B4c / fe3o4 reinforced aluminum matrix composite material and preparation method thereof

Abstract

The application provides a B4C / Fe3O4 reinforced aluminum matrix composite material and a preparation method thereof, the method fully utilizes the performance characteristics of each reinforcing phase and the matrix, the aluminum matrix composite material is collectively reinforced through mutual cooperation of the reinforcing phases, the aluminum matrix composite material is provided with a wider application space, and the aluminum matrix composite material has important significance for energy saving and emission reduction due to the characteristics of low density and high strength.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of powder metallurgy, and particularly relates to a B4C / Fe3O4 reinforced aluminum-based composite material and a preparation method thereof. BACKGROUND

[0002] Aluminum-based composite materials are widely used due to their excellent mechanical properties. The common way to reinforce aluminum-based composite materials is to implant reinforcing phases (such as carbides, nitrides, metal oxides, graphene, etc.) in the matrix in some way. By using the reinforcing phases in the aluminum-based composite material, the tensile strength, hardness, wear resistance and other mechanical properties can be greatly improved, and according to different service environments, aluminum-based composite materials suitable for the environment can be developed, and the service life can be greatly improved. At the same time, aluminum-based composite materials have a smaller mass ratio, which plays a positive role in energy saving and consumption reduction in the application process, and have great development space in the future material application field.

[0003] However, the development of aluminum-based composite materials has certain limitations. When a certain particle is used as a reinforcing phase to reinforce aluminum-based composite materials, due to the characteristics of the particles (such as large surface area, large micro size, easy aggregation, etc.), the toughness of the aluminum-based composite material is reduced while the strength is improved, and the internal defects of the material are not easy to eliminate, which limits the strengthening process of the aluminum-based material. In addition, the strengthening of a single reinforcing phase has certain limitations in improving the comprehensive performance of aluminum-based composite materials.

[0004] Improving the micro size of the reinforcing particles and their uniform dispersion in the matrix is a current research hotspot for aluminum-based composite materials. For aluminum-based composite materials with different compositions, improving the micro size and dispersion of the reinforcing phases in the matrix not only helps to improve the strength of the material, but also ensures that the material has a certain toughness. The concept of hybrid reinforcement can avoid the aggregation of the same phase by using the synergistic relationship between the reinforcing phases and the matrix, thereby improving the strengthening effect of the reinforcing phases, not only strengthening the matrix, but also facilitating the development of materials according to their functions and expanding to more application fields. SUMMARY

[0005] (I) Technical problems to be solved

[0006] The application provides a B4C / Fe3O4 reinforced aluminum-based composite material and a preparation method thereof, to solve the technical problems of how to improve the mechanical properties such as wear resistance, strength and fatigue resistance of aluminum-based composite materials, reduce the aggregation and defect tendency of the two-phase reinforcing particles in the preparation process of aluminum-based composite materials, and improve the service life of aluminum-based composite materials.

[0007] (II) Technical solutions

[0008] In order to solve the above technical problems, the present application provides a preparation method of B4C / Fe3O4 reinforced aluminum matrix composite, which comprises the following steps: mixing B4C particles, graphite and potassium ferrate according to a certain proportion, and then performing vacuum ball milling, wherein Fe3O4 is in-situ reduced on the surface of graphite; applying shearing force on the graphite by stainless steel balls, B4C and the inner wall of the ball milling tank to strip the graphene and the attached Fe3O4 on the surface of the graphite, thereby obtaining a multi-phase reinforced phase powder of graphene, Fe3O4 and B4C; performing secondary vacuum ball milling on the reinforced phase powder and pure aluminum powder; and after the reinforced phase powder and the pure aluminum powder are uniformly mixed, sequentially performing hot pressing, vacuum sintering, solid solution treatment and aging treatment, thereby finally obtaining the B4C / Fe3O4 reinforced aluminum matrix composite.

[0009] Further, the preparation method specifically comprises the following steps:

[0010] S1. Placing graphite, potassium ferrate and B4C particles into a stainless steel ball milling tank, adding steel balls into the stainless steel ball milling tank, and placing the stainless steel ball milling tank into a vacuum box to perform vacuumization;

[0011] S2. Performing high-energy ball milling on the stainless steel ball milling tank by using a planetary ball mill, thereby obtaining a multi-phase reinforced phase powder of graphene, Fe3O4 and B4C;

[0012] S3. Washing and filtering the reinforced phase powder by using deionized water, and then performing vacuum drying;

[0013] S4. Fully grinding the reinforced phase powder, mixing the reinforced phase powder with pure aluminum powder, and then adding the mixture into the stainless steel ball milling tank, and performing secondary vacuum ball milling on the stainless steel ball milling tank by using the planetary ball mill, thereby obtaining a composite powder;

[0014] S5. Performing hot pressing on the composite powder, thereby obtaining a sample;

[0015] S6. Performing vacuum sintering and heat preservation on the sample, and cooling in the furnace;

[0016] S7. Performing solid solution treatment on the sample;

[0017] S8. Performing aging treatment on the sample, thereby obtaining the B4C / Fe3O4 reinforced aluminum matrix composite.

[0018] Further, in step S1, the mass percentage of graphite is 0.1-0.5wt%, the mass percentage of potassium ferrate is 20-50wt%, and the rest is B4C particles; the ball-to-material ratio of the added steel balls is 10:1, the steel balls include three kinds of steel balls with diameters of 3mm, 5mm and 7mm, and the mass ratio of the three kinds of steel balls is 2:3:5; the vacuum degree of the stainless steel ball milling tank is-0.1MPa.

[0019] Further, in step S2, dry ball milling is adopted, the rotation speed of the planetary ball mill is 100-200 r / min, and the ball milling time is 8-16 h.

[0020] Further, in step S3, the reinforced phase powder is washed 3-5 times by deionized water, suction filtered, and then vacuum dried, the drying temperature is 60-150 DEG C, and the drying time is 6-10 h.

[0021] Further, in step S4, the mass percentage of the pure aluminum powder is 80-95%, the ball-to-material ratio of the steel balls added in the stainless steel ball mill is 10:1, the steel balls include three kinds of steel balls with diameters of 3 mm, 5 mm and 7 mm, and the mass ratio of the three kinds of steel balls is 2:3:5, the vacuum degree of the stainless steel ball mill is-0.1 MPa, dry ball milling is adopted, the rotation speed of the planetary ball mill is 100-200 r / min, the ball milling time of the second ball milling is 2-4 h, and the ball mill is stopped for 10 min every 30 min.

[0022] Further, in step S5, the composite powder is placed in a tabletting die by a tablet press, hot pressing is carried out at a pressure of 500-800 MPa, the hot pressing temperature is 150-300 DEG C, the pressure maintaining time is 30-90 min, and the sample is obtained after the pressing is completed.

[0023] Further, in step S6, the vacuum degree is-0.1 MPa, the heating rate is 5 DEG C / min, the sintering temperature is 560-580 DEG C, and the holding time is 2-10 h.

[0024] Further, in step S7, the solid solution temperature is 460-480 DEG C, the heating rate is 5 DEG C / min, the holding time is 1-2 h, and rapid water quenching is carried out, and in step S8, the aging temperature is 150-200 DEG C, the heating rate is 5 DEG C / min, the holding time is 6-10 h, and the sample is cooled in the furnace.

[0025] In addition, the application further provides a B4C / Fe3O4 reinforced aluminum matrix composite prepared by the above method.

[0026] (Three) beneficial effects

[0027] The application provides a B4C / Fe3O4 reinforced aluminum matrix composite and a preparation method thereof, the method fully utilizes the performance characteristics of each reinforced phase and the matrix, the reinforced phases cooperate with each other to jointly reinforce the aluminum matrix composite, and the aluminum matrix composite has a wider application space, and the aluminum matrix composite has important significance for energy saving and emission reduction due to the characteristics of low density and high strength.

[0028] The beneficial effects of the application specifically include:

[0029] 1. The application not only improves the mechanical properties such as wear resistance, hardness, tensile strength, etc. of the aluminum-based composite material, prolongs the service life of the aluminum-based composite material, but also further expands the application field of the aluminum-based composite material due to the excellent physical and chemical properties of B4C and in-situ reduced Fe3O4.

[0030] 2. By high-energy ball milling, the B4C particles are further refined, the high-hardness B4C helps the graphite to peel off the graphene, improves the interaction between the reinforcing phases, promotes the adhesion of potassium ferrate on the surface of graphite, and in-situ reduces Fe3O4 to fall off with the graphene, which positively promotes the continuous generation of in-situ reduced Fe3O4.

[0031] 3. The graphene additionally peeled off from the graphite during high-energy ball milling can provide a good adhesion space for the in-situ reduced Fe3O4, and the adhesion of Fe3O4 can hinder the agglomeration of graphene, and the synergistic effect of the two can cooperate with B4C to enhance the mechanical properties of the aluminum-based composite material. DETAILED DESCRIPTION

[0032] In order to make the purpose, content and advantages of the application clearer, the specific embodiments of the application will be further described in combination with examples.

[0033] The application provides a preparation method of B4C / Fe3O4 reinforced aluminum-based composite material, which comprises the following steps:

[0034] S1. Put graphite, potassium ferrate and B4C particles into a stainless steel ball mill tank, add steel balls in the stainless steel ball mill tank, and put the stainless steel ball mill tank into a vacuum box for vacuumizing.

[0035] In the application, the mass percentage of graphite is 0.1-0.5wt%, the mass percentage of potassium ferrate is 20-50wt%, and the rest is B4C particles. Excessive potassium ferrate is beneficial to the full contact and reduction of Fe3O4 on the surface of a small amount of graphite, and the addition of B4C not only can improve the shearing force on the surface of graphite to promote the peeling of graphene, but also can dilute the concentration of potassium ferrate to avoid the risk of gas expansion and self-ignition of powder in the vacuum ball milling environment. The ball-to-material ratio of the added steel balls is 10:1, the steel balls include three kinds of steel balls with diameters of 3mm, 5mm and 7mm, and the mass ratio of the three kinds of steel balls is 2:3:5. The vacuum degree of the stainless steel ball mill tank is -0.1MPa, and the stainless steel ball mill tank is vacuumized before high-energy ball milling, which can avoid the influence of air on the surface oxidation reaction of the powder.

[0036] S2. High-energy ball milling is carried out on the stainless steel ball mill tank by a planetary ball mill to obtain a multi-phase reinforced phase powder of graphene, Fe3O4 and B4C.

[0037] In the application, the dry ball milling is adopted, the rotation speed of the planetary ball mill is 100-200 r / min, and the ball milling time is 8-16 h, so that the low rotation speed and long time ball milling can avoid the damage of the graphene structure and make the reaction more sufficient.

[0038] S3. The reinforcing phase powder is washed by deionized water for 3-5 times, suction filtered, and then vacuum dried at a drying temperature of 60-150 DEG C for 6-10 h.

[0039] In the application, the deionized water is used for multiple washing and suction filtering, so that the excessive potassium ferrate, potassium ions and other impurities in the reinforcing phase powder can be removed, and the vacuum drying of the reinforcing phase powder can remove the excessive water and crystal water.

[0040] S4. The reinforcing phase powder is sufficiently ground, mixed with pure aluminum powder, and then added into a stainless steel ball mill tank, so that the stainless steel ball mill tank is subjected to secondary vacuum ball milling by a planetary ball mill, and a composite powder is obtained.

[0041] In the application, the mass percentage of the pure aluminum powder is 80-95 %, the ball-to-material ratio of the steel balls added into the stainless steel ball mill tank is 10:1, the steel balls include three kinds of steel balls with diameters of 3 mm, 5 mm and 7 mm, and the mass ratio of the three kinds of steel balls is 2:3:5. The vacuum degree of the stainless steel ball mill tank is -0.1 MPa. The dry ball milling is adopted, and the rotation speed of the planetary ball mill is 100-200 r / min. The ball milling time of the secondary ball milling is 2-4 h, and the ball mill is stopped for 10 min every 30 min, so that the powder can be sufficiently mixed, the grain refinement effect can be achieved, and the pure aluminum powder can be prevented from being adhered in large amount due to overheating or continuous ball milling in the ball mill tank.

[0042] S5. The composite powder is subjected to hot pressing forming, and a sample is obtained.

[0043] In the application, vaseline is smeared on the side surface of the tabletting die gasket, so that the sample is more easily demolded during sampling. 6 g of the composite powder is placed in a mold with a diameter of 30 mm by a tablet press, and hot pressing is carried out at a pressure of 500-800 MPa, so that the sample density is improved. The hot pressing temperature is 150-300 DEG C, and the pressure holding time is 30-90 min. After the pressing is completed, the sample is obtained.

[0044] S6. The sample is subjected to vacuum sintering, heat preservation and furnace cooling.

[0045] In the application, the vacuum degree is -0.1 MPa, the heating rate is 5 DEG C / min, the sintering temperature is 560-580 DEG C, and the heat preservation time is 2-10 h. The vacuum sintering of the sample can effectively avoid the excessive oxidation of the aluminum-based composite material and the loss of aluminum elements on the surface of the matrix during the sintering process.

[0046] S7. The sample is subjected to solid solution treatment.

[0047] In the application, the solid solution temperature is 460-480 DEG C, the heating rate is 5 DEG C / min, the holding time is 1-2h, and rapid water quenching is adopted.

[0048] S8. Aging treatment is performed on the sample to obtain the B4C / Fe3O4 reinforced aluminum matrix composite material.

[0049] In the application, the aging temperature is 150-200 DEG C, the heating rate is 5 DEG C / min, the holding time is 6-10h, and furnace cooling is adopted.

[0050] The purpose of selecting B4C and in-situ reduced Fe3O4 particles in the application is that B4C and Fe3O4 both have good physical and chemical properties (such as the neutron absorption property, high strength and good stability of B4C, high hardness, good magnetic property and high specific surface area of Fe3O4), which can play an excellent performance reinforcement effect on the aluminum matrix composite material.

[0051] The purpose of selecting graphite and potassium ferrate to prepare in-situ reduced Fe3O4 in the application is that the high electron mobility of graphite is utilized, and the potassium ferrate is reduced to Fe3O4 on the surface of graphite and gradually delaminates the graphite into graphene in the preparation process, so that the in-situ reduced Fe3O4 on the surface of graphene is obtained.

[0052] The application prepares the B4C and in-situ reduced Fe3O4 hybrid reinforced particles by high-energy ball milling, and the addition of B4C can not only improve and promote the preparation of reduced Fe3O4, but also effectively reduce the agglomeration phenomenon of the two, which is beneficial to the uniform distribution of the reinforcing phase in the matrix.

[0053] The application adopts hot pressing forming, which can improve the density of the sample preparation; and adopts vacuum sintering, which can avoid the oxidation of the aluminum matrix composite material in the sintering process and improve the bonding strength of the reinforcing phase and the matrix. Embodiment

[0054] S1. Put graphite (0.1wt%), potassium ferrate (20wt%) and B4C particles (the rest) into a stainless steel ball mill jar, add steel balls (ball-to-material ratio is 10:1, the steel balls include three kinds of steel balls with diameters of 3mm, 5mm and 7mm, and the mass ratio of the three kinds of steel balls is 2:3:5) into the stainless steel ball mill jar, put the stainless steel ball mill jar into a vacuum box to extract vacuum, and the vacuum degree is-0.1MPa.

[0055] S2. High-energy ball milling is performed on the stainless steel ball mill jar by a planetary ball mill, dry ball milling is adopted, the rotation speed of the planetary ball mill is 100r / min, the ball milling time is 12h, and the multiphase reinforced phase powder of graphene, Fe3O4 and B4C is obtained.

[0056] S3. The reinforcing phase powder was washed with deionized water for 3 times, suction filtered, and then vacuum dried at a drying temperature of 100℃ for 10h.

[0057] S4. The reinforcing phase powder was sufficiently ground and mixed with pure aluminum powder (80wt%) and then added into a stainless steel ball mill tank. The stainless steel ball mill tank was subjected to secondary vacuum ball milling (ball-to-material ratio of 10:1, the steel balls included three kinds of steel balls with diameters of 3mm, 5mm and 7mm, and the mass ratio of the three kinds of steel balls was 2:3:5; the vacuum degree of the stainless steel ball mill tank was -0.1MPa, dry ball milling was adopted, the rotation speed of the planetary ball mill was 100 / min, and the ball milling time was 2h, with a 10min pause every 30min of rotation), to obtain a composite powder.

[0058] S5. Vaseline was applied to the side of the tabletting die gasket to facilitate sample removal; 6g of the composite powder was placed in a Ф30mm die by a tablet press, and hot-pressed at a pressure of 500MPa, a hot-pressing temperature of 150℃, and a pressure maintaining time of 30min, to obtain a sample.

[0059] S6. The sample was vacuum sintered at a vacuum degree of -0.1MPa, a heating rate of 5℃ / min, a sintering temperature of 560℃, and a holding time of 2h, and then cooled in the furnace.

[0060] S7. The sample was subjected to solid solution treatment at a solid solution temperature of 460℃, a heating rate of 5℃ / min, and a holding time of 1h, and then water-quenched.

[0061] S8. The sample was subjected to aging treatment at an aging temperature of 160℃, a heating rate of 5℃ / min, and a holding time of 6h, and then cooled in the furnace, to obtain a B4C / Fe3O4 reinforced aluminum-based composite material sample. The Vickers hardness of the sample was 67-86Hv. Embodiment

[0062] S1. Graphite (0.2wt%), potassium ferrate (30wt%) and B4C particles (the balance) were placed into a stainless steel ball mill tank, steel balls (ball-to-material ratio of 10:1, the steel balls included three kinds of steel balls with diameters of 3mm, 5mm and 7mm, and the mass ratio of the three kinds of steel balls was 2:3:5) were added into the stainless steel ball mill tank, the stainless steel ball mill tank was placed into a vacuum box and vacuumized to a vacuum degree of -0.1MPa.

[0063] S2. The stainless steel ball mill tank was subjected to high-energy ball milling by a planetary ball mill, dry ball milling was adopted, the rotation speed of the planetary ball mill was 150r / min, and the ball milling time was 12h, to obtain a multi-phase reinforcing phase powder of graphene, Fe3O4 and B4C.

[0064] S3. The reinforcing phase powder is washed with deionized water for 3 times, suction filtered, and then vacuum dried at a drying temperature of 100 DEG C for 10 h.

[0065] S4. The reinforcing phase powder is sufficiently ground and mixed with pure aluminum powder (80 wt%) and then added into a stainless steel ball mill tank, and the stainless steel ball mill tank is subjected to secondary vacuum ball milling (ball-to-material ratio of 10:1, the steel balls include three kinds of steel balls with diameters of 3 mm, 5 mm and 7 mm, and the mass ratio of the three kinds of steel balls is 2:3:5; the vacuum degree of the stainless steel ball mill tank is -0.1 MPa, dry ball milling is adopted, the rotation speed of the planetary ball mill is 150 / min, and the ball milling time is 3 h, and the planetary ball mill is stopped for 10 min every 30 min), to obtain a composite powder.

[0066] S5. Vaseline is applied to the side of the tablet die gasket to facilitate sampling, 6 g of the composite powder is placed in a Ф30 mm die through a tablet press, and hot pressing is performed at a pressure of 500 MPa, a hot pressing temperature of 160 DEG C, and a pressure maintaining time of 30 min, to obtain a sample.

[0067] S6. The sample is subjected to vacuum sintering, a vacuum degree of -0.1 MPa, a heating rate of 5 DEG C / min, a sintering temperature of 570 DEG C, a holding time of 3 h, and furnace cooling.

[0068] S7. The sample is subjected to solution treatment, a solution temperature of 470 DEG C, a heating rate of 5 DEG C / min, a holding time of 2 h, and water quenching.

[0069] S8. The sample is subjected to aging treatment, an aging temperature of 160 DEG C, a heating rate of 5 DEG C / min, a holding time of 8 h, and furnace cooling, to obtain a B4C / Fe3O4 reinforced aluminum-based composite material sample. The Vickers hardness of the sample is 70-83 Hv.

[0070] The above only describes the preferred embodiments of the present application, and it should be noted that those skilled in the art can make several improvements and modifications without departing from the technical principles of the present application, and these improvements and modifications should also be considered as the protection scope of the present application.

Claims

1. A method for preparing B4C / Fe3O4 reinforced aluminum-based composite material, characterized in that, The preparation method includes the following steps: S1. Place graphite, potassium ferrate, and B4C particles into a stainless steel ball mill jar. Add steel balls to the stainless steel ball mill jar and place it in a vacuum chamber to evacuate the vacuum. The graphite content is 0.1~0.5wt%, the potassium ferrate content is 20~50wt%, and the remainder is B4C particles. The ball-to-material ratio of the added steel balls is 10:

1. The steel balls include three types with diameters of 3mm, 5mm, and 7mm, and the mass ratio of the three types of steel balls is 2:3:

5. The vacuum degree of the stainless steel ball mill jar is -0.1MPa. S2. High-energy ball milling of materials in a stainless steel ball mill jar was performed using a planetary ball mill to obtain multiphase reinforced powders of graphene, Fe3O4 and B4C; the rotation speed of the planetary ball mill was 100~200 r / min, and the ball milling time was 8~16 h. S3. The reinforcing phase powder is washed with deionized water, filtered, and then vacuum dried; S4. The reinforcing phase powder is thoroughly ground and mixed with 80-95% pure aluminum powder by mass. The mixture is then added to a stainless steel ball mill jar and subjected to secondary vacuum ball milling using a planetary ball mill to obtain composite powder. S5. The composite powder is hot-pressed to obtain a sample; S6. Vacuum sintering and heat preservation of the sample, followed by furnace cooling; S7. Perform solution treatment on the sample; S8. The sample was subjected to aging treatment to obtain B4C / Fe3O4 reinforced aluminum matrix composite material.

2. The method for preparing B4C / Fe3O4 reinforced aluminum matrix composite material as described in claim 1, characterized in that, In step S3, the reinforcing phase powder is washed and filtered 3 to 5 times with deionized water, and then vacuum dried at a temperature of 60 to 150°C for 6 to 10 hours.

3. The method for preparing B4C / Fe3O4 reinforced aluminum matrix composite material as described in claim 1, characterized in that, In step S4, the ball-to-material ratio of steel balls added to the stainless steel ball mill jar is 10:

1. The steel balls include three types with diameters of 3mm, 5mm, and 7mm, and the mass ratio of the three types of steel balls is 2:3:

5. The vacuum degree of the stainless steel ball mill jar is -0.1MPa. Dry ball milling is used, and the rotation speed of the planetary ball mill is 100~200r / min. The ball milling time for the second ball mill is 2~4h, with a 10min pause every 30min of rotation.

4. The method for preparing B4C / Fe3O4 reinforced aluminum matrix composite material as described in claim 1, characterized in that, In step S5, the composite powder is placed in the tableting mold using a tablet press and hot-pressed at a pressure of 500~800MPa. The hot-pressing temperature is 150~300℃, and the holding time is 30~90min. After pressing, the sample is obtained.

5. The method for preparing B4C / Fe3O4 reinforced aluminum matrix composite material as described in claim 1, characterized in that, In step S6, the vacuum degree is -0.1MPa, the heating rate is 5℃ / min, the sintering temperature is 560~580℃, and the holding time is 2~10h.

6. The method for preparing B4C / Fe3O4 reinforced aluminum matrix composite material as described in claim 1, characterized in that, In step S7, the solution temperature is 460~480℃, the heating rate is 5℃ / min, the holding time is 1~2h, and rapid water quenching is performed; in step S8, the aging temperature is 150~200℃, the heating rate is 5℃ / min, the holding time is 6~10h, and furnace cooling is performed.

7. A B4C / Fe3O4 reinforced aluminum-based composite material, characterized in that, The B4C / Fe3O4 reinforced aluminum matrix composite material is prepared by the method described in any one of claims 1 to 6.