating smelting device generates induction current through medium-frequency alternating current, and heating and melting of materials in the crucible are achieved. And circulating cooling water is introduced into the water-cooling pouring tire film to realize rapid cooling of a melt, so that fine as-cast magnesium alloy grains are formed.

Description

Technical Field

[0001] This application relates to the field of yttrium-containing aerospace magnesium alloy technology, and in particular to a vacuum stirring casting preparation equipment and method for yttrium-containing aerospace magnesium alloy. Background Technology

[0002] Yttrium-containing rare-earth magnesium alloys possess excellent mechanical properties, combining high strength, heat resistance, creep resistance, and corrosion resistance, meeting the performance requirements of the aerospace field. However, the strong affinity of magnesium and yttrium for oxygen, coupled with the ease of molten metal oxidation, difficulty in quality control, and large compositional fluctuations, leads to unstable performance of yttrium-containing rare-earth magnesium alloy ingots, hindering their widespread application. Currently, magnesium alloys are primarily produced using open or semi-open melting techniques. For example, the industrial semi-continuous stirring casting method for rare-earth magnesium alloys employs surface covering agents to isolate the melt from air and prevent oxidation and combustion. Commonly used covering agents for magnesium alloys fall into three categories: ① Molten salt-type covering agents, often chlorides and fluorides, are prone to agglomeration during long-term storage and produce harmful Cl2 / HCl gases after reaction; ② Gaseous covering agents often react with the magnesium melt; the commonly used SF6 is restricted due to its strong greenhouse effect; ③ Solid powder covering agents, such as sulfuric acid, boric acid, and graphite, have poor performance and are only used in special processes, with limited practical application in production. Therefore, traditional magnesium alloy manufacturing processes are insufficient to meet the quality requirements of high-performance yttrium-containing aerospace magnesium alloys.

[0003] Vacuum melting provides vacuum or protective atmosphere conditions, effectively preventing magnesium from reacting with air, facilitating the control of element loss, and achieving melt purification. It is a feasible method for preparing magnesium alloys containing reactive rare-earth element yttrium, significantly controlling yttrium loss and yttrium oxide inclusions, thus improving melt quality. However, due to the large density difference between rare-earth elements and magnesium, the precipitation of elements such as Gd and Y leads to significant compositional fluctuations in different parts of the ingot, resulting in macroscopic segregation of the main strengthening elements in rare-earth magnesium alloys. Therefore, achieving homogenization of elements with large density differences under vacuum and refining the magnesium melt are key technical problems that need to be solved in the vacuum melting of yttrium-containing rare-earth magnesium alloys. Summary of the Invention

[0004] This application provides a vacuum stirring casting equipment and method for preparing yttrium-containing aerospace magnesium alloys, which can achieve homogenization, purification, and high-quality preparation of yttrium-containing aerospace magnesium alloy ingots under vacuum / protective atmosphere.

[0005] In a first aspect, this application provides a vacuum stirring casting preparation equipment for yttrium-containing aerospace magnesium alloys, including a furnace body and a dual-material hopper, an induction heating melting device, a stirring homogenization device, and a water-cooled casting mold disposed in the furnace body. The dual-filling hopper includes an automatic feeding hopper and a secondary feeding hopper. The hopper is equipped with multiple material chambers, and each material chamber has a grid at the bottom. When the grid is opened, the material is filled under the action of gravity. The stirring and homogenizing device includes a control motor, a magnetic coupler, a stepless speed-regulating stirring blade, and a detachable crucible, which achieves homogenization of components with different densities by reversing the rotation of the blades. The induction heating melting device generates an induced current through medium-frequency alternating current to heat and melt the material in the crucible; the water-cooled casting mold achieves rapid cooling of the melt by circulating cooling water, forming fine cast magnesium alloy grains.

[0006] Furthermore, the furnace body is constructed of high-strength steel.

[0007] Furthermore, the detachable crucible is a titanium crucible.

[0008] Furthermore, the induction heating melting device achieves a rotational tilt of 0° to 90° via a rotational control shaft.

[0009] Furthermore, the water-cooled casting mold is designed with different specifications according to the ingot size.

[0010] Furthermore, it also includes a filtration device, which is installed on the water-cooled casting film to remove oxide inclusions and slag inclusions in the magnesium alloy melt.

[0011] Furthermore, it also includes an internal operating platform, on which the water-cooled casting mold is set to enable the preparation of ingots of different sizes and weights.

[0012] Secondly, this application provides a vacuum stir casting preparation method for yttrium-containing aerospace magnesium alloys, which is achieved by the vacuum stir casting preparation equipment for yttrium-containing aerospace magnesium alloys as described above; The vacuum stirring casting method for preparing the yttrium-containing aerospace magnesium alloy includes: Add the dried material to the automatic feeding hopper, add the refining agent to the secondary feeding hopper, close the hopper cover, and tighten the hopper cover bolts. Turn on the vacuum system to remove the air from inside the equipment. When the vacuum level of the equipment reaches the set value or above, fill the equipment with inert gas. Open the grid to allow the material to enter the crucible. According to the set program, heat the crucible to the set temperature at a certain heating rate to melt the material. Turn on the stirring and homogenizing device, stir forward at a certain speed for a set time, let stand for a certain time after stirring stops, and then turn on the stirring and homogenizing device again to stir in the reverse direction for a set time. Opening the grid allows the refining agent to enter the melt, reacting with the interior of the alloyed melt to remove gaseous and flux impurities from the melt. The refined melt is poured into a water-cooled casting mold, and after passing through a filtration device to remove oxide inclusions and slag, the melt solidifies to form a high-quality rare earth magnesium alloy ingot after a certain cooling rate.

[0013] Furthermore, the vacuum stir casting method for preparing the yttrium-containing aerospace magnesium alloy also includes: The heating and holding curves of the melting crucible are recorded using a crucible temperature measuring thermocouple, and the crucible temperature recording curve is automatically generated.

[0014] Furthermore, the vacuum stir casting method for preparing the yttrium-containing aerospace magnesium alloy also includes: During the casting process, the casting temperature and cooling rate are controlled by the circulating water flow rate and temperature to form a high-quality fine-grained as-cast structure.

[0015] The above-mentioned technical solution of this application has the following advantages: This application provides a vacuum stir casting preparation equipment and method for yttrium-containing aerospace magnesium alloys. Targeting high-performance aerospace magnesium alloys containing reactive elements such as yttrium, it proposes an efficient, automated, and stable engineering production-ready vacuum stir casting preparation method. It employs a self-designed vacuum casting equipment that includes automatic feeding / secondary feeding, mechanical stirring + high-frequency induction electromagnetic stirring, vacuum refining, filtration, and pouring. This solves the technical problems encountered in the traditional rare earth magnesium alloy preparation process, such as oxidation, inclusions, burn-off, and segregation, achieving homogenized, purified, and high-quality preparation of yttrium-containing aerospace magnesium alloy ingots under vacuum / protective atmosphere. Attached Figure Description

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

[0017] Figure 1 A front view of the vacuum stirring casting preparation equipment for yttrium-containing aerospace magnesium alloys provided in the embodiments of this application; Figure 2 A side view of a vacuum stir casting preparation apparatus for yttrium-containing aerospace magnesium alloys provided in an embodiment of this application; Figure 3 Images of vacuum-stirred rare earth Mg-Gd-Y alloy ingots and their microstructures provided in embodiments of this application; Figure 4 The image shows a vacuum-stirred Mg-Li-Y alloy ingot and its microstructure, provided in the embodiments of this application.

[0018] Reference numerals in the attached diagram: 1-Automatic feeding hopper, 2-Secondary feeding hopper, 3-Stepless speed-regulating stirring blade, 4-Removable crucible, 5-Induction heating melting device, 6-Water-cooled casting film, 7-Filtering device, 8-Internal operating platform of the equipment, 9-Control motor, 10-Magnetic coupler, 11-Rotation control shaft. Detailed Implementation

[0019] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application may also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and processes are omitted so as not to obscure the description of this application with unnecessary detail.

[0020] It should be understood that, when used in this application specification and the appended claims, the term "comprising" indicates the presence of the described features, integrals, steps, operations, elements and / or components, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or a collection thereof.

[0021] Furthermore, in the description of this application and the appended claims, the terms "first," "second," "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0022] References to "one embodiment" or "some embodiments" in this specification mean that one or more embodiments of this application include a specific feature, structure, or characteristic described in connection with that embodiment. Therefore, the phrases "in one embodiment," "in some embodiments," "in other embodiments," "in still other embodiments," etc., appearing in different parts of this specification do not necessarily refer to the same embodiment, but rather mean "one or more, but not all, embodiments," unless otherwise specifically emphasized. The terms "comprising," "including," "having," and variations thereof mean "including but not limited to," unless otherwise specifically emphasized. "A plurality" means "two or more."

[0023] The specific embodiments of this application will be described in further detail below with reference to the accompanying drawings and examples. The following examples are used to illustrate this application, but are not intended to limit the scope of this application.

[0024] This application provides a vacuum stirring casting preparation device for yttrium-containing aerospace magnesium alloys, including a furnace body and a dual-material hopper, an induction heating melting device, a stirring homogenization device, and a water-cooled casting mold disposed within the furnace body. The dual-material hopper includes an automatic feeding hopper and a secondary feeding hopper, with multiple material chambers inside each hopper. Each material chamber has a grid at its bottom. After the grid is opened, the material is filled under the action of gravity. The stirring homogenization device includes a control motor, a magnetic coupler, a stepless speed-regulating stirring blade, and a detachable crucible. It achieves homogenization of components with different densities through forward and reverse rotation. The induction heating melting device generates an induced current through medium-frequency alternating current to heat and melt the material in the crucible. The water-cooled casting mold achieves rapid cooling of the melt by circulating cooling water, forming fine as-cast magnesium alloy grains.

[0025] To address the urgent need for lightweight, high-strength, and high-performance magnesium alloys in the aerospace field, this application provides a stirred casting preparation device for aerospace magnesium alloys containing yttrium and other reactive elements under vacuum / protective atmosphere. The device employs a self-designed vacuum casting equipment incorporating automatic feeding / secondary feeding, mechanical stirring + high-frequency induction electromagnetic stirring, vacuum refining, filtration, and pouring. This solves the technical challenges of oxidation, inclusions, burn-off, and segregation encountered in the traditional rare-earth magnesium alloy preparation process, achieving the preparation of high-quality yttrium-containing aerospace magnesium alloys. This method can also be applied to the preparation of other reactive metallic materials.

[0026] In some embodiments, the furnace body is constructed of high-strength steel.

[0027] In some embodiments, the removable crucible is a titanium crucible.

[0028] In some embodiments, the induction heating melting apparatus achieves a rotational tilt of 0° to 90° via a rotational control shaft.

[0029] In some embodiments, the water-cooled casting mold is designed with different specifications according to the ingot size.

[0030] In some embodiments, a filtration device is also included, which is disposed on the water-cooled casting film to remove oxide inclusions and slag inclusions in the magnesium alloy melt.

[0031] In some embodiments, the equipment also includes an internal operating platform, on which the water-cooled casting mold is disposed to realize the preparation of ingots of different sizes and weights.

[0032] like Figure 1 and Figure 2As shown, this embodiment of the application utilizes a self-designed integrated smelting, refining, slag removal, and casting process within a fully enclosed magnesium alloy vacuum melting furnace. This equipment specifically includes a furnace body, a dual-loading hopper (automatic feeding hopper and secondary feeding hopper), an induction heating melting device, a stirring and homogenizing device, a water-cooled casting mold, and an observation window. The main structure employs a high-strength steel furnace body; the automatic feeding hopper 1 and the secondary feeding hopper 2 can each have multiple material chambers installed as needed. Each material chamber has an automatic / manual grille at the bottom; after opening the grille, the material fills under gravity.

[0033] Built-in vacuum stirring system: Control motor 9 and magnetic coupler 10 to realize forward and reverse rotation and speed adjustment of the stirring blades. The infinitely variable speed stirring blade 3 can be equipped with 2, 4, or 6 sets of blades, and can achieve homogenization of components with different densities through forward and reverse rotation; detachable crucible 4, to avoid reaction with magnesium melt, a titanium crucible can be selected, and the detachable crucible 4 can be cleaned and replaced periodically. Induction heating melting device 5 generates induced current through medium-frequency alternating current to heat and melt the material in the crucible. The induction heating melting device can be rotated and tilted from 0° to 90° via the rotation control shaft 11.

[0034] The water-cooled casting mold 6, equipped with cooling water pipes, achieves rapid cooling of the melt by circulating cooling water, forming fine as-cast magnesium alloy grains. Different specifications of casting molds can be designed according to the ingot size, supporting the development and production of products of various specifications and models. The filtration device 7 removes oxide inclusions and slag inclusions from the magnesium alloy melt. Placing the water-cooled mold on the internal operating platform 8 allows for the preparation of ingots of different sizes and weights.

[0035] This application embodiment also provides a vacuum stir casting preparation method for yttrium-containing aerospace magnesium alloys, which is achieved using the vacuum stir casting preparation equipment for yttrium-containing aerospace magnesium alloys as described above; the vacuum stir casting preparation method for yttrium-containing aerospace magnesium alloys includes: Add the dried material to the automatic feeding hopper, add the refining agent to the secondary feeding hopper, close the hopper cover, and tighten the hopper cover bolts. Turn on the vacuum system to remove the air from inside the equipment. When the vacuum level of the equipment reaches the set value or above, fill the equipment with inert gas. Open the grid to allow the material to enter the crucible. According to the set program, heat the crucible to the set temperature at a certain heating rate to melt the material. Turn on the stirring and homogenizing device, stir forward at a certain speed for a set time, let stand for a certain time after stirring stops, and then turn on the stirring and homogenizing device again to stir in the reverse direction for a set time. Opening the grid allows the refining agent to enter the melt, reacting with the interior of the alloyed melt to remove gaseous and flux impurities from the melt. The refined melt is poured into a water-cooled casting mold, and after passing through a filtration device to remove oxide inclusions and slag, the melt solidifies to form a high-quality rare earth magnesium alloy ingot after a certain cooling rate.

[0036] In some embodiments, the vacuum stirring casting preparation method of the yttrium-containing aerospace magnesium alloy further includes: recording the heating and holding curves of the melting crucible using a crucible temperature measuring thermocouple, and automatically generating a crucible temperature recording curve.

[0037] In some embodiments, the vacuum stirring casting preparation method of the yttrium-containing aerospace magnesium alloy further includes: during the casting process, controlling the casting temperature and cooling rate by circulating water flow rate and temperature to form a high-quality fine-grained as-cast structure.

[0038] The vacuum stirring casting method for preparing yttrium-containing aerospace magnesium alloys provided in this application specifically includes the following steps: a. Pretreatment of furnace charge: Dry the furnace charge at a temperature of 150℃~200℃; b. Loading: Place the dried materials into different material bins. Based on the experience of burning loss of different materials, add the raw materials with greater loss and requiring secondary addition to the secondary feeding bin. Alternatively, the refining agent granules can be added to the secondary feeding bin in advance. Close the feed bin cover and tighten the feed bin cover bolts.

[0039] c. Vacuuming and Protective Gas Charging: Check the air inlet valve to ensure it is closed, open the evacuation valve, and evacuate the entire furnace body and feeding system until the vacuum level reaches 10. -2 After maintaining a pressure of Pa or above for 30 seconds, open the inlet valve to inject inert gas into the furnace body, maintain a slight positive pressure, and then close the inlet valve.

[0040] d. Feeding: Open the pull-out grid of the corresponding material in the automatic feeding hopper, so that the material can be initially mixed in the transition chamber under the action of gravity. Open the pull-out grid of the transition chamber, and the material enters the crucible through the feeding hole, realizing the automatic feeding of the material.

[0041] e. Heating and melting: According to the set program, the crucible is heated to the set temperature at a certain heating rate to melt the material. The temperature is held for 30 minutes. The heating and holding curves of the melting crucible are recorded by the crucible temperature measuring thermocouple, and the crucible temperature recording curve is automatically generated.

[0042] f. Stirring and alloying: Turn on the stirring and homogenizing device and stir forward at a certain speed for 5-10 minutes to prevent the sedimentation of heavy rare earth elements. After stirring is stopped, let it stand for a certain period of time, then turn on the stirring and homogenizing device again and stir in reverse for 5-10 minutes to promote the mutual dissolution and diffusion of different alloying elements. The melt in the crucible can be observed in real time through the visual observation window.

[0043] g. Melt refining: Open the secondary charging hopper refining agent pull grid in advance to allow the refining agent to fall into the transition chamber. Open the transition chamber pull grid and the refining agent enters the melt through the feeding port. It reacts with the interior of the alloyed melt to remove gas and flux impurities from the melt. By controlling the refining temperature and refining time, the quality and performance of rare earth magnesium alloy melt are improved.

[0044] h. Melt Casting: The refined magnesium alloy melt is poured into a water-cooled casting mold for casting. The melt first passes through a ceramic filter to remove impurities and slag. The filtered, high-purity, highly uniform, and alloyed magnesium alloy melt is then cooled and solidified in the water-cooled casting mold. During the casting process, thermocouples continuously collect the casting temperature in real time, and temperature records are automatically generated. During the casting process, the casting temperature and cooling rate can be controlled by the circulating water flow rate and temperature to form a high-quality, fine-grained as-cast structure.

[0045] The following is a description through specific embodiments.

[0046] Example 1: Rare Earth Mg-Gd-Y Alloy The magnesium alloy composition of this embodiment is shown in Table 1: Table 1 Using the vacuum stirring casting method containing yttrium active rare earth elements of this application, the yttrium-containing rare earth magnesium alloy of Example 1 was successfully prepared with controllable yttrium content ranging from low to high. The preparation includes the following steps: (1) Add the dried pure magnesium, gadolinium magnesium master alloy, yttrium magnesium master alloy, zinc, and other trace alloys to the automatic feeding hopper. Add potassium borate refining agent to the secondary feeding hopper. Tighten the bolts of the feeding hopper cover. Turn on the vacuum system to remove the air from the hopper and furnace. Fill the system with high-purity argon. Open the storage cylinder and pull the grid. The material enters the transition chamber for initial mixing. Check the melting crucible and stirring device. Set the crucible heating program and prepare for the melting test.

[0047] (2) Put the material into the crucible, heat the crucible to 750°C, keep it at the melting temperature of 750°C for 30 minutes, turn on the stirring homogenizing device, stir in the forward direction at a speed of 0-300 r / min for 10 minutes, let it stand for 10 minutes after stirring stops, and then turn on the stirring homogenizing device to stir in the reverse direction for 10 minutes to promote the full dissolution and diffusion of different alloying elements, and then turn off the stirring device.

[0048] (3) Open the secondary charging silo grid in advance to allow the refining agent to enter the transition chamber for later use. Raise the crucible temperature to 780℃ refining temperature, and add the refining agent through the feed port of the secondary charging silo. The refining agent enters the melt and reacts fully. Let it stand at the refining temperature for 20 minutes to fully remove impurities such as Fe in the melt and improve the purification effect of the melt.

[0049] (4) Use a coil to rotate the melting crucible to 30°~45°, and slowly pour the refined melt into the water-cooled mold at a certain speed. The oxide inclusions and slags generated during the melting and refining process are removed by a porous ceramic filtration system. The high-purity melt solidifies into a high-quality rare earth magnesium alloy ingot after a certain cooling rate. The cooled ingot is taken out and subjected to composition, impurity and microstructure tests.

[0050] According to ICP composition analysis, the Mg-Gd-Y rare earth magnesium alloy prepared in Example 1 has extremely low impurity content: Fe content is less than 0.001 wt%, Si content is less than 0.001 wt%, and Y content is consistent with the designed composition, with a Y content deviation of <0.02 wt% between the head and tail portions. Based on microstructure analysis results (e.g.... Figure 3 As shown in the figure, the metallographic structure of the ingot obtained in this embodiment has no oxide inclusions.

[0051] Example 2: Novel Mg-Li-Y Alloy The composition of the novel magnesium-lithium alloy in this embodiment is shown in Table 2: Table 2 Using the vacuum stirring casting method containing yttrium active rare earth elements described in this application, the lithium and yttrium content in the yttrium magnesium-lithium alloy of Example 2 was successfully prepared in a controllable manner from low to high. The preparation process includes the following steps: (1) Add the dried pure magnesium, magnesium-yttrium master alloy, zinc and other trace alloys to the automatic feeding hopper, add pure lithium (or Mg-30Li master alloy) to the secondary feeding hopper, tighten the feeding hopper cover bolts, turn on the vacuum system, remove the air from the hopper and furnace body, fill the system with high-purity argon, open the storage cylinder pull grid, and the material enters the transition chamber for preliminary mixing. Check the melting crucible and stirring device, set the crucible heating program, and prepare for the melting test.

[0052] (2) Put the material into the crucible, heat the crucible to 720~750℃, keep it at 750℃ for 20 minutes, stir in the forward direction at 0-300r / min for 10 minutes, turn off the stirring homogenization device to promote the full dissolution and diffusion of different alloying elements.

[0053] (3) Open the grid of the secondary feeding hopper in advance to allow lithium to enter the transition chamber for later use. Lower the crucible temperature to 680~700℃, add lithium raw material through the feed port of the secondary feeding hopper, let it fully react in the melt, let it stand for 20 minutes at the refining temperature, turn on the stirring homogenization device, stir in the opposite direction at a speed of 0-300r / min for 10 minutes, turn off the stirring homogenization device, let it stand for 5~10 minutes after stirring stops, and prepare for casting.

[0054] (4) Use a coil to rotate the melting crucible to 30°~45°, and slowly pour the refined melt into the water-cooled mold at a certain speed. The oxide inclusions and slags generated during the melting and refining process are removed by a porous ceramic filtration system. The high-purity melt solidifies into a high-quality yttrium magnesium lithium alloy ingot after a certain cooling rate. The cooled ingot is taken out and subjected to composition, impurity and microstructure tests.

[0055] According to ICP analysis, the novel Mg-Li-Y alloy prepared in Example 2 has extremely low impurity content: Fe content is less than 0.002 wt%, Si content is less than 0.001 wt%, Li and Y content are consistent with the designed composition, and the Y content deviation between the head and tail is <0.03 wt%. Based on microstructure analysis results (e.g.... Figure 4 As shown in the figure, the metallographic structure of the ingot obtained in this embodiment has no oxide inclusions.

[0056] The vacuum stirring casting equipment and method for preparing yttrium-containing aerospace magnesium alloys provided in this application embodiment can achieve full vacuum and atmosphere protection conditions throughout the process. This solves the problems of inclusions and slags introduced by industrial covering agents in existing semi-continuous stirring casting processes for rare earth magnesium alloys, making it suitable for preparing high-purity, high-quality rare earth magnesium alloys. By using composite stirring to achieve homogenization of the magnesium alloy melt under vacuum conditions—namely, active stirring with multiple stirring paddles operating with infinitely variable speed in both forward and reverse directions—combined with electromagnetic stirring generated by electromagnetic induction, the problem of macroscopic component segregation caused by the sedimentation of heavy rare earth elements due to density differences is effectively solved. This allows for the preparation of highly homogenized, high-performance rare earth magnesium alloy melts.

[0057] The inability to refine the melt under vacuum conditions is a current technical challenge in vacuum melting of magnesium alloys. This application addresses this issue by introducing a secondary feeding chamber to add refining agent particles. These particles react chemically with the alloyed melt, effectively removing gases and flux impurities. Combined with a ceramic filtration system within the water-cooled casting membrane, this effectively removes inclusions and slag from the rare-earth magnesium alloy melt, solving the refining problem of magnesium alloy melts under vacuum conditions. The high-quality yttrium-containing aerospace magnesium alloy prepared using this application exhibits almost no oxidation reaction of reactive elements such as Y and Mg under vacuum / protective atmosphere, extremely low alloy element burn-off rate, and extremely low content of impurities such as Fe and Si in the ingot. Furthermore, the composition of the ingot head, middle, and tail is uniform, resulting in a material utilization rate as high as 95%.

[0058] This application embodiment achieves the overall melting, refining, and casting process of yttrium-containing rare earth magnesium alloys under vacuum or a protective atmosphere by combining vacuum automatic feeding, vacuum heating and melting, stirring and homogenization, melt refining and filtration, and water-cooled film casting. This increases the flexibility of equipment users in primary and secondary feeding, ensures the homogenization and cleanliness of the rare earth magnesium alloy melt, and effectively reduces the environmental hazards of covering agents, SF6, and other protective gases. It is beneficial to the preparation of green, high-performance, high-quality, automated, and stable active rare earth magnesium alloys, and can be extended to the vacuum melting and preparation process of other magnesium alloys and non-ferrous metals.

[0059] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application.

[0060] It should be clarified that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. This application is not limited to the specific structures described above and shown in the figures. Furthermore, for the sake of brevity, detailed descriptions of known methods and techniques are omitted here.

[0061] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. An apparatus for vacuum-stir-casting production of yttrium-containing aerospace magnesium alloy, characterized in that, The device comprises a furnace body, a charging double hopper, an induction heating smelting device, a stirring homogenization device, and a water-cooled casting membrane. The charging double hopper comprises an automatic charging hopper and a secondary charging hopper, and a plurality of material chambers are arranged in the hopper. The stirring homogenization device comprises a control motor, a magnetic coupler, a stepless speed-adjusting stirring paddle, and a detachable crucible. The induction heating smelting device generates an induced current through a medium-frequency alternating current to heat and melt the material in the crucible.

2. The vacuum-stir-cast production apparatus for yttrium-containing aerospace magnesium alloy according to claim 1, wherein The water-cooled casting membrane realizes rapid cooling of the melt by circulating cooling water to form fine as-cast magnesium alloy grains.

3. The vacuum-stir-cast production apparatus for yttrium-containing aerospace magnesium alloy according to claim 1, wherein The furnace body is made of high-strength steel structure.

4. The vacuum-stir-cast apparatus for producing yttrium-containing aerospace magnesium alloy according to claim 1, wherein The detachable crucible is made of titanium.

5. The vacuum-stir-cast apparatus for producing yttrium-containing aerospace magnesium alloy according to claim 1, wherein The induction heating smelting device realizes rotation and inclination of 0°-90° through a rotating control shaft.

6. The apparatus for vacuum-stir-casting yttrium-containing aerospace magnesium alloy according to claim 1, wherein, The water-cooled casting membrane is designed in different specifications according to the size of the ingot.

7. The vacuum-stir-cast apparatus for producing yttrium-containing aerospace magnesium alloy according to claim 1, wherein The device further comprises a filtering device arranged on the water-cooled casting membrane to remove oxide inclusions and slag in the magnesium alloy melt.

8. A method of vacuum-stir-cast production of yttrium-containing aerospace magnesium alloy, characterized in that, The device further comprises an internal operating platform on which the water-cooled casting membrane is arranged to prepare ingots of different sizes and weights. The device is used for the vacuum stirring casting preparation of the yttrium-containing aviation magnesium alloy. The method comprises the following steps: After drying, the material is added to the automatic charging hopper, and a refining agent is added to the secondary charging hopper. The vacuum system is opened to remove air inside the device. When the vacuum degree of the device reaches a set value or above, inert gas is filled into the device. The grating is opened to make the material enter the crucible. The stirring homogenization device is opened to stir in a forward direction at a certain speed for a set time.

9. The vacuum-stir-cast yttrium-containing aerospace magnesium alloy production method according to claim 8, wherein, The grating is opened to make the refining agent enter the melt to react with the internal melt after alloying to remove gas and flux impurities in the melt. The refined melt is poured into the water-cooled casting membrane, and the filtering device removes oxide inclusions and slag.

10. The vacuum-stir-cast yttrium-containing aerospace magnesium alloy production method according to claim 8, wherein, The melt is solidified to form high-quality rare earth magnesium alloy ingots after a certain cooling speed. The method further comprises the following steps: The temperature recording curve of the crucible is automatically generated by recording the temperature rising and holding curve of the smelting crucible through a crucible temperature measuring thermocouple. In the casting process, the pouring temperature and cooling rate are controlled by the circulating water flow and temperature to form high-quality fine-grained as-cast structure.

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