Vacuum thixo-extrusion forming apparatus for experimental silicon carbide reinforced aluminum matrix composite

Abstract

The utility model relates to semi -solid extrusion forming technical field, concretely relates to experimental silicon carbide reinforced aluminium matrix composite material vacuum thixotropic extrusion forming equipment, include: sealed box, sealed box is connected with the vacuum pipeline, and its box body inside is equipped with the heating coil, extrusion forming subassembly, including forming table, press -down portion and ejection portion, the forming table is opened forming cavity and spacing channel, the press -down portion is equipped with the first pressure block, another end is connected with the power pole that extends into the sealed box and is penetrated, the power pole is sealedly connected with sealed box and can drive press -down portion reciprocating motion up and down along its axial direction, ejection portion is located at least partly in spacing channel, and its one end located in forming cavity is equipped with the second pressure block with the second pressure block of forming cavity adaptation, the first pressure block and second pressure block between form extrusion space. Through above setting, can improve the density of composite material, mechanical property and thermophysical property, can improve preparation efficiency.

Description

Technical Field

[0001] This utility model relates to a vacuum thixotropic extrusion molding equipment for experimental silicon carbide reinforced aluminum matrix composites, belonging to the field of semi-solid extrusion molding technology. Background Technology

[0002] With the rapid development of electronic technology, logic circuits are increasingly widely used in aerospace, military, and civilian fields. Electronic devices are developing towards lightweight, high integration, low cost, and high reliability, with increasingly compact structures. However, issues such as heat dissipation and thermal stability are becoming particularly prominent. High volume fraction SiCp / Al (silicon carbide particle-reinforced aluminum matrix composite) is more suitable for electronic packaging in fields such as microwave integrated circuits, power modules, and microprocessor cover plates due to its advantages such as high thermal conductivity, low expansion, low density, and good mechanical properties. However, the processing of high volume fraction SiCp / Al composites is currently difficult. How to further improve its mechanical properties, thermophysical properties, and density is the key to preparation, which directly affects whether its performance can meet the requirements of electronic packaging. A large number of experiments are needed to prepare higher performance high volume fraction SiCp / Al. Therefore, it is of great practical significance to study a new vacuum thixotropic extrusion molding equipment for experimental preparation of silicon carbide-reinforced aluminum matrix composites. Utility Model Content

[0003] This invention addresses the shortcomings of existing technologies by providing a vacuum thixotropic extrusion molding equipment for experimental silicon carbide-reinforced aluminum matrix composites.

[0004] The technical solution of this utility model to solve the above-mentioned technical problems is as follows: Experimental silicon carbide reinforced aluminum matrix composite vacuum thixotropic extrusion molding equipment, including: a sealed box, the sealed box being connected to a vacuum pipeline, and a heating coil being provided inside the box.

[0005] An extrusion forming assembly is disposed inside the sealed housing and includes a forming platform, a pressing part, and an ejecting part. The forming platform has a forming cavity and a limiting channel that are interconnected and penetrate the forming platform. One end of the pressing part is provided with a first pressing block adapted to the forming cavity, and the other end is connected to a power rod that extends through and into the sealed housing. The power rod is sealed to the sealed housing and can drive the pressing part to move up and down along its axial direction. The ejecting part is at least partially located in the limiting channel, and one end of the ejecting part located in the forming cavity is provided with a second pressing block adapted to the forming cavity. An extrusion space is formed between the first pressing block and the second pressing block.

[0006] Furthermore, the bottom surface of the first pressing block is provided with a protrusion, and the top surface of the second pressing block opposite to the first pressing block is provided with a recess that cooperates with the protrusion. The cross-sectional profile of the protrusion is a continuous arc forming a protrusion towards the direction of the second pressing block, and the cross-sectional profile of the recess is a continuous arc forming a recess towards the interior of the second pressing block.

[0007] Furthermore, the radius of curvature of the protruding section is smaller than the radius of curvature of the recessed section.

[0008] Furthermore, the radius of curvature of the protruding section is 0.9-0.97 times that of the radius of curvature of the recessed section.

[0009] Furthermore, the power rod, forming cavity, pressing part and ejection part are coaxially arranged and all have a circular cross-sectional shape.

[0010] Furthermore, the maximum projected length of the protrusion on the axis of the pressing part is 0.1-0.15 times the diameter of the first pressing block, and the maximum projected length of the recess on the axis of the ejection part is 1.1-1.15 times the maximum projected length of the protrusion on the axis of the pressing part.

[0011] Furthermore, several load-bearing columns are connected below the forming platform, and the load-bearing columns are fixedly connected to the forming platform by fastening bolts. The lower end of the ejector part passes through the limiting channel and extends to the bottom of the forming platform.

[0012] Furthermore, an end block is connected to the end of the pressing part away from the first pressing block, and the power rod extends through into the sealing box and is connected to the end block. The end block is coaxially arranged with the pressing part.

[0013] Furthermore, a support block coaxial with the ejector is provided at the lower end of the ejector. An automatic ejector assembly is provided between the support block and the ejector. The automatic ejector assembly includes a guide rod and a tension spring. One end of the guide rod is fixedly connected to the forming table, and the other end passes through the support block and slides with the support block. The tension spring is sleeved on the guide rod. One end of the tension spring is connected to the forming table, and the other end is connected to the support block. When the tension spring is in a free state, there is a preset distance between the second pressure block and the bottom of the forming cavity.

[0014] Furthermore, at least four sets of automatic ejection components are evenly arranged circumferentially in the ejector section.

[0015] The beneficial effects of this utility model are:

[0016] (1): The sealed box is connected to a vacuum pipeline and a heating coil is installed inside it. During the preparation of composite materials, a stable vacuum environment is formed inside the box, and the extrusion molding component is heated uniformly. This makes the box inside a stable preparation environment, which can effectively avoid the phenomenon of segregation and agglomeration of composite materials due to local temperature differences in the extrusion molding component. It can also effectively control the porosity of composite materials, avoid the presence of a large number of pores and microcracks in the prepared composite material structure, and effectively improve the density of composite materials.

[0017] (2): By limiting and guiding the ejector part through the limiting channel, it can prevent the second pressure block from being deflected under pressure during the preparation of composite materials, which would generate oblique pressure, causing damage to the forming table or affecting the final performance of the prepared composite material. After the preparation work is completed, the ejector part can be ejected upward through the limiting through hole, which is convenient for taking out the prepared composite material and for cleaning the extrusion forming component, effectively improving the preparation efficiency and further ensuring that the silicon carbide reinforced aluminum matrix composite material with the required density, mechanical properties and thermophysical properties is obtained. Attached Figure Description

[0018] Figure 1 This is a schematic cross-sectional view of the vacuum thixotropic extrusion molding equipment provided in an embodiment of the present invention.

[0019] Figure 2 This is a schematic diagram of the cross-sectional structure of the forming table provided in an embodiment of the present utility model;

[0020] Figure 3 This is a schematic diagram of the cross-sectional structure of the ejector section provided in an embodiment of the present utility model;

[0021] Figure 4 This is a schematic cross-sectional view of the pressing part provided in an embodiment of the present utility model.

[0022] Figure label:

[0023] 1. Sealed housing; 2. Vacuum piping; 3. Forming table; 31. Forming cavity; 32. Limiting channel; 4. Pressing part; 41. First pressing block; 411. Protrusion; 42. End block; 5. Ejection part; 51. Second pressing block; 511. Recess; 52. Support block; 6. Power rod; 7. Support column; 8. Guide rod; 9. Tension spring. Detailed Implementation

[0024] The specific embodiments of this utility model are described in detail below. This utility model can be implemented in many ways different from those described herein, and those skilled in the art can make similar improvements without departing from the spirit of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed herein.

[0025] Unless otherwise defined, 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 invention pertains. The terminology used is for describing particular embodiments only and is not intended to limit the scope of this invention.

[0026] In the description of this utility model, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0027] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "setting" should be interpreted broadly. For example, they can refer to a fixed connection or setting, a detachable connection or setting, or an integral connection or setting. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0028] Example

[0029] like Figure 1-4 As shown, this utility model provides a vacuum thixotropic extrusion molding equipment for experimental silicon carbide reinforced aluminum matrix composites, including: a sealed box 1, the sealed box 1 being connected to a vacuum pumping pipe 2, and a heating coil being provided inside the box; the vacuum pumping pipe 2 being connected to a vacuum pumping device, used to provide a vacuum preparation environment for the thixotropic extrusion molding equipment described in this application when preparing composite materials; the heating coil is electrically heated, and it should be noted that the heating coil is a technical means well known to those skilled in the art, therefore it is not shown in the accompanying drawings;

[0030] An extrusion molding assembly is disposed inside the sealed housing 1 and includes a molding stage 3, a pressing part 4, and an ejector part 5. The molding stage 3 has a molding cavity 31 and a limiting channel 32 that are interconnected and penetrate through the molding stage 3. One end of the pressing part 4 is integrally formed with a first pressing block 41 adapted to the molding cavity 31, and the other end is connected to a power rod 6 that extends through and into the sealed housing 1. The power rod 6 is sealed to the sealed housing 1 and can drive the pressing part 4 to move up and down along its axial direction. It should be noted that the upper end of the power rod 6 is connected to a hydraulic press (not shown in the attached figure). To ensure the performance of the prepared composite material, an adapter is used. The first pressure block 41 and the forming cavity 31 have the same cross-sectional shape and are fitted with a clearance. This will not be described in detail below. The power rod 6 and the sealing box 1 are sealed together by a dynamic seal. The ejector part 5 is at least partially located in the limiting channel 32. One end of the ejector part 5 located in the forming cavity 31 is integrally formed with a second pressure block 51 that is adapted to the forming cavity 31. A compression space is formed between the first pressure block 41 and the second pressure block 51. Preferably, in order to ensure uniform downward pressure and avoid oblique pressure, the power rod 6, the forming cavity 31, the downward pressure part 4 and the ejector part 5 are coaxially arranged and all have a circular cross-sectional shape. In the figure, the dotted line X1 is the central axis. In the preparation of composite materials, the pre-treated mixed material is placed on the second pressure block 51 in the forming cavity 31. The interior of the sealed box 1 is heated to a preset temperature by a heating coil, so that the extrusion forming assembly is heated evenly. By drawing a vacuum, a vacuum environment is formed inside the sealed box 1. Then, the power rod 6 drives the first pressure block 41 to press down. The mixed material is continuously pressed by the preset pressure to reduce shrinkage and obtain a dense structure, thereby preparing a silicon carbide reinforced aluminum matrix composite material with the required density, mechanical properties and thermophysical properties.

[0031] First, the sealed chamber, connected to a vacuum pipeline and equipped with a heating coil, creates a stable vacuum environment inside during the composite material preparation process. The extrusion molding assembly is heated uniformly, ensuring a stable preparation environment within the chamber. This effectively prevents segregation and agglomeration of the composite material due to uneven local temperatures within the extrusion molding assembly, and effectively controls the porosity of the composite material, avoiding numerous pores and microcracks within the resulting microstructure, thus significantly improving the density of the composite material. Second, the limiting channel limits and guides the ejector section. This prevents the second pressure block from shifting under pressure during composite material preparation, avoiding oblique pressure that could damage the molding stage or affect the final properties of the composite material. After preparation, the ejector section is pushed upwards through the limiting through-hole, facilitating the removal of the prepared composite material and cleaning of the extrusion molding assembly, effectively improving preparation efficiency and further ensuring that the silicon carbide reinforced aluminum matrix composite material meets the required density, mechanical properties, and thermophysical properties.

[0032] Specifically, such as Figure 3 , 4 As shown, the bottom surface of the first pressing block 41 is provided with a protrusion 411, and the protrusion 411 and the first pressing block 41 are integral structures formed by processing. The top surface of the second pressing block 51 opposite to the first pressing block 41 is provided with a recess 511 that cooperates with the protrusion 411. The cross-sectional profile of the protrusion 411 is a continuous arc forming a protrusion towards the second pressing block 51, and the cross-sectional profile of the recess 511 is a continuous arc forming a recess towards the interior of the second pressing block 51. With this configuration, when the pressing part 4 is pressed downwards, the protrusion 411 protrudes from the central area and preferentially contacts the central area of ​​the mixed material. The central area of ​​the mixed material forms the initial pressure point. During the continuous pressing process, the protrusion 411 gradually applies pressure from the central area of ​​the mixed material to its surroundings, forming a gradient pressure expansion from the center to the surroundings. This causes the mixed material to creep from the central area to the surroundings until the entire mixed material is under pressure. By controlling the pressure process of the mixed material spreading from the center to the surroundings, the gas in the central area of ​​the mixed material can be effectively guided out, enhancing the degassing effect and solving the problems of poor density and excessive porosity in the central area of ​​the prepared composite material.

[0033] Specifically, the radius of curvature of the arc of the protrusion 411 is smaller than that of the arc of the recess 511; preferably, the radius of curvature of the arc of the protrusion 411 is 0.9-0.97 times that of the arc of the recess 511. This limitation serves to further improve the density and mechanical properties of the composite material. If the radius of curvature of the arc of the protrusion 411 is less than 0.9 times that of the arc of the recess 511, the mixed material will excessively accumulate around the edges, leading to uneven particle distribution, significant segregation and agglomeration, and reduced mechanical properties of the composite material. Only when the radius of curvature of the arc of the protrusion 411 is 0.9-0.97 times that of the arc of the recess 511 can the degassing effect be further enhanced and the porosity reduced while ensuring the mechanical properties of the composite material.

[0034] Specifically, such as Figure 3 , 4As shown, the maximum projected length L1 of the protrusion 411 on the axis of the pressing part 4 is 0.1-0.15 times the diameter D of the first pressing block 41, and the maximum projected length L2 of the recess 511 on the axis of the ejector part 5 is 1.1-1.15 times the maximum projected length L1 of the protrusion 411 on the axis of the pressing part 4. This design is crucial, ensuring that during thixotropic extrusion, the protrusion 411 and the recess 511 effectively guide the mixed material through degassing, reducing porosity and preventing interfacial delamination or excessive formation of brittle phases due to increased local shear stress. This ensures the density, mechanical properties, and thermophysical properties of the composite material, avoids excessive wear of the extrusion molding components due to excessive local shear stress, and allows the prepared composite material to be a cylinder with approximately flat ends, facilitating subsequent processing.

[0035] With the above settings, under the same preparation conditions, the composite material prepared by the thixotropic extrusion molding equipment described in this application has a dense internal structure, uniform particle distribution, increased density by 12%, and increased thermal conductivity by 8%, achieving the performance requirements for electronic packaging.

[0036] Specifically, several support columns 7 are connected below the forming platform 3. The support columns 7 are fixedly connected to the forming platform 3 by fastening bolts. The lower end of the ejector part 5 passes through the limiting channel 32 and extends below the forming platform 3. With this arrangement, the forming platform 3 is fixed in the central area of ​​the sealed box 1, further ensuring uniform heating. Furthermore, by setting the lower end of the ejector part 5 to extend below the forming platform 3, after preparation, the ejector part 5 can be lifted upwards to remove the prepared composite material without the need for auxiliary tools.

[0037] Specifically, the end of the pressing part 4 away from the first pressing block 41 is detachably connected to an end block 42 by a fastening bolt. The power rod 6 extends through the sealed housing 1 and is connected to the end block 42. The end block 42 is coaxially arranged with the pressing part 4. Preferably, a buffer pad is provided at the contact position between the end block 42 and the pressing part 4 and the power rod 6. This arrangement effectively buffers the downward pressure and prevents the pressing part 4 from deforming.

[0038] Specifically, such as Figure 1 , 3As shown, a support block 52 coaxial with the ejector part 5 is provided at the lower end of the ejector part 5. The support block 52 and the ejector part 5 are detachably connected by fastening bolts. An automatic ejection assembly is provided between the support block 52 and the ejector part 5. The automatic ejection assembly includes a guide rod 8 and a tension spring 9. One end of the guide rod 8 is fixedly connected to the forming table 3, and the other end passes through the support block 52 and slides with the support block 52. The tension spring 9 is sleeved on the guide rod 8. One end of the tension spring 9 is connected to the forming table 3, and the other end is connected to the support block 52. When the tension spring 9 is in a free state, there is a preset distance between the second pressure block 51 and the bottom of the forming cavity 31. Preferably, at least four sets of automatic ejection assemblies are evenly arranged circumferentially on the ejector part 5. During composite material preparation, the lower pressing part 4 moves downward, and the ejector part 5 is pressed downward until the second pressing block 51 abuts against the bottom of the forming cavity 31. At this time, the tension spring 9 is in a stretched state. After the composite material is prepared, the lower pressing part 4 moves upward, and the tension spring 9 provides a restoring force to drive the ejector part 5 and the prepared composite material upward to a position that is easy to pick up. Through the above settings, automatic ejection can be achieved, simplifying the operation process and further improving the preparation efficiency. At the same time, it can further avoid the second pressing block 51 being slightly deflected under pressure, generating oblique pressure, which could damage the forming table 3 or affect the final properties of the prepared composite material.

[0039] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are exhaustively listed. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0040] For those skilled in the art, various modifications and improvements can be made without departing from the concept of this utility model, and these modifications and improvements are all within the protection scope of this utility model. The protection scope of this utility model is defined by the appended claims.

Claims

1. A vacuum thixotropic extrusion molding apparatus for experimental silicon carbide reinforced aluminum matrix composites, characterized in that, include: A sealed enclosure, which is connected to a vacuum pipeline and has a heating coil inside the enclosure; An extrusion forming assembly is disposed inside the sealed housing and includes a forming platform, a pressing part, and an ejecting part. The forming platform has a forming cavity and a limiting channel that are interconnected and penetrate the forming platform. One end of the pressing part is provided with a first pressing block adapted to the forming cavity, and the other end is connected to a power rod that extends through and into the sealed housing. The power rod is sealed to the sealed housing and can drive the pressing part to move up and down along its axial direction. The ejecting part is at least partially located in the limiting channel, and one end of the ejecting part located in the forming cavity is provided with a second pressing block adapted to the forming cavity. An extrusion space is formed between the first pressing block and the second pressing block.

2. The vacuum thixotropic extrusion molding equipment according to claim 1, characterized in that, The bottom surface of the first pressing block is provided with a protrusion, and the top surface of the second pressing block opposite to the first pressing block is provided with a recess that cooperates with the protrusion. The cross-sectional profile of the protrusion is a continuous arc forming a protrusion towards the second pressing block, and the cross-sectional profile of the recess is a continuous arc forming a recess towards the interior of the second pressing block.

3. The vacuum thixotropic extrusion molding equipment according to claim 2, characterized in that, The radius of curvature of the arc of the protruding part is smaller than the radius of curvature of the arc of the recessed part.

4. The vacuum thixotropic extrusion molding equipment according to claim 3, characterized in that, The radius of curvature of the arc of the protruding part is 0.9-0.97 times that of the radius of curvature of the arc of the concave part.

5. The vacuum thixotropic extrusion molding equipment according to claim 4, characterized in that, The power rod, forming cavity, pressing part and ejection part are coaxially arranged and all have a circular cross-sectional shape.

6. The vacuum thixotropic extrusion molding equipment according to claim 5, characterized in that, The maximum projected length of the protrusion on the axis of the pressing part is 0.1-0.15 times the diameter of the first pressing block, and the maximum projected length of the recess on the axis of the ejection part is 1.1-1.15 times the maximum projected length of the protrusion on the axis of the pressing part.

7. The vacuum thixotropic extrusion molding apparatus according to any one of claims 1-6, characterized in that, Several load-bearing columns are connected below the forming platform. The load-bearing columns are fixedly connected to the forming platform by fastening bolts. The lower end of the ejector part passes through the limiting channel and extends to the bottom of the forming platform.

8. The vacuum thixotropic extrusion molding equipment according to claim 7, characterized in that, The end of the pressing part away from the first pressing block is connected to an end block, the power rod extends through into the sealing box and is connected to the end block, and the end block is coaxially arranged with the pressing part.

9. The vacuum thixotropic extrusion molding equipment according to claim 7, characterized in that, The lower end of the ejector section is provided with a support block coaxial with the ejector section. An automatic ejector assembly is provided between the support block and the ejector section. The automatic ejector assembly includes a guide rod and a tension spring. One end of the guide rod is fixedly connected to the forming table, and the other end passes through the support block and slides with the support block. The tension spring is sleeved on the guide rod. One end of the tension spring is connected to the forming table, and the other end is connected to the support block. When the tension spring is in a free state, there is a preset distance between the second pressure block and the bottom of the forming cavity.

10. The vacuum thixotropic extrusion molding equipment according to claim 9, characterized in that, At least four sets of automatic ejection components are evenly arranged around the circumference of the ejector section.

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