Metal matrix composite material and preparation method thereof

Abstract

The invention relates to a metal-based composite material and a preparation method thereof. The preparation method of the metal-based composite material comprises the following steps: uniformly mixing tetraethoxysilane, an acidic material and water, and fully reacting to obtain a passivation solution; the passivation solution and metal powder are evenly mixed, drying treatment is carried out after full reaction, and dried passivation powder is obtained; and the dried passivated powder is subjected to aging treatment, and the metal-based composite material is obtained. In the metal-based composite material prepared by adopting the preparation method of the metal-based composite material, the nanoscale silicon dioxide particles are uniformly distributed on the insulating film, so that the corrosion resistance of the metal powder is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of metal materials, and in particular to a metal-based composite material and a preparation method thereof. Background Art

[0002] Metal soft magnetic powder core is a common soft magnetic material, which is widely used in electronic communications, switching power supplies and other fields. Metal soft magnetic powder core adopts powder metallurgy to make metal powder, and is made through insulation coating, pressing molding, high-temperature heat treatment and other processes. It has the characteristics of low high-frequency eddy current loss, high magnetic permeability and high temperature stability. Among them, the insulation coating process is one of the key steps. Insulation coating refers to uniformly coating a layer of insulating film on the surface of magnetic particles to reduce the loss of magnetic powder core when used at high frequency. Generally, the insulation coating layer is required to be thin and uniform, with good bonding performance, high thermal stability and high resistivity to reduce the energy loss caused by eddy current loss. However, the traditional coating layer is difficult to be evenly distributed on the surface of metal powder, resulting in poor corrosion resistance of metal powder. Summary of the invention

[0003] Based on this, it is necessary to provide a metal-based composite material and a preparation method thereof to address the problem of how to improve the corrosion resistance of metal powder.

[0004] A method for preparing a metal matrix composite material comprises the following steps:

[0005] Evenly mix ethyl orthosilicate, acidic substance and water, and obtain a passivation solution after sufficient reaction;

[0006] The passivation solution and the metal powder are mixed evenly, and after sufficient reaction, drying is performed to obtain a dried passivation powder; and

[0007] The dried passivated powder is subjected to aging treatment to obtain a metal-based composite material.

[0008] In the preparation method of the above metal-based composite material, first, tetraethyl orthosilicate is hydrolyzed in an acidic environment to form a granular precipitate; wherein the acidic substance is used to provide an acidic environment, which can serve as a passivator for metal powder and an acidic hydrolysis promoter for tetraethyl orthosilicate; then, the passivation solution and the metal powder are mixed to undergo an oxidation-reduction reaction to form an insulating film, and at the same time, the pH value of the acidic substance gradually decreases, and the decrease in pH value causes the tetraethyl orthosilicate hydrolyzate to gel and precipitate on the insulating film; finally, after aging treatment, the alcohol functional groups in the hydrolysis product can be cracked to obtain nano-scale silicon dioxide uniformly dispersed on the surface of the metal powder. In the metal-based composite material prepared by the preparation method of the above metal-based composite material, the nano-scale silicon dioxide particles are uniformly distributed on the insulating film, which is beneficial to improving the corrosion resistance of the metal powder.

[0009] In a feasible implementation, the acidic substance is selected from at least one of phosphoric acid, water-soluble phosphates, nitric acid and nitrates.

[0010] In a feasible implementation, the mass ratio of the acidic substance to the tetraethyl orthosilicate is 1:3 to 3:4.

[0011] In a feasible implementation, the mass ratio of the sum of the tetraethyl orthosilicate and the acidic substance to the metal powder is 1:500 to 1:50.

[0012] In a feasible implementation, the mass ratio of the sum of the tetraethyl orthosilicate and the acidic substance to the water is 1:5 to 1:2.

[0013] In a feasible implementation, during the operation of uniformly mixing the passivation solution and the metal powder and allowing them to fully react, the temperature is maintained at 30° C. to 50° C.

[0014] In a feasible implementation, the drying process is performed at a temperature of 60°C to 120°C.

[0015] In a feasible implementation, the temperature of the aging treatment is 120° C. to 500° C., the time of the aging treatment is 60 minutes to 600 minutes, and the atmosphere of the aging treatment is air, nitrogen or a vacuum environment.

[0016] In a feasible implementation, the metal powder is selected from iron powder, iron-silicon series soft magnetic powder, iron-based amorphous soft magnetic powder, iron-based amorphous nanocrystalline powder and Fe 50 Ni 50 At least one of a series of powders.

[0017] A metal matrix composite material is prepared by any of the above-mentioned methods for preparing the metal matrix composite material.

[0018] In the metal-based composite material prepared by the preparation method of the metal-based composite material, nano-scale silicon dioxide particles are evenly distributed on the insulating film, which is beneficial to improving the anti-corrosion performance of the metal powder. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The present invention is a flowchart of a method for preparing a metal-based composite material according to an embodiment of the present invention. DETAILED DESCRIPTION

[0020] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present invention, so the present invention is not limited by the specific embodiments disclosed below.

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0022] See also Figure 1 A method for preparing a metal matrix composite material according to an embodiment of the present invention comprises the following steps:

[0023] S10, uniformly mix ethyl orthosilicate, acidic substance and water, and obtain a passivation solution after sufficient reaction.

[0024] Among them, tetraethyl orthosilicate is hydrolyzed in an acidic environment to form a network state precipitate.

[0025] Among them, the acidic substance is used to provide an acidic environment, which can be used as a passivator for metal powders and as an acid hydrolysis promoter of tetraethyl orthosilicate. On the one hand, it can chemically react with the surface of metal powders, and on the other hand, it can be used as an acid hydrolysis promoter of tetraethyl orthosilicate to generate a silicon dioxide organic complex.

[0026] In the passivation solution of step S10, ethyl orthosilicate and acidic substances are used as passivators, and water is used as a medium to ensure that the metal powder is in full contact with the passivator.

[0027] In a feasible implementation, the acidic substance is selected from at least one of phosphoric acid, water-soluble phosphates, nitric acid and nitrates.

[0028] In a feasible implementation, after the ethyl orthosilicate, the acidic substance and the water are uniformly mixed and fully reacted, the temperature is maintained at 25° C. to 45° C. In this temperature range, divalent iron salts can be formed, while too high a temperature will form trivalent iron, and too low a temperature will result in a slow reaction, affecting efficiency.

[0029] Furthermore, the temperature in this step may be, but is not limited to, 25° C., 30° C., 35° C., 40° C. or 45° C. Furthermore, the pH value of the passivation solution may be any value between 1.0 and 3.0, for example, the pH value of the passivation solution may be, but is not limited to, 1.0, 2.0 or 3.0.

[0030] In a feasible implementation, the mass ratio of the acidic substance to tetraethyl orthosilicate is 1:3 to 3:4. Further, the mass ratio of the acidic substance to tetraethyl orthosilicate can be, but is not limited to, 1:3, 1:2, 2:3 or 3:4.

[0031] In a feasible implementation, the mass ratio of the sum of ethyl orthosilicate and the acidic substance to water is 1:5 to 1:2. Further, the mass ratio of the sum of ethyl orthosilicate and the acidic substance to water can be, but is not limited to, 1:5, 1:4, 1:3 or 1:2.

[0032] S20, uniformly mixing the passivation solution and metal powder obtained in step S10, and drying after sufficient reaction to obtain dried passivation powder.

[0033] In step S20, after the passivation solution and the metal powder are mixed, an oxidation-reduction reaction occurs to form an insulating film, and at the same time, the pH value of the acidic substance gradually decreases, and the decrease in pH value causes the hydrolyzate of ethyl orthosilicate to gel and precipitate on the insulating film. When the metal powder is an iron-based powder, after the passivation solution and the metal powder are mixed, an oxidation-reduction reaction occurs to form a divalent iron salt structure.

[0034] In a feasible implementation, the mass ratio of the sum of ethyl orthosilicate and the acidic substance to the metal powder is 1:500 to 1:50. Further, the mass ratio of the sum of ethyl orthosilicate and the acidic substance to the metal powder can be, but is not limited to, 1:500, 1:400, 1:300, 1:200, 1:100 or 1:50.

[0035] In a feasible implementation, during the operation of mixing the passivation solution and the metal powder evenly and fully reacting, the temperature is maintained at 30°C to 50°C. The operation of mixing the passivation solution and the metal powder evenly is as follows: pouring the passivation solution into the metal powder and stirring for 1 minute to 100 minutes. Furthermore, the temperature in this step may be, but is not limited to, 30°C, 35°C, 40°C, 45°C or 50°C.

[0036] In a feasible implementation, the temperature of the drying process is 60° C. to 120° C. Furthermore, the atmosphere of the drying process may be air or nitrogen.

[0037] In a feasible implementation, the metal powder is selected from iron powder, iron-silicon series soft magnetic powder, iron-based amorphous soft magnetic powder, iron-based amorphous nanocrystalline powder and Fe 50 Ni50 At least one of a series of powders.

[0038] S30, performing aging treatment on the dried passivation powder obtained in step S20 to obtain a metal-based composite material.

[0039] The aging treatment is to cleave the alcohol functional groups in the hydrolysis product, leaving only the structure of silica, and remove the crystal water molecules in the gel silica and iron salt structure. After the aging treatment, nano-scale silica particles can be formed that are evenly dispersed on the surface of the metal powder.

[0040] In a feasible implementation, the temperature of the aging treatment is 100°C to 500°C, the time of the aging treatment is 60 minutes to 600 minutes, and the atmosphere of the aging treatment is air, nitrogen or a vacuum environment. Further, the temperature of the aging treatment may be, but is not limited to, 100°C, 200°C, 300°C, 400°C or 500°C, and the time of the aging treatment may be, but is not limited to, 60 minutes, 120 minutes, 180 minutes, 240 minutes, 300 minutes, 360 minutes, 420 minutes, 480 minutes, 540 minutes or 600 minutes. Further, the temperature of the aging treatment is 100°C to 200°C, and the atmosphere of the aging treatment may be air, nitrogen or a vacuum environment, preferably air; the temperature of the aging treatment is 200°C to 500°C, and the atmosphere of the aging treatment is nitrogen or a vacuum environment.

[0041] In the preparation method of the above metal-based composite material, first, tetraethyl orthosilicate is hydrolyzed in an acidic environment to form a network state precipitate; wherein the acidic substance is used to provide an acidic environment, which can serve as a passivator for metal powder and an acidic hydrolysis promoter for tetraethyl orthosilicate; then, the passivation solution and the metal powder are mixed to undergo an oxidation-reduction reaction to form an insulating film, and at the same time, the pH value of the acidic substance gradually decreases, and the decrease in pH value causes the tetraethyl orthosilicate hydrolyzate to gel and precipitate on the insulating film; finally, after aging treatment, the alcohol functional groups in the hydrolysis product can be cracked to obtain nano-scale silicon dioxide uniformly dispersed on the surface of the metal powder. In the metal-based composite material prepared by the preparation method of the above metal-based composite material, the nano-scale silicon dioxide particles are uniformly distributed on the insulating film, which is beneficial to improving the corrosion resistance of the metal powder.

[0042] A metal-based composite material according to one embodiment is prepared by any of the above-mentioned methods for preparing a metal-based composite material.

[0043] In the metal-based composite material prepared by the preparation method of the metal-based composite material, nano-scale silicon dioxide particles are evenly distributed on the insulating film, which is beneficial to improving the anti-corrosion performance of the metal powder.

[0044] With reference to the above implementation contents, in order to make the technical solution of the present invention more specific, clear and easy to understand, the technical solution of the present invention is now exemplified. However, it should be noted that the contents to be protected by the present invention are not limited to the following embodiments.

[0045] Example 1

[0046] The metal powder is Fe with a volume average particle size D50 of 10 μm. 50 Ni 50 The powder (prepared by aerosolization) was then sieved through 500 mesh to obtain the powder of this particle size segment.

[0047] Tetraethyl orthosilicate, phosphoric acid and pure water were mixed evenly and stirred with a magnetic stirrer at room temperature of 25°C for 60 minutes to complete hydrolysis. The temperature after hydrolysis was 30°C and after standing for 1 hour, it was 25°C to obtain a passivation solution.

[0048] The passivation liquid and the metal powder are mixed and stirred, and then the temperature is raised to 30°C, and the stirring is continued for 30 minutes, and then the mixture is dried at 80°C for 60 minutes to obtain a dried passivation powder;

[0049] The dried passivated powder is subjected to atmospheric aging treatment at 150° C. for 60 minutes to obtain a soft magnetic metal composite powder;

[0050] Among them, the mass ratios of phosphoric acid (specifically 85% concentration of industrial phosphoric acid) and tetraethyl orthosilicate are 0.2%:0.8%, 0.25%:0.75%, 0.33%:0.66%, 0.33%:0.44%, and 0.5%:0.5% respectively; pure water is used as a medium to ensure that the powder is in full contact with the passivator (i.e., tetraethyl orthosilicate and phosphoric acid), and this embodiment selects water: passivator (mass ratio) = 3:1.

[0051] Performance Test:

[0052] The performance test mainly examines the salt spray corrosion resistance. The soft magnetic metal composite powder after aging treatment is mixed with 2% epoxy resin and dried to make granulated particles that are easy to press and form. The magnetic ring size has an outer diameter of 20mm and an inner diameter of 8mm. After weighing 2.5g of granulated particles, it is formed into a magnetic ring at 500MPa. The magnetic ring is then cured with epoxy resin at 160℃-60 minutes.

[0053] The cured magnetic ring was then placed in a salt spray corrosion test chamber for testing. The test parameters were: salt water deposition of 36 ml / 24 hours, the salt water was a 5% NaCl aqueous solution, and the sample was placed at 45° to the horizontal direction. The test results are shown in Table 1.

[0054] Table 1

[0055]

[0056]

[0057] It can be seen from Table 1 that compared with the mass ratios of phosphoric acid to tetraethyl orthosilicate of 0.2%:0.8% and 0.5%:0.5%, the mass ratios of phosphoric acid to tetraethyl orthosilicate of 0.25%:0.75%, 0.33%:0.66% and 0.33%:0.44% have better anti-corrosion performance.

[0058] Example 2

[0059] The metal powder is Fe with a volume average particle size D50 of 10 μm. 50 Ni 50 The powder (prepared by aerosolization) was then sieved through 500 mesh to obtain the powder of this particle size segment.

[0060] Tetraethyl orthosilicate, phosphoric acid and pure water were mixed evenly and stirred with a magnetic stirrer at room temperature of 25°C for 60 minutes to complete hydrolysis. The temperature after hydrolysis was 30°C and after standing for 1 hour, it was 25°C to obtain a passivation solution.

[0061] The passivation liquid and the metal powder are mixed and stirred, and then the temperature is raised to 30°C, and the stirring is continued for 30 minutes, and then the mixture is dried at 80°C for 60 minutes to obtain a dried passivation powder;

[0062] The dried passivated powder is subjected to atmospheric aging treatment at 150° C. for 60 minutes to obtain a soft magnetic metal composite powder;

[0063] The mass ratio of phosphoric acid (specifically 85% industrial phosphoric acid) to tetraethyl orthosilicate is 3 / 4, and the mass ratio of the total content of the two (i.e., the passivator) to the metal powder is 0.21%, 0.35%, 0.70%, 1.40%, and 2.00%, respectively; water is used as a medium to ensure that the powder and the passivator are in full contact, and this embodiment selects water: passivator (mass ratio) = 3:1.

[0064] Performance Testing:

[0065] The performance test mainly examines the salt spray corrosion resistance. The soft magnetic metal composite powder after aging treatment is mixed with 2% epoxy resin and dried to make granulated particles that are easy to press and form. The magnetic ring size has an outer diameter of 20mm and an inner diameter of 8mm. After weighing 2.5g of granulated particles, it is formed into a magnetic ring at 500MPa. The magnetic ring is then cured with epoxy resin at 160℃-60 minutes.

[0066] The cured magnetic ring was then placed in a salt spray corrosion test chamber for testing. The test parameters were a salt water deposition volume of 36 ml / 24 hours, a 5% NaCl aqueous solution, and the sample was placed at 45° to the horizontal direction. The test results are shown in Table 2.

[0067] Table 2

[0068]

[0069] Example 3

[0070] The metal powder is Fe with a volume average particle size D50 of 10 μm. 50 Ni 50 The powder is prepared by gas atomization and then sieved through 500 meshes to obtain the powder of this particle size range.

[0071] Tetraethyl orthosilicate, phosphoric acid and pure water were mixed evenly and stirred with a magnetic stirrer at room temperature of 25°C for 60 minutes to complete hydrolysis. The temperature after hydrolysis was 30°C and after standing for 1 hour, it was 25°C to obtain a passivation solution.

[0072] The passivation liquid and the metal powder are mixed and stirred, and the temperature is controlled at 30°C, 35°C, 40°C, 50°C, and 55°C respectively. After continuing to stir for 30 minutes, the mixture is dried at 80°C-60 minutes to obtain a dried passivation powder;

[0073] The dried passivated powder is subjected to atmospheric aging treatment at 150° C. for 60 minutes to obtain a soft magnetic metal composite powder;

[0074] Among them, the mass ratio of phosphoric acid (specifically 85% concentration of industrial phosphoric acid) to tetraethyl orthosilicate is 3 / 4, and the total passivator (i.e. phosphoric acid and tetraethyl orthosilicate) content is 0.7%; water is used as a medium to ensure that the powder and the passivator are in full contact, and this embodiment selects water: passivator (mass ratio) = 3:1.

[0075] Performance Test:

[0076] The performance test mainly examines the salt spray corrosion resistance. The soft magnetic metal composite powder after aging treatment is mixed with 2% epoxy resin and dried to make granulated particles that are easy to press and form. The magnetic ring size has an outer diameter of 20mm and an inner diameter of 8mm. After weighing 2.5g of granulated particles, it is formed into a magnetic ring at 500MPa. The magnetic ring is then cured with epoxy resin at 160℃-60 minutes.

[0077] The cured magnetic ring was then placed in a salt spray corrosion test chamber for testing. The test parameters were: salt water deposition of 36 ml / 24 hours, the salt water was a 5% NaCl aqueous solution, and the sample was placed at 45° to the horizontal direction. The test results are shown in Table 3.

[0078] Table 3

[0079]

[0080]

[0081] Example 4

[0082] The metal powder is Fe with a volume average particle size D50 of 10 μm. 50 Ni 50 The powder is prepared by gas atomization and then sieved through 500 meshes to obtain the powder of this particle size range.

[0083] Tetraethyl orthosilicate, phosphoric acid and pure water were mixed evenly and stirred with a magnetic stirrer at room temperature of 25°C for 60 minutes to complete hydrolysis. The temperature after hydrolysis was 30°C and after standing for 1 hour, it was 25°C to obtain a passivation solution.

[0084] The passivation liquid and the metal powder are mixed and stirred, and the temperature is controlled at 30°C. After continuing to stir for 30 minutes, the mixture is dried at 80°C for 60 minutes to obtain a dried passivation powder.

[0085] The dried passivated powder was subjected to aging treatment at 100, 120, 200, 250, 300, 400, 500, and 550° C. (nitrogen protection was used above 200° C. to prevent oxidation of the powder) for 60 minutes to obtain a soft magnetic metal composite powder;

[0086] Among them, the mass ratio of phosphoric acid (85% concentration of industrial phosphoric acid) to tetraethyl orthosilicate is 3 / 4, and the total passivator (i.e., phosphoric acid and tetraethyl orthosilicate) content is 0.7%; water is used as a medium to ensure that the powder and the passivator are in full contact, and this embodiment selects water: passivator (mass ratio) = 3:1.

[0087] Performance Test:

[0088] The performance test mainly examines the salt spray corrosion resistance. The soft magnetic metal composite powder after aging treatment is mixed with 2% epoxy resin and dried to make granulated particles that are easy to press and form. The magnetic ring size has an outer diameter of 20mm and an inner diameter of 8mm. After weighing 2.5g of granulated particles, it is formed into a magnetic ring at 500MPa. The magnetic ring is then cured with epoxy resin at 160℃-60 minutes.

[0089] The cured magnetic ring was then placed in a salt spray corrosion test chamber for testing. The test parameters were a salt water deposition volume of 36 ml / 24 hours, a 5% NaCl aqueous solution, and the sample was placed at 45° to the horizontal direction. The test results are shown in Table 4.

[0090] Table 4

[0091]

[0092] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0093] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A method for preparing a metal matrix composite material, characterized in that: The steps include: Evenly mix ethyl orthosilicate, acidic substance and water, and obtain a passivation solution after sufficient reaction; The passivation solution and the metal powder are mixed evenly, and after sufficient reaction, drying is performed to obtain a dried passivation powder; and The dried passivated powder is subjected to aging treatment to obtain a metal-based composite material.

2. The method for preparing the metal matrix composite material according to claim 1, characterized in that: The acidic substance is selected from at least one of phosphoric acid, water-soluble phosphates, nitric acid and nitrates.

3. The method for preparing the metal matrix composite material according to claim 1, characterized in that: The mass ratio of the acidic substance to the tetraethyl orthosilicate is 1:3 to 3:

4.

4. The method for preparing the metal matrix composite material according to claim 1, characterized in that: The mass ratio of the sum of the tetraethyl orthosilicate and the acidic substance to the metal powder is 1:500 to 1:

50.

5. The method for preparing the metal matrix composite material according to claim 1, characterized in that: The mass ratio of the sum of the tetraethyl orthosilicate and the acidic substance to the water is 1:5 to 1:

2.

6. The method for preparing the metal matrix composite material according to claim 1, characterized in that: During the process of mixing the passivation solution and the metal powder evenly and allowing them to react fully, the temperature is maintained at 30° C. to 50° C.

7. The method for preparing the metal matrix composite material according to claim 1, characterized in that: The temperature of the drying process is 60°C to 120°C.

8. The method for preparing the metal matrix composite material according to claim 1, characterized in that: The temperature of the aging treatment is 120° C. to 500° C., the time of the aging treatment is 60 minutes to 600 minutes, and the atmosphere of the aging treatment is air, nitrogen or a vacuum environment.

9. The method for preparing the metal matrix composite material according to claim 1, characterized in that: The metal powder is selected from iron powder, iron-silicon series soft magnetic powder, iron-based amorphous soft magnetic powder, iron-based amorphous nanocrystalline powder and Fe 50 Ni 50 At least one of a series of powders.

10. A metal matrix composite material, characterized in that: The metal matrix composite material is prepared by the preparation method of any one of claims 1 to 9.

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