Complex-shape multi-material forming device and method based on magnetorheological core and microwaves

Abstract

The invention relates to a complex-shape multi-material forming device and method based on a magnetorheological core and microwaves. The device comprises a mold core internally provided with a cavity, a magnetorheological fluid conveying assembly, the magnetorheological core, a magnetic field generating assembly and a microwave generating assembly, and a feeding opening is formed in the top of the mold core; the magneto-rheological mold core is arranged in the mold cavity and is replaced through the feeding hole; the magnetorheological fluid conveying assembly is used for conveying magnetorheological fluid into an inner cavity of the magnetorheological core or pumping out the magnetorheological fluid in the inner cavity of the magnetorheological core. The magnetic field generating assembly applies a magnetic field to the magnetorheological fluid in the magnetorheological core, so that the magnetorheological fluid is solidified; and the microwave generation assembly is used for sintering and forming the material entering the cavity through the feeding hole. The magneto-rheological material is used as the mold core, so that various materials with different inner cavity shapes can be prepared, and the materials are combined in a staggered manner; meanwhile, a microwave heating technology is utilized to quickly and uniformly heat the materials, so that the combination of multiple materials is facilitated; and the method is suitable for processing a multi-material structure formed by staggering and combining various complex-shaped materials.

Description

Technical Field

[0001] The present invention belongs to the field of advanced manufacturing technology, and particularly relates to a complex-shaped multi-material forming device and method based on a magnetorheological core and microwave. Background Art

[0002] In modern engineering design and product development, the demand for high-performance and multi-functional integrated components is increasing day by day. Single materials often fail to meet the comprehensive requirements for various physical and chemical properties (such as mechanical strength, toughness, thermal conductivity, electromagnetic properties, corrosion resistance, biocompatibility, etc.) in complex application scenarios. Therefore, multi-material structures have emerged. By precisely arranging and combining materials with different characteristics in space, performance optimization and complementarity can be achieved, obtaining comprehensive performance advantages far beyond single materials. For example, in the consumer goods field, such as a tool handle with a soft grip, it usually combines a hard polymer core (such as polypropylene) providing structural support with a soft elastomeric outer layer (such as TPE) providing a comfortable grip and anti-slip performance; in the automotive industry, interior components such as instrument panels integrate a rigid structural skeleton, a soft foam layer for impact energy absorption, and a surface layer with both aesthetics and durability; in pipeline applications, such as in the biomedical and energy fields, there is an even greater need for multi-material pipeline components with internal rust and corrosion prevention and external flexibility and wear resistance, such as reinforced thermoplastic composite pipes (RTP / TCP). In some fields, these pipeline components also need to be manufactured into complex spiral structures. In the field of lattice structures, the internal and external multi-material composite lattice structures have important application prospects in heat dissipation, shock absorption and other fields.

[0003] In particular, multi-material components with complex shapes or complex internal cavity structures exhibit great application potential and value. Such structures can achieve a high degree of functional integration. For example: constructing internal fluid channels for efficient thermal management (heating or cooling); forming lightweight lattice or honeycomb sandwich structures to improve specific strength and specific stiffness; manufacturing biological scaffolds with specific pore structures and functional gradients to guide tissue regeneration; or directly constructing reaction chambers, waveguide structures or integrated circuit paths inside the components. Especially for multi-material structures with multiple nested layers from the inside out, more precise performance regulation and functional stratification can be achieved, for example, having unique advantages in fields such as energy absorption, electromagnetic shielding, and drug controlled release.

[0004] However, traditional manufacturing methods face significant challenges and limitations when preparing the above-mentioned complex-shaped, especially multi-material components with fine and complex internal cavity structures or multi-layer nested structures.

[0005] Multi-component injection molding (such as two-shot injection molding, two-color injection molding) can manufacture some multi-material parts with external coatings or simple interface combinations. However, for complex internal cavities with concave or interleaved features, as well as multi-layer nested structures that need to be built layer by layer, the mold design becomes extremely complex, costly, and even physically difficult to implement a feasible core-pulling scheme. Co-extrusion molding is mainly applicable to manufacturing continuous profiles or films with parallel layered structures and is difficult to achieve three-dimensional complex shapes and non-parallel internal cavities. Bonding or mechanical assembly can combine prefabricated parts of different materials, but often introduces interface weaknesses, increases processes, and is difficult to achieve seamless integration, especially for complex internal structure combinations. Additive manufacturing (3D printing) shows potential in manufacturing complex shapes, but still faces challenges in multi-material printing, such as material compatibility, interface bonding strength, printing speed, internal cavity precision control, and effective and selective curing of different materials (especially materials that require high-temperature sintering or special curing) in a confined space.

[0006] A core technical bottleneck is that it is difficult for existing technologies to conveniently and efficiently create and remove temporary cores (also known as mandrels, cores) used to define complex internal cavities, especially in cases where different materials need to be deposited and cured sequentially and layer by layer to form nested structures. Traditional removable cores (such as metals, sand cores, low-melting-point alloys, water-soluble materials) often have problems such as shape limitations, difficult removal, possible material contamination, or inability to adapt to subsequent special curing processes.

[0007] Therefore, there is an urgent need to develop a new manufacturing technology that can break through the limitations of existing methods and achieve efficient and precise forming of multi-material parts with complex shapes, fine internal cavities, and multi-layer nested structures. Summary of the Invention

[0008] The present invention makes improvements to the above problems existing in the prior art. That is, the technical problem to be solved by the present invention is to provide a complex-shaped multi-material forming device and method based on magnetorheological cores and microwaves, which is reasonably designed and used for producing multi-material structures with multi-layer nesting and interleaved features.

[0009] To achieve the above object, the technical solution adopted by the present invention is: a complex-shaped multi-material forming device based on a magnetorheological core and microwave, including a mold core with a cavity inside, a magnetorheological fluid conveying component, a magnetorheological core, a magnetic field generating component, and a microwave generating component. The top of the mold core has a feed port communicating with the cavity; the magnetorheological core is arranged in the cavity and can be replaced through the feed port; the magnetorheological fluid conveying component is connected to the magnetorheological core for conveying magnetorheological fluid into the inner cavity of the magnetorheological core or pumping out the magnetorheological fluid in the inner cavity of the magnetorheological core; the magnetic field generating component is used to apply a magnetic field to the magnetorheological fluid in the inner cavity of the magnetorheological core to solidify the magnetorheological fluid; the microwave generating component is used to sinter and form the material entering the cavity through the feed port.

[0010] Further, the magnetorheological fluid conveying component includes a storage tank storing magnetorheological fluid, a delivery pump, and a magnetorheological fluid delivery pipe. One end of the magnetorheological fluid delivery pipe is connected to the storage tank, and the other end passes through the feed port and is connected to the magnetorheological core in the cavity; the delivery pump is installed on the magnetorheological fluid delivery pipe, and the delivery pump conveys the magnetorheological fluid in the storage tank to the magnetorheological core through the magnetorheological fluid delivery pipe, or conveys the magnetorheological fluid in the magnetorheological core to the storage tank.

[0011] Further, a magnetic flux port is arranged at the bottom of the mold core, and the position of the magnetic flux port corresponds to that of the feed port; the magnetic field generating component includes a magnetic field emitter and a magnetic field receiver. The magnetic field emitter and the magnetic field receiver are distributed on the upper and lower sides of the mold core. The magnetic field emitter corresponds to the position of the feed port and emits a magnetic field downward; the magnetic field receiver corresponds to the position of the magnetic flux port and receives the magnetic field.

[0012] Further, the microwave generating component includes a first microwave generator and a second microwave generator. The first microwave generator is located on the left side of the mold core, and the microwave output end of the first microwave generator is connected to the left end of the mold core through a first waveguide; the second microwave generator is located on the front side of the mold core, and the microwave output end of the second microwave generator is connected to the front end of the mold core through a second waveguide.

[0013] Further, the mold core includes an upper mold core and a lower mold core that are integrally connected up and down. The inner cavities of the upper mold core and the lower mold core are spliced along the up and down direction to form a cavity.

[0014] Further, the mold core includes a left mold core and a right mold core that are integrally connected left and right. The inner cavities of the left mold core and the right mold core are spliced along the left and right direction to form a cavity.

[0015] Furthermore, the mold core is made of a microwave-transparent material, and a coating layer is provided on the outside of the mold core. The coating layer is made of a material with microwave reflection and magnetic field penetration functions, and a relief hole is provided at the magnetic flux port of the coating layer; a steel mesh plate is arranged in the magnetic flux port.

[0016] Furthermore, the coating layer is a mesh-shaped flexible fabric woven from a conductive material, and the mesh hole diameter of the coating layer is 1 - 2 mm.

[0017] Furthermore, the mesh hole diameter of the steel mesh plate is 3 - 4 mm.

[0018] Another technical solution adopted by the present invention is: a complex-shaped multi-material forming method based on a magnetorheological core and microwaves, comprising the following steps: Step (1): Install the first magnetorheological core in the cavity of the mold core in a non-magnetic softening state, and connect the magnetorheological fluid delivery assembly to the first magnetorheological core; Step (2): The transfer pump injects the magnetorheological fluid into the first magnetorheological core through the magnetorheological fluid delivery pipe. The magnetic field emitter emits a magnetic field, and the magnetic field receiver receives the magnetic field, so that the magnetorheological fluid in the first magnetorheological core solidifies; Step (3): Feed the material of the first layer of the multi-material structure into the cavity of the mold core through the feed port. The first microwave generator generates the first microwave and sends the first microwave into the cavity through the first waveguide; the second microwave generator generates the second microwave and sends the second microwave into the cavity through the second waveguide. The first microwave and the second microwave sinter and form the material of the first layer of the multi-material structure; Step (4): Stop the magnetic field emitter from emitting the magnetic field, and at the same time stop the magnetic field receiver from receiving the magnetic field, so that the magnetorheological fluid in the first magnetorheological core becomes soft. Use the transfer pump to pump the magnetorheological fluid out of the first magnetorheological core, and then take out the first magnetorheological core from the cavity through the feed port; Step (5): Install the second magnetorheological core in the cavity of the mold core in a non-magnetic softening state, and connect the magnetorheological fluid delivery assembly to the second magnetorheological core; Step (6): The transfer pump injects the magnetorheological fluid into the second magnetorheological core through the magnetorheological fluid delivery pipe; the magnetic field emitter emits a magnetic field, and the magnetic field receiver receives the magnetic field, so that the magnetorheological fluid in the second magnetorheological core solidifies; Step (7): Feed the material of the second layer of the multi-material structure into the cavity through the feed port. The first microwave generator generates the first microwave and sends the first microwave into the interior of the cavity using the first waveguide; the second microwave generator generates the second microwave and sends the second microwave into the interior of the cavity using the second waveguide. The first microwave and the second microwave sinter and form the material of the second layer of the multi-material structure; Step (8): Stop the magnetic field emitter from emitting the magnetic field and simultaneously stop the magnetic field receiver from receiving the magnetic field, making the magnetorheological fluid in the second magnetorheological core soften. Use a transfer pump to extract the magnetorheological fluid from the second magnetorheological core, and then take out the second magnetorheological core from the cavity through the feed port. Step (9): Repeat the above process to form other layers of the multi-material structure, obtaining a multi-material structure with a combination of various different inner cavity structures.

[0019] Compared with the prior art, the present invention has the following effects: The present invention is reasonably designed. By using magnetorheological materials as the cores, materials with various different inner cavity shapes can be prepared and combined in an interleaved manner. At the same time, by using microwave heating technology, the materials can be heated quickly and uniformly, which is beneficial to the combination between multi-materials. The present invention is applicable to processing multi-material structures in which multi-materials with various complex shapes are interleaved and combined. Description of the Drawings

[0020] Figure 1 is a schematic structural diagram of an embodiment of the present invention; Figure 2 is Figure 1 the front view sectional schematic diagram of Figure 3 is a schematic diagram of the forming process of a multi-layer capsule in an embodiment of the present invention (forming of the outer layer material); Figure 4 is Figure 3 the front view sectional schematic diagram of Figure 5 is a schematic diagram of the forming process of a multi-layer capsule in an embodiment of the present invention (introduction of the second magnetorheological core); Figure 6 is Figure 5 the front view sectional schematic diagram of Figure 7 is a schematic diagram of the forming process of a multi-layer capsule in an embodiment of the present invention (forming of the inner layer material); Figure 8 is Figure 7 the front view sectional schematic diagram of Figure 9 is a schematic diagram of the overall structure of a multi-layer capsule in an embodiment of the present invention; Figure 10 is Figure 9 the front view sectional schematic diagram of Figure 11 is a schematic structural diagram of the coating layer in an embodiment of the present invention; Figure 12 is a schematic diagram of the forming process of a soft grip tool handle in an embodiment of the present invention (introduction of the first magnetorheological core); Figure 13 is Figure 12 the front view sectional schematic diagram of Figure 14 It is a schematic diagram of the forming process of the soft grip tool handle in the embodiment of the present invention (forming of the soft rubber outer layer material); Figure 15 is Figure 14 the front view sectional schematic diagram of Figure 16 It is a schematic diagram of the forming process of the soft grip tool handle in the embodiment of the present invention (introduction of the second magnetorheological core); Figure 17 is Figure 16 the front view sectional schematic diagram of Figure 18 It is a schematic diagram of the forming process of the soft grip tool handle in the embodiment of the present invention (forming of the hard core skeleton); Figure 19 is Figure 18 the front view sectional schematic diagram of Figure 20 It is a schematic diagram of the overall structure of the soft grip tool handle in the embodiment of the present invention; Figure 21 It is a schematic diagram of the hard core skeleton structure of the soft grip tool handle in the embodiment of the present invention; Figure 22 It is a schematic diagram of the soft rubber outer layer structure of the soft grip tool handle in the embodiment of the present invention.

[0021] In the figure 1 - 6: 1 - mold core; 2 - cavity; 3 - magnetorheological core; 4 - steel mesh plate; 11 - upper mold core; 12 - lower mold core; 13 - feed port; 14 - magnetic flux port; 21. First microwave generator; 22 - first waveguide; 23 - second microwave generator; 24 - second waveguide; 31 - magnetic field emitter; 32 - magnetic field receiver; 41 - first kind of magnetorheological core; 42 - magnetorheological fluid delivery pipe; 43 - delivery pump; 44 - storage tank; 45 - second kind of magnetorheological core; Figures 7 - 13 Among them: 46 - first kind of magnetorheological core A; 47 - second kind of magnetorheological core A; 51 - left mold core; 52 - right mold core; 53 - feed port; 54 - magnetic flux port; 61 - material with microwave reflection and magnetic field penetration function; 71 - first kind of multi - material outer layer; 72 - first kind of multi - material inner layer; 73 - multi - material core; 74 - sealing material; 81 - second kind of multi - material outer layer; 811 - locking protrusion of the second kind of multi - material outer layer; 82 - second kind of multi - material inner layer; 821 - cavity of the second kind of multi - material inner layer; 822 - locking groove of the second kind of multi - material inner layer. Detailed implementation manners

[0022] The present invention will be further described in detail below with reference to the accompanying drawings and specific implementation manners.

[0023] Such as Figures 1 - 2As shown, the present invention is a complex-shaped multi-material forming device based on a magnetorheological core and microwaves, which uses an innovative idea of combining microwave heating technology with a magnetorheological material core to produce a multi-material structure with multiple layers of nesting and interlaced features, specifically: it includes a core 1 with a cavity 2 inside, a magnetorheological fluid delivery component, a magnetorheological core 3, a magnetic field generating component and a microwave generating component, the core 1 has a feed port 13 connected to the cavity 2 at the top middle position, and the feed port is used to facilitate the materials of each layer of the multi-material structure to enter the cavity; the magnetorheological core 3 is arranged in the cavity 2 The magnetorheological core can be replaced through the feed port 13, that is, the magnetorheological core is taken out of the cavity from the feed port or loaded into the cavity through the feed port; the magnetorheological fluid delivery component is connected to the magnetorheological core 3, and the magnetorheological fluid delivery component is used to deliver magnetorheological fluid to the inner cavity of the magnetorheological core 3 or extract the magnetorheological fluid from the inner cavity of the magnetorheological core 3; the magnetic field generating component is used to apply a magnetic field to the magnetorheological fluid in the inner cavity of the magnetorheological core 3 to solidify the magnetorheological fluid in the inner cavity of the magnetorheological core; the microwave generating component is used to sinter and form the material entering the cavity through the feed port 13. By using magnetorheological material as a core, a variety of materials with different inner cavity shapes can be prepared and staggered; at the same time, by using microwave heating technology, the material can be quickly and evenly heated, which is conducive to the combination of multiple materials; the present invention is suitable for processing a multi-material structure in which a variety of complex-shaped materials are staggered.

[0024] When the forming device is working, the first magnetorheological core 41 enters the mold cavity 2 through the feed port 13 in a non-magnetic softened state, and then magnetorheological fluid is added and a magnetic field is passed to solidify it. The first material enters the mold cavity 2 through the feed port 13 and is solidified under microwave heating. Then the first magnetorheological core 41 softens and exits the mold cavity 2 in a non-magnetic state, and the second magnetorheological core 45 enters the mold cavity 2 through the feed port 13 in a non-magnetic softened state, and then magnetorheological fluid is added and a magnetic field is passed to solidify it. The second material enters the mold cavity through the feed port 13 and is solidified under microwave heating; this is repeated to obtain a multi-material structure with a variety of different inner cavity structure combinations.

[0025] In this embodiment, each layer of the multi-material structure can be a powder or a liquid. When forming different inner cavity structures of different materials, the magnetorheological core can be replaced as needed, for example, the first magnetorheological core 41 can be changed to the second magnetorheological core 45, the third magnetorheological core, the fourth magnetorheological core, etc.

[0026] In this embodiment, the magnetorheological fluid conveying assembly includes a storage tank 44 storing magnetorheological fluid, a conveying pump 43, and a magnetorheological fluid conveying pipe 42. One end of the magnetorheological fluid conveying pipe 42 is connected to the storage tank 44, and the other end passes through the feed port 13 and is connected to the magnetorheological core 3 in the cavity 2. The conveying pump 43 is installed on the magnetorheological fluid conveying pipe 42. The conveying pump 43 conveys the magnetorheological fluid in the storage tank 44 to the magnetorheological core 3 through the magnetorheological fluid conveying pipe 42, or conveys the magnetorheological fluid in the magnetorheological core 3 to the storage tank 44.

[0027] In this embodiment, a magnetic flux port 14 is provided at the middle position of the bottom of the mold core 1. The magnetic flux port 14 corresponds to the position of the feed port 13, and the magnetic flux port is not communicated with the cavity.

[0028] In this embodiment, the magnetic field generating assembly includes a magnetic field emitter 31 and a magnetic field receiver 32. The magnetic field emitter 31 and the magnetic field receiver 32 are distributed on the upper and lower sides of the middle part of the mold core 1. The magnetic field emitter 31 corresponds to the position of the feed port 13 and emits a magnetic field downward. The magnetic field receiver 32 corresponds to the position of the magnetic flux port 14 and receives the magnetic field emitted by the magnetic field emitter 31, and uses this magnetic field to solidify the magnetorheological fluid in the magnetorheological core.

[0029] In this embodiment, the microwave generating assembly includes a first microwave generator 21 and a second microwave generator 23. The first microwave generator 21 is located on the left side of the mold core 1. The microwave output end of the first microwave generator 21 is connected to the middle part of the left end of the mold core 1 through a first waveguide 22. The second microwave generator 23 is located in front of the mold core 1. The microwave output end of the second microwave generator 23 is connected to the middle part of the front end of the mold core 1 through a second waveguide 24. The first microwave generator generates a first type of microwave and sends the first type of microwave into the cavity through the first waveguide. The second microwave generator generates a second type of microwave and sends the second type of microwave into the cavity through the second waveguide. The first type of microwave and the second type of microwave sinter and form the material entering the cavity through the feed port.

[0030] In this embodiment, the mold core is of a split and spliced structure, and there are two forms. One is splicing up and down, and the other is splicing left and right. Specifically: When the mold core is in the form of splicing up and down: the mold core 1 includes an upper mold core 11 and a lower mold core 12 that are connected and integrated up and down. The inner cavities of the upper mold core 11 and the lower mold core 12 are spliced along the up and down directions to form the cavity 2. In this form, the feed port 13 is located at the middle position of the top of the upper mold core 11, and the magnetic flux port 14 is located at the middle position of the bottom of the lower mold core 12. The first waveguide 22 is connected to the left end of the connection between the upper and lower mold cores, and the second waveguide 24 is connected to the front end of the connection between the upper and lower mold cores. When the mold core is in a left - right splicing form: The mold core 1 includes a left mold core 51 and a right mold core 52 which are joined together left and right. The inner cavities of the left mold core 51 and the right mold core 52 are spliced along the left - right direction to form the cavity 2. In this form, the feed port 13 is located at the middle position at the top of the joint of the left and right mold cores, and the magnetic flux port 14 is located at the middle position at the bottom of the joint of the left and right mold cores; The first waveguide 22 is connected to the middle part of the left end of the left mold core 51, and the second waveguide 24 is connected to the middle part of the front end of the joint of the left and right mold cores.

[0031] In this embodiment, the mold core 1 (including the upper mold core 11, the lower mold core 12, the left mold core 51, and the right mold core 52) is made of a microwave - transparent material that does not absorb and convert microwaves. Further, the outside of the mold core 1 is uniformly wrapped or coated with a coating layer, and this coating layer is arranged on the outside of the mold core in a uniformly wrapped or coated manner. The coating layer is made of a material 61 with microwave reflection and magnetic field penetration functions, such as a mesh - like flexible fabric woven from conductive materials such as carbon fiber or metal wire. The mesh hole diameter of the coating layer is 1 - 2 mm.

[0032] In this embodiment, the coating layer is provided with a relief hole at the magnetic flux port 14. A steel mesh plate 4 is arranged inside the magnetic flux port, that is: in the area of the magnetic flux port 14, the mold core is not wrapped or coated with a material having microwave reflection and magnetic field penetration functions, but a steel plate with a distributed mesh hole diameter of 3 - 4 mm, a total diameter of 30 mm, and a thickness of 1 mm is embedded.

[0033] In this embodiment, the complex - shape multi - material forming method based on the magnetorheological core and microwave includes the following steps: Step (1): Load the first kind of magnetorheological core 41 in the demagnetized and softened state into the cavity 2 of the mold core 1, and connect the magnetorheological fluid delivery assembly to the first kind of magnetorheological core 41; Step (2): The transfer pump 43 fills the magnetorheological fluid in the storage tank 44 into the first kind of magnetorheological core 41 through the magnetorheological fluid delivery pipe 42. The magnetic field emitter 31 emits a magnetic field, and the magnetic field receiver 32 receives the magnetic field to solidify the magnetorheological fluid in the first kind of magnetorheological core 41; Step (3): Feed the material of the first layer of the multi - material structure into the cavity 2 of the mold core through the feed port 13. The first microwave generator 21 generates the first kind of microwave and sends the first kind of microwave into the cavity 2 through the first waveguide 22; The second microwave generator 23 generates the second kind of microwave and sends the second kind of microwave into the cavity 2 through the second waveguide 24. The first kind of microwave and the second kind of microwave sinter and form the material of the first layer of the multi - material structure; Step (4): Stop the magnetic field emitter 31 from emitting the magnetic field and simultaneously stop the magnetic field receiver 32 from receiving the magnetic field, so that the magnetorheological fluid in the first magnetorheological core 41 becomes soft. Use the transfer pump 43 to pump the magnetorheological fluid out of the first magnetorheological core 41 into the storage tank, and then take out the first magnetorheological core 41 from the cavity through the feed port. Step (5): Load the second magnetorheological core 45 into the cavity 2 of the mold core 1 in a magnetically softened state, and connect the magnetorheological fluid delivery assembly to the second magnetorheological core 45. Step (6): The transfer pump 43 pumps the magnetorheological fluid in the storage tank into the second magnetorheological core 45 through the magnetorheological fluid delivery pipe 42; the magnetic field emitter 31 emits a magnetic field, and the magnetic field receiver 32 receives the magnetic field, so that the magnetorheological fluid in the second magnetorheological core 45 solidifies. Step (7): The material of the second layer of the multi-material structure enters the cavity through the feed port 13. The first microwave generator 21 generates the first microwave and uses the first waveguide 22 to send the first microwave into the interior of the cavity 2; the second microwave generator 23 generates the second microwave and uses the second waveguide 24 to send the second microwave into the interior of the cavity 2. The first microwave and the second microwave sinter and form the material of the second layer of the multi-material structure. Step (8): Stop the magnetic field emitter 31 from emitting the magnetic field and simultaneously stop the magnetic field receiver 32 from receiving the magnetic field, so that the magnetorheological fluid in the second magnetorheological core 45 becomes soft. Use the transfer pump 43 to pump the magnetorheological fluid out of the second magnetorheological core 45 into the storage tank, and then take out the second magnetorheological core 45 from the cavity 2 through the feed port. Step (9): Repeat the above steps to form other layers of the multi-material structure. Each formed layer corresponds to a magnetorheological core, and in this way, a multi-material structure with various combinations of internal cavity structures can be obtained.

[0034] In this embodiment, the magnetorheological material, as an intelligent material, can rapidly and reversibly undergo huge changes in viscosity or yield strength under an externally applied magnetic field. Utilizing this property, the magnetorheological material, as a dynamically reconfigurable core that can be "cured on demand, softened on demand", reused, and injected and removed through small holes, provides a new solution for the forming of complex internal cavities and the sequential construction of multi-layer materials. Microwave heating, as a volume heating method, has the advantages of rapidity, selectivity, high energy efficiency, etc. Applying it to multi-material forming can achieve rapid, uniform or selective heating and curing / sintering of specific materials or regions, especially facilitating the processing of materials with different thermophysical properties, promoting good interfacial bonding between heterogeneous materials, and potentially shortening the overall manufacturing cycle.

[0035] Combining magnetorheological core technology with microwave heating curing technology overcomes the bottleneck of traditional processes in manufacturing complex inner cavity structures and multi-layer nested multi-material components, opening up a new path of great significance for the manufacture of high-performance, high-integration, complex structure multi-material components. The device and method proposed in the present invention are based on this innovative concept and aim to provide an efficient and flexible technical solution that can manufacture unprecedented complex multi-material structures.

[0036] Specific implementation process 1 Taking a multi-layer capsule with a multi-material structure as an example, it has a two-layer structure (outer layer and inner layer) with a core drug inside. When the mold core is spliced up and down, combined with the attached Figures 1 - 11 The forming method comprises the following steps: Step (1): Figure 1 As shown, the first magnetorheological core 41 in the shape of an ellipsoid is loaded into the interior of the upper mold core 11 and the lower mold core 12 (i.e., the mold cavity 2 of the mold core) in a non-magnetic softened state, and the storage tank 44 stores magnetorheological fluid, and the storage tank 44, the delivery pump 43, the magnetorheological fluid delivery pipe 42, and the first magnetorheological core 41 are connected; Step (2): If Figure 3 As shown, the delivery pump 43 pours the magnetorheological fluid in the storage tank 44 into the first magnetorheological core 41 through the magnetorheological fluid delivery pipe 42, the magnetic field transmitter 31 emits a magnetic field, and the magnetic field receiver 32 receives the magnetic field, so that the magnetorheological fluid in the ellipsoidal first magnetorheological core 41 solidifies; Step (3): the first multi-material outer layer 71 acrylic resin powder with a small amount of carbon black is introduced into the core cavity 2 through the feed port 13, the first microwave generator 21 generates a first microwave of 2.45 GHz, and the first microwave is sent into the cavity 2 through the first waveguide 22; the second microwave generator 23 generates a second microwave of 2.45 GHz, and the second microwave is sent into the cavity 2 through the second waveguide 24, and the first multi-material outer layer acrylic resin powder with a small amount of carbon black is sintered and formed by the first microwave and the second microwave; Step (4): Figure 5 As shown, the magnetic field transmitter 31 is stopped from emitting the magnetic field, and the magnetic field receiver 32 is stopped from receiving the magnetic field, so that the magnetorheological fluid in the first magnetorheological core 41 in the shape of an ellipsoid becomes soft, and the magnetorheological fluid is pumped out of the first magnetorheological core 41 into the storage tank by the delivery pump 43, and then the first magnetorheological core 41 in the shape of an ellipsoid is taken out from the mold cavity through the feed port 13; Step (5): replacing the first magnetorheological core 41 with a reduced ellipsoidal shape with a second magnetorheological core 45, loading the second magnetorheological core 45 with a reduced ellipsoidal shape into the cavity 2 of the mold core 1 in a non-magnetic softened state, and connecting the magnetorheological fluid delivery assembly with the second magnetorheological core 45 with a reduced ellipsoidal shape; Step (6): Figure 7 As shown, the delivery pump 43 pours the magnetorheological fluid in the storage tank into the second magnetorheological core 45 in the reduced ellipsoidal shape through the magnetorheological fluid delivery pipe 42; the magnetic field transmitter 31 transmits the magnetic field, and the magnetic field receiver 32 receives the magnetic field, so that the magnetorheological fluid in the second magnetorheological core 45 in the reduced ellipsoidal shape is solidified; Step (7): the liquid of the first multi-material inner layer 72 polyethylene glycol enters the cavity through the feed port 13, the first microwave generator 21 generates a first microwave of 2.45 GHz, and uses the first waveguide 22 to send the first microwave into the cavity; the second microwave generator 23 generates a second microwave of 2.45 GHz, and uses the second waveguide 24 to send the second microwave into the cavity, and the first multi-material inner layer 72 polyethylene glycol is sintered and formed by the first microwave and the second microwave; Step (8): stop the magnetic field transmitter 31 from emitting the magnetic field, and stop the magnetic field receiver 32 from receiving the magnetic field, so that the magnetorheological fluid in the second magnetorheological core 45 becomes soft, and use the delivery pump 43 to extract the magnetorheological fluid from the reduced ellipsoidal second magnetorheological core 45 to the storage tank 44, and then take the reduced ellipsoidal second magnetorheological core 45 out of the mold cavity 2 through the feed port 13; Step (9): Figures 9 - 10 As shown, the multi-material core drug 73 is injected into the cavity in the middle of the multi-material inner layer polyethylene glycol 72, and then the gap is sealed with a sealing material acrylic resin 74, so as to form a complete multi-material structure.

[0037] The multi-material multi-layer capsule in this embodiment has an outer layer of enteric material, which can prevent the core drug from being decomposed in gastric juice, and the ellipsoidal shape is easier to swallow. The inner layer of polyethylene glycol is a sustained-release material, which can regulate the time of drug release. In this embodiment, the thickness of the outer layer can be controlled by adjusting the inner cavity size of the outer layer of acrylic resin plus a small amount of carbon black, thereby regulating the enteric time effect, and the drug content can also be regulated by adjusting the cavity size in the middle of the inner layer. By controlling the shape of the magnetorheological variable core, multi-layer capsules of different shapes and capacities can be designed.

[0038] In this embodiment, the melting point of the inner layer polyethylene glycol is about 60° C., and the melting point of the outer layer acrylic resin is about 100° C. to 200° C., so the solidification of the inner layer will not cause the outer layer to melt, soften, deform or degrade.

[0039] Specific implementation process 2 Taking a multi-material structure soft grip tool handle as an example, which has a two-layer structure (outer layer, inner layer), when the mold core is in a left and right splicing form, combined with the attached Figures 11 - 22 , the forming method includes the following steps: Step (1): As Figure 11 shown, load the first ellipsoidal magnetorheological core A46 in the non-magnetic softening state into the interiors of the left mold core 51 and the right mold core 52 (i.e., the cavity 2 of the mold core 1), and connect the storage tank 44, the transfer pump 43, the magnetorheological fluid transfer pipe 42, and the first ellipsoidal magnetorheological core A46; Step (2): As Figure 13 shown, the transfer pump 43 injects the magnetorheological fluid in the storage tank 44 into the first ellipsoidal magnetorheological core A46 through the magnetorheological fluid transfer pipe 42, the magnetic field emitter 31 emits a magnetic field, and the magnetic field receiver 32 receives the magnetic field to solidify the magnetorheological fluid in the first ellipsoidal magnetorheological core A46; Step (3): The powder of the second multi-material outer layer 81 thermoplastic vulcanizate (TPV) with a small amount of carbon black enters the cavity 2 of the mold core through the feed port 13. The first microwave generator 21 generates the first microwave at 2.45 GHz and sends the first microwave into the cavity 2 through the first waveguide 22; the second microwave generator 23 generates the second microwave at 2.45 GHz and sends the second microwave into the cavity 2 through the second waveguide 24, and sinter and form the powder of the second multi-material outer layer 81 thermoplastic vulcanizate (TPV) with a small amount of carbon black through the first microwave and the second microwave; Step (4): As Figure 15 shown, stop the magnetic field emitter 31 from emitting the magnetic field, and at the same time stop the magnetic field receiver 32 from receiving the magnetic field, so that the magnetorheological fluid in the first ellipsoidal magnetorheological core A46 becomes soft, use the transfer pump 43 to pump the magnetorheological fluid out of the first ellipsoidal magnetorheological core A46 into the storage tank 44, and then take out the first ellipsoidal magnetorheological core A46 from the cavity through the feed port; Step (5): Replace the first ellipsoidal magnetorheological core A46 with the second rhomboidal magnetorheological core A47, load the second rhomboidal magnetorheological core A47 in the non-magnetic softening state into the cavity 2 of the mold core 1, and connect the magnetorheological fluid transfer assembly with the second rhomboidal magnetorheological core A47, as Figure 10 shown; Step (6): As Figure 17 shown, the transfer pump 43 injects the magnetorheological fluid in the storage tank into the second rhomboidal magnetorheological core A47 through the magnetorheological fluid transfer pipe 42; the magnetic field emitter 31 emits a magnetic field, and the magnetic field receiver 32 receives the magnetic field to solidify the magnetorheological fluid in the second rhomboidal magnetorheological core A47; Step (7): The powder of the second multi-material inner layer of 82% ABS plastic with a small amount of carbon black enters the cavity through the feed port 13. The first microwave generator 21 generates the first microwave at 2.45 GHz and uses the first waveguide 22 to send the first microwave into the cavity. The second microwave generator 23 generates the second microwave at 2.45 GHz and uses the second waveguide 24 to send the second microwave into the cavity. The powder of the second multi-material inner layer of ABS plastic with a small amount of carbon black is sintered and formed by the first microwave and the second microwave. Step (8): Stop the magnetic field emitter 31 from emitting the magnetic field and at the same time stop the magnetic field receiver 32 from receiving the magnetic field, so that the magnetorheological fluid in the rhombic second magnetorheological core A47 becomes soft. Use the transfer pump 43 to pump the magnetorheological fluid out of the rhombic second magnetorheological core A47 into the storage tank 44, and then take out the rhombic second magnetorheological core A47 from the cavity 2 through the feed port 13. Step (9): Obtain a soft grip tool handle.

[0040] In the soft grip tool handle of this embodiment, the outer layer is thermoplastic vulcanizate (TPV), which provides a comfortable grip, anti-slip performance, and shock absorption effect. The ellipsoidal shape is more convenient to hold. The inner layer is ABS plastic with a small amount of carbon black as a high-strength material, which provides the overall rigidity, structural strength of the handle, and the connection basis with the metal rod.

[0041] In this embodiment, by adjusting the shapes of the ellipsoidal first magnetorheological core A46 and the rhombic second magnetorheological core A47, a rhombic space 821 can be formed at the center of the second multi-material inner layer of ABS plastic with a small amount of carbon black, which is convenient for connection with the metal rod. There is a locking groove 822 on the side, which can cooperate with the locking protrusion 811 inside the second multi-material outer layer of thermoplastic vulcanizate (TPV) with a small amount of carbon black for connection. In this embodiment, the overall comfort of the grip can be controlled by regulating the inner cavity size of the outer layer of thermoplastic vulcanizate (TPV) to control the thickness of the outer layer, and the assembly area size with metal rods of different materials can also be adjusted by adjusting the size of the rhombic space 821 in the middle of the inner layer.

[0042] Through the complex inner cavity structure and rapid microwave sintering brought by the magnetorheological core, different materials are firmly combined together by hot melting and mechanical locking structures to form a macroscopic whole with obvious functional partitions.

[0043] In this embodiment, the melting point of the inner layer of ABS plastic is about 100°C to 120°C, and the melting point of the outer layer of thermoplastic vulcanizate (TPV) is about 160°C to 170°C. Therefore, the curing of the inner layer will not cause the melting, softening deformation or degradation of the outer layer.

[0044] The advantages of the present invention are: (1) Break through the bottleneck of complex internal cavity forming and achieve high-degree-of-freedom internal structure manufacturing: The present invention utilizes magnetorheological materials as dynamically reconfigurable cores, which can achieve in-situ curing and softening under magnetic field control and can be conveniently injected and removed through small holes. This fundamentally overcomes the limitations of traditional rigid cores and sacrificial cores in terms of shape complexity, removal difficulty, material contamination, and multi-step forming, making it possible to manufacture components with fine depressions, interlaced features, multi-layer nesting, and asymmetric complex internal cavity structures, greatly expanding the design freedom of the internal structure of multi-material components; (2) Achieve multi-layer nested multi-material structure manufacturing: By sequentially introducing magnetorheological cores of different shapes and depositing and curing materials layer by layer, the present invention can conveniently construct multi-material structures with multi-layer nesting features, which are difficult or even impossible to achieve by traditional injection molding, extrusion, and other processes, providing a new approach for the design and manufacturing of functional gradient materials, controlled release systems, integrated devices, etc.; (3) Improve the forming efficiency and interface bonding quality: Combining microwave heating technology can rapidly and efficiently heat and cure or sinter powder or liquid materials in volume. Compared with traditional heat conduction heating, microwave heating is fast, which helps to shorten the manufacturing cycle; its volume heating characteristics may achieve a more uniform temperature distribution, which is beneficial to improving the material density and performance; at the same time, rapid heating and in-situ curing may promote interface diffusion and chemical bonding between different material layers, thereby obtaining a stronger interface bonding force; (4) Enhance manufacturing flexibility and reduce mold costs: Under the condition of using the same set of external molds, only by replacing or adjusting the shape of the internal magnetorheological core, multi-material components with different internal structures can be manufactured, which greatly reduces the cost and time required for developing and manufacturing complex molds for different internal structure designs, improves the flexibility of the manufacturing system and its adaptability to small-batch and customized production (5) Potential material selection diversity and selective heating possibility: The present invention can theoretically be applied to a variety of powder or liquid materials (such as polymers, ceramics, composite materials, etc.) that can be cured / sintered by microwave heating; in addition, by using dual microwave sources (which may achieve different frequency or mode control) and the differences in microwave absorption characteristics of different materials, there is the potential to achieve selective heating of specific material layers, thereby more precisely controlling the forming process and final performance of complex multi-material structures.

[0045] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that: still, the specific implementation manners of the present invention can be modified or some technical features can be equivalently replaced; without departing from the spirit of the technical solutions of the present invention, they should all be covered within the scope of the technical solutions claimed by the present invention.

Claims

1. A complex-shaped multi-material forming device based on a magnetorheological core and microwave, characterized in that: It includes a mold core (1) with a cavity (2) inside, a magnetorheological fluid conveying component, a magnetorheological core (3), a magnetic field generating component, and a microwave generating component. The top of the mold core (1) has a feed port (13) communicating with the cavity (2); the magnetorheological core (3) is arranged inside the cavity (2) and can be replaced through the feed port (13); the magnetorheological fluid conveying component is connected to the magnetorheological core (3) for conveying magnetorheological fluid into the inner cavity of the magnetorheological core (3) or pumping out the magnetorheological fluid in the inner cavity of the magnetorheological core (3); the magnetic field generating component is used to apply a magnetic field to the magnetorheological fluid in the inner cavity of the magnetorheological core (3) to solidify the magnetorheological fluid; the microwave generating component is used to sinter and form the material entering the cavity (2) through the feed port (13).

2. The complex-shaped multi-material forming device based on a magnetorheological core and microwave according to claim 1, characterized in that: The magnetorheological fluid conveying component includes a storage tank (44) storing magnetorheological fluid, a delivery pump (43), and a magnetorheological fluid conveying pipe (42). One end of the magnetorheological fluid conveying pipe (42) is connected to the storage tank (44), and the other end passes through the feed port (13) and is connected to the magnetorheological core (3) inside the cavity (2); the delivery pump (43) is installed on the magnetorheological fluid conveying pipe (42), and the delivery pump (43) conveys the magnetorheological fluid in the storage tank (44) to the magnetorheological core (3) through the magnetorheological fluid conveying pipe (42), or conveys the magnetorheological fluid in the magnetorheological core (3) to the storage tank (44).

3. The complex-shaped multi-material forming device based on a magnetorheological core and microwave according to claim 1, characterized in that: A magnetic flux port (14) is provided at the bottom of the mold core (1), and the position of the magnetic flux port (14) corresponds to that of the feed port (13); the magnetic field generating component includes a magnetic field emitter (31) and a magnetic field receiver (32). The magnetic field emitter (31) and the magnetic field receiver (32) are distributed on the upper and lower sides of the mold core (1). The magnetic field emitter (31) corresponds to the position of the feed port (13) and emits a magnetic field downward; the magnetic field receiver (32) corresponds to the position of the magnetic flux port (14) and receives the magnetic field.

4. The complex-shaped multi-material forming device based on a magnetorheological core and microwave according to claim 1, wherein: The microwave generating component includes a first microwave generator (21) and a second microwave generator (23). The first microwave generator (21) is located on the left side of the mold core (1), and the microwave output end of the first microwave generator (21) is connected to the left end of the mold core (1) through a first waveguide (22); the second microwave generator (23) is located on the front side of the mold core (1), and the microwave output end of the second microwave generator (23) is connected to the front end of the mold core (1) through a second waveguide (24).

5. The complex-shaped multi-material forming device based on a magnetorheological core and microwave according to claim 1, characterized in that: The mold core (1) includes an upper mold core (11) and a lower mold core (12) connected and integrated up and down. The inner cavities of the upper mold core (11) and the lower mold core (12) are spliced along the up and down direction to form the cavity (2).

6. The complex-shaped multi-material forming device based on a magnetorheological core and microwaves according to claim 1, characterized in that: The mold core (1) includes a left mold core (51) and a right mold core (52) connected and integrated left and right. The inner cavities of the left mold core (51) and the right mold core (52) are spliced along the left and right direction to form the cavity (2).

7. The complex-shaped multi-material forming device based on a magnetorheological core and microwave according to claim 3, wherein: The mold core (1) is made of microwave transparent material. A coating layer is arranged on the outside of the mold core (1). The coating layer is made of a material (61) having microwave reflection and magnetic field penetration functions. The coating layer is provided with a clearance hole at the magnetic flux opening (14). A steel mesh plate (4) is arranged in the magnetic flux opening.

8. The complex-shaped multi-material forming device based on a magnetorheological core and microwaves according to claim 7, characterized in that: The coating layer is a mesh-shaped flexible fabric woven from a conductive material, and the mesh diameter of the coating layer is 1 to 2 mm.

9. The complex-shaped multi-material forming device based on a magnetorheological core and microwave according to claim 7, characterized in that: The mesh diameter of the steel mesh plate (4) is 3 to 4 mm.

10. A complex shape multi-material forming method based on a magnetorheological core and microwave, characterized in that: The method comprises adopting a complex shape multi-material forming device based on a magnetorheological core and microwaves as claimed in any one of claims 1 to 9, comprising the following steps: Step (1): inserting the first magnetorheological core (41) into the cavity (2) of the mold core (1) in a non-magnetic softened state, and connecting the magnetorheological fluid delivery component to the first magnetorheological core (41); Step (2): the delivery pump (43) injects the magnetorheological fluid into the first magnetorheological core (41) through the magnetorheological fluid delivery pipe (42), the magnetic field transmitter (31) emits a magnetic field, and the magnetic field receiver (32) receives the magnetic field, so that the magnetorheological fluid in the first magnetorheological core (41) solidifies; Step (3): the material of the first layer of the multi-material structure is introduced into the mold cavity (2) of the mold core (1) through the feed port (13); the first microwave generator (21) generates a first type of microwave, and the first type of microwave is sent into the mold cavity (2) through the first waveguide (22); the second microwave generator (23) generates a second type of microwave, and the second type of microwave is sent into the mold cavity (2) through the second waveguide (24); the first type of microwave and the second type of microwave sinter the material of the first layer of the multi-material structure; Step (4): stopping the magnetic field transmitter (31) from emitting a magnetic field and stopping the magnetic field receiver (32) from receiving a magnetic field, so that the magnetorheological fluid in the first magnetorheological core (41) becomes soft, using a delivery pump (43) to extract the magnetorheological fluid from the first magnetorheological core (41), and then taking the first magnetorheological core (41) out of the mold cavity through the feed port (13); Step (5): inserting the second magnetorheological core (45) into the mold cavity (2) of the mold core (1) in a non-magnetic softened state, and connecting the magnetorheological fluid delivery component to the second magnetorheological core (45); Step (6): the delivery pump (43) injects the magnetorheological fluid into the second magnetorheological core (45) through the magnetorheological fluid delivery pipe (42); The magnetic field transmitter (31) transmits a magnetic field, and the magnetic field receiver (32) receives the magnetic field, so that the magnetorheological fluid in the second magnetorheological core (45) solidifies; Step (7): the material of the second layer of the multi-material structure enters the cavity through the feed port (13); the first microwave generator (21) generates a first type of microwave, and uses the first waveguide (22) to send the first type of microwave into the cavity (2); the second microwave generator (23) generates a second type of microwave, and uses the second waveguide (24) to send the second type of microwave into the cavity (2); the first microwave and the second microwave sinter the material of the second layer of the multi-material structure; Step (8): Stop the magnetic field emitter (31) from emitting a magnetic field and at the same time stop the magnetic field receiver (32) from receiving a magnetic field, so that the magnetorheological fluid in the second magnetorheological core (45) becomes soft. Use the transfer pump (43) to pump out the magnetorheological fluid from the second magnetorheological core (45), and then take out the second magnetorheological core (45) from the cavity through the feed port; Step (9): Repeat the above process to form other layers of the multi-material structure, and obtain a multi-material structure with a combination of various different inner cavity structures.

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