An electromagnetically assisted pressure-boosting aluminum alloy lost foam casting forming device and method

Abstract

This invention discloses an electromagnetically assisted pressure-boosting lost foam casting apparatus and method for aluminum alloys. The apparatus includes an electromagnetic pressure-boosting module and a lifting device module. A liftable electromagnetic coil is placed outside the sand box. During casting, three-phase alternating current is supplied to the electromagnetic coil, generating a traveling wave magnetic field in the coil windings. Under the action of the traveling wave magnetic field, the molten aluminum generates an induced current. The charged molten aluminum cuts the magnetic field lines during the casting process, generating a downward constant magnetic field force, which greatly promotes the flow of aluminum alloy melt micro-aggregates in the mold cavity, improves the filling power, accelerates the casting speed, and makes the filling complete, the structure refined and dense, significantly reducing casting defects and improving the mechanical properties of the casting. After casting, the electromagnetic pressure-boosting module is lifted by the lifting device module, and the sand box is transferred to the sand drop area for the next process operation, improving work efficiency. This invention also provides an electromagnetically assisted pressure-boosting lost foam casting method for aluminum alloys to reduce casting defects and improve the mechanical properties of castings.

Description

Technical Field

[0001] This invention relates to the field of lost foam casting of aluminum alloys, and specifically to an electromagnetically assisted pressure-boosting lost foam casting forming device and method for aluminum alloys. Background Technology

[0002] Lost foam casting technology involves foaming EPS, ETMMA, or EPMMA foam beads into molds, then assembling the foam boards into clusters using cutting and bonding methods to create a model with a structure and size similar to the casting. A special lost foam coating is then applied to the model surface using brushing or dipping methods. After the coating is dried, the white model is buried in dry sand. During the filling process, the dry sand is vibrated on a vibrating table to compact it, filling the model as completely as possible without damaging it. Molten metal is then poured in, causing the foam model to vaporize and produce the casting. After cooling, the sand is removed, the casting is taken out, and finally, it is polished to obtain the desired casting.

[0003] Lost foam casting offers high dimensional accuracy, and because the model is assembled from foam plastic, its appearance and structure are unrestricted, allowing for a high degree of freedom and making it suitable for manufacturing extremely precise and complex components. Lost foam casting eliminates the need for mold assembly and demolding, and also avoids the steps of sand core making, significantly reducing workload and greatly increasing production efficiency compared to traditional sand casting.

[0004] However, the melting of the foam pattern generates a large amount of gas, affecting the pouring speed and direction of the molten aluminum. Furthermore, aluminum alloy castings have lower pouring temperatures than cast steel, and the heat from the molten metal consumed during foam pattern melting has a more significant cooling effect on the molten aluminum. This is especially true for larger, complex, thin-walled castings poured under gravity. Due to insufficient filling power and rapid cooling of the molten aluminum, casting defects such as incomplete filling, cold shuts, porosity, and pinholes are easily observed, resulting in non-dense castings with severely reduced mechanical properties. Existing electromagnetic-assisted lost foam casting technology (see Chinese invention patent CN202310908175.1) primarily improves casting performance by applying electromagnetic stirring force. However, since it cannot generate directional electromagnetic pressure to enhance the filling capacity of the molten aluminum, it struggles to address casting defects caused by insufficient filling power and rapid cooling of the molten aluminum. Moreover, existing technologies do not separate the casting module and the electromagnetic auxiliary module; each sand box must be equipped with independent electromagnetic auxiliary equipment. This not only increases resource consumption but also complicates the sand removal process, reduces production efficiency, and fails to meet the needs of industrial production. Summary of the Invention

[0005] The purpose of this invention is to provide an electromagnetically assisted pressure-boosting aluminum alloy lost foam casting forming device and method to solve the problems of casting defects caused by insufficient filling power and excessive cooling of aluminum liquid, which are difficult to solve in the existing technology, as well as high resource consumption, complex process and low production efficiency.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] An electromagnetically assisted pressure-boosting aluminum alloy lost foam casting forming device includes: an electromagnetic pressure-boosting module and a lifting device module;

[0008] The electromagnetic booster module includes a magnetic yoke, winding coils, an upper fixed sleeve, a lower fixed sleeve, and a screw. Four magnetic yokes are arranged around the square sand box. The magnetic yokes are made of silicon steel and have six salient poles, with the coil windings wound around the six salient poles respectively. The upper and lower fixed sleeves are installed on the top and bottom of the magnetic yokes respectively and are connected by a screw. A pull ring is provided on the upper fixed sleeve. The six winding coils on each magnetic yoke are divided into two groups. The three winding coils in each group are connected in a Y-type configuration and are supplied with three-phase alternating current. The first, second, and third winding coils from top to bottom are in the same phase as the fourth, fifth, and sixth winding coils respectively. The corresponding first, second, third, fourth, fifth, and sixth winding coils on each magnetic yoke are connected in series to ensure the same phase.

[0009] The lifting device module includes two symmetrically arranged left and right parts on both sides of the electromagnetic booster module. The left and right parts are identical and each includes a column, a cantilever, and an electric hoist. The column is equipped with a cantilever, and the cantilever is equipped with an electric hoist. The lower hook of the electric hoist is connected to the pull ring of the upper fixed sleeve. Under the action of the electric hoist, the electromagnetic booster module realizes the lifting function.

[0010] Furthermore, the width of the magnetic yoke is less than the width of the sand box, and the distance between the salient poles of the magnetic yoke is equal; two limiting strips are welded around the upper and lower fixing sleeves, and the distance between each pair of limiting strips is the width of the magnetic yoke, which is used to limit the lateral movement of the magnetic yoke; bolt through holes are provided on the outer side of the limiting strips for bolt connection; pads are provided at the four corners of the bottom of the lower fixing sleeve, and the height of the pads is greater than the height of the nut at the bottom of the screw.

[0011] Furthermore, in the lifting device module, a fixing plate is provided on the column, and the cantilever is connected to the fixing plate; eight reinforcing plates are provided at the bottom of the column, and the column is fixed to the ground by rivets; two limiting blocks are provided at the upper part of the column, and the limiting blocks are connected to the cantilever.

[0012] Furthermore, the cantilever adopts an I-beam structure, and the electric hoist is fixed to the cantilever by a connecting pin.

[0013] Furthermore, the motors of the two electric hoists are connected in series on the same switch.

[0014] Secondly, the present invention provides a method for electromagnetically assisted pressure-boosting aluminum alloy lost foam casting using the electromagnetically assisted pressure-boosting aluminum alloy lost foam casting forming device described above, comprising the following steps:

[0015] Step 1: Use an intermittent steam pre-expansion machine to pre-foam the EPS beads. Place the pre-foamed beads into a curing chamber for curing. After preheating the mold to 70°C, inject the fully cured beads into the cavity using a material gun. Introduce steam to foam and shape the beads. After cooling, demold to obtain the white mold pattern of each part of the casting. Cut and glue the white molds that make up the casting. Then combine the casting white mold with the gating system white mold into a cluster to obtain the complete casting white mold pattern.

[0016] Step 2: Apply aluminum alloy lost foam casting coating to the surface of the white mold, and then dry it;

[0017] Step 3: Place the coated white model into the sand box and add dry sand layer by layer into the sand box, compacting it while adding sand. Under the premise of ensuring that the model does not deform, the dry sand in the sand box achieves a high and uniform filling density.

[0018] Step four: Degassing, slag removal, refining, purifying, and settling of the aluminum solution;

[0019] Step 5: The sand box moves from the compaction zone to the casting zone via a conveyor belt. The electric hoist is turned on, and the lifting device module lowers the electromagnetic booster module to supply three-phase AC power to the winding coil, forming a traveling wave magnetic field. The aluminum liquid is then poured. Under the action of the traveling wave magnetic field, the aluminum liquid generates an induced current. The charged aluminum liquid cuts the magnetic field lines to obtain a downward electromagnetic driving force, melting the foam white mold and forming the casting.

[0020] Step 6: Reverse the electric hoist, lift the electromagnetic booster module, and the sand box will move from the pouring area to the sand drop area via the conveyor belt. Turn the sand box over and pour out the dry sand and castings. Place the castings in water to cool, vibrate to break them or knock off the surface coating and clean the castings.

[0021] Step 7: Perform T6 heat treatment on the casting, then machine to remove the gating system, and finally grind, shot blast, and inspect to obtain the desired casting.

[0022] Furthermore, in step one, the maximum diameter of the EPS beads does not exceed 1 / 8 to 1 / 10 of the minimum wall thickness of the casting, and the bead density is selected as 15 to 25 g / L; during pre-foaming, the pressure of the pre-foaming machine pipeline is controlled within 0.1 to 0.2 MPa, the pressure of the expansion chamber is controlled within 0.03 to 0.06 MPa, the pre-foaming temperature is controlled within 80 to 100°, the pre-foaming time is 2 to 5 min, and the curing time is controlled within 12 to 24 h.

[0023] Furthermore, in step two, the coating is composed of diatomaceous earth, mullite, sodium bentonite, CMC, PVA, water glass, additives, and water. When using it, the dry powder coating and water are mixed in a preset ratio, and then stirred at high speed for more than two hours, followed by stirring at low speed for two hours. The prepared coating is then evenly applied to the white model and left to air dry naturally for more than 24 hours. The coating is applied twice, with the second application done only after the first application is completely dry. Before pouring, the coating must be completely dry.

[0024] Furthermore, in step three, the dry sand particle size is 70-140 mesh. During vibration, XYZ three-dimensional vibration is selected, with a vibration frequency of 35-50 Hz and an amplitude of 2 mm. When filling the sand, the bottom sand filling height is first determined according to the height of the casting, and then the sand is filled layer by layer according to the structure of the casting, so that the dry sand height after each filling is in the difficult-to-fill structure, including holes, interlayers, and corners.

[0025] Furthermore, in step four, the melt purification process involves transferring the molten aluminum alloy into a refining furnace, adding refining agent twice at 730–750°C, removing slag twice, and purging with argon gas.

[0026] In step five, a three-phase alternating current with a frequency of 30-60Hz and a current of 40-80A is applied, and the number of coil turns is 40-80.

[0027] In step seven, the alloy composition is A356 aluminum-silicon alloy, and the heat treatment process is as follows: solution temperature is 535-540℃, solution time is 6-8h; quenching temperature is 60-80℃, quenching time is 2-3min; aging temperature is 160-190℃, aging time is 4-8h.

[0028] The present invention has the following beneficial effects:

[0029] This invention proposes an electromagnetically assisted pressure-boosting lost foam casting forming device for aluminum alloys. A liftable electromagnetic coil is placed outside the sand box. During casting, three-phase alternating current is supplied to the electromagnetic coil, and the coil winding generates a traveling wave magnetic field. Under the action of the traveling wave magnetic field, the molten aluminum generates an induced current. The charged molten aluminum cuts the magnetic field lines during the casting process, generating a downward constant magnetic field force. This significantly promotes the flow of aluminum alloy melt micro-aggregates in the mold cavity, improves the filling power, accelerates the casting speed, makes the filling complete, the structure refined and dense, greatly reduces casting defects, and improves the mechanical properties of the casting.

[0030] This invention proposes an electromagnetically assisted pressure-boosting lost foam casting forming device for aluminum alloys. After the casting is poured, the electromagnetic pressure-boosting module is lifted by the lifting device, and the sand box goes to the sand drop area for the next process operation. When the next sand box arrives at the pouring area, the coil is lowered again for pouring, and so on, which greatly reduces the difficulty of operation and improves the work efficiency.

[0031] This invention also provides a complete electromagnetic-assisted pressure-boosting lost foam casting method for aluminum alloys, applicable to most aluminum alloy castings, which can significantly reduce casting defects and improve the mechanical properties of castings. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the structure of an electromagnetically assisted pressure-boosting aluminum alloy lost foam casting forming device proposed in this invention;

[0034] Figure 2 This is a schematic diagram of the electromagnetic boosting module in an electromagnetically assisted boosting aluminum alloy lost foam casting forming device proposed in this invention.

[0035] Figure 3 This is a schematic diagram of the lifting device module in an electromagnetically assisted pressure-boosting aluminum alloy lost foam casting forming device proposed in this invention.

[0036] Diagram description: 1-Magnetic yoke; 2-Winding coil; 3-Upper fixing sleeve; 4-Lower fixing sleeve; 5-Screw; 6-Foot pad; 7-Column; 8-Limit stop; 9-Fixing plate; 10-Cantilever; 11-Connecting pin; 12-Electric hoist. Detailed Implementation

[0037] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments. It should be pointed out that the following detailed description is illustrative and intended to provide an explanation of the embodiments described herein. Unless otherwise indicated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0038] Reference Figures 1-3 This invention provides an electromagnetically assisted pressure-boosting aluminum alloy lost foam casting forming device, including an electromagnetic pressure-boosting module and a lifting device module. The electromagnetic pressure-boosting module consists of a magnetic yoke 1, a winding coil 2, an upper fixing sleeve 3, a lower fixing sleeve 4, a screw 5, and a pad 6; the lifting device module consists of two identical parts, left and right, each consisting of a column 7, a limit stop 8, a fixing plate 9, a cantilever 10, a connecting pin 11, and an electric hoist 12.

[0039] In the electromagnetic booster module, four magnetic yokes 1 are arranged around the square sand box. The upper fixing sleeve 3 and the lower fixing sleeve 4 are installed on the top and bottom of the magnetic yokes 1 respectively. The upper fixing sleeve 3 and the lower fixing sleeve 4 are connected by bolts 5 to connect the four magnetic yokes 1 into a whole for lifting and lowering. The width of the magnetic yoke 1 should be smaller than the width of the sand box to ensure that there is space for the bolts to be installed.

[0040] In this embodiment, the magnetic yoke 1 is made of silicon steel, and each magnetic yoke 1 has six salient poles. The coil windings 2 are wound on the six silicon steel salient poles respectively, and the distance between the salient poles is equal to ensure that the coil windings 2 between the salient poles do not interfere. The first and sixth salient poles should have sufficient distance from the top and bottom of the magnetic yoke 1 to ensure that the upper and lower fixing sleeves 4 can be installed normally.

[0041] In this embodiment, the six winding coils 2 on each yoke 1 are divided into two groups. The three winding coils 2 in each group are connected in a Y-type manner and three-phase alternating current is applied. The first, second, and third winding coils 2 from top to bottom should have the same phase as the fourth, fifth, and sixth winding coils 2 respectively. The corresponding first, second, third, fourth, fifth, and sixth winding coils 2 on each yoke 1 should be connected in series to ensure the same phase, thereby providing an efficient and stable traveling wave magnetic field.

[0042] In this embodiment, two limiting strips are welded around the perimeter of the fixing sleeve 4. The distance between each pair of limiting strips is the width of the magnetic yoke 1, which is used to limit the lateral movement of the magnetic yoke 1. Bolt through holes are provided on the outer side of the limiting strips for bolt connection.

[0043] In this embodiment, two pull rings are welded to the top of the upper fixed sleeve 3. The pull rings are connected to the lower hook of the electric hoist 12 to facilitate lifting and lowering. The distance between the pull rings should be as large as possible to ensure the lifting and lowering stability of the electromagnetic booster module during the lifting and lowering process.

[0044] In this embodiment, a rubber pad 6 is connected to each of the four corners of the bottom of the lower fixing sleeve, which can prevent the lower fixing sleeve 4 from directly contacting the ground and reduce the wear of the lower fixing sleeve 4. The height of the pad 6 is greater than the height of the nut to facilitate the installation of bolts and nuts.

[0045] In the lifting device module, a cantilever 10 is installed on the column 7. The fixing plate 9 on the column can both connect the cantilever 10 and restrict the rotation of the cantilever 10. An electric hoist 12 is installed on the cantilever 10 through a connecting pin 11. The lower hooks of the two electric hoists 12 are connected to the pull ring of the upper fixing sleeve 4. Under the action of the electric hoists 12, the electromagnetic booster device can realize the lifting function.

[0046] In this embodiment, the lifting device is divided into two parts, left and right. The two parts are identical but separate from each other, leaving space directly above the sand box to avoid affecting the pouring of aluminum liquid.

[0047] In this embodiment, the bottom of the column 7 is provided with eight reinforcing plates to maintain the stability of the support, and the column 7 is fixed to the ground by rivets.

[0048] In this embodiment, there are two limiting blocks 8 on the upper part of the column 7. The limiting blocks 8 not only limit the movement, but also connect the cantilever 10, reduce stress concentration, and enhance the support stability of the column.

[0049] In this embodiment, the cantilever 10 adopts an I-beam structure to enhance its load-bearing capacity, and the electric hoist 12 is fixed to the cantilever 10 by a connecting pin.

[0050] In this embodiment, the motors of the two electric hoists 12 on the left and right sides should be connected in series on the same switch, so that the electromagnetic booster module rises and falls synchronously on both sides, ensuring the stability of the lifting process.

[0051] As can be seen from the above embodiments, the present invention provides an electromagnetically assisted pressure-boosting lost foam casting forming device for aluminum alloys. A liftable electromagnetic coil is placed outside the sand box. During casting, three-phase alternating current is supplied to the electromagnetic coil, generating a traveling wave magnetic field in the coil windings. Under the action of the traveling wave magnetic field, the molten aluminum generates an induced current. The charged molten aluminum cuts the magnetic field lines during the casting process, generating a downward constant magnetic field force, which significantly promotes the flow of aluminum alloy melt micro-aggregates in the mold cavity, improves the filling power, accelerates the casting speed, and results in complete filling, refined and dense structure. This significantly reduces casting defects and improves the mechanical properties of the casting. After casting is completed, the electromagnetic pressure-boosting module is lifted by the lifting device, and the sand box is moved to the sand drop area for the next process operation. When the next sand box arrives at the casting area, the coil is lowered again for casting, and so on. This significantly reduces the difficulty of operation and improves work efficiency. The present invention also provides a complete electromagnetically assisted pressure-boosting lost foam casting process for aluminum alloys to reduce casting defects and improve the mechanical properties of castings.

[0052] This embodiment also provides a method for forming an electromagnetically assisted pressure-boosting aluminum alloy lost foam casting, including the following steps:

[0053] Step 1, Foam Model Making:

[0054] A. Foam Bead Foaming and Molding: EPS beads are pre-foamed using an intermittent steam pre-foaming machine. The pre-foamed beads are then placed in a curing chamber for curing. After the mold is preheated to about 70°C, the fully cured beads are injected into the cavity using a material gun. Steam is then introduced to foam and mold the beads. After cooling, the beads are demolded to obtain the white mold pattern of each part of the casting.

[0055] B. Cut and glue the white molds that make up the casting, and then combine the casting white molds with the gating system white molds into a cluster to obtain a complete casting white mold pattern.

[0056] Step 2, apply special coating: apply special aluminum alloy lost foam casting coating to the surface of the white mold, and then dry.

[0057] Step 3, Sand box compaction: Place the coated white model into the sand box, add dry sand layer by layer into the sand box, and compact it while adding sand. Under the premise of ensuring that the model does not deform, the dry sand in the sand box achieves a high and uniform filling density.

[0058] Step 4, Melt purification: The aluminum solution is degassed, slag removed, refined, purified, and allowed to settle.

[0059] Step 5, Pouring: The sand box moves from the compaction zone to the pouring zone via a conveyor belt. The electric hoist is turned on, and the lifting device lowers the electromagnetic booster module to supply three-phase AC power to the winding coil, forming a traveling wave magnetic field. The aluminum liquid is then poured. Under the action of the traveling wave magnetic field, the aluminum liquid generates an induced current. The charged aluminum liquid cuts the magnetic field lines to obtain a downward electromagnetic driving force, which quickly melts the foam white mold, forming a dense, complete casting with high surface quality and good mechanical properties.

[0060] Step 6, Sand Drop: Reverse the electric hoist, lift the electromagnetic booster module, and the sand box will travel from the pouring area to the sand drop area via the conveyor belt. Turn the sand box over and pour the dry sand and castings out of the sand box. Place the castings in water for rapid cooling, vibrate to break them or knock off the surface coating and clean the castings.

[0061] Step 7, heat treatment: The casting is subjected to T6 heat treatment, then the gating system is removed by machining, and finally the casting is obtained after grinding, shot blasting, and inspection.

[0062] In this embodiment, the maximum diameter of the EPS beads in step one should not exceed 1 / 8 to 1 / 10 of the minimum wall thickness of the casting, and the bead density should be selected as 15 to 25 g / L. During pre-foaming, the pressure of the pre-foaming machine pipeline is controlled within 0.1 to 0.2 MPa, the pressure of the expansion chamber is controlled within 0.03 to 0.06 MPa, the pre-foaming temperature is controlled within 80 to 100°, the pre-foaming time is 2 to 5 min, and the curing time is controlled within 12 to 24 h.

[0063] In this embodiment, the coating in step two is composed of diatomaceous earth, mullite, sodium bentonite, CMC, PVA, water glass, appropriate additives, and water. Water glass refers to an aqueous solution of sodium silicate. When using the coating, the dry powder coating and water are mixed in a preset ratio, stirred at high speed for at least two hours, and then stirred at low speed for two hours to ensure uniform density and viscosity. The prepared coating is then evenly applied to a white mold and allowed to air dry naturally for at least 24 hours. Two coats are applied; the second coat is applied only after the first coat is completely dry. Before pouring, the coating must also be completely dry to ensure optimal coating performance.

[0064] In this embodiment, the dry sand particle size in step three is 70-140 mesh. Specifically, XYZ three-dimensional vibration is selected, with a vibration frequency of 35-50 Hz and an amplitude of 2 mm. When filling the sand, the bottom sand filling height is first determined according to the height of the casting to make the bottom sand height as large as possible to reduce the sand filling time. Then, the sand is filled layer by layer according to the casting structure, so that the dry sand height after each filling is in the difficult-to-fill structure such as holes, interlayers, and corners, so as to ensure that the dry sand in the sand box obtains a high and uniform filling density without deforming the pattern.

[0065] In this embodiment, the melt purification process in step four involves transferring the molten aluminum alloy into a refining furnace, adding refining agent twice at 730–750°C, removing slag twice, and purging with argon gas.

[0066] In this embodiment, in step five, the frequency of the three-phase alternating current is 30-60Hz, the current is 40-80A, and the number of coil turns is 40-80.

[0067] In this embodiment, in step seven, the heat treatment process varies depending on the alloy composition. Taking A356 aluminum-silicon alloy as an example, the selectable heat treatment regime is as follows: solution temperature of 535-540℃, solution time of 6-8h; quenching temperature of 60-80℃, quenching time of 2-3min; aging temperature of 160-190℃, aging time of 4-8h.

[0068] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the scope of the invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0069] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An electromagnetically assisted pressure-boosting lost foam casting forming device for aluminum alloys, characterized in that, include: Electromagnetic booster module and lifting device module; The electromagnetic booster module includes a magnetic yoke (1), a winding coil (2), an upper fixing sleeve (3), a lower fixing sleeve (4), and a screw (5); four magnetic yokes (1) are arranged around the square sand box; the magnetic yoke (1) is made of silicon steel and has six salient poles, and the coil winding (2) is wound around the six salient poles respectively; The upper fixing sleeve (3) and the lower fixing sleeve (4) are respectively installed on the top and bottom of the magnetic yoke (1). The upper fixing sleeve (3) and the lower fixing sleeve (4) are connected by a screw (5). A pull ring is provided on the upper fixing sleeve (3). The six winding coils (2) on each magnetic yoke (1) are divided into two groups. The three winding coils (2) in each group are connected in a Y-type manner and three-phase AC power is applied. The first, second, and third winding coils (2) from top to bottom are connected to the fourth, fifth, and sixth winding coils (2) with the same phase of AC power. The corresponding first, second, third, fourth, fifth, and sixth winding coils (2) on each magnetic yoke (1) are connected in series to ensure the same phase. The lifting device module includes two symmetrical parts arranged on both sides of the electromagnetic booster module. The two parts are identical and each includes a column (7), a cantilever (10), and an electric hoist (12). The column (7) is provided with a cantilever (10), and the cantilever (10) is provided with an electric hoist (12). The lower hook of the electric hoist (12) is connected to the pull ring of the upper fixed sleeve (3). Under the action of the electric hoist (12), the electromagnetic booster module realizes the lifting function.

2. The electromagnetically assisted pressure-boosting aluminum alloy lost foam casting forming device according to claim 1, characterized in that, The width of the magnetic yoke (1) is smaller than the width of the sand box, and the distance between the salient poles of the magnetic yoke (1) is equal; Two limiting strips are welded around the upper fixing sleeve (3) and the lower fixing sleeve (4). The distance between each pair of limiting strips is the width of the magnetic yoke (1) to limit the lateral movement of the magnetic yoke (1). Bolt through holes are provided on the outer side of the limiting strips for bolt connection. Pads (6) are provided at the four corners of the bottom of the lower fixing sleeve (4). The height of the pads (6) is greater than the height of the nut at the bottom of the screw (5).

3. The electromagnetically assisted pressure-boosting aluminum alloy lost foam casting forming device according to claim 2, characterized in that, In the lifting device module, a fixing plate (9) is provided on the column (7), and the cantilever (10) is connected to the fixing plate (9); the bottom of the column (7) is provided with eight reinforcing plates, and the column (7) is fixed to the ground by rivets; the upper part of the column (7) is provided with two limiting blocks (8), and the limiting blocks (8) are connected to the cantilever (10).

4. The electromagnetically assisted pressure-boosting aluminum alloy lost foam casting forming device according to claim 3, characterized in that, The cantilever (10) adopts an I-beam structure, and the electric hoist (12) is fixed to the cantilever (10) by a connecting pin (11).

5. The electromagnetically assisted pressure-boosting aluminum alloy lost foam casting forming device according to claim 4, characterized in that, The motors of the two electric hoists (12) are connected in series on the same switch.

6. A method for electromagnetically assisted pressure-boosting lost foam casting of aluminum alloys using the electromagnetically assisted pressure-boosting lost foam casting forming device as described in claim 1, characterized in that, Includes the following steps: Step 1: Use an intermittent steam pre-expansion machine to pre-foam the EPS beads. Place the pre-foamed beads into a curing chamber for curing. After preheating the mold to 70°C, inject the fully cured beads into the cavity using a material gun. Introduce steam to foam and shape the beads. After cooling, demold to obtain the white mold pattern of each part of the casting. Cut and glue the white molds that make up the casting. Then combine the casting white mold with the gating system white mold into a cluster to obtain the complete casting white mold pattern. Step 2: Apply aluminum alloy lost foam casting coating to the surface of the white mold, and then dry it; Step 3: Place the coated white model into the sand box and add dry sand layer by layer into the sand box, compacting it while adding sand. Under the premise of ensuring that the model does not deform, the dry sand in the sand box achieves a high and uniform filling density. Step four involves degassing, slag removal, refining, purifying, and settling the aluminum solution. Step 5: The sand box moves from the compaction zone to the casting zone via a conveyor belt. The electric hoist is turned on, and the lifting device module lowers the electromagnetic booster module to supply three-phase AC power to the winding coil, forming a traveling wave magnetic field. The aluminum liquid is then poured. Under the action of the traveling wave magnetic field, the aluminum liquid generates an induced current. The charged aluminum liquid cuts the magnetic field lines to obtain a downward electromagnetic driving force, melting the foam white mold and forming the casting. Step 6: Reverse the electric hoist, lift the electromagnetic booster module, and the sand box will move from the pouring area to the sand drop area via the conveyor belt. Turn the sand box over and pour out the dry sand and castings. Place the castings in water to cool, vibrate to break them or knock off the surface coating and clean the castings. Step 7: Perform T6 heat treatment on the casting, then machine to remove the gating system, and finally grind, shot blast, and inspect to obtain the desired casting.

7. The electromagnetically assisted pressure-boosting lost foam casting method for aluminum alloys according to claim 6, characterized in that, In step one, the maximum diameter of the EPS beads should not exceed 1 / 8 to 1 / 10 of the minimum wall thickness of the casting, and the bead density should be selected as 15 to 25 g / L. During pre-foaming, the pressure in the pre-foaming machine pipeline should be controlled within 0.1 to 0.2 MPa, the pressure in the expansion chamber should be controlled within 0.03 to 0.06 MPa, the pre-foaming temperature should be controlled within 80 to 100°, the pre-foaming time should be 2 to 5 min, and the curing time should be controlled within 12 to 24 h.

8. The electromagnetically assisted pressure-boosting lost foam casting method for aluminum alloys according to claim 7, characterized in that, In step two, the coating is made of diatomaceous earth, mullite, sodium bentonite, CMC, PVA, water glass, additives and water. When using it, the dry powder coating and water are mixed in a preset ratio, and then stirred at high speed for more than two hours, followed by stirring at low speed for two hours. The prepared coating is then evenly applied to the white model and left to air dry naturally for more than 24 hours. The coating is applied twice, and the second coat is applied only after the first coat is completely dry. Before pouring, ensure that the coating is completely dry.

9. The electromagnetically assisted pressure-boosting lost foam casting method for aluminum alloys according to claim 8, characterized in that, In step three, the dry sand particle size is 70-140 mesh. During vibration, XYZ three-dimensional vibration is selected, with a vibration frequency of 35-50 Hz and an amplitude of 2 mm. When filling the sand, the bottom sand filling height is first determined according to the height of the casting, and then the sand is filled layer by layer according to the structure of the casting, so that the dry sand height after each filling is in the difficult-to-fill structure, including holes, interlayers, and corners.

10. The electromagnetically assisted pressure-boosting lost foam casting method for aluminum alloys according to claim 9, characterized in that, In step four, the melt purification process involves transferring the molten aluminum alloy into a refining furnace, adding refining agent twice at 730–750°C, removing slag twice, and purging with argon gas. In step five, a three-phase alternating current with a frequency of 30-60Hz and a current of 40-80A is applied, and the number of coil turns is 40-80. In step seven, the alloy composition is A356 aluminum-silicon alloy, and the heat treatment process is as follows: solution temperature is 535-540℃, solution time is 6-8h; quenching temperature is 60-80℃, quenching time is 2-3min; aging temperature is 160-190℃, aging time is 4-8h.

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