A method for producing a stepped-pore aluminum alloy material having tubular cell micro-holes

Abstract

The application relates to the field of porous metal material preparation, in particular to a preparation method of a stepped-pore aluminum alloy material with tubular cell micropores, raw materials of which include pure aluminum powder, manganese powder, copper powder, titanium powder, titanium hydride powder and wood fiber powder; wherein the preparation process is as follows: (1) mixing the powders according to three proportions to form mixed powders; (2) pouring the mixed powders into a mold for three times to carry out layered pre-pressing and overall compaction; (3) sintering, quenching the compacted precursor to obtain the stepped-pore aluminum alloy material with tubular cell micropores; the preparation process is simple, the process steps are less, the cost is low, and the stepped-pore aluminum alloy material with tubular cell micropores meets the use requirements of the automobile industry.

Description

Technical fields:

[0001] This invention relates to the field of porous metal material preparation, and in particular to a method for preparing a stepped-porous aluminum alloy material with tracheid micropores. Background technology:

[0002] A method for preparing a stepped porous aluminum alloy material with tracheid micropores is mainly used to solve the impact resistance problem of battery pack shells for new energy vehicles. The high porosity of the porous material improves the energy absorption characteristics of the material. The different porosity of each layer of the stepped pores can achieve simultaneous compression of multiple layers, further improving the energy absorption capacity. The tracheid micropores have the characteristics of wood fibers, which can improve the structural support of the porous material.

[0003] Currently, porous metallic materials possess advantages such as low density, high porosity, and large specific surface area, making them widely used in industries such as construction, metallurgy, and medicine. Porous aluminum alloys are also used in the automotive industry as cushioning materials to ensure vehicle safety. However, current porous aluminum alloys are primarily homogeneous pores. Under impact or collision, their pore structure collapses rapidly from the impact surface, resulting in poor short-term energy absorption. Furthermore, mainstream porous aluminum alloys have relatively low strength and poor support, which needs improvement for their application in the automotive industry. Therefore, developing porous aluminum alloy materials that better meet the needs of the automotive industry is an inevitable trend in industry development. Summary of the Invention:

[0004] In order to overcome the shortcomings and deficiencies of the existing technology, the purpose of this invention is to provide a method for preparing a stepped porous aluminum alloy material with tracheid micropores. Pure aluminum powder is mixed with various metal powders such as manganese powder, copper powder, and titanium powder. By using titanium hydride as a foaming agent and wood fiber as a pore-forming agent, the mixed powder is powder metallurgically processed in three layers with different proportions. This allows the material to have tracheid micropores while utilizing pores, thereby improving the energy absorption effect.

[0005] The technical solution provided by this invention is:

[0006] A method for preparing a stepped-porosity aluminum alloy material with tracheid micropores, comprising a mixed powder made from the following raw materials in parts by weight:

[0007] The material has a three-layered stepped pore structure, and the proportions of the three layers of the mixed powder are different:

[0008] Layer 1: Pure aluminum powder: 100-110 parts

[0009] Manganese powder: 2-4 parts

[0010] Copper powder: 4-6 parts

[0011] Titanium powder: 7-10 parts

[0012] Titanium hydride powder: 8-12 parts

[0013] Wood fiber powder: 2-3 parts

[0014] Second layer: Pure aluminum powder: 100-110 parts

[0015] Manganese powder: 2-4 parts

[0016] Copper powder: 4-6 parts

[0017] Titanium powder: 7-10 parts

[0018] Titanium hydride powder: 8-12 parts

[0019] Wood fiber powder: 4-5 parts

[0020] Three layers: Pure aluminum powder: 100-110 parts

[0021] Manganese powder: 2-4 parts

[0022] Copper powder: 4-6 parts

[0023] Titanium powder: 7-10 parts

[0024] Titanium hydride powder: 8-12 parts

[0025] Wood fiber powder: 6-7 parts

[0026] The method for preparing the mixed powder includes the following steps:

[0027] (1) The wood fiber powder is treated with polyethylene glycol to reduce the agglomeration of wood fibers in the mixture;

[0028] (2) The three powders in the above proportions are mixed for 12 hours respectively, and the mixture is taken out to obtain three layers of the required mixed powder.

[0029] The preparation method of the precursor of the stepped-porosity aluminum alloy material with tracheid micropores includes the following steps:

[0030] (1) Pour the mixed powder into the mold in three layers, and pre-press it after each layer is poured in to ensure that the powder between each layer does not mix;

[0031] (2) The three layers of mixed powder are compacted in the mold to obtain the precursor of the stepped porous aluminum alloy material with tracheid micropores.

[0032] The preparation method of the stepped-porosity aluminum alloy material with tracheid micropores is as follows:

[0033] (1) The compacted precursor of the stepped porous aluminum alloy material with tracheid micropores is placed in an air environment and sintered in a tube furnace.

[0034] (2) After sintering for 5-10 minutes, the material is quenched in water to obtain the stepped porous aluminum alloy material with tracheid micropores.

[0035] The preparation mechanism of the stepped porous aluminum alloy material with tracheid micropores of the present invention is as follows: the melting point of aluminum is about 660℃, while the melting points of manganese, copper, and titanium are 1246℃, 1084.6℃, and 1668℃, respectively. That is, at 800℃ in the tube furnace, the aluminum can reach a molten state, while the manganese powder, copper powder, and titanium powder do not reach a molten state and can form reinforcing particles, improving the mechanical properties of the material. Furthermore, the carbonization temperature of wood fiber is 250-350℃, and the decomposition start temperature of titanium hydride is about 600℃. This leads to the carbonization and decomposition of wood fiber, which can form carbonized tracheid micropores in the metal. Further, the titanium hydride powder decomposes to produce hydrogen gas, which forms pores during the dispersion process. In this process, the stepped porous aluminum alloy material with tracheid micropores is finally formed.

[0036] The wood fiber is 20 mesh. At 20 mesh, the fiber has a relatively complete tracheid structure. The tracheid structure increases micropores and connects pores. By changing the wood fiber content in each layer, the number of tracheid structures in each layer can be increased, and the connectivity of pores in each layer can be changed. In addition, the wood fiber has the function of blocking hydrogen gas from escaping, thereby changing the pore structure of each layer and forming a stepped pore.

[0037] The particle size of the pure aluminum powder is 0-20 μm.

[0038] The manganese powder, copper powder, and titanium powder are all 500 mesh, and the titanium hydride powder is 350 mesh.

[0039] In the process of pressing the precursor of the stepped porous aluminum alloy material with tracheid micropores, manual pre-pressing is required after each layer is placed in the mold to ensure that each layer is initially compacted. After all three layers are pre-pressed, they are finally compacted for 10-15 minutes under a jack of 40MPa-45MPa.

[0040] In step (1) of the preparation method of the stepped porous aluminum alloy material with tracheid micropores, the sintering temperature is 800℃.

[0041] The preparation method of the stepped porous aluminum alloy material with tracheid micropores as described above includes the following steps: mixing aluminum powder, manganese powder, copper powder, titanium powder, titanium hydride powder and wood fiber powder in three proportions, then performing a pre-pressing process for each layer and a room temperature pressing process in the mold, and finally obtaining the stepped porous aluminum alloy material with tracheid micropores after sintering.

[0042] The beneficial effects of this invention: The present invention provides a method for preparing a stepped-porous aluminum alloy with tracheid micropores. The mechanism is as follows: Aluminum has a melting point of approximately 660℃, while manganese, copper, and titanium have melting points of 1246℃, 1084.6℃, and 1668℃, respectively. At 800℃ in the tubular furnace, aluminum reaches a molten state, while manganese, copper, and titanium powders do not, allowing them to form reinforcing particles and improve the material's mechanical properties. Furthermore, the carbonization temperature of wood fiber is 250-350℃, and the decomposition initiation temperature of titanium hydride is approximately 600℃. This leads to the formation of carbonized tracheid micropores within the metal during the carbonization and decomposition of the wood fiber. Further, the decomposition of titanium hydride powder generates hydrogen gas, which forms pores during its dissipation. This process ultimately results in the formation of the stepped-porous aluminum alloy with tracheid micropores. The material prepared by this method introduces tracheid micropores, resulting in good overall structural support, high compressive strength, and good energy absorption, meeting the requirements of the automotive industry. Attached image description:

[0043] Figure 1 This is a macroscopic electron microscope image of the material obtained by the preparation method of the stepped porous aluminum alloy with tracheid micropores of the present invention.

[0044] Figure 2 This is a scanning electron microscope (SEM) image of the material obtained by the preparation method of the stepped porous aluminum alloy with tracheid micropores of the present invention.

[0045] Figure 3 This is an energy dispersive spectroscopy (EDS) image of the material obtained by the preparation method of the stepped-porosity aluminum alloy with tracheid micropores according to the present invention.

[0046] Figure 4 This is the compressive strength test curve of the material obtained by the preparation method of the stepped porous aluminum alloy with tracheid micropores of the present invention.

[0047] Figure 5 This is the energy absorption capacity curve of the material obtained by the preparation method of the stepped porous aluminum alloy with tracheid micropores of the present invention.

[0048] Figure 6 This is a schematic flowchart of the preparation method of the stepped porous aluminum alloy material with tracheid micropores of the present invention.

[0049] The present invention will now be described in detail with reference to the accompanying drawings:

[0050] As shown in the attached figure, a method for preparing a stepped-porosity aluminum alloy material with tracheid micropores includes pure aluminum powder, manganese powder, copper powder, titanium powder, titanium hydride powder, and wood fiber powder as raw materials, and the steps are as follows:

[0051] (1) The wood fiber powder is treated with polyethylene glycol to reduce the agglomeration of wood fibers in the mixture;

[0052] (2) The three powders in the above proportions are mixed for 12 hours respectively, and the mixture is taken out to obtain three layers of the required mixed powder.

[0053] (3) Pour the mixed powder into the mold in three layers, and pre-press it after each layer is poured in to ensure that the powder between each layer does not mix;

[0054] (4) The three-layer mixed powder is compacted in the mold to obtain a precursor of stepped porous aluminum alloy material with tracheid micropores;

[0055] (5) The compacted precursor of the stepped porous aluminum alloy material with tracheid micropores is placed in an air environment and sintered in a tube furnace.

[0056] (6) After sintering for 5-10 minutes, the material is quenched in water to obtain the stepped porous aluminum alloy material with tracheid micropores.

[0057] The ratio of the three layers of mixed powder is as follows:

[0058] ① Pure aluminum powder: manganese powder: copper powder: titanium powder: titanium hydride powder: wood fiber powder = 100:2:4:7:8 / 10:2;

[0059] ② Pure aluminum powder: manganese powder: copper powder: titanium powder: titanium hydride powder: wood fiber powder = 100:2:4:7:8 / 10:4;

[0060] ③ Pure aluminum powder: manganese powder: copper powder: titanium powder: titanium hydride powder: wood fiber powder = 100:2:4:7:8 / 10:6;

[0061] Two sample ratios of the mixed powder were obtained respectively.

[0062] The wood fiber is 20 mesh. At 20 mesh, the fiber has a relatively complete tracheid structure. The tracheid structure increases micropores and connects pores. By changing the wood fiber content in each layer, the number of tracheid structures in each layer can be increased, and the connectivity of pores in each layer can be changed. In addition, the wood fiber has the function of blocking hydrogen gas from escaping, thereby changing the pore structure of each layer and forming a stepped pore.

[0063] The aluminum alloy powder has a particle size of 0-20 μm.

[0064] The manganese powder, copper powder, and titanium powder are all 500 mesh, and the titanium hydride powder is 350 mesh.

[0065] The mixed powder is compacted in the mold for 10-15 minutes under a jack with a pressure of 40MPa-45MPa.

[0066] The precursor sintering temperature of the stepped porous aluminum alloy material with tracheid micropores is 800℃.

[0067] The present invention discloses a method for preparing stepped porous aluminum alloy with tracheid micropores. The prepared material has diverse pores. The introduction of reinforcing particles and tracheid micropores increases the compressive strength and energy absorption capacity of the material. The preparation process is simple, has fewer process steps, and has lower cost, which meets the requirements of the automotive industry.

[0068] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for preparing a stepped-porosity aluminum alloy material with tracheid micropores, characterized in that, The raw materials include pure aluminum powder, manganese powder, copper powder, titanium powder, titanium hydride powder, and wood fiber powder. The preparation steps are as follows: (1) The wood fiber powder is treated with polyethylene glycol to reduce the agglomeration of wood fibers in the mixture; (2) Mix the pure aluminum powder, manganese powder, copper powder, titanium powder, titanium hydride powder and wood fiber powder in three proportions for 12 hours respectively, and then take them out to obtain three layers of the required mixed powder. (3) Pour the mixed powder into the mold in three layers, and pre-press it after each layer is poured in to ensure that the powder between each layer does not mix; (4) The three-layer mixed powder is compacted in the mold to obtain a precursor of stepped porous aluminum alloy material with tracheid micropores; (5) The compacted precursor of the stepped porous aluminum alloy material with tracheid micropores is placed in an air environment and sintered in a tube furnace. (6) After sintering for 5-10 minutes, the material is quenched in water to obtain the stepped porous aluminum alloy material with tracheid micropores.

2. The method for preparing a stepped-porosity aluminum alloy material with tracheid micropores according to claim 1, characterized in that: The proportions of the mixed powders in the three layers are as follows: ① Pure aluminum powder: manganese powder: copper powder: titanium powder: titanium hydride powder: wood fiber powder = 100:2:4:7:8 / 10:2; ② Pure aluminum powder: manganese powder: copper powder: titanium powder: titanium hydride powder: wood fiber powder = 100:2:4:7:8 / 10:4; ③ Pure aluminum powder: manganese powder: copper powder: titanium powder: titanium hydride powder: wood fiber powder = 100:2:4:7:8 / 10:6; Two sample ratios of the mixed powder were obtained respectively.

3. The method for preparing a stepped-porosity aluminum alloy material with tracheid micropores according to claim 1, characterized in that: The wood fiber is 20 mesh. At 20 mesh, the fiber has a relatively complete tracheid structure. The tracheid structure increases micropores and connects pores. By changing the wood fiber content in each layer, the number of tracheid structures in each layer can be increased, the connectivity of pores in each layer can be changed, and the wood fiber has the function of blocking hydrogen gas from escaping, thereby changing the pore structure of each layer and forming a stepped pore.

4. The method for preparing a stepped-porosity aluminum alloy material with tracheid micropores according to claim 1, characterized in that: The mixed powder is finally compacted in the mold under a jack of 40MPa-45MPa for 10-15 minutes.

5. The method for preparing a stepped-porosity aluminum alloy material with tracheid micropores according to claim 1, characterized in that: The precursor sintering temperature of the stepped porous aluminum alloy material with tracheid micropores is 800℃.

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