Vacuum levitation melting method and apparatus

Abstract

This invention relates to the field of vacuum levitation melting technology, specifically to a vacuum levitation melting method and apparatus. The vacuum levitation melting method includes: feeding metal charge into a crucible unit within a melting chamber; evacuating the melting chamber after the metal charge has been fed; energizing an induction coil on the outside of the crucible unit with an alternating current once the vacuum level in the melting chamber reaches a preset value; acquiring melting parameters in real time while the induction coil is energized; and dynamically adjusting the magnetic permeable gap of the crucible unit based on the melting parameters. This solves the problem that the crucible cannot simultaneously achieve both magnetic field coupling effect and crucible stability at different stages of melting, thus limiting melting efficiency and melt quality.

Description

Technical Field

[0001] This invention relates to the field of vacuum levitation melting technology, and more specifically, to a vacuum levitation melting method and apparatus. Background Technology

[0002] A vacuum levitation melting furnace is a specialized metallurgical equipment that utilizes high-frequency electromagnetic induction to achieve non-contact levitation heating and melting of molten metal. Existing equipment of this type mainly consists of a vacuum chamber unit, a high-frequency induction generator unit, a melting crucible assembly, a power control unit, and a vacuum unit. The high-frequency induction generator unit and the melting crucible assembly are the core functional units. The alternating magnetic field generated by the high-frequency induction generator unit can penetrate the crucible structure and act on the metal charge, simultaneously achieving non-contact levitation and rapid heating and melting of the charge. This type of equipment has outstanding advantages such as a high-purity melting environment, no crucible contact contamination, and fast temperature control response, effectively avoiding inherent defects in traditional melting processes such as crucible impurity incorporation and melt composition segregation.

[0003] However, most existing crucibles are integral or segmented fixed structures. These crucibles remain fixed throughout the heating and melting process, and the corresponding magnetic circuit parameters and magnetic flux are also constant. This makes it difficult to simultaneously achieve both magnetic field coupling effect and crucible structural stability throughout the entire process of initial heating, metal melting, and completion of melting. Summary of the Invention

[0004] To address the problem that crucibles cannot simultaneously achieve magnetic field coupling effects and crucible stability at different stages of melting, thus limiting melting efficiency and melt quality, this invention provides a vacuum suspension melting method and apparatus.

[0005] In a first aspect, this application provides a vacuum levitation melting method, the vacuum levitation melting method comprising:

[0006] The metal charge is fed into the crucible unit of the melting chamber;

[0007] Once the metal charge has been fed into the furnace, the melting chamber is evacuated.

[0008] Once the vacuum level in the melting chamber reaches a preset value, an alternating current is applied to the induction coil outside the crucible unit; wherein, the crucible unit and the induction coil are coaxially arranged.

[0009] Based on the fact that the induction coil is energized, the melting parameters are acquired in real time; the melting parameters include at least one of melting temperature, induction power, induction current, and equivalent impedance;

[0010] The magnetic permeable gap of the crucible unit is dynamically adjusted according to the melting parameters; the magnetic permeable gap is located on the circumferential wall of the crucible unit.

[0011] Optionally, dynamically adjusting the magnetically permeable gap of the crucible unit according to the melting parameters includes:

[0012] Based on the melting parameters reaching the threshold for establishing the shape of the melt within the crucible unit, the magnetic permeability size of the magnetic permeable gap is increased by a first magnitude so that the shape of the melt gradually reaches a hump shape; wherein, the magnetic permeability size is the dimension of the magnetic permeable gap extending circumferentially along the crucible unit;

[0013] Based on the melting parameters reaching the morphology maintenance threshold of the melt within the crucible unit, the magnetic permeability dimension is increased by a second magnitude; wherein the second magnitude is greater than the first magnitude; when the melting parameters reach the morphology maintenance threshold, the hump-shaped morphology of the melt is in a stable state.

[0014] Optionally, the step of increasing the magnetic permeability size of the magnetic permeable gap by a first magnitude based on the threshold value of the molten body morphology within the crucible unit reached by the melting parameters, so that the molten body morphology gradually reaches a hump shape, includes:

[0015] Based on the melting parameters reaching the threshold for establishing the shape of the melt in the crucible unit, the crucible body and the extension wall of the crucible unit are controlled to rotate relative to each other around the axis of the crucible unit at a preset speed, so that the magnetic permeable size increases by the first amplitude, and the shape of the melt gradually reaches a hump shape.

[0016] The crucible body and the extension wall are movably connected; a first gap exists between the crucible body and the extension wall; the angle between the extension direction of the first gap and the axis of the crucible unit is a first angle; the first angle is less than 45°; the magnetically permeable gap includes the first gap.

[0017] Optionally, increasing the magnetic permeability dimension by a second magnitude based on the melting parameters reaching the morphology maintenance threshold of the melt within the crucible unit includes:

[0018] Based on the melting parameters reaching the morphology maintenance threshold of the melt in the crucible unit, the crucible body and the extension wall are controlled to move and separate along the axial direction of the crucible unit at a preset speed, so as to increase the magnetic permeable dimension by the second amplitude;

[0019] Wherein, there is a second gap between the crucible body and the extended wall; the angle between the extension direction of the second gap and the axis of the crucible unit is a second angle; the second angle is greater than 45° and less than 90°; the magnetically permeable gap includes the second gap.

[0020] Optionally, the step of dynamically adjusting the magnetically permeable gap of the crucible unit according to the melting parameters further includes:

[0021] Based on the melting parameters reaching the first end threshold, the crucible body and the extension wall are controlled to move relatively closer along the axial direction of the crucible unit at the preset speed until the second gap reaches its minimum value.

[0022] Optionally, the step of dynamically adjusting the magnetically permeable gap of the crucible unit according to the melting parameters further includes:

[0023] Based on the second gap reaching its minimum value and the melting parameters reaching the second end threshold, the crucible body and the extension wall are controlled to rotate relative to each other around the axis of the crucible unit at the preset rotation speed until the first gap reaches its minimum value.

[0024] Optionally, the preset rotational speed is negatively correlated with the first included angle; the preset moving speed is negatively correlated with the second included angle.

[0025] Secondly, this application provides a vacuum levitation melting apparatus, applied to any of the optional vacuum levitation melting methods described in the first aspect, the vacuum levitation melting apparatus comprising:

[0026] A crucible unit includes a crucible body and an extending wall. The crucible body includes a crucible bottom and a first arc-shaped plate. The crucible bottom is a cylindrical structure closed at one end. The first arc-shaped plate is located at the open end face of the crucible bottom and is fixedly connected to the crucible bottom. The extending wall includes an annular body and a second arc-shaped plate. The crucible bottom is coaxial with the annular body. The second arc-shaped plate is located at the end face of the annular body and is fixedly connected to the annular body. The first and second arc-shaped plates are arranged circumferentially along the crucible unit. During relative rotation of the crucible body and the extending wall, the first and second arc-shaped plates can overlap. The gap between the first and second arc-shaped plates is a first gap. The gap between the first arc-shaped plate and the annular body, and the gap between the second arc-shaped plate and the crucible bottom, are both second gaps. The magnetically permeable gap of the crucible unit includes the first gap and the second gap.

[0027] An induction coil is wound around the outer periphery of the crucible unit.

[0028] Optionally, the angle between the extension direction of the first gap and the axis of the crucible unit is a first angle; the first angle is greater than or equal to 0°; the first angle is less than 45°.

[0029] The angle between the extension direction of the second gap and the axis of the crucible unit is the second angle; the second angle is greater than 45°; the second angle is less than or equal to 90°.

[0030] Optionally, the extension direction of the first slit is parallel to the axis of the crucible unit; the extension direction of the second slit is perpendicular to the axis of the crucible unit.

[0031] The present invention has the following advantages:

[0032] 1. By acquiring melting parameters in real time when the induction coil is energized, and dynamically adjusting the magnetic permeable gap on the circumferential wall of the crucible unit according to the melting parameters, it is possible to achieve fine control over the shape of the magnetic permeable gap and the distribution of magnetic flux in the crucible, matching the working conditions of different stages in the entire melting cycle.

[0033] 2. This application limits the magnetic flux in the initial stage of melting to establish a stable and uniform initial heating environment, avoiding unstable displacement or splashing of solid or semi-molten metal in the early stage of heating; during the melting process, the magnetic flux is continuously enhanced within a controlled range, ensuring the overall stability of the crucible while maintaining the stability of the suspension height and shape of the molten metal, ultimately solving the problem that existing crucible units cannot take into account both magnetic field coupling effect and crucible stability at different stages of melting, resulting in limited melting efficiency and melt quality. Attached Figure Description

[0034] Figure 1 A flowchart of the vacuum suspension melting method of Example 1 is shown;

[0035] Figure 2 A schematic diagram of the crucible unit of the vacuum suspension melting apparatus is shown.

[0036] Figure 3 It shows Figure 2 A schematic diagram of the crucible body in the vacuum suspension melting device;

[0037] Figure 4 It shows Figure 2 A schematic diagram of the extended wall of the vacuum suspension melting device;

[0038] Figure 5 A schematic diagram of the vacuum levitation melting device is shown.

[0039] Figure 6 A schematic diagram showing the crucible body and the extended wall rotating to open the first slit is shown;

[0040] Figure 7 A schematic diagram showing the closed fit between the crucible body and the extended wall is shown;

[0041] Figure 8 A schematic diagram of the magnetic flux is shown when the crucible body and the extended wall are in closed contact.

[0042] Figure 9 A schematic diagram of the magnetic flux is shown when the crucible body and the extended wall have the first gap open;

[0043] Figure 10 A schematic diagram showing the magnetic flux through the first and second slits opened by the crucible body and the extended wall is shown.

[0044] Reference numerals: crucible unit 10; crucible body 11; crucible bottom 111; first arc plate 112; extension wall 12; annular body 121; second arc plate 122; induction coil 20. Detailed Implementation

[0045] The present disclosure will now be discussed with reference to several exemplary embodiments. It should be understood that these embodiments are discussed only to enable those skilled in the art to better understand and thus implement the present disclosure, and are not intended to imply any limitation on the scope of the disclosure.

[0046] As used herein, the term "comprising" and its variations are to be interpreted as open-ended terms meaning "including but not limited to". The term "based on" is to be interpreted as "at least partially based on". The terms "one embodiment" and "an embodiment" are to be interpreted as "at least one embodiment". The term "another embodiment" is to be interpreted as "at least one other embodiment". The terms "upper", "lower", "left", "right", "front", "rear", "top", "bottom", "inner", "outer", "vertical", "horizontal", "lateral", "longitudinal", etc., indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. These terms are primarily for the purpose of better describing this application and its embodiments and are not intended to limit the indicated devices, elements, or components to having a specific orientation or being constructed and operated in a specific orientation. Furthermore, some of the above terms may be used to indicate other meanings besides orientations or positional relationships; for example, the term "upper" may in some cases indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this application according to the specific circumstances. In addition, the terms "installed", "set up", "equipped with", "connected", and "linked" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, elements, or components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. Furthermore, the terms "first," "second," etc., are mainly used to distinguish different devices, elements, or components (the specific types and structures may be the same or different), and are not used to indicate or imply the relative importance or quantity of the indicated devices, elements, or components. Unless otherwise stated, "a plurality of" means two or more.

[0047] Existing crucibles remain fixed throughout the heating and melting process, with corresponding constant magnetic circuit parameters and magnetic flux. This makes it difficult to simultaneously achieve both effective magnetic field coupling and crucible structural stability throughout the entire process, from initial heating and metal melting to completion of melting. To address these issues, this application provides a vacuum levitation melting method and apparatus.

[0048] Example 1:

[0049] In this embodiment, a vacuum suspension melting method is provided. For example... Figure 1 As shown, the vacuum suspension melting method includes steps S10 to S50, and the vacuum suspension melting method executes steps S10, S20, S30, S40 and S50 in sequence.

[0050] Step S10: The metal charge is placed into the crucible unit 10 of the melting chamber, so that the metal charge to be melted is stably placed in the effective heating area of ​​the crucible unit 10, providing a stable material basis for the subsequent vacuum melting and electromagnetic heating processes, and avoiding the impact of the metal charge filling position deviation on the stability of the subsequent heating process.

[0051] Step S20: After the metal charge has been added, the melting chamber is evacuated. This operation establishes a vacuum environment in the melting chamber before the metal charge is heated, effectively preventing the metal charge from undergoing oxidation reactions with active gases in the air during the subsequent high-temperature melting process, ensuring the purity of the molten metal, and providing a low-interference environment for the stable suspension of the molten metal during the subsequent electromagnetic heating process.

[0052] In step S30, after the vacuum level of the melting chamber reaches a preset value, an alternating current is passed through the induction coil 20 outside the crucible unit 10. The crucible unit 10 and the induction coil 20 are coaxially arranged to ensure that the alternating magnetic field generated after the alternating current is passed through the induction coil 20 can act uniformly and stably on the metal charge inside the crucible unit 10.

[0053] Step S40: Based on the energized state of the induction coil 20, the melting parameters are acquired in real time. The melting parameters include at least one of melting temperature, induction power, induction current, and equivalent impedance. By acquiring the melting parameters in real time, the real-time operating status of the melting process and the melting progress of the metal charge can be accurately monitored throughout the entire process, providing accurate and real-time data and triggering conditions for the dynamic adjustment of the subsequent melting process.

[0054] When the magnetically permeable gap on the circumferential wall of the crucible unit 10 increases, the alternating magnetic field generated by the induction coil 20 more easily penetrates the crucible and acts on the metal charge, increasing eddy current losses inside the metal charge, increasing heat generation, and raising the melting temperature accordingly. When the magnetically permeable gap decreases, the magnetic field penetration effect weakens, the heating efficiency of the metal charge decreases, and the melting temperature decreases accordingly. When the magnetically permeable gap increases, the electromagnetic coupling between the induction coil 20 and the metal charge strengthens, more electromagnetic energy is converted into thermal energy of the metal charge, and the induced power output by the induction coil 20 increases accordingly. When the magnetically permeable gap decreases, the electromagnetic coupling weakens, the energy transfer efficiency decreases, and the induced power output by the induction coil 20 decreases accordingly. As the magnetically permeable gap increases, the electromagnetic coupling strengthens, the load is equivalent to heavier, and the induced current in the induction coil 20 increases accordingly. As the magnetically permeable gap decreases, the electromagnetic coupling weakens, the load is equivalent to lighter, and the induced current in the induction coil 20 decreases accordingly. When the magnetic permeable gap increases, the electromagnetic feedback effect of the metal charge on the induction coil 20 is enhanced, and the equivalent impedance of the system observed from the induction coil 20 side decreases; when the magnetic permeable gap decreases, the electromagnetic feedback effect of the metal charge on the induction coil 20 is weakened, and the equivalent impedance of the system increases.

[0055] Step S50: The magnetic permeable gap of the crucible unit 10 is dynamically adjusted according to the melting parameters. The magnetic permeable gap is located on the circumferential wall of the crucible unit 10. In the initial stage of melting, the crucible unit 10 is kept under minimal magnetic permeability conditions, effectively limiting magnetic flux leakage and establishing a stable and uniform initial electromagnetic heating environment. This prevents unstable displacement or splashing of solid or semi-molten metal charge due to sudden changes in electromagnetic force during the initial heating stage. As the melting parameters change, the magnetic permeable gap on the circumferential wall of the crucible unit 10 is adjusted to continuously increase the magnetic flux within a controlled range. This increases the electromagnetic force intensity without compromising overall stability, gradually forming a hump-shaped suspension of the molten metal charge. Simultaneously, the dynamically adjusted gap width is controllable, and the magnetic field strength changes gradually, which helps maintain the stability of the suspension height and shape of the molten metal charge. This achieves precise establishment and stable control of the molten pool shape, effectively avoiding molten metal splashing caused by sudden changes in magnetic flux.

[0056] Further, step S50 includes steps S51 and S52, and the vacuum suspension melting method sequentially executes steps S10, S20, S30, S40, S51, and S52.

[0057] Step S51: Based on the melting parameters reaching the threshold for establishing the morphology of the melt within the crucible unit 10, the magnetic permeability size of the magnetic permeable gap is increased by a first magnitude. In the initial stage of melting, the crucible unit 10 is placed under minimum magnetic permeability conditions. Increasing the magnetic permeability size of the magnetic permeable gap by a relatively small first magnitude allows the magnetic flux to increase gradually, enabling the melt morphology to gradually reach a hump shape. This avoids problems such as splashing and displacement of the melt caused by sudden changes in the magnetic field, thus achieving a stable establishment of the molten pool morphology. The magnetic permeability size is the dimension of the magnetic permeable gap extending circumferentially along the crucible unit 10.

[0058] Step S52: Based on the melting parameters reaching the morphology maintenance threshold of the melt within crucible unit 10, the magnetic permeability dimension is increased by a second amplitude. The second amplitude is greater than the first amplitude. When the melting parameters reach the morphology maintenance threshold, the hump-shaped morphology of the melt is stable. This allows for further enhancement of the magnetic flux by increasing the magnetic permeability dimension by a second amplitude after the molten pool morphology has stabilized, strengthening the induction heating efficiency and electromagnetic stirring effect, while avoiding molten pool instability caused by large adjustments, thus achieving synergistic optimization of melting efficiency and molten pool stability.

[0059] Further, step S51 includes step S511, in which the vacuum suspension melting method sequentially executes steps S10, S20, S30, S40, S511, and S52.

[0060] Step S511: Based on the melting parameters reaching the threshold for establishing the shape of the melt in the crucible unit 10, control the crucible body 11 and the extension wall 12 of the crucible unit 10 to rotate relative to each other around the axis of the crucible unit 10 at a preset speed. The rotation action can achieve continuous and smooth adjustment of the magnetic permeability size, so that the magnetic flux can be steadily increased, avoiding the instability of the molten pool caused by sudden magnetic field changes, so as to increase the magnetic permeability size by the first amplitude, and ensure that the shape of the melt gradually stabilizes and reaches a hump shape.

[0061] The crucible body 11 and the extension wall 12 are movably connected to ensure stable execution of the adjustment action. A first gap exists between the crucible body 11 and the extension wall 12, providing a channel for magnetic field penetration. Figure 6 As shown, the angle between the extension direction of the first gap and the axis of the crucible unit 10 is the first angle, which is less than 45°. This first angle is the smallest angle between the extension direction of the first gap and the axis of the crucible unit 10. This rotational adjustment results in a smaller magnetically permeable dimension and a gentler change in the magnetic field gradient, which is beneficial for maintaining the stability of the molten metal charge's suspension height and shape. Therefore, the rotation of the crucible body 11 and the extension wall 12 is mainly used to establish and stabilize the molten pool shape. The magnetically permeable gap includes the first gap.

[0062] Further, step S52 includes step S521, in which the vacuum suspension melting method sequentially executes steps S10, S20, S30, S40, S511, and S521.

[0063] Step S521: Based on the melting parameters reaching the morphology maintenance threshold of the melt in the crucible unit 10, the crucible body 11 and the extension wall 12 are controlled to move and separate along the axial direction of the crucible unit 10 at a preset speed. The magnetic permeability size can be significantly and stably adjusted through axial movement. Under the premise of stable molten pool morphology, the magnetic flux can be rapidly increased so that the magnetic permeability size increases by a second magnitude, thereby enhancing the induction heating efficiency and electromagnetic stirring effect, and improving melting efficiency and melt purity.

[0064] Among them, such as Figure 7 As shown, a second gap exists between the crucible body 11 and the extension wall 12. The angle between the extension direction of the second gap and the axis of the crucible unit 10 is a second angle, which is greater than 45° and less than 90°. This makes the axial adjustment of the second gap have a more significant impact on the magnetic permeability dimension, allowing for large-scale adjustment of the magnetic permeability dimension through axial movement, thus meeting the high magnetic field flux requirements during the molten pool morphology maintenance stage. The magnetic permeability gap includes the second gap.

[0065] like Figure 8 A schematic diagram of the magnetic flux is shown when the crucible body 11 and the extension wall 12 are closed and fitted together. The crucible unit 10 is coaxially arranged with the outer induction coil 20. After an alternating current is passed through the induction coil 20, an alternating magnetic field is generated distributed along the axial direction of the crucible unit 10. The magnetic flux mainly passes through the magnetically permeable gap of the crucible unit 10 along the axial direction, generating electromagnetic induction and electromagnetic levitation effect on the molten metal inside the crucible.

[0066] like Figure 9 A schematic diagram of the magnetic flux is shown when the crucible body 11 and the extension wall 12 have the first gap open. The extension direction of the first gap is close to the axial direction of the crucible unit 10, that is, the first angle between the first gap and the axis of the crucible unit 10. When the magnetic flux passes through the first gap along the axial direction, the magnetic field is more evenly distributed and changes more gently in the circumferential direction, which can make the electromagnetic force on the molten metal more stable, thereby ensuring that the process of establishing the suspension state of the molten metal is more stable and avoiding violent shaking or loss of control of the molten metal.

[0067] like Figure 10A schematic diagram showing the magnetic flux through the first and second gaps of the crucible body 11 and the extension wall 12 is illustrated. The extension direction of the second gap is approximately perpendicular to the axial direction of the crucible unit 10, i.e., the second included angle between the second gap and the axis of the crucible unit 10. When the magnetic flux passes through the second gap along the axial direction, it can significantly enhance the electromagnetic effect intensity while ensuring uniform magnetic field distribution and stable melt suspension, thereby accelerating the heating, melting, and morphological stabilization of the melt and improving the overall melting efficiency. Therefore, this application, by setting a first gap approximately axial and a second gap approximately perpendicular to the axial direction in combination, achieves stable field establishment and stable molding primarily through the first gap during the melt morphological establishment stage, and achieves stable shape preservation and efficient melting primarily through the second gap during the melt morphological maintenance stage. This effectively improves the efficiency and control precision of vacuum suspension melting while ensuring the stability of suspension melting.

[0068] Furthermore, step S50 also includes step S53, in which the vacuum suspension melting method sequentially executes steps S10, S20, S30, S40, S511, S521, and S53.

[0069] Step S53: Based on the melting parameters reaching the first end threshold, control the crucible body 11 and the extension wall 12 to move relatively close along the axial direction of the crucible unit 10 at a preset speed until the second gap reaches its minimum value. This can reduce the second gap by axial reset when melting enters the final stage, thus gradually reducing the magnetic flux and electromagnetic force intensity, avoiding the collapse of the molten pool and the splashing of the melt caused by the sudden drop in magnetic field, ensuring the stability of the melting final stage, and enhancing the overall structural rigidity of the crucible unit 10, providing a stable structural environment for the subsequent cooling and solidification process.

[0070] Furthermore, step S50 also includes step S54, in which the vacuum suspension melting method sequentially executes steps S10, S20, S30, S40, S511, S521, S53, and S54.

[0071] In step S54, based on the second gap reaching its minimum value and the melting parameters reaching the second end threshold, the crucible body 11 and the extension wall 12 are controlled to rotate relative to each other around the axis of the crucible unit 10 at a preset speed until the first gap reaches its minimum value. This allows the first gap to be closed further by rotation after the second gap has been reset, so that the overall magnetic permeable gap of the crucible unit 10 reaches its minimum state, further reducing the magnetic field flux, and allowing the molten metal to cool and solidify smoothly in a confined and uniformly weakened magnetic field environment.

[0072] Furthermore, the preset rotation speed is negatively correlated with the first included angle. Specifically, the corresponding rotation speed is matched according to the size of the first included angle. When the first included angle is small, the accuracy of the magnetic permeability size adjustment is ensured by reducing the preset rotation speed. When the first included angle is large, the adjustment efficiency is improved by increasing the preset rotation speed, thereby achieving a balance between accuracy and efficiency during the rotation adjustment process.

[0073] The preset moving speed is negatively correlated with the second included angle. Specifically, the axial moving speed is matched according to the size of the second included angle. When the second included angle is small, the preset moving speed is reduced to ensure the smoothness of the magnetic permeability dimension adjustment. When the second included angle is large, the preset moving speed is increased to improve the adjustment efficiency. This achieves synergistic optimization of stability and efficiency during axial adjustment, avoiding magnetic field abrupt changes and molten pool instability caused by mismatch between adjustment speed and structural parameters.

[0074] Example 2:

[0075] In this embodiment, this application provides a vacuum suspension melting apparatus, applied to a vacuum suspension melting method in Embodiment 1, such as... Figure 2 As shown, the vacuum levitation melting device includes a crucible unit 10 and an induction coil 20.

[0076] The crucible unit 10, as the core carrier of the smelting process, provides a closed containment space for the smelting of the metal charge. The crucible unit 10 includes a crucible body 11 and an extended wall 12. Figure 3 As shown, the crucible body 11 includes a crucible bottom 111 and a first arc-shaped plate 112. The crucible bottom 111 is a cylindrical structure closed at one end, capable of accommodating the metal charge and molten metal, providing a stable spatial carrier for the smelting process. The first arc-shaped plate 112 is located at the open end face of the crucible bottom 111 and is fixedly connected to the crucible bottom 111, ensuring the connection strength and positional stability of the first arc-shaped plate 112 and the crucible bottom 111, and providing a fixed structural reference for adjusting the magnetically permeable gap. Figure 4As shown, the extension wall 12 includes an annular body 121 and a second arc-shaped plate 122. The crucible bottom 111 is coaxial with the annular body 121, ensuring the coaxiality of the crucible body 11 and the extension wall 12 during relative movement, avoiding uneven magnetic field distribution and adjustment jamming caused by eccentricity. The second arc-shaped plate 122 is located on the end face of the annular body 121 and is fixedly connected to the annular body 121, ensuring the connection strength and positional stability of the second arc-shaped plate 122 and the annular body 121, forming an adjustable gap structure in conjunction with the first arc-shaped plate 112. The first arc-shaped plate 112 and the second arc-shaped plate 122 are arranged circumferentially along the crucible unit 10, providing a structural basis for circumferential rotation adjustment of the magnetic permeability dimension. During the relative rotation of the crucible body 11 and the extension wall 12, the first arc-shaped plate 112 and the second arc-shaped plate 122 can overlap, and the magnetic permeability dimension of the first gap can be continuously adjusted by changing the overlap area, thereby realizing the controllable adjustment of the magnetic permeability of the crucible unit 10. The gap between the first arc-shaped plate 112 and the second arc-shaped plate 122 is the first gap, and the gap between the first arc-shaped plate 112 and the annular body 121 and the gap between the second arc-shaped plate 122 and the crucible bottom 111 are the second gaps. These gaps provide a magnetic permeability channel for axial movement adjustment, enabling large-scale and highly efficient adjustment of the magnetic permeability. The magnetic permeability gaps of the crucible unit 10, including the first gap and the second gap, allow for multi-dimensional and wide-range adjustment of the magnetic permeability of the crucible unit 10, solving the problem of the unadjustable magnetic permeability of traditional fixed-gap crucibles.

[0077] like Figure 5 As shown, the induction coil 20 is wound around the outer periphery of the crucible unit 10, and can generate an alternating magnetic field when an alternating current is applied, providing a magnetic field source for the induction heating and suspension melting of the metal charge. The extension trajectory of the induction coil 20 is a spiral trajectory, and the axis of the spiral trajectory coincides with the axis of the crucible unit 10.

[0078] Furthermore, the angle between the extension direction of the first gap and the axis of the crucible unit 10 is the first included angle; the first included angle is greater than or equal to 0° and less than 45°. This ensures that when the crucible body 11 and the extension wall 12 rotate relative to each other, the magnetic permeability dimension of the first gap can achieve a smooth and precise linear change with the rotation angle, adapting to the need for stable magnetic field adjustment during the molten pool morphology establishment stage, and avoiding melt instability caused by sudden changes in the magnetic field.

[0079] The angle between the extension direction of the second gap and the axis of the crucible unit 10 is called the second angle, which is greater than 45° and less than or equal to 90°. This allows for a higher proportion of axial extension of the second gap, ensuring that when the crucible body 11 and the extension wall 12 move axially relative to each other, the magnetic permeability dimension of the second gap can change significantly and efficiently with the axial displacement. This adapts to the high magnetic field flux requirements during the molten pool morphology maintenance stage, while also ensuring the stability of the adjustment process.

[0080] Furthermore, the extension direction of the first gap is parallel to the axis of the crucible unit 10, so that the magnetic permeability dimension of the first gap changes linearly only with the relative rotation angle between the crucible body 11 and the extension wall 12. This eliminates the interference of axial displacement on the magnetic permeability dimension of the first gap, further improving the accuracy and predictability of magnetic permeability dimension control during rotation adjustment, and ensuring the stability of magnetic field adjustment during the molten pool morphology establishment stage. The extension direction of the second gap is perpendicular to the axis of the crucible unit 10, so that the magnetic permeability dimension of the second gap changes linearly only with the relative axial displacement between the crucible body 11 and the extension wall 12. This eliminates the interference of rotation angle on the magnetic permeability dimension of the second gap, achieving decoupling between rotation adjustment and axial adjustment. This significantly improves the controllability and accuracy of magnetic permeability gap adjustment, while enabling axial adjustment to maximize the adjustment of magnetic permeability dimension, further improving melting efficiency and magnetic field coupling effect.

[0081] Those skilled in the art will understand that the above embodiments are specific examples of implementing this disclosure, and in practical applications, various changes can be made in form and detail without departing from the scope of this disclosure.

Claims

1. A vacuum levitation melting method, characterized by, The vacuum suspension melting method includes: The metal charge is fed into the crucible unit of the melting chamber; Once the metal charge has been fed into the furnace, the melting chamber is evacuated. Once the vacuum level in the melting chamber reaches a preset value, an alternating current is applied to the induction coil outside the crucible unit; wherein, the crucible unit and the induction coil are coaxially arranged. Based on the fact that the induction coil is energized, the melting parameters are acquired in real time; the melting parameters include at least one of melting temperature, induction power, induction current, and equivalent impedance; The magnetic permeable gap of the crucible unit is dynamically adjusted according to the melting parameters; the magnetic permeable gap is located on the circumferential wall of the crucible unit. The step of dynamically adjusting the magnetically permeable gap of the crucible unit according to the melting parameters includes: Based on the melting parameters reaching the threshold for establishing the morphology of the melt within the crucible unit, the crucible body and the extension wall of the crucible unit are controlled to rotate relative to each other around the axis of the crucible unit at a preset rotational speed, so that the magnetic permeability dimension increases by a first magnitude, and the morphology of the melt gradually reaches a hump shape; wherein, the magnetic permeability dimension is the dimension of the magnetic permeability gap extending circumferentially along the crucible unit; the crucible body and the extension wall are movably connected; there is a first gap between the crucible body and the extension wall; the angle between the extension direction of the first gap and the axis of the crucible unit is a first angle; the first angle is less than 45°; the magnetic permeability gap includes the first gap; Based on the melting parameters reaching the shape maintenance threshold of the melt within the crucible unit, the crucible body and the extension wall are controlled to move and separate along the axial direction of the crucible unit at a preset speed, so that the magnetic permeability dimension increases by a second magnitude; wherein, the second magnitude is greater than the first magnitude; when the melting parameters reach the shape maintenance threshold, the hump-shaped shape of the melt is in a stable state; there is a second gap between the crucible body and the extension wall; the angle between the extension direction of the second gap and the axis of the crucible unit is a second angle; the second angle is greater than 45° and less than 90°; the magnetic permeability gap includes the second gap.

2. A vacuum levitation melting method according to claim 1, characterized by, The step of dynamically adjusting the magnetically permeable gap of the crucible unit according to the melting parameters further includes: Based on the melting parameters reaching the first end threshold, the crucible body and the extension wall are controlled to move relatively closer along the axial direction of the crucible unit at the preset speed until the second gap reaches its minimum value.

3. A vacuum levitation melting method according to claim 2, wherein The step of dynamically adjusting the magnetically permeable gap of the crucible unit according to the melting parameters further includes: Based on the second gap reaching its minimum value and the melting parameters reaching the second end threshold, the crucible body and the extension wall are controlled to rotate relative to each other around the axis of the crucible unit at the preset rotation speed until the first gap reaches its minimum value.

4. A vacuum levitation melting method according to claim 1, wherein The preset rotational speed is negatively correlated with the first included angle; the preset moving speed is negatively correlated with the second included angle.

5. A vacuum levitation melting apparatus for use in a vacuum levitation melting method according to any one of claims 1 to 4, characterized by, The vacuum levitation melting apparatus includes: A crucible unit includes a crucible body and an extending wall. The crucible body includes a crucible bottom and a first arc-shaped plate. The crucible bottom is a cylindrical structure closed at one end. The first arc-shaped plate is located at the open end face of the crucible bottom and is fixedly connected to the crucible bottom. The extending wall includes an annular body and a second arc-shaped plate. The crucible bottom is coaxial with the annular body. The second arc-shaped plate is located at the end face of the annular body and is fixedly connected to the annular body. The first arc-shaped plate and the second arc-shaped plate are arranged circumferentially along the crucible unit. During relative rotation of the crucible body and the extending wall, the first arc-shaped plate and the second arc-shaped plate... The arc-shaped plates can overlap; the gap between the first arc-shaped plate and the second arc-shaped plate is a first gap; the gap between the first arc-shaped plate and the annular body and the gap between the second arc-shaped plate and the crucible bottom are both second gaps; the magnetically permeable gap of the crucible unit includes the first gap and the second gap; the angle between the extension direction of the first gap and the axis of the crucible unit is a first angle; the first angle is greater than or equal to 0°; the first angle is less than 45°; the angle between the extension direction of the second gap and the axis of the crucible unit is a second angle; the second angle is greater than 45°; the second angle is less than or equal to 90°; An induction coil is wound around the outer periphery of the crucible unit.

6. The vacuum suspension melting apparatus according to claim 5, characterized in that, The first slit extends in a direction parallel to the axis of the crucible unit; the second slit extends in a direction perpendicular to the axis of the crucible unit.

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