A method for preparing high-electrical and thermal-conductive metal materials based on neuron bionic structure

Abstract

The present invention discloses a method for preparing a highly conductive and thermally conductive metal material based on a neuron-inspired bionic structure. The method is suitable for the structural design of metal materials with high conductivity and thermal conductivity enhancement efficiency and isotropy, and belongs to the field of highly conductive and thermally conductive metal materials and their structural design. By introducing a neuron-inspired structural reinforcement phase and forming a continuous, efficient neuron-inspired mesh transmission structure formed by mutual bridging, a metal material with high conductivity and thermal conductivity enhancement efficiency and excellent isotropy is prepared. The synergistic strengthening effect of the neuron-inspired conductive structure significantly improves the strengthening efficiency of the reinforcement phase, and the excellent isotropy ensures the comprehensive conductive capacity of the highly conductive and thermally conductive metal material.

Description

Technical Field

[0001] The present invention relates to the field of high-conductivity and thermal-conductivity metal materials and their structural design, and relates to a method for preparing a high-conductivity and thermal-conductivity metal material based on a neuron bionic structure, and specifically to a method for preparing a metal material based on the characteristics of a neuron bionic structure, which has high conductivity and thermal-conductivity enhancement efficiency and isotropy. Background Art

[0002] Current research on highly conductive and thermally conductive metal materials primarily focuses on the selection and design of materials that incorporate a specific, highly conductive and thermally conductive reinforcing phase, such as carbon fiber, diamond, or silicon carbide. The extent to which conductive properties (both electrical and thermal conductivity) can be optimized through material selection and design is very limited. The fundamental reason is that the conductive properties of metal materials depend on the volume fraction of the reinforcing phase. This reinforcing phase often exhibits poor interfacial bonding with the bulk and tends to agglomerate, making it difficult to introduce sufficient amounts of this reinforcing phase into the matrix. However, a small amount of reinforcing phase makes it difficult to construct a continuous conductive pathway, resulting in low conductivity enhancement efficiency. Furthermore, the manufacturing process for the highly conductive and thermally conductive metal materials currently under investigation is primarily based on powder metallurgy. The anisotropic microstructure after extrusion results in anisotropic conductive properties, meaning that enhanced electrical and thermal conductivity is only achieved along the extrusion direction. Therefore, exploring new design strategies for highly conductive and thermally conductive reinforcing phases is a key measure to improve enhancement efficiency and achieve isotropy.

[0003] There are two key issues that need to be addressed regarding the electrical and thermal conductivity of metal materials. First, defect scattering in metal materials deteriorates conductivity. Defects in metal materials, such as dissolved atoms, second phases, various interfaces, and impurities, scatter the electron transport process, reducing the mean free path and thus leading to deterioration of electrical and thermal conductivity. The efficient conduction of current and heat flow in metal materials requires a continuous conduction channel for electrons. Second, the anisotropy of conductivity, which is determined by factors such as deformation process and texture. Deformation processes such as extrusion and rolling lead to anisotropy in the structure of metal materials, which directly causes anisotropy in conductivity. The conductivity along the deformation direction is often better than that perpendicular to the deformation direction due to the density of the structure and the directional arrangement of the conductive and thermally conductive enhancing phases. The anisotropy of conductivity limits the application scenarios of such metal materials, and their overall conductivity is poorer than that of isotropic metal materials.

[0004] The structural design of the reinforcement phase is a powerful solution to the above two problems. The structural design of the reinforcement phase helps to build a continuous and efficient conduction path, improve the reinforcement efficiency, and achieve isotropy of the conduction performance. Furthermore, the biomimetic structural design of the reinforcement phase is currently a hot research frontier. For example, the literature reports on spider web-like high thermal conductivity phase change nanocomposites for battery thermal management. However, the isotropy of this material has not been reported, and the application scenarios and sample size are limited.

[0005] After literature and patent searches, no related or similar methods for designing neuron bionic structures of highly conductive and thermally conductive isotropic metal materials were found that are related to or similar to the present invention. Summary of the Invention

[0006] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to address the problems of low strengthening efficiency and anisotropy of highly conductive and thermally conductive metal materials. By designing a metal material enhanced phase structure, a neuron bionic conduction structure is constructed to significantly improve the strengthening efficiency while achieving isotropy of the conduction performance.

[0007] In order to achieve the above-mentioned technical effects, the present invention proposes a method for preparing a high-conductivity and thermal-conductivity metal material based on a neuron bionic structure. This is different from the existing methods. By organically integrating the planar and filamentous reinforcing phases of the neuron-like structure, a continuous and efficient mesh transmission structure is constructed, and a metal material with high electrical and thermal conductivity enhancement efficiency (electrical and thermal conductivity is better than that of the matrix) and excellent isotropy is prepared. In addition, the conductive properties of the commonly used high-conductivity and thermal-conductivity reinforcing phases often show great anisotropy (two orders of magnitude) along the characteristic direction and perpendicular to the characteristic direction, such as the axial and radial directions of carbon fibers, and the in-plane and perpendicular-to-surface thermal conductivity of graphite sheets. The introduced neuron mesh transmission structure can not only further improve the reinforcement efficiency and achieve isotropy, but also give full play to the electrical and thermal conductivity potential of the anisotropic reinforcing phase.

[0008] The design principle of this invention is that the research on neurons found that the transmission rate of neuronal electrical signals is very fast, up to 120m / s, which is 10 times the propagation speed of free electrons in metals (0.75mm / s). 6 times. One of the reasons is that the various ion channels in neurons react quickly. There are more than 860 million neurons in the human brain, and each neuron can be connected to another 10,000 neurons. All the bridged neurons eventually build an efficient and stable mesh transmission structure, realizing all activities at all levels from basic life activities to advanced human functions. According to the Wiedemann-Franz law, the electrical conductivity and thermal conductivity of metals are closely related. Therefore, through the study of the cutting-edge and superiority of the neuronal mesh structure, a neuronal bionic continuous mesh efficient conduction structure is constructed. There are three main points in the construction of this bionic structure. First, corresponding to the rapid reaction channels of ions in neurons, the enhanced phase has excellent conduction properties. Secondly, the enhanced phase needs to have the planar and filamentous morphology characteristics of the neuronal structure respectively. Thirdly, there should be some kind of interaction between the two (such as van der Waals force and wettability between carbon materials) or an appropriate pre-connection process should be used to achieve bridging to build a network structure.

[0009] The purpose of the present invention is achieved through the following technical solutions:

[0010] In the first aspect, the present invention provides a method for preparing a highly conductive and thermally conductive metal material based on a neuron bionic structure, wherein a neuron-like structure reinforcing phase is introduced into a matrix material, wherein the neuron-like structure reinforcing phase includes a neuron-like structure planar reinforcing phase and a neuron-like structure filamentous reinforcing phase, and the neuron-like structure reinforcing phase is uniformly dispersed in the matrix material.

[0011] As an embodiment of the present invention, the preparation method imitates the neuron structure, and constructs an efficient and stable continuous network transmission structure by simultaneously introducing and bridging planar and filamentous reinforcement phases, thereby preparing a metal material with high electrical and thermal conductivity, enhanced efficiency and excellent isotropy.

[0012] As an embodiment of the present invention, the volume percentage of the neuron-like structure reinforcement phase in the metal material is 1%-20%, and the volume ratio of the neuron-like structure planar reinforcement phase to the neuron-like structure filament reinforcement phase is 1:1-1:3.

[0013] As an embodiment of the present invention, the neuron-mimicking structure planar reinforcement phase includes at least one of graphite sheet, silicon carbide, aluminum nitride, diamond, copper foil, aluminum foil, silver foil, and gold foil.

[0014] As an embodiment of the present invention, the neuron-mimicking structure filamentous reinforcement phase includes at least one of carbon fiber, copper wire, silver wire, and gold wire.

[0015] As an embodiment of the present invention, the matrix material includes at least one of magnesium alloy, aluminum alloy, and copper alloy.

[0016] As an embodiment of the present invention, the magnesium alloy includes at least one of SA42 (Mg-4Sm-2Al) magnesium alloy, LA42 (Mg-4La / Ce-2Al) magnesium alloy, ZK61 magnesium alloy, and AZ91 magnesium alloy; the aluminum alloy includes at least one of ADC10 aluminum alloy and ADC12 aluminum alloy; and the copper alloy includes at least one of CA103 copper alloy and CDA122 copper alloy.

[0017] As an embodiment of the present invention, the matrix material is SA42 magnesium alloy.

[0018] As an embodiment of the present invention, the preparation method comprises the following steps:

[0019] S1, pre-spreading powder: add the neuron-like structure reinforcement phase at the bottom of the melting device and stir at low speed;

[0020] S2, smelting: adding the raw alloy to the smelting device of step S1, and smelting to prepare an alloy melt;

[0021] S3, refining: adjusting the temperature of the alloy melt obtained in step S2, adding a refining agent for refining, and obtaining an alloy melt;

[0022] S4. Cooling, dispersing and pouring: After the melt is cooled to a certain temperature (increase the flow rate of protective gas), stir it quickly, then heat the melt to a certain temperature and pour it to obtain a neuron bionic structure metal material.

[0023] As one embodiment of the present invention, in step S1, to ensure that the neuron-like planar and filamentary reinforcement phases bridge as much as possible to form a continuous and efficient network transmission structure, the volume ratio of the neuron-like planar reinforcement phase to the neuron-like filamentary reinforcement phase is 1:1-1:3, and the volume percentage of the neuron-like reinforcement phase in the metal material is 1%-20%. To construct a neuron-like network transmission structure, the proportion of the neuron-like filamentary reinforcement phase should be greater than the neuron-like planar reinforcement phase, that is, greater than 1:1. A ratio of less than 1:3 can facilitate the effective connection of as many neuron-like filamentary and planar reinforcement phases as possible.

[0024] As an embodiment of the present invention, in step S1, the pre-spreading of powder is to break through the surface tension of the melt and solve the problem of flammability of magnesium during the feeding process.

[0025] As an embodiment of the present invention, in step S1, the low-speed stirring rate is 50-100 r / min and the stirring time is 3-10 min. The low-speed stirring is to ensure the pre-lapping and preliminary dispersion of the reinforcing phase powder.

[0026] As an embodiment of the present invention, in step S2, the smelting temperature is 720-750°C.

[0027] As an embodiment of the present invention, in step S3, the temperature is adjusted to 740-760°C.

[0028] As an embodiment of the present invention, in step S3, the refining agent includes at least one of RJ-6, JDMJ, and HE. After refining is completed, the oxidized slag on the surface of the melt is removed.

[0029] As an embodiment of the present invention, in step S4, the melt is cooled to 560-10101°C. For different alloys, magnesium alloys are cooled to 620-6501°C, aluminum alloys are cooled to 560-6601°C, and copper alloys are cooled to 810-10101°C.

[0030] As some embodiments of the present invention, in step S4, the magnesium alloy melt is cooled to 620-6501°C. If the stirring temperature is too high, the magnesium melt is prone to oxidation and combustion; if the stirring temperature is too low (below the solidus line), solidification will occur. Therefore, the stirring temperature range should be selected in the semi-solid temperature range of the magnesium alloy.

[0031] As an embodiment of the present invention, in step S4, the flow rate of the protective gas is increased during the rapid stirring process, and the protective gas includes at least one of a mixed gas (99 vol.% CO2+1 vol.% SF6) or argon.

[0032] As an embodiment of the present invention, in step S4, the rapid stirring rate is 200-1000 r / min and the rapid stirring time is 5-15 min. Rapid stirring is performed to ensure that the neuron-like structure reinforcement phase is uniformly dispersed in the matrix material.

[0033] As an embodiment of the present invention, in step S4, the temperature is raised to 710-730° C. for pouring.

[0034] In a second aspect, the present invention provides a high electrical and thermal conductive metal material based on a neuron bionic structure obtained by the preparation method.

[0035] Different from the existing high-conductivity and thermal conductivity metal material preparation technologies such as powder metallurgy + extrusion, firstly, the design method of the present invention can further improve the reinforcement efficiency due to the mutual bridging of the planar and filamentous reinforcement phases of the neuron-like structure to form a continuous and efficient transmission path; secondly, the high-conductivity and thermal conductivity metal material prepared by this method is isotropic; thirdly, the introduced neuron network heat transfer structure can also give full play to the electrical and thermal conductivity potential of the anisotropic conductive reinforcement phase.

[0036] Compared with the prior art, the present invention has the following beneficial effects:

[0037] 1. Highly efficient conductivity enhancement. Metal materials with neuron-inspired structures exhibit superior conductivity compared to metal materials with a single reinforcement phase. This synergistic enhancement effect stems from the neuron-inspired continuous mesh conduction structure (i.e., the neuron-inspired continuous mesh transmission structure). Electrons and phonons can be continuously transmitted along this path, reducing their scattering probability in low-conductivity substrates. This synergistic enhancement effect also reduces the total amount of reinforcement phase required to achieve a given conductivity indicator, thereby improving material utilization and reducing material costs.

[0038] 2. Isotropic conductivity. Compared to metal materials produced using processes such as powder metallurgy and deformation, the anisotropy of their conductivity is determined by factors such as the deformation process and texture. Deformation processes such as extrusion and rolling lead to anisotropy in the metal material's structure, which directly causes anisotropy in its conductivity. However, the neuron-inspired metal material produced by the present invention exhibits isotropic conductivity in all directions.

[0039] 3. Give full play to the electrical and thermal conductivity potential of the anisotropic reinforcing phase. The high electrical and thermal conductivity reinforcing phase in the metal material is often anisotropic, and the conduction capacity along the plane (radial) and perpendicular to the plane (axial) varies greatly (two orders of magnitude). The mutual connection of the neuron bionic structure reinforcing phase in the present invention can give full play to the electrical and thermal conductivity potential of the anisotropic reinforcing phase.

[0040] 4. This invention proposes a new structural design strategy for highly conductive and thermally conductive metal materials. By designing a neuron-inspired continuous, efficient, and mesh-like conductive structure, a highly conductive and thermally conductive metal material with high reinforcement efficiency and excellent isotropy is achieved. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Other features, objects and advantages of the present invention will become more apparent upon reading the detailed description of non-limiting embodiments with reference to the following drawings:

[0042] Figure 1 The neuron-like continuous network transmission structure of the magnesium-based material prepared in Example 1;

[0043] Figure 2 The two-dimensional and three-dimensional microstructures of the magnesium-based material structure and neuron structure prepared in Example 1. DETAILED DESCRIPTION

[0044] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. The following examples are implemented under the premise of the technical solution of the present invention, provide detailed implementation methods and specific operating procedures, and will help those skilled in the art to further understand the present invention. It should be pointed out that the scope of protection of the present invention is not limited to the following embodiments, and a number of adjustments and improvements made under the premise of the concept of the present invention all fall within the scope of protection of the present invention.

[0045] Example 1

[0046] SA42 magnesium alloy is used as the matrix (tested, its conductivity is 16.1×10 6 S / m, thermal conductivity is 110W / (m·K)), 2.5vol.% high electrical and thermal conductivity neuron-like filamentous carbon fiber reinforcement phase and 2.5vol.% neuron-like planar graphite sheet reinforcement phase are added to construct Figure 1 The neuron-inspired high electrical and thermal conductivity structure (i.e., the neuron-inspired continuous mesh transmission structure) shown in FIG. specifically includes the following steps:

[0047] S1. Pre-powdering: In order to solve the problems of melt surface tension and flammability of magnesium during the charging process, 2.5 vol.% neuron-like filamentous carbon fibers and 2.5 vol.% neuron-like planar graphite sheets were added to the bottom of the melting crucible in advance, and mechanically stirred at a low speed of 50 r / min for 5 minutes to ensure the pre-overlapping and preliminary dispersion of the reinforcing phase powder.

[0048] S2, smelting: adding SA42 magnesium alloy to the smelting crucible of step S1 and smelting at 720° C. to prepare alloy melt;

[0049] S3, refining: adjusting the temperature of the alloy melt obtained in step S2 to 740° C., adding refining agent RJ-6 for refining, and removing the slag on the surface of the melt after refining to obtain an alloy melt;

[0050] S4, cooling, dispersion and pouring: When the melt is cooled to 650℃, stir at 500r / min for 10min. After stirring, pour when the temperature rises to 720℃ to obtain a neuron-like high electrical and thermal conductivity isotropic magnesium-based material. Its structure is compared with the neuron structure. Figure 2 During the stirring process, the flow rate of the mixed protective gas (99 vol.% CO2+1 vol.% SF6) was increased.

[0051] Samples were taken longitudinally and transversely from the bottom of the magnesium-based material to test electrical and thermal conductivity.

[0052] Comparative Example 1

[0053] The preparation steps of this comparative example are basically the same as those of Example 1, except that in step S3, 5 vol.% of neuron-like filamentous carbon fiber reinforcement phase is added.

[0054] Samples were taken horizontally and vertically from the bottom of the magnesium-based material to test the electrical and thermal conductivity.

[0055] Comparative Example 2

[0056] The preparation steps of this comparative example are basically the same as those of Example 1, except that: in step S3, 5 vol.% of a planar graphite sheet reinforcement phase with a simulated neuron structure is added.

[0057] Samples were taken horizontally and vertically from the bottom of the magnesium-based material to test the electrical and thermal conductivity.

[0058] Comparative Example 3

[0059] Using SA42 magnesium alloy powder as the matrix, 2.5 vol.% of highly conductive and thermally conductive neuron-like filamentous carbon fibers and 2.5 vol.% of neuron-like planar graphite flakes were added as reinforcements through ball milling, hot pressing, and extrusion. The ball milling speed was 300 r / min; the hot pressing was performed at a temperature of 522°C and a pressure of 30 MPa under vacuum; and the extrusion process was performed at a temperature of 350°C and an extrusion ratio of 25:1, all conventional techniques in the art.

[0060] Samples were taken from the bottom of the magnesium-based material in the transverse direction (parallel to the extrusion direction) and the longitudinal direction (perpendicular to the extrusion direction) to test the electrical conductivity and thermal conductivity.

[0061] Performance Testing

[0062] Test method: Test the conductivity (electrical conductivity and thermal conductivity) of the material at room temperature (25°C). The electrical conductivity of the composite material was measured at room temperature using the eddy current method (Sigma 2008A). The thermal diffusivity α was measured using a laser transient thermal conductivity meter (LFA467HT). By comparing the standard samples (Cu, ) to test the specific heat capacity C p The density ρ was measured by an electronic density meter (ET-320). The thermal conductivity λ is given by λ=ραC p The test results are shown in Table 1 and Table 2.

[0063] Table 1 Electrical conductivity of magnesium-based materials in Examples and Comparative Examples

[0064] sample <![CDATA[Longitudinal conductivity / 10 6 S·m -1 > Enhanced efficiency <![CDATA[Transverse conductivity / 10 6 S·m -1 > Enhanced efficiency Example 1 19.7 22.3％ 19.7 22.3％ Comparative Example 1 17.8 10.6％ 18.0 11.8％ Comparative Example 2 17.7 9.9％ 17.6 9.3％ Comparative Example 3 16.5 2.5％ 17.1 6.2％

[0065] Table 2 Thermal conductivity of magnesium-based materials in Examples and Comparative Examples

[0066] sample <![CDATA[Longitudinal thermal conductivity / W·(m·K) -1 > Enhanced efficiency <![CDATA[Transverse thermal conductivity / W·(m·K) -1 > Enhanced efficiency Example 1 135 22.7％ 137 24.5％ Comparative Example 1 125 13.6％ 126 14.5％ Comparative Example 2 122 10.9％ 121 10.0％ Comparative Example 3 113 2.7％ 117 6.5％

[0067] In summary, according to comparative examples 1-2, it can be seen that the metal material prepared by only introducing a planar reinforcing phase of a neuron-like structure or a filamentous reinforcing phase of a neuron-like structure into the matrix cannot construct a neuron-like continuous network transmission structure, resulting in its electrical conductivity and thermal conductivity being much lower than that of Example 1. At the same time, the planar reinforcing phase of a neuron-like structure and the filamentous reinforcing phase of a neuron-like structure are introduced into the matrix; according to comparative example 1, it can be seen that the use of traditional hot pressing sintering and extrusion processes to introduce the planar reinforcing phase of a neuron-like structure and the filamentous reinforcing phase of a neuron-like structure will cause anisotropy in the conductive properties of the metal material, resulting in lower electrical conductivity and thermal conductivity.

[0068] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art may make various variations or modifications within the scope of the claims, which do not affect the essence of the present invention.

Claims

1. A method for preparing a high-electrical and thermal-conductive metal material based on a neuron bionic structure, characterized in that: Introducing a neuron-like structure reinforcement phase into the matrix material, wherein the neuron-like structure reinforcement phase includes a neuron-like structure planar reinforcement phase and a neuron-like structure filament reinforcement phase, and the neuron-like structure reinforcement phase is uniformly dispersed in the matrix material; The preparation method comprises the following steps: S1, pre-spreading powder: add the neuron-like structure reinforcement phase at the bottom of the melting device and stir at low speed; S2, smelting: adding the raw alloy to the smelting device of step S1, and smelting to prepare an alloy melt; S3, refining: adjusting the temperature of the alloy melt obtained in step S2, adding a refining agent for refining, and obtaining an alloy melt; S4, cooling, dispersing and pouring: After the melt is cooled to a certain temperature, it is quickly stirred, and then the melt is heated to a certain temperature and poured to obtain a neuron bionic structure metal material; In step S1, the low-speed stirring speed is 50-100 r / min, and the stirring time is 3-10 min; In step S4, the rapid stirring speed is 200-1000 r / min, and the rapid stirring time is 5-15 min.

2. The preparation method according to claim 1, characterized in that The volume percentage of the neuron-like structure reinforcement phase in the metal material is 1%-20%, and the volume ratio of the neuron-like structure planar reinforcement phase to the neuron-like structure filament reinforcement phase is 1:1-1:

3.

3. The preparation method according to claim 1, characterized in that The neuron-like structure planar reinforcement phase includes at least one of graphite sheets, silicon carbide, aluminum nitride, diamond, copper foil, aluminum foil, silver foil, and gold foil.

4. The preparation method according to claim 1, characterized in that The neuron-like structure filamentous reinforcement phase includes at least one of carbon fiber, copper wire, silver wire and gold wire.

5. The preparation method according to claim 1, characterized in that The matrix material includes at least one of magnesium alloy, aluminum alloy and copper alloy.

6. The preparation method according to claim 1, characterized in that In step S4, the melt is cooled to 560-1030°C.

7. A high electrical and thermal conductive metal material based on a neuron bionic structure obtained by the preparation method according to any one of claims 1 to 6.

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