Cu@basalt fiber / porous aluminum composite material and preparation method thereof

Abstract

This invention discloses a Cu@basalt fiber / porous aluminum composite material and its preparation method, belonging to the field of material preparation technology. The method of this invention utilizes diffusion between copper atoms on the surface of basalt fibers and aluminum atoms in the porous aluminum matrix to generate a metallurgical bonding interface, improving the interfacial bonding force. This results in a material with both high strength and high sound absorption properties, meeting the application requirements in sound absorption and noise reduction technologies. The obtained material has a porosity of 81.71%–83.38%, a pore size of 0.4 mm–0.5 mm, a basalt fiber volume fraction of 7 vol.%–8 vol.%, a fiber diameter of 20 μm–30 μm, and a fiber length of 1 mm–2 mm. The compressive yield strength of the in-situ diffusion metallurgically reinforced Cu@basalt fiber / porous aluminum composite material can reach 4.71 MPa–5.37 MPa, which is 5.4%–7.62% higher than that of basalt fiber / porous aluminum composite materials with the same porosity and pore size.

Description

Technical Field

[0001] This invention belongs to the field of porous sound-absorbing composite materials, and in particular relates to a Cu@basalt fiber / porous aluminum composite material and its preparation method. Background Technology

[0002] Noise pollution has become a serious environmental problem, and its harm to people's daily behavior and mental health is increasing. In order to reduce noise pollution, related sound-absorbing materials have emerged and are constantly developing.

[0003] Currently, common porous metal sound-absorbing materials include porous aluminum, porous copper, porous magnesium, porous iron, and porous titanium. Among them, porous aluminum, due to its advantages such as light weight, low density, high specific strength, and strong heat exchange and dissipation capacity, is widely used in various sound-absorbing and energy-absorbing materials in aerospace, transportation, and construction industries, such as engine (electric) covers and sound barriers. However, due to its porous structure, porous aluminum has relatively low mechanical properties. Therefore, how to ensure its high sound absorption performance while also maintaining high strength is an important problem that needs to be solved.

[0004] To address the issue of the need for further improvement in the mechanical properties of porous sound-absorbing materials, this invention uses Cu@basalt fiber as the reinforcement and employs percolation and in-situ diffusion methods to induce atomic diffusion between copper atoms on the surface of the basalt fiber and aluminum atoms in the porous aluminum matrix, forming an in-situ diffusion metallurgical bonding interface. This fully utilizes the high strength characteristics of the reinforcement to enhance the interfacial bonding strength of the porous sound-absorbing material, resulting in an in-situ diffusion metallurgical reinforced Cu@basalt fiber / porous aluminum composite material with both high strength and high sound absorption performance. Summary of the Invention

[0005] To address the problems described in the technical background, the present invention aims to provide a Cu@basalt fiber / porous aluminum composite material. This composite material uses AlSi12 alloy as the matrix and Cu@basalt fiber as the reinforcement. A Cu-Al interfacial diffusion layer is formed using percolation and in-situ diffusion methods to obtain an in-situ diffusion-reinforced Cu@basalt fiber / porous aluminum composite material. The thickness of the Cu-Al interfacial diffusion layer is 0.071 μm to 1.23 μm, and the porosity is 81.71% to 83.38%. The volume fraction of basalt fiber in the Cu@basalt fiber / porous aluminum composite material is 7 vol.% to 8 vol.%.

[0006] The in-situ diffusion metallurgically reinforced Cu@basalt fiber / porous aluminum composite material of this invention exhibits a compressive yield strength of 4.71 MPa to 5.37 MPa, which is 5.4% to 7.62% higher than that of basalt fiber / porous aluminum composite materials with the same porosity and pore size.

[0007] The thickness of the Cu-Al interface diffusion layer is 0.071 μm to 1.23 μm, the volume fraction of basalt fiber in the Cu@basalt fiber / porous aluminum composite material is 7 vol.% to 8 vol.%, and the porosity is 81.71% to 83.38%.

[0008] The purpose of this invention is to provide a method for preparing the Cu@basalt fiber / porous aluminum composite material, which forms a metallurgical bonding interface through atomic diffusion. This interface has good bonding performance and can effectively improve the overall strength of the material. The method involves copper plating of basalt fibers, mixing the copper-plated basalt fibers with salt, pressing them into a preform, percolating the preform with molten aluminum to obtain the Cu@basalt fiber / aluminum composite material, washing to remove salt, and then performing in-situ diffusion to obtain the Cu@basalt fiber / porous aluminum composite material. By controlling the diffusion temperature and time, only atomic diffusion occurs at the interface between the basalt fibers and the porous aluminum matrix without chemical reaction, thus avoiding the formation of intermediate phases and forming a Cu / Al interface diffusion layer. The specific steps include:

[0009] (1) Copper is plated on the surface of basalt fiber to obtain Cu@basalt fiber. Cu@basalt fiber and NaCl particles are mixed to obtain a mixture, and then pressed into a preform.

[0010] (2) After heating and melting AlSi12 alloy, aluminum alloy melt is pressed into the pores of preform by percolation method to prepare Cu@basalt fiber / aluminum composite material containing NaCl.

[0011] (3) The Cu@basalt fiber / aluminum composite material containing NaCl was obtained by dissolving NaCl in water to obtain Cu@basalt fiber / porous aluminum composite material.

[0012] (4) The Cu@basalt fiber / porous aluminum composite material was heated and diffused in situ, and then air-cooled to obtain Cu@basalt fiber / porous aluminum composite material with in situ diffusion metallurgical bonding reinforcement.

[0013] Preferably, in step (1) of the present invention, the NaCl particles are 0.4 mm to 0.5 mm in diameter, and the basalt fibers are 20 μm to 30 μm in diameter and 1 mm to 2 mm in length.

[0014] Preferably, in the mixture of step (1) of the present invention, the mass percentage of Cu@basalt fiber is 2% to 3% and the mass percentage of NaCl particles is 97% to 98%.

[0015] Preferably, the pressure applied during the preparation of the preform in step (1) of the present invention is 24 kN to 25.5 kN.

[0016] Preferably, the pressure used in the seepage method in step (2) of the present invention is 0.3MPa to 0.45MPa.

[0017] Preferably, in step (4) of the present invention, the in-situ diffusion temperature is 250℃~350℃ and the heat preservation time is 30~60min.

[0018] Preferably, the specific process of copper plating on the surface of the basalt fiber of the present invention is as follows:

[0019] (1) Basalt fiber is degreased and degummed, then washed with water; 3% to 5% NaOH is used for etching for 30 min to 45 min, followed by water washing; 0.2% to 0.5% SnCl2 is used for sensitization for 3 min to 5 min, followed by water washing; 0.05% to 0.1% silver ammonia solution is used for activation for 1 min to 3 min, followed by water washing.

[0020] (2) Electroless copper plating with sodium hypophosphite for 45 min to 60 min at 65℃~80℃ and pH value 9.5~11.0; the plating solution consists of: copper sulfate 15 g~30 g / L, sodium hypophosphite 15 g~25 g / L, nickel sulfate 0.5~0.8 g / L, citric acid 25 g~40 g / L, thiourea 1 mg~3 mg / L, boric acid 20 g~30 g / L, and polyethylene glycol (600) 0.05 g~0.1 g / L.

[0021] (3) Wash with water and dry.

[0022] AlSi12 alloy melt is pressed into the pores of a percolation preform to form an in-situ diffusion-metallurgically reinforced Cu@basalt fiber / porous aluminum composite material. On one hand, when the material is subjected to stress, the basalt fibers in the matrix deflect and displace, absorbing some of the compressive energy, transferring and dispersing stress, and reducing local stress concentration. Simultaneously, the basalt fibers can pin cracks and inhibit crack propagation, impede compressive strain, and alter the compression collapse path, thereby improving the in-situ diffusion-metallurgically reinforced Cu@basalt fiber / porous aluminum composite material. The compressive yield strength of porous aluminum composites is improved. On the other hand, copper and aluminum atoms undergo atomic diffusion at high temperatures, forming a metallurgical bonding interface. This interface tightly connects the basalt fiber and the matrix, effectively transferring stress between the fiber and the matrix, reducing stress concentration at the interface, and enhancing the overall strength, stiffness, and impact resistance of the material. At the same time, it improves the durability and stability of the composite material. Therefore, the metallurgical interface formed through atomic diffusion plays a key role in interfacial reinforcement in in-situ diffusion metallurgically reinforced Cu@basalt fiber / porous aluminum composites.

[0023] Inventive Principles

[0024] (1) Principle of controlling the thickness of diffusion layer at metallurgical interface:

[0025] Through the in-situ diffusion of copper atoms on basalt fibers and aluminum atoms in the porous aluminum matrix at high temperatures, a stable and uniform metallurgical bonding interface is formed between the basalt fibers and the aluminum alloy matrix. This interface is a solid solution diffusion interface of Cu and Al, with no brittle phase formation, thus improving the overall strength of the material.

[0026] For planar diffusion, the diffusion thickness model is as follows:

[0027]

[0028] Where D0 is the diffusion constant (unit: m). 2 / s), Q is the activation energy (unit: kJ / mol), and R is the gas constant (unit: J·K). -1 T is absolute temperature (unit: K).

[0029] Since the diffusion rate of aluminum in copper is much greater than the diffusion rate of copper in aluminum, it can be approximated as aluminum diffusing in copper, taking D0≈1.6×10 -5 m 2 / s, Q≈136KJ / mol, R=8.314J·K -1 The diffusion layer thickness under different temperature and time conditions can be obtained at 250℃ (523K) for 30 min and 350℃ (623K) for 60 min.

[0030] (2) In-situ diffusion composite enhancement principle:

[0031] In the in-situ diffusion composite process, the ideal interface between Cu@basalt fiber and aluminum matrix should only undergo in-situ diffusion, forming a uniform diffusion layer with a clean interface and no other brittle phases. The thickness, uniformity, and purity of the atomic diffusion layer determine the strength of the metallurgical bonding interface. When the temperature and time of in-situ diffusion exceed 350℃ and 60min, respectively, the θ phase (Al2Cu) is generated at the interface. It typically exhibits hard and brittle characteristics, with very poor ductility compared to aluminum and copper, and easily becomes a crack initiation source, thus weakening the interfacial bonding strength. Therefore, in-situ diffusion composite is used to control the in-situ diffusion time and temperature to prevent the formation of the θ phase.

[0032] By combining the Gibson-Ashby model with experimental data, the relationship between porosity and compressive yield strength of Cu@basalt fiber / porous aluminum composites can be obtained:

[0033]

[0034] Where, σ c Compressive yield strength (MPa) of Cu@basalt fiber / porous aluminum composite material. Porosity of Cu@basalt fiber / porous aluminum composite material.

[0035] The relationship between porosity and compressive yield strength of basalt fiber / porous aluminum composite materials with the same pore size (0.5 mm) is as follows:

[0036]

[0037] in, Compressive yield strength (MPa) of basalt fiber / porous aluminum composite material Porosity of basalt fiber / porous aluminum composite material.

[0038] Beneficial effects of the present invention

[0039] This invention obtains an in-situ diffusion-reinforced Cu@basalt fiber / porous aluminum composite material with a compressive yield strength of 4.71–5.37 MPa through a percolation method, which is 5.4%–7.62% higher than that of basalt fiber / porous aluminum composite materials with the same porosity and pore size. The metallurgical bonding interface is formed through atomic diffusion between copper atoms on the basalt fiber surface and aluminum atoms in the porous aluminum matrix, improving the interfacial bonding force. It has both high strength and high sound absorption properties, which can meet the application requirements of sound absorption and noise reduction technologies. Attached Figure Description

[0040] Figure 1 Flowchart of in-situ diffusion metallurgical bonding process for reinforcing Cu@basalt fiber / porous aluminum composite materials.

[0041] Figure 2 The images show SEM images (a) and (b) of basalt fibers from Example 2.

[0042] Figure 3 This is a macroscopic structural diagram of the in-situ diffusion metallurgical bonded reinforced Cu@basalt fiber / porous aluminum composite material in Example 2.

[0043] Figure 4 This is a SEM image of the in-situ diffusion metallurgical bonded reinforced Cu@basalt fiber / porous aluminum composite material in Example 2. Detailed Implementation

[0044] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited to the content described.

[0045] Example 1

[0046] This embodiment prepares an in-situ diffusion metallurgically reinforced Cu@basalt fiber / porous aluminum composite material through the following steps.

[0047] (1) Basalt fiber with a diameter of 20μm and a length of 1mm is used for degreasing and degumming.

[0048] (2) Basalt fiber pretreatment: deionized water cleaning, drying, dilute sulfuric acid etching, deionized water cleaning, and drying.

[0049] (3) At 65℃ and pH 10, copper was chemically plated for 45 min using a plating solution containing: 15 g / L copper sulfate, 15 g / L sodium hypophosphite, 0.5 g / L nickel sulfate, 25 g / L citric acid, 1 mg / L thiourea, 20 g / L boric acid, and 0.05 g / L polyethylene glycol (600) to obtain Cu@basalt fiber.

[0050] (4) Mix NaCl particles with a particle size of 0.5 mm and Cu@basalt fiber with a volume fraction of 8 vol.% and press them into a Cu@basalt fiber and salt particle mixed preform under a pressure of 24 kN.

[0051] (5) The AlSi12 alloy is heated to 650℃ to melt, and the AlSi12 alloy melt is pressed into the pores of the Cu@basalt fiber and salt particle mixed preform under a pressure of 0.4MPa to obtain salt-containing Cu@basalt fiber / aluminum composite material.

[0052] (6) Salt-containing Cu@basalt fiber / aluminum composite material was desalted by water dissolution to obtain Cu@basalt fiber / porous aluminum composite material with a porosity of 81.71%.

[0053] (7) Cu@basalt fiber / porous aluminum composite material was subjected to in-situ diffusion treatment at 250℃ for 30 min to allow atomic diffusion between copper atoms on the surface of Cu@basalt fiber and aluminum atoms in the porous aluminum matrix to form a metallurgical bonding interface. After air cooling, an in-situ diffusion metallurgically reinforced Cu@basalt fiber / porous aluminum composite material with an interface diffusion layer thickness of 0.017 μm and a compressive strength of 5.15 MPa was obtained. The compressive yield strength was increased by 6.2% compared with basalt fiber / porous aluminum composite material with the same porosity and pore size.

[0054] Example 2

[0055] This embodiment prepares an in-situ diffusion metallurgically reinforced Cu@basalt fiber / porous aluminum composite material through the following steps.

[0056] (1) Basalt fiber with a diameter of 20μm and a length of 1mm is used for degreasing and degumming.

[0057] (2) Basalt fiber pretreatment including deionized water cleaning, drying, dilute sulfuric acid etching, deionized water cleaning, and drying, such as... Figure 2 As shown in (a).

[0058] (3) Copper was chemically plated for 50 min at 70℃ and pH 10 using a plating solution containing: 15 g / L copper sulfate, 15 g / L sodium hypophosphite, 0.5 g / L nickel sulfate, 25 g / L citric acid, 1 mg / L thiourea, 20 g / L boric acid, and 0.05 g / L polyethylene glycol (600) to obtain Cu@basalt fibers. Figure 2 As shown in (b).

[0059] (4) Mix NaCl particles with a particle size of 0.5 mm and Cu@basalt fiber with a volume fraction of 8 vol.% and press them into a Cu@basalt fiber and salt particle mixed preform under a pressure of 24.5 kN.

[0060] (5) The AlSi12 alloy is heated to 650℃ to melt, and the AlSi12 alloy melt is pressed into the pores of the Cu@basalt fiber and salt particle mixed preform under a pressure of 0.4MPa to obtain salt-containing Cu@basalt fiber / aluminum composite material.

[0061] (6) Salt-containing Cu@basalt fiber / aluminum composite material was desalted by water dissolution, resulting in a Cu@basalt fiber / porous aluminum composite material with a porosity of 82.33%. Its macroscopic structure is as follows: Figure 3 As shown.

[0062] (7) Cu@basalt fiber / porous aluminum composite material was subjected to in-situ diffusion treatment at 250℃ for 30 min to induce atomic diffusion between copper atoms on the surface of Cu@basalt fiber and aluminum atoms in the porous aluminum matrix, forming a metallurgical bonding interface. After air cooling, an in-situ diffusion-reinforced Cu@basalt fiber / porous aluminum composite material sample with a diffusion layer thickness of 0.32 μm and a compressive strength of 5.37 MPa was obtained. Its compressive yield strength was 7.62% higher than that of basalt fiber / porous aluminum composite material with the same porosity and pore size. Its SEM image is shown below. Figure 4 As shown.

[0063] Example 3

[0064] This embodiment prepares in-situ diffusion metallurgically reinforced Cu@basalt fiber / porous aluminum composite material samples through the following steps.

[0065] (1) Basalt fiber with a diameter of 20μm and a length of 1mm is used for degreasing and degumming.

[0066] (2) Basalt fiber pretreatment: deionized water cleaning, drying, dilute sulfuric acid etching, deionized water cleaning, and drying.

[0067] (3) At 75℃ and pH 10, copper was electroplated for 55 min using a plating solution containing: 15 g / L copper sulfate, 15 g / L sodium hypophosphite, 0.5 g / L nickel sulfate, 25 g / L citric acid, 1 mg / L thiourea, 20 g / L boric acid, and 0.05 g / L polyethylene glycol (600) to obtain Cu@basalt fiber.

[0068] (4) Mix NaCl particles with a particle size of 0.5 mm and Cu@basalt fiber with a volume fraction of 8 vol.% and press them into a Cu@basalt fiber and salt particle mixed preform under a pressure of 25 kN.

[0069] (5) The AlSi12 alloy is heated to 650℃ to melt, and the AlSi12 alloy melt is pressed into the pores of the Cu@basalt fiber and salt particle mixed preform under a pressure of 0.4MPa to obtain salt-containing Cu@basalt fiber / aluminum composite material.

[0070] (6) Salt-containing Cu@basalt fiber / aluminum composite material was desalted by water dissolution to obtain Cu@basalt fiber / porous aluminum composite material with a porosity of 83.25%.

[0071] (7) Cu@basalt fiber / porous aluminum composite material was subjected to in-situ diffusion treatment at 250℃ for 30 min to allow atomic diffusion between copper atoms on the surface of Cu@basalt fiber and aluminum atoms in the porous aluminum matrix to form a metallurgical bonding interface. After air cooling, an in-situ diffusion metallurgically reinforced Cu@basalt fiber / porous aluminum composite material sample with a diffusion layer thickness of 0.87 μm and a compressive strength of 4.71 MPa was obtained. The compressive yield strength was increased by 5.4% compared with basalt fiber / porous aluminum composite material with the same porosity and pore size.

[0072] Example 4

[0073] This embodiment prepares an in-situ diffusion metallurgically reinforced Cu@basalt fiber / porous aluminum composite material through the following steps.

[0074] (1) Basalt fiber with a diameter of 20μm and a length of 1mm is used for degreasing and degumming.

[0075] (2) Basalt fiber pretreatment: deionized water cleaning, drying, dilute sulfuric acid etching, deionized water cleaning, and drying.

[0076] (3) At 80℃ and pH 10, copper was chemically plated for 60 min using a plating solution containing: 15 g / L copper sulfate, 15 g / L sodium hypophosphite, 0.5 g / L nickel sulfate, 25 g / L citric acid, 1 mg / L thiourea, 20 g / L boric acid, and 0.05 g / L polyethylene glycol (600) to obtain Cu@basalt fiber.

[0077] (4) Mix NaCl particles with a particle size of 0.5 mm and Cu@basalt fiber with a volume fraction of 8 vol.% and press them into a Cu@basalt fiber and salt particle mixed preform under a pressure of 25.5 kN.

[0078] (5) The AlSi12 alloy is heated to 650℃ to melt, and the AlSi12 alloy melt is pressed into the pores of the Cu@basalt fiber and salt particle mixed preform under a pressure of 0.4MPa to obtain salt-containing Cu@basalt fiber / aluminum composite material.

[0079] (6) Salt-containing Cu@basalt fiber / aluminum composite material was desalted by water dissolution to obtain Cu@basalt fiber / porous aluminum composite material with a porosity of 83.38%.

[0080] (9) Cu@basalt fiber / porous aluminum composite material was subjected to in-situ diffusion treatment at 250℃ for 30 min to induce atomic diffusion between copper atoms on the surface of Cu@basalt fiber and aluminum atoms in the porous aluminum matrix to form a metallurgical bonding interface. After air cooling, an in-situ diffusion metallurgically reinforced Cu@basalt fiber / porous aluminum composite material sample with a diffusion layer thickness of 1.23 μm and a compressive strength of 4.74 MPa was obtained. The compressive yield strength was increased by 5.8% compared with basalt fiber / porous aluminum composite material with the same porosity and pore size.

Claims

1. A method for preparing Cu@basalt fiber / porous aluminum composite material, characterized in that: The process involves copper plating of basalt fibers, mixing the copper-plated basalt fibers with salt, pressing them into a preform, and then percolating the preform with molten aluminum to obtain a Cu@basalt fiber / aluminum composite material. After washing to remove the salt, in-situ diffusion is performed to obtain a Cu@basalt fiber / porous aluminum composite material. By controlling the diffusion temperature and time, only atomic diffusion occurs at the interface between the basalt fibers and the porous aluminum matrix, without chemical reaction, thus avoiding the formation of intermediate phases. This results in a Cu / Al interface diffusion layer, leading to an in-situ diffusion metallurgically bonded and reinforced Cu@basalt fiber / porous aluminum composite material. The preparation method specifically includes the following steps: (1) Copper is plated on the surface of basalt fiber to obtain Cu@basalt fiber. Cu@basalt fiber and NaCl particles are mixed to obtain a mixture, and then pressed into a preform. (2) After heating and melting AlSi12 alloy, aluminum alloy melt is pressed into the pores of preform by percolation method to prepare Cu@basalt fiber / aluminum composite material containing NaCl. (3) The Cu@basalt fiber / aluminum composite material containing NaCl was dissolved in water to remove NaCl and obtain Cu@basalt fiber / porous aluminum composite material; (4) The Cu@basalt fiber / porous aluminum composite material was heated and diffused in situ. After air cooling, the Cu@basalt fiber / porous aluminum composite material with in situ diffusion metallurgical bonding reinforcement was obtained. The in situ diffusion temperature was 250℃~350℃ and the holding time was 30~60min. The composite material uses AlSi12 alloy as the matrix and Cu@basalt fiber as the reinforcement. A Cu-Al interface diffusion layer is formed by percolation and in-situ diffusion methods to obtain an in-situ diffusion metallurgically reinforced Cu@basalt fiber / porous aluminum composite material. The thickness of the Cu-Al interface diffusion layer is 0.071µm~1.23µm, the porosity is 81.71%~83.38%, and the volume fraction of basalt fiber in the Cu@basalt fiber / porous aluminum composite material is 7 vol.%~8 vol.%.

2. The preparation method of Cu@basalt fiber / porous aluminum composite material according to claim 1, characterized in that: In step (1), the NaCl particles are 0.4 mm to 0.5 mm in diameter, and the basalt fibers are 20 µm to 30 µm in diameter and 1 mm to 2 mm in length.

3. The preparation method of Cu@basalt fiber / porous aluminum composite material according to claim 1, characterized in that: In step (1), the mass percentage of Cu@basalt fiber in the mixture is 2%~3%, and the mass percentage of NaCl particles is 97%~98%.

4. The preparation method of Cu@basalt fiber / porous aluminum composite material according to claim 1, characterized in that: The pressure applied during the preparation of the preform in step (1) is 24 kN to 25.5 kN.

5. The method for preparing Cu@basalt fiber / porous aluminum composite material according to claim 1, characterized in that: The pressure used in the seepage method in step (2) is 0.3MPa~0.45MPa.

6. The preparation method of Cu@basalt fiber / porous aluminum composite material according to claim 1, characterized in that, The specific process of copper plating on the surface of basalt fiber is as follows: (1) Basalt fiber is degreased and degummed, then washed with water; 3%~5% NaOH is used for etching for 30min~45min, followed by water washing; 0.2%~0.5% SnCl2 is used for sensitization for 3min~5min, followed by water washing; Activate with 0.05%~0.1% silver ammonia solution for 1 min~3 min, then wash with water; (2) Electroless copper plating with sodium hypophosphite for 45 min to 60 min at 65℃ to 80℃ and pH value of 9.5 to 11.0; the composition of the plating solution includes: copper sulfate 15 g to 30 g / L, sodium hypophosphite 15 g to 25 g / L, nickel sulfate 0.5 to 0.8 g / L, citric acid 25 g to 40 g / L, thiourea 1 mg to 3 mg / L, boric acid 20 g to 30 g / L, polyethylene glycol (600) 0.05 g to 0.1 g / L; (3) Wash with water and dry.

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