Oxide hollow sphere reinforced metal matrix composite and method for manufacturing the same

Abstract

The application relates to the technical field of composite materials, in particular to an oxide hollow sphere reinforced metal matrix composite material and a preparation method thereof. The method comprises the following steps: sintering treatment is conducted on hollow glass beads to obtain a hollow glass bead preform; the hollow glass bead preform is added into a sodium hydroxide solution for pretreatment to obtain a pretreated hollow glass bead preform; a nano structure is generated on the surface of the pretreated hollow glass bead preform to obtain a complex surface hollow glass bead preform; the complex surface hollow glass bead preform and a metal block are placed in a graphite mold, pressure is applied to the metal block, the two are heated to a preset temperature through a direct current pulse current, and heat preservation is conducted for 10-20 minutes; after cooling, heat treatment is conducted to obtain the oxide hollow sphere reinforced metal matrix composite material. The hollow sphere reinforced metal matrix composite material prepared by the application has the characteristics of light weight, high compressive strength and high temperature resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of composite materials, in particular to an oxide hollow sphere reinforced metal matrix composite material and a preparation method thereof. BACKGROUND

[0002] The hollow sphere reinforced metal matrix composite material has great application potential in the preparation of structural / functional integrated energy-absorbing materials for aerospace. In order to meet the needs of preparing energy-absorbing materials for aerospace, the hollow sphere reinforced metal matrix composite material needs to have the characteristics of light weight, high compressive strength and good energy-absorbing performance. The commonly used hollow spheres are hollow glass microspheres and oxide hollow spheres. Hollow glass microspheres have the advantages of light weight, good sphericity and high energy-absorbing efficiency, which can effectively reduce the density of the hollow sphere reinforced metal matrix composite material and improve the compressive strength of the composite material. However, at high temperatures, hollow glass microspheres will soften and cause serious damage, greatly reducing the mechanical properties of the composite material and greatly limiting its engineering application. At the same time, the wettability between hollow glass microspheres and the metal matrix is poor, which also affects the energy-absorbing performance of the composite material. Oxide hollow spheres such as alumina hollow spheres have the advantages of high strength and high temperature resistance, and their use temperature can reach 1800℃, which is higher than that of hollow glass microspheres (1200℃). To some extent, it can solve the problem of high-temperature use of hollow spheres. However, the density of alumina hollow spheres is large, so the hollow sphere reinforced metal matrix composite material prepared by using alumina hollow spheres cannot have the characteristic of light weight. It can be seen that the existing hollow sphere reinforced metal matrix composite material cannot have the characteristics of light weight, high compressive strength and high temperature resistance. SUMMARY

[0003] The technical problem solved by the present application is that the existing hollow sphere reinforced metal matrix composite material cannot have the characteristics of light weight, high compressive strength and high temperature resistance.

[0004] To solve the above technical problems, the technical scheme adopted by the present application is as follows:

[0005] A preparation method of an oxide hollow sphere reinforced metal matrix composite material, comprising:

[0006] Step S1, sintering treatment is performed on hollow glass microspheres to obtain a hollow glass microsphere preform;

[0007] Step S2, the hollow glass microsphere preform is added into a sodium hydroxide solution, stirred and reacted at 70-90℃ for 1-2h, then washed and dried to obtain a pretreated hollow glass microsphere preform;

[0008] Step S3, polyvinylpyrrolidone, n-pentanol, ethanol, water, a sodium citrate solution and ammonia water are uniformly mixed to obtain an emulsion;

[0009] Step S4, the pre-treatment hollow glass microsphere preform is added into the emulsion, tetraethyl orthosilicate is added, and mixing is uniformly performed to obtain a reaction mixture; the reaction mixture is incubated at 30-60℃ for 22-26h, the spherical substance is separated, and after washing, drying is performed to obtain a complex surface hollow glass microsphere preform;

[0010] Step S5, the complex surface hollow glass microsphere preform and the metal block are placed in a graphite mold, the metal block is pressed on the complex surface hollow glass microsphere preform, under vacuum condition, the metal block is applied with a pressure of 0.5-5MPa, and the complex surface hollow glass microsphere preform and the metal block are heated to a preset temperature by a direct current pulse current, incubation is performed for 10-20min, and cooling is performed to obtain an intermediate composite material; wherein, the direct current pulse current flows from the metal block to the complex surface hollow glass microsphere preform, and the preset temperature is greater than the melting point of the metal block.

[0011] Step S6, the intermediate composite material is subjected to heat treatment to obtain an oxide hollow sphere reinforced metal matrix composite material.

[0012] Preferably, in the step S1, the sintering treatment is performed at a temperature of 650-700℃ for 1-2h.

[0013] Preferably, in the emulsion, the mass ratio of the polyvinylpyrrolidone, the n-pentanol, the ethanol, the water, the sodium citrate solution and the ammonia water is (1-20):(80-99):(1-10):(1-20):(1-5):(1-8), the concentration of the sodium citrate solution is 0.1-0.2mol / L, and the mass fraction of the ammonia water is 20%.

[0014] Preferably, in the step S5, the direct current pulse current has a size of 1000-10000A.

[0015] Preferably, the volume ratio of the metal block to the total volume of the hollow glass microspheres is greater than 1.5.

[0016] Preferably, the material of the metal block is aluminum or magnesium.

[0017] Preferably, the material of the metal block is aluminum, and the heat treatment comprises: incubating the intermediate composite material at 496℃ for 2h, and then incubating at 175℃ for 7h.

[0018] Preferably, the material of the metal block is magnesium, and the heat treatment comprises: incubating the intermediate composite material at 340℃ for 2h, quenching in water at 70-75℃, and then incubating at 180℃ for 10h.

[0019] Preferably, in step S1, the hollow glass microspheres are obtained by: pouring hollow glass microsphere powder into a container filled with water, stirring evenly, letting it stand to allow the hollow glass microspheres and water to separate into layers, filtering out the upper layer of undamaged hollow glass microspheres, and drying to obtain the hollow glass microspheres.

[0020] Compared with existing technologies, this invention first sintersects hollow glass microspheres to obtain hollow glass microsphere preforms. Then, it pretreats the hollow glass microsphere preforms with sodium hydroxide solution, forming a large number of hydroxyl groups on the surface of the hollow glass microspheres. This facilitates the subsequent reaction with the hydrolysis products of tetraethyl orthosilicate in the emulsion. After hydrolysis of tetraethyl orthosilicate in the emulsion, a large number of hydrolysis products containing silanol groups are generated. These hydrolysis products undergo a condensation reaction on the surface of the pretreated hollow glass microsphere preforms in a specific emulsion system, thereby forming a uniform and dense three-dimensional nanostructure on the surface of the hollow glass microsphere preforms. This greatly increases the specific surface area of ​​the hollow glass microspheres, thereby improving the bonding area between the hollow glass microspheres and the metal matrix, and thus improving the compressive strength of the hollow sphere-reinforced metal matrix composite material. Furthermore, this invention employs a DC pulsed current heating method to melt a metal block. Under relatively low pressure, the molten metal is infiltrated into the pores of the hollow glass microsphere preform. During this process, free metal ions in the molten metal replace the Si in the hollow glass microsphere preform, thereby transforming the hollow glass microspheres into metal oxide hollow spheres (such as alumina hollow spheres). Since the DC pulsed current flows from the metal block to the complex-surface hollow glass microsphere preform, the metal ions migrate towards the reaction interface, accelerating the transformation of the hollow glass microspheres into metal oxide hollow spheres. Compared to hollow glass microspheres, metal oxide hollow spheres exhibit better high-temperature resistance, resulting in a hollow sphere-reinforced metal matrix composite material with superior high-temperature performance. Because the transformation from hollow glass microspheres to metal oxide hollow spheres is a displacement reaction, the overall mass of the reaction system remains unchanged, thus the resulting hollow sphere-reinforced metal matrix composite material is also lightweight. Additionally, heat treatment in this invention can further enhance the mechanical properties of the hollow sphere-reinforced metal matrix composite material. In summary, the hollow sphere reinforced metal matrix composite material prepared by this invention has the characteristics of being lightweight, having high compressive strength, and being resistant to high temperatures.

[0021] The present invention also provides an oxide hollow sphere reinforced metal matrix composite material, which is prepared by the method described above for preparing oxide hollow sphere reinforced metal matrix composite materials. Attached Figure Description

[0022] Figure 1 This is a schematic flowchart of the preparation method of oxide hollow sphere reinforced metal matrix composite material in an embodiment of the present invention;

[0023] Figure 2This is a schematic diagram of heating a complex surface hollow glass microsphere preform and a metal block using a DC pulse current in an embodiment of the present invention.

[0024] Figure 3 The image shown is a scanning electron microscope image of the hollow glass microsphere preform in Example 1.

[0025] Figure 4 This is a scanning electron microscope image of the complex-surface hollow glass microsphere preform in Example 1.

[0026] Explanation of reference numerals in the attached figures:

[0027] 1. Large graphite ring, 2. Small graphite ring, 3. Complex surface hollow glass microsphere preform, 4. Conductive lower pressure head, 5. Metal block, 6. Conductive upper pressure head, 7. Pulse current generator. Detailed Implementation

[0028] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0029] It should be noted that, unless otherwise specified, the features in the embodiments of this invention can be combined with each other. The terms "comprising," "including," "containing," and "having" are non-limiting, meaning that other steps and other components that do not affect the result can be added. The above terms cover the terms "composed of" and "substantially composed of." Unless otherwise specified, materials, equipment, and reagents are commercially available.

[0030] like Figure 1 As shown, this embodiment of the invention provides a method for preparing an oxide hollow sphere reinforced metal matrix composite material, comprising:

[0031] Step S1: Sinter the hollow glass microspheres to obtain a hollow glass microsphere preform.

[0032] Step S2: Add the hollow glass microsphere preform to the sodium hydroxide solution, stir and react at 70-90℃ for 1-2 hours, wash and dry to obtain the pretreated hollow glass microsphere preform.

[0033] Step S3: Mix polyvinylpyrrolidone, n-pentanol, ethanol, water, sodium citrate solution and ammonia water evenly to obtain an emulsion;

[0034] Step S4: Add the pretreated hollow glass microsphere preform to the emulsion, add tetraethyl orthosilicate, mix evenly to obtain a reaction mixture; keep the reaction mixture at 30-60℃ for 22-26h, separate the spherical material, wash and dry to obtain a complex surface hollow glass microsphere preform.

[0035] Step S5: Place the complex surface hollow glass microsphere preform and the metal block in a graphite mold, with the metal block pressing on top of the complex surface hollow glass microsphere preform. Under vacuum conditions, apply a pressure of 0.5-5 MPa to the metal block, and simultaneously heat the complex surface hollow glass microsphere preform and the metal block to a preset temperature using a DC pulse current. Hold the temperature for 10-20 minutes, then cool to obtain an intermediate composite material. The DC pulse current flows from the metal block to the complex surface hollow glass microsphere preform, and the preset temperature is higher than the melting point of the metal block.

[0036] Step S6: Heat-treat the intermediate composite material to obtain an oxide hollow sphere reinforced metal matrix composite material.

[0037] Compared with the prior art, the embodiments of the present invention first sinter hollow glass microspheres to obtain hollow glass microsphere preforms, and then pretreat the hollow glass microsphere preforms with sodium hydroxide solution to form a large number of hydroxyl groups on the surface of the hollow glass microspheres, which facilitates the subsequent reaction with the hydrolysis products of tetraethyl orthosilicate in the emulsion. After the tetraethyl orthosilicate is hydrolyzed in the emulsion, a large number of hydrolysis products containing silanol groups are generated. These hydrolysis products undergo a condensation reaction on the surface of the pretreated hollow glass microsphere preforms in a specific emulsion system, thereby generating a uniform and dense three-dimensional nanostructure on the surface of the hollow glass microsphere preforms, which greatly increases the specific surface area of ​​the hollow glass microspheres, thereby increasing the bonding area between the hollow glass microspheres and the metal matrix, and thus improving the compressive strength of the hollow sphere-reinforced metal matrix composite material. Furthermore, this embodiment of the invention employs a DC pulsed current heating method to melt the metal block. Under relatively low pressure, the molten metal is infiltrated into the pores of the hollow glass microsphere preform. During this process, free metal ions in the molten metal replace the Si in the hollow glass microsphere preform, thereby transforming the hollow glass microspheres into metal oxide hollow spheres (such as alumina hollow spheres). Since the DC pulsed current flows from the metal block to the complex-surface hollow glass microsphere preform, the metal ions migrate towards the reaction interface, thus accelerating the transformation of the hollow glass microspheres into metal oxide hollow spheres. Compared to hollow glass microspheres, metal oxide hollow spheres have better high-temperature resistance, resulting in a hollow sphere-reinforced metal matrix composite material with superior high-temperature resistance. Because the transformation from hollow glass microspheres to metal oxide hollow spheres is a displacement reaction, the mass of the entire reaction system remains unchanged, thus the resulting hollow sphere-reinforced metal matrix composite material is also lightweight. Additionally, heat treatment in this embodiment of the invention can further improve the mechanical properties of the hollow sphere-reinforced metal matrix composite material. In summary, the hollow sphere reinforced metal matrix composite material prepared according to the embodiments of the present invention has the characteristics of being lightweight, having high compressive strength, and being resistant to high temperatures.

[0038] In some embodiments of the present invention, such as Figure 2As shown, the graphite mold includes a large graphite ring 1 and a small graphite ring 2. The inner hole of the small graphite ring 2 is used to place the complex surface hollow glass microsphere preform 3. In use, firstly, the conductive downward pressure head 4 is inserted into the inner hole of the large graphite ring 1 from below. Then, the complex surface hollow glass microsphere preform 3 is placed in the inner hole of the small graphite ring 2. A metal block 5 is pressed onto the complex surface hollow glass microsphere preform 3. After wrapping all three components with graphite paper (not shown in the figure), they are placed into the inner hole of the large graphite ring 1, so that the conductive downward pressure head 4 presses against the small graphite ring 2 from below. Then, the conductive upward pressure head 6 is pressed onto the metal block 5. Both the pressure head 6 and the conductive lower pressure head 4 are cylindrical, and their outer diameters are the same as the inner diameter of the large graphite ring 1. Therefore, the conductive upper pressure head 6 and the large graphite ring 1 are electrically connected, and the conductive lower pressure head 4 and the large graphite ring 1 are also electrically connected. The conductive upper pressure head 6 is connected to the positive terminal of the pulse current generator 7, and the conductive lower pressure head 4 is connected to the negative terminal of the pulse current generator 7. Vertical pressure is applied to the metal block through the conductive upper pressure head 6 and the conductive lower pressure head 4, and the pulse current generator 7 is turned on to perform heating. The outer diameter of the small graphite ring 2 is r, the inner diameter of the large graphite ring 1 is R, and the thickness of the graphite paper is h, where (Rr) ≥ h.

[0039] In some embodiments of the present invention, in step S1, the sintering temperature is 650-700℃ and the time is 1-2h.

[0040] In some embodiments of the present invention, the mass ratio of the polyvinylpyrrolidone, n-pentanol, ethanol, water, sodium citrate solution, and ammonia in the emulsion is (1-20):(80-99):(1-10):(1-20):(1-5):(1-8), the concentration of the sodium citrate solution is 0.1-0.2 mol / L, and the mass fraction of the ammonia is 20%; the mass ratio of the hollow glass microspheres to the emulsion is (1-15):(84-165).

[0041] In some embodiments of the present invention, in step S2, the concentration of the sodium hydroxide solution is 0.1-0.5 mol / L.

[0042] In some embodiments of the present invention, the ratio of the volume of the metal block to the total volume of the hollow glass microspheres is greater than 1.5.

[0043] In some embodiments of the present invention, the metal block is made of aluminum or magnesium. When the metal block is made of aluminum, the heat treatment includes: holding the intermediate composite material at 496°C for 2 hours, and then holding it at 175°C for 7 hours. When the metal block is made of magnesium, the heat treatment includes: holding the intermediate composite material at 340°C for 2 hours, quenching it in water at 70-75°C, and then holding it at 180°C for 10 hours.

[0044] In some embodiments of the present invention, in step S1, the hollow glass microspheres are obtained by the following method: pouring hollow glass microsphere powder into a container filled with water, stirring evenly, letting it stand so that the hollow glass microspheres and water separate into layers, filtering out the upper layer of undamaged hollow glass microspheres, and drying to obtain the hollow glass microspheres.

[0045] The present invention also provides an oxide hollow sphere reinforced metal matrix composite material, which is prepared by the method described above for preparing oxide hollow sphere reinforced metal matrix composite materials.

[0046] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention.

[0047] Example 1

[0048] 1.1 Pour H40 hollow glass microsphere powder into a container filled with water, stir evenly, and let stand to allow the hollow glass microspheres and water to separate into layers. Filter out the upper layer of undamaged hollow glass microspheres, and dry them to obtain hollow glass microspheres.

[0049] 1.2. Pour 45g of hollow glass microspheres into a crucible, shake to remove air, place the crucible in a muffle furnace, sinter at 700℃ for 1h, cool, and obtain a hollow glass microsphere preform.

[0050] 1.3. The hollow glass microsphere preform was placed in a 0.5 mol / L NaOH solution and reacted at 90℃ for 1 h under magnetic stirring. After removal, it was washed with deionized water until the pH value was neutral and dried in an oven at 110℃ for 2 h to obtain the pretreated hollow glass microsphere preform.

[0051] 1.4 Mix 60g of polyvinylpyrrolidone powder with 480g of n-pentanol and sonicate for 2 hours to ensure uniform mixing, thus obtaining the first mixture.

[0052] 1.5 Add 15.8g of anhydrous ethanol to the first mixture, stir magnetically for 5min, sonicate for 5min, then add 16.8g of deionized water, stir magnetically for 5min, sonicate for 5min, then add 16.2g of 0.18mol / L sodium citrate solution, stir magnetically for 5min, sonicate for 5min to obtain the second mixture.

[0053] 1.6 Add 24g of ammonia water with a mass fraction of 20% to the second mixture, stir magnetically for 5 minutes, and sonicate for 5 minutes to mix it evenly to obtain an emulsion.

[0054] 1.7 Add the pretreated hollow glass microspheres to the emulsion, then add 12g of tetraethyl orthosilicate, stir until homogeneous, and obtain the reaction mixture.

[0055] 1.8 The reaction mixture was kept at 40°C for 24 hours, the spherical material was separated, washed three times with ethanol and deionized water in sequence, and then dried to obtain a complex surface hollow glass microsphere preform.

[0056] 1.9 First, insert the conductive downward pressure head into the inner hole of the large graphite ring from below. Place the complex surface hollow glass microsphere preform into the inner hole of the small graphite ring. Then, press the aluminum block onto the complex surface hollow glass microsphere preform. After wrapping all three with graphite paper, place them into the inner hole of the large graphite ring, so that the conductive downward pressure head presses against the small graphite ring from below. Then, press the conductive upward pressure head onto the aluminum block. Connect the conductive upward pressure head to the positive terminal of the pulse current generator and the conductive downward pressure head to the negative terminal of the pulse current generator. Apply a vertical pressure of 1 MPa to the aluminum block through the conductive upward pressure head and the conductive downward pressure head. Turn on the pulse current generator to heat the complex surface hollow glass microsphere preform and the aluminum block to 700°C, hold for 10 minutes, and cool to obtain the intermediate composite material. The above process is carried out in a vacuum chamber, and the volume ratio of the aluminum block to the total volume of the hollow glass microspheres is 2.

[0057] 1.10. The intermediate composite material is kept at 496°C for 2 hours and then at 175°C for 7 hours to obtain an alumina hollow sphere reinforced aluminum matrix composite material.

[0058] Figure 3 The image shown is a scanning electron microscope image of the hollow glass microsphere preform in Example 1. Figure 4 These are scanning electron microscope (SEM) images of the complex-surface hollow glass microsphere prefabrication from Example 1. Figure 4 As can be seen, nanostructures are uniformly grown on the surface of the hollow glass microsphere preform.

[0059] Example 2

[0060] 2.1 Pour H40 hollow glass microsphere powder into a container filled with water, stir evenly, and let stand to allow the hollow glass microspheres and water to separate into layers. Filter out the upper layer of undamaged hollow glass microspheres, and dry them to obtain hollow glass microspheres.

[0061] 2.2 Pour 45g of hollow glass microspheres into a crucible, shake to remove air, place the crucible in a muffle furnace, sinter at 650℃ for 1h, cool, and obtain hollow glass microsphere preform.

[0062] 2.3. The hollow glass microsphere preform was placed in a 0.5 mol / L NaOH solution and reacted at 90℃ for 1 h under magnetic stirring. After removal, it was washed with deionized water until the pH value was neutral and dried in an oven at 110℃ for 2 h to obtain the pretreated hollow glass microsphere preform.

[0063] 2.4 Mix 60g of polyvinylpyrrolidone powder with 480g of n-pentanol and sonicate for 2 hours to ensure uniform mixing, thus obtaining the first mixture.

[0064] 2.5 Add 15.8g of anhydrous ethanol to the first mixture, stir magnetically for 5min, sonicate for 5min, then add 16.8g of deionized water, stir magnetically for 5min, sonicate for 5min, then add 16.2g of 0.18mol / L sodium citrate solution, stir magnetically for 5min, sonicate for 5min to obtain the second mixture.

[0065] 2.6 Add 24g of ammonia water with a mass fraction of 20% to the second mixture, stir magnetically for 5 minutes, and sonicate for 5 minutes to mix it evenly to obtain an emulsion.

[0066] 2.7 Add the pretreated hollow glass microspheres to the emulsion, then add 12g of tetraethyl orthosilicate, stir evenly to obtain the reaction mixture.

[0067] 2.8 The reaction mixture was kept at 40°C for 24 hours, the spherical material was separated, washed three times with ethanol and deionized water in sequence, and then dried to obtain a complex surface hollow glass microsphere preform.

[0068] 2.9 First, insert the conductive downward pressure head into the inner hole of the large graphite ring from below. Place the complex surface hollow glass microsphere preform into the inner hole of the small graphite ring. Then, press the magnesium block onto the complex surface hollow glass microsphere preform. After wrapping all three with graphite paper, place them into the inner hole of the large graphite ring, so that the conductive downward pressure head presses against the small graphite ring from below. Then, press the conductive upward pressure head onto the magnesium block. Connect the conductive upward pressure head to the positive terminal of the pulse current generator and the conductive downward pressure head to the negative terminal of the pulse current generator. Apply a vertical pressure of 1 MPa to the magnesium block through the conductive upward pressure head and the conductive downward pressure head. Turn on the pulse current generator and heat the complex surface hollow glass microsphere preform and the magnesium block to 700°C, hold for 10 minutes, and cool to obtain the intermediate composite material. The above process is carried out in a vacuum chamber, and the volume ratio of the magnesium block to the total volume of the hollow glass microspheres is 2.

[0069] 2.10. The intermediate composite material is kept at 340℃ for 2 hours, quenched in water at 70-75℃, and then kept at 180℃ for 10 hours to obtain magnesium oxide hollow sphere reinforced magnesium matrix composite material.

[0070] Comparative Example

[0071] H40 hollow glass microsphere powder is poured into a container of water, stirred evenly, and allowed to stand to allow the hollow glass microspheres and water to separate into layers. The undamaged hollow glass microspheres on the upper layer are filtered out and dried to obtain hollow glass microspheres.

[0072] 45g of hollow glass microspheres were poured into a crucible, shaken to remove air, and then placed in a muffle furnace for sintering at 700℃ for 1 hour. After cooling, the hollow glass microsphere preform was obtained.

[0073] A conductive downward pressure head is inserted into the inner hole of a large graphite ring from below. A hollow glass microsphere preform is placed into the inner hole of a small graphite ring, and then an aluminum block is pressed onto the hollow glass microsphere preform. All three are then wrapped with graphite paper (not shown in the figure) and placed back into the inner hole of the large graphite ring, with the conductive downward pressure head pressing against the small graphite ring from below. A conductive upward pressure head is then pressed onto the aluminum block. The conductive upward pressure head is connected to the positive terminal of a pulse current generator, and the conductive downward pressure head is connected to the negative terminal of the pulse current generator. A vertical pressure of 1 MPa is applied to the aluminum block through the conductive upward and downward pressure heads. The pulse current generator is then turned on, heating the hollow glass microsphere preform and the aluminum block to 700°C, holding for 10 minutes, and then cooling to obtain the intermediate composite material. The above process is carried out in a vacuum chamber, and the volume ratio of the aluminum block to the total volume of the hollow glass microspheres is 2.

[0074] The intermediate composite material was kept at 496°C for 2 hours and then at 175°C for 7 hours to obtain an alumina hollow sphere reinforced aluminum matrix composite material.

[0075] Experimental Example

[0076] Quasi-static compression tests were conducted on the alumina hollow sphere reinforced aluminum matrix composites obtained in Example 1 and the comparative example to test their compressive strength. The loading rate of the indenter was 1 mm / min, and the specimen was a cylinder with a diameter of 8 mm and a height of 10 mm. The compressive strength of the alumina hollow sphere reinforced aluminum matrix composite obtained in the comparative example was 303.71 MPa, while the compressive strength of the alumina hollow sphere reinforced aluminum matrix composite obtained in Example 1 was 336.25 MPa. Therefore, the alumina hollow sphere reinforced aluminum matrix composite obtained in Example 1 has a higher compressive strength than the comparative example.

[0077] Furthermore, it should be noted that although the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A method for producing an oxide hollow sphere-reinforced metal matrix composite material, characterized by comprising the steps of: include: ​ Step S1: Sinter the hollow glass microspheres to obtain a hollow glass microsphere preform. Step S2: Add the hollow glass microsphere preform to a sodium hydroxide solution, stir and react at 70-90℃ for 1-2 hours, wash and dry to obtain the pretreated hollow glass microsphere preform. Step S3: Mix polyvinylpyrrolidone, n-pentanol, ethanol, water, sodium citrate solution, and ammonia water evenly to obtain an emulsion; in the emulsion, the mass ratio of polyvinylpyrrolidone, n-pentanol, ethanol, water, sodium citrate solution, and ammonia water is (1-20):(80-99):(1-10):(1-20):(1-5):(1-8), the concentration of sodium citrate solution is 0.1-0.2 mol / L, and the mass fraction of ammonia water is 20%; Step S4: Add the pretreated hollow glass microsphere preform to the emulsion, add tetraethyl orthosilicate, mix evenly to obtain a reaction mixture; keep the reaction mixture at 30-60℃ for 22-26h, separate the spherical material, wash and dry to obtain a complex surface hollow glass microsphere preform; Step S5: Place the complex surface hollow glass microsphere preform and the metal block in a graphite mold, with the metal block pressing on top of the complex surface hollow glass microsphere preform. Under vacuum conditions, apply a pressure of 0.5-5 MPa to the metal block, and simultaneously heat the complex surface hollow glass microsphere preform and the metal block to a preset temperature using a DC pulse current. Hold the temperature for 10-20 minutes, then cool to obtain an intermediate composite material. The DC pulse current flows from the metal block to the complex surface hollow glass microsphere preform, and the preset temperature is higher than the melting point of the metal block. Step S6: Heat-treat the intermediate composite material to obtain an oxide hollow sphere reinforced metal matrix composite material.

2. The method for preparing oxide hollow sphere reinforced metal matrix composite material according to claim 1, characterized in that, In step S1, the sintering temperature is 650-700℃ and the time is 1-2h.

3. The method of claim 1, wherein the oxide hollow sphere reinforced metal matrix composite is prepared by the steps of: preparing a slurry by mixing the oxide hollow spheres, the metal powder, and the binder; and sintering the slurry. In step S5, the magnitude of the DC pulse current is 1000-10000A.

4. The method of claim 1, wherein the oxide hollow sphere reinforced metal matrix composite is prepared by the steps of: preparing a slurry by mixing the oxide hollow spheres, the metal powder, and the binder; and sintering the slurry. The ratio of the volume of the metal block to the total volume of the hollow glass microspheres is greater than 1.

5.

5. The method of claim 1, wherein the oxide hollow sphere reinforced metal matrix composite is prepared by the steps of: preparing a slurry by mixing the oxide hollow spheres, the metal powder, and the binder; and sintering the slurry. The metal block is made of aluminum or magnesium.

6. The method of claim 5, wherein the oxide hollow sphere reinforced metal matrix composite is prepared by the steps of: preparing a slurry by mixing the oxide hollow spheres, the metal powder, and the binder; and sintering the slurry. The metal block is made of aluminum, and the heat treatment includes: holding the intermediate composite material at 496°C for 2 hours, and then holding it at 175°C for 7 hours.

7. The method of claim 5, wherein the oxide hollow sphere reinforced metal matrix composite is prepared by the steps of: preparing a slurry by mixing the oxide hollow spheres, the metal powder, and the binder; and sintering the slurry. The metal block is made of magnesium, and the heat treatment includes: holding the intermediate composite material at 340°C for 2 hours, quenching it in water at 70-75°C, and then holding it at 180°C for 10 hours.

8. The method of claim 1, wherein the oxide hollow sphere reinforced metal matrix composite is prepared by the steps of: preparing a slurry by mixing the oxide hollow spheres, the metal powder, and the binder; and sintering the slurry. In step S1, the hollow glass microspheres are obtained as follows: hollow glass microsphere powder is poured into a container filled with water, stirred evenly, and allowed to stand so that the hollow glass microspheres and water separate into layers. The undamaged upper layer of hollow glass microspheres is filtered out, and the mixture is dried to obtain the hollow glass microspheres.

9. An oxide hollow sphere reinforced metal matrix composite, characterized by, The composite material was prepared using the method described in any one of claims 1-8 for the preparation of oxide hollow sphere reinforced metal matrix composites.

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