A method for preparing porous aluminum and porous aluminum

Abstract

This invention provides a method for preparing porous aluminum and porous aluminum. The method includes: selecting a target mold and a target aluminum tube assembly; the target mold has a cavity, and the sidewall of the cavity has a first positioning hole array; the target aluminum tube assembly is matched with the first positioning hole array; the target aluminum tube assembly is inserted into the cavity through the first positioning hole array to form a target aluminum tube array; molten aluminum is poured into the cavity, and the cavity is sealed with a cover plate, wherein the molten aluminum and the target aluminum tube assembly are made of the same material; a preset pressure is applied to the cover plate and maintained for a preset time to allow the molten aluminum in the cavity to solidify, thereby obtaining a porous aluminum sample. This invention solves the problems of high difficulty in controlling pore uniformity, complex processes, and high costs in the prior art.

Description

Technical Field

[0001] This invention relates to the technical field of methods for preparing porous aluminum, and more specifically, to a method for preparing porous aluminum and porous aluminum. Background Technology

[0002] In the current automotive industry's pursuit of lightweighting, enhanced safety, and optimized thermal management, porous metal materials, with their unique combination of properties, demonstrate broad application prospects. Among them, porous aluminum, possessing both the inherent properties of metallic aluminum and the unique functions imparted by continuous channels, is considered an ideal lightweight functional / structural integrated material. To fully leverage the advantages of porous aluminum in the aforementioned high-performance automotive applications, precise control over its pore size and shape is crucial.

[0003] However, existing methods for preparing porous aluminum mainly include melt foaming, powder sintering, and directional solidification, which have the main problems of difficulty in controlling pore uniformity, complex processes, and high costs.

[0004] There is currently no effective solution to the aforementioned technical problems. Summary of the Invention

[0005] The main objective of this invention is to provide a method for preparing porous aluminum and porous aluminum, so as to solve the problems of difficulty in controlling pore uniformity, complex process and high cost in the prior art.

[0006] To achieve the above objectives, according to one aspect of the present invention, a method for preparing porous aluminum is provided, comprising: selecting a target mold and a target aluminum tube assembly, the target mold having a cavity, the sidewall of the cavity having a first positioning hole array, and the target aluminum tube assembly being configured to match the first positioning hole array; inserting the target aluminum tube assembly through the first positioning hole array into the cavity to form a target aluminum tube array; pouring molten aluminum into the cavity and sealing the cavity with a cover plate, wherein the molten aluminum and the target aluminum tube assembly are made of the same material; applying a preset pressure to the cover plate and maintaining it for a preset time to allow the molten aluminum in the cavity to solidify, thereby obtaining a porous aluminum sample.

[0007] Furthermore, after obtaining the porous aluminum sample, the method also includes the following steps: removing the cover plate, taking out the sample after the target mold has cooled to a preset temperature; removing excess material from the outer surface of the sample to obtain the finished porous aluminum product.

[0008] Furthermore, before pouring the molten aluminum into the mold cavity, the method also includes the following steps: heating the initial aluminum material to a preset temperature under a protective atmosphere to obtain molten aluminum; wherein the initial aluminum material is set to be the same material as the target aluminum tube assembly, and the preset temperature is T1, 700℃≤T1≤750℃.

[0009] Furthermore, the first positioning hole array includes at least one of a square hole array, a regular hexagonal hole array, a circular hole array, and an irregular hole array.

[0010] Furthermore, the target mold includes a cubic mold, which includes a first sidewall and a third sidewall disposed opposite to each other along the length direction of the cavity, a second sidewall and a fourth sidewall disposed opposite to each other along the width direction of the cavity, and a bottom wall and an opening disposed opposite to each other along the height direction of the cavity, with a cover plate disposed in a matching manner with the opening.

[0011] Furthermore, a first positioning hole array is provided on the bottom wall, and a second positioning hole array is provided on the cover plate, the second positioning hole array being matched with the first positioning hole array provided on the bottom wall.

[0012] Furthermore, the first sidewall, second sidewall, third sidewall, fourth sidewall, and bottom wall are all provided with a first positioning hole array. Each first positioning hole array is a square hole array. The target aluminum tube group is inserted into the cavity through the first positioning hole array to form the target aluminum tube array, including the following steps: inserting the first aluminum tube group of the target aluminum tube group into the first positioning hole array of the first sidewall and the first positioning hole array of the third sidewall, the wall thickness of the first aluminum tube group is D1, 0.1mm≤D1≤10mm; inserting the second aluminum tube group of the target aluminum tube group into the first positioning hole array of the second sidewall and the first positioning hole array of the fourth sidewall, the wall thickness of the second aluminum tube group is D2, 0.1mm≤D2≤10mm; inserting the third aluminum tube group of the target aluminum tube group into the first positioning hole array of the bottom wall, the wall thickness of the third aluminum tube group is D3, 0.1mm≤D3≤10mm; wherein, the first aluminum tube group, the second aluminum tube group, and the third aluminum tube group are jointly erected to form the target aluminum tube array.

[0013] Furthermore, the first sidewall, second sidewall, third sidewall, and fourth sidewall are each provided with a first positioning hole array. Each first positioning hole array is a regular hexagonal hole array. The target aluminum tube group is inserted into the cavity through the first positioning hole array to form the target aluminum tube array, including the following steps: inserting the fourth aluminum tube group of the target aluminum tube group into the first positioning hole array of the first sidewall and the first positioning hole array of the third sidewall. The wall thickness of the fourth aluminum tube group is D4, 0.1mm≤D4≤10mm; inserting the fifth aluminum tube group of the target aluminum tube group into the first positioning hole array of the second sidewall and the first positioning hole array of the fourth sidewall. The wall thickness of the fifth aluminum tube group is D5, 0.1mm≤D5≤10mm; wherein, the fourth aluminum tube group and the fifth aluminum tube group are jointly erected to form the target aluminum tube array.

[0014] Furthermore, the first sidewall, second sidewall, third sidewall, fourth sidewall, and bottom wall are all provided with a first positioning hole array. The first positioning hole arrays on the first sidewall and the third sidewall are circular hole arrays, the first positioning hole arrays on the second sidewall and the fourth sidewall are square hole arrays, and the first positioning hole array on the bottom wall is a regular hexagonal hole array. The target aluminum tube assembly is inserted into the cavity through the first positioning hole array to form the target aluminum tube array, including the following steps: inserting the sixth aluminum tube group from the target aluminum tube group into the first positioning hole of the first sidewall. The first positioning hole array on the third sidewall has a wall thickness of D6, 0.1mm≤D6≤10mm; the seventh aluminum tube group in the target aluminum tube group is inserted into the first positioning hole array on the second sidewall and the first positioning hole array on the fourth sidewall, with a wall thickness of D7, 0.1mm≤D7≤10mm; the eighth aluminum tube group in the target aluminum tube group is inserted into the first positioning hole array on the bottom wall, with a wall thickness of D8, 0.1mm≤D8≤10mm; the sixth, seventh, and eighth aluminum tube groups together form the target aluminum tube array.

[0015] According to another aspect of the present invention, a porous aluminum is provided, which is prepared by the above-described method for preparing porous aluminum.

[0016] By applying the technical solution of this invention, a cavity is set in the target mold, and a first positioning hole array is opened on the side wall of the cavity. The geometric parameters such as the hole arrangement of the first positioning holes can be controlled. The target aluminum tube group is set in a matching manner with the first positioning hole array to ensure that the geometric parameters of the first positioning holes can be precisely matched with the target aluminum tubes. The target aluminum tube group is inserted into the first positioning hole array, so that the aluminum tube group is precisely set into the target aluminum tube array in the cavity. The aluminum liquid and the target aluminum tube group are of the same material. After pouring, it is maintained under the preset pressure applied by the cover plate for a preset time, so that a completely consistent hole structure can be obtained. By pouring the aluminum liquid into the cavity, the material is added, which reduces material waste and improves material utilization. The process is simple, the equipment requirements are low, the operation is simple, and the cost is low. The stability and performance consistency of the hole structure are maintained. By controlling the geometric parameters and structure of the first positioning hole array, the uniformity of the pores can be controlled, while simplifying the process and reducing the manufacturing cost. Attached Figure Description

[0017] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0018] Figure 1 A flowchart of a first embodiment of a method for preparing porous aluminum according to the present invention is shown;

[0019] Figure 2 A flowchart of a second embodiment of the method for preparing porous aluminum according to the present invention is shown;

[0020] Figure 3 A flowchart of a third embodiment of the method for preparing porous aluminum according to the present invention is shown;

[0021] Figure 4 A flowchart of a fourth embodiment of a method for preparing porous aluminum according to the present invention is shown;

[0022] Figure 5 A flowchart of a fifth embodiment of a method for preparing porous aluminum according to the present invention is shown;

[0023] Figure 6 A schematic diagram of the structure of porous aluminum according to an embodiment of the present invention is shown;

[0024] Figure 7 A schematic diagram of the structure of a mold according to an embodiment of the present invention is shown;

[0025] Figure 8 A schematic diagram of an aluminum tube array according to an embodiment of the present invention is shown;

[0026] Figure 9 A top view of an aluminum tube array according to an embodiment of the present invention is shown;

[0027] Figure 10 A left view of an aluminum tube array according to an embodiment of the present invention is shown;

[0028] Figure 11 A schematic diagram of a porous aluminum top cover plate according to an embodiment of the present invention is shown;

[0029] Figure 12 A schematic diagram of the final product of porous aluminum according to an embodiment of the present invention is shown;

[0030] Figure 13 A flowchart of a method for preparing porous aluminum with adjustable pore size and pore shape according to an embodiment of the present invention is shown;

[0031] Figure 14 A flowchart illustrating a method for preparing square-hole porous aluminum according to an embodiment of the present invention is shown;

[0032] Figure 15 A flowchart illustrating a method for preparing porous aluminum with a biomimetic honeycomb structure according to an embodiment of the present invention is shown.

[0033] Figure 16 A flowchart illustrating a method for preparing porous aluminum with combined shapes according to an embodiment of the present invention is shown. Detailed Implementation

[0034] 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.

[0035] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0036] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented, for example, in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0037] Exemplary embodiments according to this application will now be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments may be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of this application is thorough and complete, and that the concept of these exemplary embodiments is fully conveyed to those skilled in the art. In the drawings, for clarity, the thickness of layers and regions may be exaggerated, and the same reference numerals are used to denote the same devices, and therefore their description will be omitted.

[0038] With the automotive industry's continuous pursuit of lightweighting, enhanced safety, and optimized thermal management performance, porous metallic materials, with their unique combination of properties, are showing broad application prospects. Among them, porous aluminum, possessing both the inherent properties of metallic aluminum and the unique functions imparted by continuous channels, is considered an ideal lightweight functional / structural integrated material, and has significant potential application value in the field of key automotive components.

[0039] In collision energy absorption boxes, the unique porous structure of porous aluminum can absorb energy through deformation and rupture of the pore walls during a collision. The energy absorption process can be precisely controlled by designing the pore size and shape, ensuring personnel safety. For engine intercoolers, porous aluminum is expected to reduce the temperature of boosted air and improve intake efficiency due to its excellent heat dissipation performance and fluid permeability. Its continuous channels ensure uniform heat dissipation and stable performance. For mufflers, the porous structure of porous aluminum may effectively absorb and disperse sound waves, reducing exhaust noise. Its lightweight properties also help reduce the weight of the muffler, thereby improving overall vehicle performance. In the thermal management of new energy vehicle battery packs, if applied to the thermal management interlayer, porous aluminum can ensure consistent battery pack temperature and maintain battery performance and lifespan due to its good thermal conductivity. Its porous structure can also increase the heat exchange area, improve heat dissipation efficiency, and act as a buffer to ensure battery pack stability during driving. However, to fully realize the advantages of porous aluminum in these high-performance automotive applications, precise control of its pore size and shape is crucial. Different automotive components have varying performance requirements for porous aluminum due to their functional differences. Only by precisely controlling the pore size and shape can the performance consistency, functional adaptability, and long-term stability of porous aluminum be ensured. Currently, the main methods for preparing porous aluminum in the industry include melt foaming, powder sintering, directional solidification, deposition, and infiltration casting.

[0040] Combination Figures 1 to 16 As shown, according to a specific embodiment of this application, a method for preparing porous aluminum is provided.

[0041] Specifically, such as Figure 1 As shown, the method for preparing porous aluminum includes:

[0042] Step S100: Select a target mold and a target aluminum tube assembly. The target mold has a cavity, and the side wall of the cavity is provided with a first positioning hole array. The target aluminum tube assembly is set in a matching manner with the first positioning hole array.

[0043] Step S200: The target aluminum tube assembly is inserted into the cavity through the first positioning hole array to form the target aluminum tube array;

[0044] Step S300: Pour molten aluminum into the cavity and seal the cavity with a cover plate, wherein the molten aluminum is made of the same material as the target aluminum tube assembly;

[0045] Step S400: Apply a preset pressure to the cover plate and maintain it for a preset time to allow the molten aluminum in the cavity to solidify, thereby obtaining a porous aluminum sample.

[0046] In step S100, by opening a first positioning hole array on the side wall of the cavity, and setting the target aluminum tube group in a matching manner with the first positioning hole array, the first positioning hole array provides a positioning reference for the insertion of the target aluminum tube group. The geometric parameters of the first positioning hole can be precisely matched with the target aluminum tube, so that the uniformity of the pores can be better controlled.

[0047] In step S200, the target aluminum tube assembly is inserted into the cavity through the first positioning hole array to form the target aluminum tube array, so that the positioning holes can accurately constrain and position the aluminum tube array, forming a rigid skeleton with a complete structure.

[0048] In step S300, by pouring molten aluminum into the mold cavity and sealing the mold cavity with a cover plate, a completely sealed high-pressure solidification system is formed. Setting the molten aluminum and the target aluminum tube to be of the same material can ensure that there are no impurity phases between the molten aluminum and the aluminum tube interface, and ensure that the aluminum tube and the molten aluminum are completely metallurgically bonded.

[0049] In step S400, by applying a preset pressure to the cover plate and maintaining it for a preset time, the density of the aluminum liquid is effectively improved and the pore structure is maintained. By setting the preset pressure and preset time, it is easy to formulate the optimal process parameters, simplify the process flow, and allow the aluminum liquid in the cavity to solidify, thereby obtaining a porous aluminum sample.

[0050] Based on steps S100 to S400, a cavity is set in the target mold, and a first positioning hole array is opened on the side wall of the cavity. The geometric parameters such as the hole arrangement of the first positioning holes can be controlled. The target aluminum tube group is set in a matching manner with the first positioning hole array to ensure that the geometric parameters of the first positioning holes can be precisely matched with the target aluminum tubes. The target aluminum tube group is inserted into the first positioning hole array, so that the aluminum tube group is precisely set into the target aluminum tube array in the cavity. The aluminum liquid and the target aluminum tube group are of the same material. After pouring, it is maintained under the preset pressure applied by the cover plate for a preset time to obtain a completely consistent hole structure. By pouring the aluminum liquid into the cavity, the material is added, which reduces material waste and improves material utilization. The process is simple, the equipment requirements are low, the operation is simple, and the cost is low. The stability and performance consistency of the hole structure are maintained. By controlling the geometric parameters and structure of the first positioning hole array, the uniformity of the pores can be controlled, while simplifying the process and reducing the manufacturing cost.

[0051] Specifically, such as Figure 2 As shown, after obtaining the porous aluminum sample in step S400, the method further includes the following steps:

[0052] Step S410: Remove the cover plate and take out the sample after the target mold has cooled to the preset temperature;

[0053] Step S420: Remove excess material from the outer surface of the sample to obtain the finished porous aluminum product.

[0054] In step S410, the sample is removed by removing the cover plate when the target mold cools to the preset temperature, ensuring that the sample remains stable in a uniform temperature field, avoiding deformation or cracking of the pore structure, and maintaining the uniformity of pore distribution.

[0055] In step S420, by cutting off the excess material on the outer surface of the sample, the unsolidified aluminum material on the sample surface can be removed, the size and contour of the finished product can be precisely controlled, and a porous aluminum finished product can be obtained, ensuring that the porous aluminum finished product meets the requirements.

[0056] Based on steps S410 to S420, the sample is removed when the target mold is cooled to a preset temperature, and the excess material on the outer surface of the sample is removed to obtain a porous aluminum finished product. This ensures that the porous aluminum finished product meets the design requirements in terms of pore size, pore spacing and surface flatness, and significantly improves the yield and control accuracy of the finished product.

[0057] Specifically, in step S300, before pouring the molten aluminum into the mold cavity, the method further includes the following steps:

[0058] Step S310: Heat the initial aluminum material to a preset temperature under a protective atmosphere to obtain molten aluminum;

[0059] The initial aluminum material is set to be the same as the target aluminum tube assembly, and the preset temperature is T1, where 700℃≤T1≤750℃.

[0060] In step S310, the protective atmosphere refers to an inert gas environment to ensure that the aluminum liquid surface is in oxygen-free. By heating the initial aluminum material to a preset temperature under the protective atmosphere, the generation of metal compounds in the aluminum liquid can be effectively avoided, thus ensuring the purity of the aluminum liquid. By setting the initial aluminum material to be the same as the target aluminum tube assembly, and setting the preset temperature to T1, where 700℃≤T1≤750℃, the bonding strength is improved.

[0061] Furthermore, the first positioning hole array includes at least one of a square hole array, a regular hexagonal hole array, a circular hole array, and an irregular hole array.

[0062] In this embodiment, by setting the first positioning hole array to at least one of square hole array, regular hexagonal hole array, circular hole array, and irregular hole array, the target aluminum tube group can be precisely inserted. It is then erected into a corresponding three-dimensional spatial array structure, forming different shaped channels according to different array shapes, thus enhancing the diversity of the porous aluminum hole structure.

[0063] Furthermore, the target mold includes a cubic mold, which includes a first sidewall and a third sidewall disposed opposite to each other along the length direction of the cavity, a second sidewall and a fourth sidewall disposed opposite to each other along the width direction of the cavity, and a bottom wall and an opening disposed opposite to each other along the height direction of the cavity, with a cover plate disposed in a matching manner with the opening.

[0064] In this embodiment, by designing the target mold to include a first sidewall and a third sidewall that are positioned opposite each other along the length of the cavity, and a second sidewall and a fourth sidewall that are positioned opposite each other along the width of the cavity, the target aluminum tube assembly can be inserted through the first positioning hole array and erected into a target aluminum tube array. Thus, the length, width, and height are all constrained by the positioning hole structure of the first sidewall, the third sidewall, the second sidewall, the fourth sidewall, and the bottom wall, forming a stable support. The six-sided closed structure of the cubic mold effectively prevents the target aluminum tube array from shifting, tilting, or collapsing, ensuring that its spatial configuration remains accurate and unchanged throughout the solidification process.

[0065] Specifically, a first positioning hole array is provided on the bottom wall, and a second positioning hole array is provided on the cover plate. The second positioning hole array is matched with the first positioning hole array provided on the bottom wall.

[0066] In this embodiment, by providing a first positioning hole array on the bottom wall and a second positioning hole array on the cover plate, the second positioning hole array is matched with the first positioning hole array on the bottom wall, so that when the target aluminum tube assembly is inserted into the cavity to form the target aluminum tube array, its bottom end is precisely limited by the first positioning hole array and its top end is constrained by the second positioning hole array, which significantly improves the stability of the aluminum tube.

[0067] Specifically, in step S100, the first sidewall, second sidewall, third sidewall, fourth sidewall, and bottom wall are all provided with a first positioning hole array. Each first positioning hole array is a square hole array. The target aluminum tube assembly is inserted into the cavity through the first positioning hole array to form the target aluminum tube array. Figure 3 As shown, it includes the following steps:

[0068] Step S110: Insert the first aluminum tube group in the target aluminum tube group into the first positioning hole array of the first side wall and the first positioning hole array of the third side wall. The wall thickness of the first aluminum tube group is D1, 0.1mm≤D1≤10mm.

[0069] Step S120: Insert the second aluminum tube group in the target aluminum tube group into the first positioning hole array of the second side wall and the first positioning hole array of the fourth side wall. The wall thickness of the second aluminum tube group is D2, 0.1mm≤D2≤10mm.

[0070] Step S130: Insert the third aluminum tube group in the target aluminum tube group into the first positioning hole array on the bottom wall. The wall thickness of the third aluminum tube group is D3, 0.1mm≤D3≤10mm.

[0071] The first aluminum tube group, the second aluminum tube group, and the third aluminum tube group are together erected to form the target aluminum tube array.

[0072] In this embodiment, by providing a first positioning hole array on the first sidewall, second sidewall, third sidewall, fourth sidewall, and bottom wall, and each first positioning hole array being a square hole array, the first aluminum tube group, the second aluminum tube group, and the third aluminum tube group form a three-dimensional square hole structure in the cavity along the length, width, and height directions.

[0073] In step S110, by inserting the first aluminum tube group in the target aluminum tube group into the first positioning hole array of the first sidewall and the first positioning hole array of the third sidewall, the structural rigidity along the length direction of the aluminum tube is ensured. The wall thickness D1 of the first aluminum tube group is set to the range of 0.1mm≤D1≤10mm, which avoids deformation of the aluminum tube and improves the structural stability of the aluminum tube.

[0074] In step S120, by inserting the second aluminum tube group in the target aluminum tube group into the first positioning hole array of the second side wall and the first positioning hole array of the fourth side wall, the structural rigidity of the aluminum tube along the width direction is ensured. The square hole arrays of the second and fourth side walls of the target aluminum tube group are rigidly fixed, so that the aluminum tube is fixed at both ends. The wall thickness D2 of the second aluminum tube group is set to 0.1mm≤D2≤10mm, ensuring that the wall thickness range of the aluminum tube is consistent in different directions, thus ensuring the stability of the aluminum tube.

[0075] In step S130, by inserting the third aluminum tube group in the target aluminum tube group into the first positioning hole array on the bottom wall, the structural stability of the aluminum tube group in the height direction is ensured. The wall thickness of the third aluminum tube group is D3, 0.1mm≤D3≤10mm, which can effectively resist pressure. While ensuring a high porosity, it also ensures the lightweight of the aluminum tube group.

[0076] Based on steps S110 to S130, by inserting the first aluminum tube group into the first positioning hole array of the first sidewall and the first positioning hole array of the third sidewall, the second aluminum tube group into the first positioning hole array of the second sidewall and the first positioning hole array of the fourth sidewall, and the third aluminum tube group into the first positioning hole array of the bottom wall, the first, second, and third aluminum tube groups are coordinated to form a three-dimensional square hole network structure in the cavity along the length, width, and height directions. The wall thickness D1 of the first aluminum tube group satisfies 0.1mm≤D1≤10mm, the wall thickness D2 of the second aluminum tube group satisfies 0.1mm≤D2≤10mm, and the wall thickness D3 of the third aluminum tube group satisfies 0.1mm≤D3≤10mm. This control of the wall thickness range ensures that the aluminum tubes in each direction maintain structural stability during casting and pressurization, avoiding deformation or melting due to excessively thin walls, or insufficient porosity due to excessively thick walls. It also provides channels for heat conduction and balances the cooling rates in the three directions.

[0077] Specifically, in step S100, the first sidewall, second sidewall, third sidewall, and fourth sidewall are each provided with a first positioning hole array. Each first positioning hole array is a regular hexagonal hole array, which passes through the first positioning hole array into the cavity to form the target aluminum tube array, such as... Figure 4 As shown, it includes the following steps:

[0078] Step S140: Insert the fourth aluminum tube group in the target aluminum tube group into the first positioning hole array of the first side wall and the first positioning hole array of the third side wall. The wall thickness of the fourth aluminum tube group is D4, 0.1mm≤D4≤10mm.

[0079] Step S150: The fifth aluminum tube group in the target aluminum tube group is inserted into the first positioning hole array of the second side wall and the first positioning hole array of the fourth side wall. The wall thickness of the fifth aluminum tube group is D5, 0.1mm≤D5≤10mm.

[0080] Among them, the fourth and fifth aluminum tube groups are jointly erected to form the target aluminum tube array.

[0081] Based on steps S140 to S150, by inserting the fourth aluminum tube group into the first positioning hole array of the first sidewall and the first positioning hole array of the third sidewall, and by inserting the fifth aluminum tube group into the first positioning hole array of the second sidewall and the first positioning hole array of the fourth sidewall, the fourth and fifth aluminum tube groups are cross-constructed into the target aluminum tube array within the cavity. The wall thickness D4 of the fourth aluminum tube group satisfies 0.1mm≤D4≤10mm, and the wall thickness D5 of the fifth aluminum tube group satisfies 0.1mm≤D5≤10mm. This structural design ensures that the aluminum tubes are symmetrically arranged along the regular hexagonal hole array in three-dimensional space, so that the hole structure formed after the aluminum liquid solidifies exhibits a regular hexagonal symmetrical distribution in the length, width, and height directions, significantly improving the uniformity of material pores and ensuring the consistency of the mechanical properties of the aluminum tube group.

[0082] Furthermore, the first sidewall, second sidewall, third sidewall, fourth sidewall, and bottom wall are all provided with a first positioning hole array. The first positioning hole arrays on the first sidewall and the third sidewall are circular hole arrays, the first positioning hole arrays on the second sidewall and the fourth sidewall are square hole arrays, and the first positioning hole array on the bottom wall is a regular hexagonal hole array. The target aluminum tube assembly is inserted into the cavity through the first positioning hole array to form the target aluminum tube array. Figure 5 As shown, it includes the following steps:

[0083] Step S160: The sixth aluminum tube group in the target aluminum tube group is inserted into the first positioning hole array of the first side wall and the first positioning hole array of the third side wall. The wall thickness of the sixth aluminum tube group is D6, 0.1mm≤D6≤10mm.

[0084] Step S170: Insert the seventh aluminum tube group in the target aluminum tube group into the first positioning hole array of the second side wall and the first positioning hole array of the fourth side wall. The wall thickness of the seventh aluminum tube group is D7, 0.1mm≤D7≤10mm.

[0085] Step S180: Insert the eighth aluminum tube group in the target aluminum tube group into the first positioning hole array on the bottom wall. The wall thickness of the eighth aluminum tube group is D8, 0.1mm≤D8≤10mm.

[0086] Among them, the sixth, seventh and eighth aluminum tube groups are jointly erected to form the target aluminum tube array.

[0087] In step S160, by inserting the sixth aluminum tube group in the target aluminum tube group into the first positioning hole array on the first sidewall and the first positioning hole array on the third sidewall, the aluminum tube group is made into a circular hole array along its length. The circular holes are relatively smooth, without sharp corners, and have continuous curves. The arc boundaries can effectively disperse the lateral impact force during the injection of molten aluminum, reducing stress concentration on the aluminum tube. Setting the wall thickness D6 of the sixth aluminum tube group to 0.1mm≤D6≤10mm effectively improves the bending resistance of the aluminum tube group in the length direction.

[0088] In step S170, by inserting the seventh aluminum tube group in the target aluminum tube group into the first positioning hole array of the second side wall and the first positioning hole array of the fourth side wall, the aluminum tube group is made into a square array along the width direction. The square array holes have right-angled boundaries and high symmetry. Setting the wall thickness D7 of the seventh aluminum tube group to 0.1mm≤D7≤10mm is beneficial to maintaining the orientation of the aluminum tube group in the width direction and improving the overall torsional stiffness.

[0089] In step S180, by inserting the eighth aluminum tube group in the target aluminum tube group into the first positioning hole array on the bottom wall, the aluminum tube group is arranged in a regular hexagonal array along the height direction. The regular hexagon has a high porosity, and at the same time, it can optimize the stress dispersion path and improve the heat conduction capacity. The wall thickness D7 of the seventh aluminum tube group is set to 0.1mm≤D7≤10mm, which improves the porosity and heat conduction of the aluminum tube group.

[0090] Based on steps S160 to S180, by setting the first positioning hole array on the first sidewall and the first positioning hole array on the third sidewall as circular hole arrays, the first positioning hole array on the second sidewall and the first positioning hole array on the fourth sidewall as square hole arrays, and the first positioning hole array on the bottom wall as a regular hexagonal hole array, the hole structure along the length direction presents a circular cross-section, the hole structure along the width direction presents a square cross-section, and the hole structure along the height direction presents a regular hexagonal shape. This allows the molten aluminum to form hole structures with differentiated geometric shapes in the three dimensions of length, width, and height. By flexibly selecting built-in aluminum tubes with different diameters and cross-sectional shapes, an aluminum tube array is designed and constructed to accurately "replicate" the required hole structure. Furthermore, the metallurgical bonding between the same type of aluminum material ensures the integrated performance and interface strength of the component, successfully achieving the precise design and controllable forming of the internal hole structure of the porous aluminum component.

[0091] According to another specific embodiment of this application, a porous aluminum is also provided, which is prepared by the above-described method for preparing porous aluminum.

[0092] By applying the technical solution of this embodiment, a cavity is set in the target mold, and a first positioning hole array is opened on the side wall of the cavity. The geometric parameters such as the hole arrangement of the first positioning holes can be controlled. The target aluminum tube group is set in a matching manner with the first positioning hole array to ensure that the geometric parameters of the first positioning holes can be precisely matched with the target aluminum tubes. This allows for better control of the uniformity of the porosity of the porous aluminum. The target aluminum tube group is inserted into the first positioning hole array, so that the aluminum tube group is precisely set into the target aluminum tube array in the cavity. The aluminum liquid is poured into the cavity. The aluminum liquid and the target aluminum tube group are made of the same material, which improves the surface flatness of the porous aluminum. After pouring, the pressure is maintained for a preset time under the preset pressure applied by the cover plate, which can obtain a completely consistent hole structure and maintain the stability and performance consistency of the hole structure in the porous aluminum.

[0093] This application also provides an exemplary embodiment of a method for preparing porous aluminum with adjustable pore size and pore shape.

[0094] Specifically, such as Figure 13 As shown, the method for preparing porous aluminum with adjustable pore size and pore shape includes the following steps:

[0095] Step S10, provide a mold with a cavity, such as Figure 7 As shown, the mold has multiple sets of precisely positioned positioning holes pre-installed on its sidewall. Aluminum tubes one, two, and three with specific diameters, shapes, and wall thicknesses are selected. Then, aluminum tubes one, two, and three are inserted into the positioning holes along the mold sidewall in a crisscrossing and penetrating manner in three-dimensional space, thus forming a stable and regularly arranged array of aluminum tubes within the mold cavity, as shown. Figures 8 to 10 As shown;

[0096] Step S20: Metallic aluminum of the same material as the aluminum tube array is heated under a protective atmosphere until it is completely melted into a homogeneous molten aluminum (temperature controlled at 700℃–750℃). The molten aluminum is then smoothly poured into the mold cavity containing the assembled aluminum tube array using a gating system, ensuring the cavity is fully filled. Immediately afterwards, a top cover plate with clearance holes is installed, such as… Figure 11 As shown, mechanical pressure is applied and maintained to promote close contact between the high-temperature molten aluminum and the surface of the thin-walled aluminum tube. Under continuous pressure, the elements between the molten aluminum and the aluminum tube are mutually diffused, forming a metallurgical bonding interface with continuous composition and dense structure.

[0097] Step S30: Maintain pressure until the molten aluminum initially solidifies, then release the pressure and allow the mold to cool naturally to room temperature. This integrates the array of aluminum tubes with the poured molten aluminum substrate, forming a monolithic porous aluminum part with controllable pore size. Subsequently, the mold is opened, the sample is removed, and further machining is performed to remove excess aluminum tubes, obtaining the final product. Figure 12 As shown.

[0098] Preferably, the pre-set hole system on the mold sidewall in step S10 is determined based on the tube shapes of aluminum tube one, aluminum tube two, and aluminum tube three. The respective diameters and shapes of aluminum tube one, aluminum tube two, and aluminum tube three can be designed according to the specific requirements of the final product regarding fluid flowability, specific surface area, or lightweight structure. The aluminum tubes have cross-sections including but not limited to conventional geometric shapes such as circles, squares, and hexagons, or custom-defined irregular contours such as arcs or S-shapes; and their diameter or shape can be consistent along the length of the tube body, or it can be a gradually changing or non-uniform structure with differences between different tube sections. The wall thickness of the aluminum tubes ranges from 0.1mm to 10mm.

[0099] Preferably, the aluminum tubes 1, 2, and 3 in step S10, as well as the aluminum metal used for casting in step 2, can be industrial pure aluminum or any series of cast aluminum alloys, such as A356, 6061, etc. The specific materials can be uniformly selected and matched according to the requirements of the final component for mechanical properties, corrosion resistance, or thermal conductivity. At the same time, the external shape and structural materials of the mold can be customized according to the final three-dimensional contour of the target porous aluminum part to achieve near-net-shape forming.

[0100] Preferably, the upper cover plate in step 20 has an operating handle fixedly mounted on its body, and is machined with avoidance holes corresponding to the position and shape of the top of the aluminum tube array inside the mold cavity. This design facilitates safe and efficient pressurization and mold opening operations for operators, and ensures that the upper cover plate can accurately avoid the protruding aluminum tubes when pressurizing, achieving uniform pressure application.

[0101] Specifically, such as Figure 14 As shown, Example 1 provides a method for preparing porous aluminum with square holes, specifically including the following steps:

[0102] Step S1: Provide a cubic mold with an internal cavity of 100mm × 100mm × 100mm. Multiple sets of high-precision square positioning holes are machined on the sidewalls of the mold. These square holes are 5.02mm × 5.02mm in size (slightly larger than the aluminum tube cross-section for easy insertion), with a hole spacing of 5.00mm, and their positions on each sidewall are strictly corresponding. Three sets of industrial aluminum tubes made of AlSi7Mg are selected, designated as aluminum tube one, aluminum tube two, and aluminum tube three, respectively. Their cross-sections are standard squares with a side length of 5.00mm and a wall thickness of 0.5mm. The tube surfaces are smooth to ensure smooth inner walls of the channels after demolding. These three sets of square aluminum tubes are then inserted sequentially through the square positioning holes on the sidewalls along the X, Y, and Z orthogonal directions of the mold.

[0103] Step S2: Industrial AlSi7Mg aluminum of the same material is heated to 720℃ under argon protection, melting into a homogeneous molten aluminum. A mold preheated to 200℃ is placed at the pouring station, and the molten aluminum is smoothly poured into the mold cavity. After pouring, a special top cover plate is quickly installed. The lower surface of this top cover plate is machined with square clearance holes (5.05mm × 5.05mm) that precisely match the square cross-section of the top of the aluminum tube array. A pressure of 8MPa is applied to the top cover plate using a press and held for 45 seconds. The pressure forces the molten aluminum to tightly wrap around the surface of each square aluminum tube and squeezes out excess aluminum, forming a smooth top surface.

[0104] Step S3: After holding the pressure until the molten aluminum solidifies, release the pressure and slowly cool the entire mold assembly to room temperature in still air. After complete cooling, open the mold and remove the part. Subsequently, perform subsequent machining to remove excess aluminum tubing, resulting in a porous aluminum component with regular square channels inside.

[0105] Specifically, such as Figure 15 As shown, Example 2 provides a method for preparing porous aluminum with a biomimetic honeycomb structure, specifically including the following steps:

[0106] Step S4: Provide a flat rectangular mold with an internal cavity of 100mm × 100mm × 20mm. Multiple sets of high-precision regular hexagonal positioning holes are machined on the four side walls of the mold, all of which together form a regular two-dimensional honeycomb lattice. Select aluminum tubes made of 5A06 rust-resistant aluminum, with a regular hexagonal cross-section, a side-to-side distance of 5.00mm, and a wall thickness of 0.5mm. Insert these hexagonal aluminum tubes into the positioning holes along a direction perpendicular to the large surface of the mold (Z-direction), forming a dense biomimetic honeycomb aluminum tube array.

[0107] Step S5: Heating 5A06 aluminum alloy of the same material to 700℃ under argon protection melts it into a homogeneous molten aluminum. Placing a mold preheated to 200℃ at the pouring station, the molten aluminum is smoothly poured into the mold cavity. After pouring, a special top cover is quickly installed. The lower surface of this top cover is machined with honeycomb-shaped clearance holes that precisely match the top of the hexagonal aluminum tube array. A pressure of 10MPa is applied to the top cover using a press and held for 40 seconds. The pressure forces the molten aluminum to tightly wrap around the surface of each hexagonal aluminum tube and squeezes out excess aluminum, forming a smooth upper surface.

[0108] Step S6: After the pressure holding is completed, the part is air-cooled to room temperature. After complete cooling, the mold is opened and the part is removed for subsequent machining. Excess aluminum tubes are removed to obtain a two-dimensional honeycomb biomimetic porous aluminum plate with high strength and high specific stiffness.

[0109] Specifically, such as Figure 16As shown, Example 3 provides a method for preparing porous aluminum with combined shapes, specifically including the following steps:

[0110] Step S7: Provide a cubic mold with an internal cavity of 120mm × 120mm × 120mm. Three sets of positioning holes of different shapes are precisely machined on the sidewalls of the mold: circular holes with a diameter of 3.02mm in the X direction, square holes with a diameter of 4.02mm × 4.02mm in the Y direction, and regular hexagonal holes with a side-to-side distance of 3.52mm in the Z direction. The hole spacing of all hole systems is 4.00mm. An aluminum tube array is constructed using three different cross-sectional shapes of aluminum alloy tubes: tube one is a circular tube with a diameter of 3.00mm and a wall thickness of 0.3mm; tube two is a square tube with a side length of 4.00mm and a wall thickness of 0.5mm; tube three is a hexagonal tube with a side-to-side distance of 3.50mm and a wall thickness of 0.4mm. All aluminum tubes are made of A356 aluminum alloy. These three sets of aluminum tubes of different shapes are inserted into the corresponding positioning hole system along the X, Y and Z directions respectively, forming a three-dimensional aluminum tube array with composite geometric features in the mold cavity;

[0111] Step S8: Heating the A356 aluminum alloy to 730°C under argon protection utilizes its excellent fluidity to obtain a high-quality melt. Placing the mold, preheated to 250°C, at the pouring station, and smoothly pouring the molten aluminum into the mold cavity. After pouring, quickly cover the mold with a special top cover plate, the lower surface of which is machined with clearance holes corresponding to the aluminum tube array. Applying a pressure of 8MPa to the top cover plate using a press and holding the pressure for 60 seconds;

[0112] Step S9: After holding the pressure until the aluminum liquid solidifies, release the pressure and slowly cool the entire mold assembly to room temperature in still air. After complete cooling, open the mold, remove the part, and perform machining to remove excess aluminum tubes. Finally, obtain a porous aluminum component with composite shaped holes consisting of intersecting circular, square, and hexagonal channels.

[0113] The technical solution using the embodiments of this application has the following advantages:

[0114] (1) By flexibly selecting built-in aluminum tubes with different diameters and cross-sectional shapes, an aluminum tube array is designed and built to accurately "replicate" the required hole structure. The metallurgical combination between the same type of aluminum material ensures the integrated performance and interface strength of the component, and successfully realizes the precise design and controllable forming of the internal hole structure of the porous aluminum component.

[0115] (2) The embodiments of this application adopt the method of adding materials, which reduces material waste and improves material utilization. Compared with 3D printing technology, its process is simple, equipment requirements are low, operation is simple and cost is low, breaking through the bottleneck of existing porous aluminum preparation technology that is difficult to balance between structural control, process complexity and production cost.

[0116] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0117] In addition to the above, it should be noted that the terms "one embodiment," "another embodiment," and "embodiment" used in this specification refer to specific features, structures, or characteristics described in connection with that embodiment, which are included in at least one embodiment described in the general description of this application. The appearance of the same expression in multiple places in the specification does not necessarily refer to the same embodiment. Furthermore, when a specific feature, structure, or characteristic is described in connection with any embodiment, the intention is to suggest that implementing such a feature, structure, or characteristic in conjunction with other embodiments also falls within the scope of this invention.

[0118] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0119] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing porous aluminum, characterized in that, include: Select a target mold and a target aluminum tube assembly. The target mold has a cavity, and the sidewall of the cavity is provided with a first positioning hole array. The target aluminum tube assembly is set in a matching manner with the first positioning hole array. The target aluminum tube assembly is inserted into the cavity through the first positioning hole array to form the target aluminum tube array; Molten aluminum is poured into the cavity and sealed with a cover plate, wherein the molten aluminum is made of the same material as the target aluminum tube assembly; A preset pressure is applied to the cover plate and maintained for a preset time to allow the molten aluminum in the cavity to solidify, thereby obtaining a sample of porous aluminum.

2. The method for preparing porous aluminum according to claim 1, characterized in that, After obtaining the porous aluminum sample, the method further includes the following steps: Remove the cover plate and take out the sample after the target mold has cooled to a preset temperature; Excess material on the outer surface of the sample is removed to obtain the finished porous aluminum product.

3. The method for preparing porous aluminum according to claim 1, characterized in that, Before pouring the molten aluminum into the mold cavity, the method further includes the following steps: The initial aluminum material is heated to a preset temperature under a protective atmosphere to obtain the molten aluminum; The initial aluminum material is the same as the material of the target aluminum tube assembly, and the preset temperature is T1, where 700℃≤T1≤750℃.

4. The method for preparing porous aluminum according to claim 2 or 3, characterized in that, The first positioning hole array includes at least one of square hole array, regular hexagonal hole array, circular hole array, and irregular hole array.

5. The method for preparing porous aluminum according to claim 4, characterized in that, The target mold includes a cubic mold, which includes a first sidewall and a third sidewall disposed opposite to each other along the length direction of the cavity, a second sidewall and a fourth sidewall disposed opposite to each other along the width direction of the cavity, and a bottom wall and an opening disposed opposite to each other along the height direction of the cavity, wherein the cover plate is disposed in a matching manner with the opening.

6. The method for preparing porous aluminum according to claim 5, characterized in that, The bottom wall is provided with the first positioning hole array, and the cover plate is provided with the second positioning hole array, which is matched with the first positioning hole array provided on the bottom wall.

7. The method for preparing porous aluminum according to claim 6, characterized in that, The first sidewall, the second sidewall, the third sidewall, the fourth sidewall, and the bottom wall are all provided with the first positioning hole array, and each of the first positioning hole arrays is a square hole array. The target aluminum tube assembly is inserted into the cavity through the first positioning hole array to form the target aluminum tube array, including the following steps: The first aluminum tube group in the target aluminum tube group is inserted into the first positioning hole array of the first sidewall and the first positioning hole array of the third sidewall. The wall thickness of the first aluminum tube group is D1, 0.1mm≤D1≤10mm. The second aluminum tube group in the target aluminum tube group is inserted into the first positioning hole array of the second side wall and the first positioning hole array of the fourth side wall. The wall thickness of the second aluminum tube group is D2, 0.1mm≤D2≤10mm. The third aluminum tube group in the target aluminum tube group is inserted into the first positioning hole array on the bottom wall. The wall thickness of the third aluminum tube group is D3, 0.1mm≤D3≤10mm. The first aluminum tube group, the second aluminum tube group, and the third aluminum tube group are collectively arranged to form the target aluminum tube array.

8. The method for preparing porous aluminum according to claim 5, characterized in that, The first sidewall, the second sidewall, the third sidewall, and the fourth sidewall are all provided with the first positioning hole array. Each of the first positioning hole arrays is a regular hexagonal hole array. The target aluminum tube assembly is inserted into the cavity through the first positioning hole array to form the target aluminum tube array, including the following steps: The fourth aluminum tube group in the target aluminum tube group is inserted into the first positioning hole array of the first sidewall and the first positioning hole array of the third sidewall. The wall thickness of the fourth aluminum tube group is D4, 0.1mm≤D4≤10mm. The fifth aluminum tube group in the target aluminum tube group is inserted into the first positioning hole array of the second side wall and the first positioning hole array of the fourth side wall. The wall thickness of the fifth aluminum tube group is D5, 0.1mm≤D5≤10mm. The fourth aluminum tube group and the fifth aluminum tube group are together erected to form the target aluminum tube array.

9. The method for preparing porous aluminum according to claim 6, characterized in that, The first sidewall, second sidewall, third sidewall, fourth sidewall, and bottom wall are all provided with the first positioning hole array. The first positioning hole arrays on the first sidewall and the third sidewall are circular hole arrays, the first positioning hole arrays on the second sidewall and the fourth sidewall are square hole arrays, and the first positioning hole array on the bottom wall is a regular hexagonal hole array. The target aluminum tube assembly is inserted into the cavity through the first positioning hole array to form the target aluminum tube array, including the following steps: The sixth aluminum tube group in the target aluminum tube group is inserted into the first positioning hole array of the first sidewall and the first positioning hole array of the third sidewall. The wall thickness of the sixth aluminum tube group is D6, 0.1mm≤D6≤10mm. The seventh aluminum tube group in the target aluminum tube group is inserted into the first positioning hole array of the second side wall and the first positioning hole array of the fourth side wall. The wall thickness of the seventh aluminum tube group is D7, 0.1mm≤D7≤10mm. The eighth aluminum tube group in the target aluminum tube group is inserted into the first positioning hole array on the bottom wall. The wall thickness of the eighth aluminum tube group is D8, and 0.1mm≤D8≤10mm. The sixth aluminum tube group, the seventh aluminum tube group, and the eighth aluminum tube group are collectively arranged to form the target aluminum tube array.

10. A porous aluminum, characterized in that, The porous aluminum is prepared using the porous aluminum preparation method according to any one of claims 1-9.

Images