CN108359852B - A kind of graphene-enhanced high-silicon aluminum-based composite material and preparation method thereof - Google Patents

Abstract

A graphene-enhanced high-silicon-aluminum-based composite material and a preparation method thereof. The composite material contains components by mass percentage: silicon: 15.0-20.0%, copper: 2.0-4.0%, magnesium: 0.5-1.0%, titanium: 0.05- 0.07%, boron: 0.02-0.05%, graphene: 0.3-0.6%, and the balance is aluminum; preparation method: 1) Mix the ingredients of the raw materials under gas protection to obtain alloy powder; 2) Press the alloy powder After sintering the billet into a block, vacuum sintering to obtain the sintered billet; 3) according to different silicon content, quenching treatment + tempering treatment, or multi-directional forging + annealing treatment, to obtain graphene-enhanced high silicon aluminum Matrix composite material; the method of the present invention makes the distribution of reinforcing phase particles more uniform, and generates a large number of dislocations inside the material, and the dislocation cells are broken into sub-crystals or fine crystals to achieve fine-grain strengthening; the tensile strength is increased to more than 400MPa; At the same time, the yield strength of the material is increased to more than 236MPa.

Description

A kind of graphene-enhanced high-silicon aluminum-based composite material and preparation method thereof

technical field

The invention relates to the field of graphene application technology, in particular to a graphene-reinforced high-silicon aluminum-based composite material and a preparation method thereof.

Background technique

Aluminum-silicon composites have the advantages of high specific strength and specific stiffness, low thermal expansion coefficient, good wear resistance and volume stability, and high enough high temperature strength, which are widely used in aerospace and automobile manufacturing. When the silicon content exceeds 12.6% of the Al-Si eutectic point composition, although the strength is further improved, due to the increased size and irregular shape of the silicon particles embedded in the matrix, the matrix is severely split, and stress is formed at the tip of the silicon phase. Concentration reduces the tensile strength of the material and deteriorates the machinability of the material. At present, the silicon content of commonly used aluminum-silicon matrix composites is basically lower than that of eutectic components. The reinforcements of aluminum-silicon matrix composites are mainly divided into particle reinforcement and fiber reinforcement, but their production costs are high, and particle reinforcement and fiber reinforcement are used. There is less and less potential for further reinforcement of aluminum matrix composites.

SUMMARY OF THE INVENTION

In view of the deficiencies of the prior art, the present invention provides a graphene-reinforced high-silicon aluminum-based composite material and a preparation method thereof.

The graphene-reinforced high-silicon-aluminum-based composite material of the present invention contains the following components by mass percentage: silicon: 15.0-20.0%, copper: 2.0-4.0%, magnesium: 0.5-1.0%, titanium: 0.05-0.07%, boron : 0.02 to 0.05%, graphene: 0.3 to 0.6%, and the balance is aluminum.

The above-mentioned graphene-enhanced high-silicon-aluminum-based composite material, the first preferred solution containing components by mass percentage is: silicon: 15.0-18.0%, copper: 3.0-4.0%, magnesium: 0.5-1.0%, titanium: 0.05- 0.06%, boron: 0.02-0.03%, graphene: 0.3-0.6%, and the balance is aluminum.

The above-mentioned graphene-enhanced high-silicon aluminum-based composite material contains the second preferred solution by mass percentage: silicon: 18.0-20.0%, copper: 2.0-3.0%, magnesium: 0.5-1.0%, titanium: 0.06-0.07% , boron: 0.03 to 0.05%, graphene: 0.3 to 0.6%, and the balance is aluminum.

The preparation method of the graphene-reinforced high-silicon aluminum-based composite material of the present invention specifically comprises the following steps:

Step 1, Mixing:

After proportioning according to the composition percentage of graphene-enhanced high-silicon-aluminum-based composite material, under the protection of inert gas or nitrogen, put it into a mixing tank, mix at a speed of 30-50 r/min for 24-36 hours, and let stand for 1-2 hours After that, mix the materials at a speed of 30-40 r/min for 24-36 hours, and let stand to dissipate heat to normal temperature to obtain uniformly mixed alloy powder;

Step 2, Compression Sintering:

(1) Pour the evenly mixed alloy powder into a pressing mold under the protection of an inert gas, hold the pressure at 220-250 MPa for 5-8 minutes, and demold it to obtain a massive sintered billet;

(2) vacuum sintering the bulk sintered billet, the sintering temperature is 560-575 ℃, and after the sintering time is 1.5-2 hours, it is cooled to room temperature with the furnace to obtain the sintered billet;

Step 3, subsequent heat treatment:

Regarding the composition ratio of the graphene-reinforced high-silicon aluminum-based composite material in step 1, when 15.0%≤silicon mass percentage <18%, the following treatments (a) and (b) are used:

(a) quenching the sintered billet, the quenching temperature is 500°C, and the holding time is 1-3h and then water-cooled;

(b) Tempering the quenched billet, the tempering temperature is 150-200°C, and the holding time is 1-3h and then air-cooled to obtain a graphene-reinforced high-silicon-aluminum-based composite material;

For the composition ratio of the graphene-reinforced high-silicon aluminum-based composite material in step 1, when 18.0%≤silicon mass percentage≤20.0%%, the following treatments (c) and (d) are used:

(c) Multi-directional forging is performed on the sintered billet, the forging temperature is 480-500 °C, the deformation speed is 2-4 mm/s, and the forging deformation direction is changed for each forging pass;

(d) annealing the forged billet, the annealing temperature is 180-200 °C, and the annealing time is 1-3 h, to obtain a graphene-reinforced high-silicon-aluminum-based composite material.

The preparation method of the above-mentioned graphene-enhanced high-silicon aluminum-based composite material, wherein:

In the step 1, loading into the mixing tank is performed in a gas-protected glove isolation box.

In the step 1, the inert gas is argon.

In the step 1, the mixing is carried out in a three-dimensional space motion mixing ball mill.

In the step 1, the mixture is mixed at a rotational speed of 30-40 r/min for 24-36 hours and then left to stand for 1-2 hours. The purpose is to prevent the temperature of the mixing tank from rising due to continuous rotation for a long time, causing cold welding of the powder in the tank. Therefore, pause for 1 to 2 hours.

In the step 2, a 0.5MN double-column manual hydraulic press is used for molding.

In the step 2, vacuum sintering adopts a vacuum hot pressing sintering furnace.

In the step 2, the sintering time is determined according to the amount of alloy powder.

In the step 3, a resistance furnace is used for the quenching treatment. The quenching holding time is determined according to the size of the part.

In the step 3, the multi-directional forging adopts a double-column manual hydraulic press.

In the step 3, a total of 5 to 10 passes of forging are performed.

Graphene itself is a high-performance nanomaterial with high strength, good flexibility, excellent electrical and thermal conductivity and optical properties. Because of its unique structure, it has Dirac-Fermi characteristics, strange quantum Hall effect and minimum quantum conductivity, etc. nature. Compared with traditional reinforcements, it has greater specific strength, specific surface area and lower production cost, making it the most ideal reinforcement material to replace ceramic fibers, carbon nanotubes and hard particles. At present, A390, ZL117, KS282 and other common high-silicon aluminum alloys with silicon content of about 15% to 22% at home and abroad have higher specific strength and lower thermal expansion coefficient, especially suitable for aircraft model and motorcycle piston materials. With the increase of silicon content, coarse, large, large, or tabular silicon particles appear, and mechanical properties, especially elongation, are significantly reduced. Improving the morphology and distribution of silicon particles in the aluminum matrix and refining the dispersion of silicon particles are crucial to improving the mechanical properties of high-silicon aluminum-based materials. The addition of graphene significantly improves the morphology of silicon particles in the high-silicon aluminum-based composite material, has a refining effect on the silicon particles, and improves the comprehensive mechanical properties of the aluminum-silicon composite material.

Compared with the prior art, the graphene-reinforced high-silicon aluminum-based composite material and the preparation method thereof have the following beneficial effects:

The invention prepares a high-performance graphene-reinforced high-silicon-aluminum-based composite material with high strength and hardness by selecting a specific formula, and has the advantages of light weight, wear resistance, high thermal conductivity, low thermal expansion coefficient, and good cutting process. The advantages of performance, and also have excellent thermal conductivity, can be widely used in aerospace, precision instruments and automotive manufacturing.

The addition of graphene nanomaterials improves the tensile strength and yield strength of the high-silicon-aluminum matrix composite, and its elongation also increases. The addition of graphene nanosheets refines and disperses the silicon particles in the high-silicon-aluminum matrix composite structure, and the tensile strength of the material increases from 328MPa to more than 400MPa, an increase of more than 20%; at the same time, the yield strength of the material increases from 202MPa The above is increased to above 236MPa. The improvement effect is obviously better than that of other materials reinforced high silicon aluminum matrix composites. The addition of graphene improved the morphology and distribution of silicon particles, resulting in improved yield strength and plasticity.

With the increase of Si content, the thermal crack resistance of the composite material is improved. In order to maximize the strength of the graphene-aluminum-silicon-based composite material, the graphene-reinforced high-silicon-aluminum-based composite material with Si content close to 20% adopts a The forging process can make the distribution of the reinforcement phase particles more uniform, and generate a large number of dislocations inside the material, and the dislocation cells are broken into sub-crystals or fine crystals to achieve the effect of fine-grain strengthening.

Description of drawings

Fig. 1 Microstructure and morphology of the graphene-reinforced high-silicon-aluminum-based composite material prepared in Example 1 of the present invention;

Fig. 2 Microstructure and morphology of the graphene-reinforced high-silicon-aluminum-based composite material prepared in Example 2 of the present invention;

Fig. 3 Microstructure and morphology of the graphene-reinforced high-silicon aluminum-based composite material prepared in Example 3 of the present invention;

Fig. 4 Microstructure and morphology of the graphene-reinforced high-silicon aluminum-based composite material prepared in Example 4 of the present invention.

Detailed ways

Example 1

A graphene-enhanced high-silicon-aluminum-based composite material, which contains the following components by mass percentage: silicon: 15.0%, copper: 4.0%, magnesium: 1.0%, titanium: 0.06%, boron: 0.03%, graphene: 0.5% , and aluminum is the remainder.

The preparation method of the above-mentioned graphene-enhanced high-silicon aluminum-based composite material specifically comprises the following steps:

Step 1, Mixing:

The composition of the graphene-reinforced high-silicon-aluminum-based composite material is calculated by mass percentage: silicon 15.0%, copper 4.0%, magnesium 1.0%, titanium 0.06%, boron 0.03%, graphene 0.5%, and aluminum is the balance.

In the glove isolation box under the protection of argon gas, the various raw material powders of 700 mesh were batched according to the above mass percentages and put into the mixing tank, and then the mixing tank was assembled on the ball mill, and then moved in the three-dimensional space mixing ball mill. , Mixing at a speed of 40r/min for 30h, after standing for 1h, the purpose is to prevent the temperature of the mixing tank from rising due to long-term continuous rotation, causing cold welding of the powder in the tank, repeat the continuous rotation and mixing for 30h, and let it stand After dissipating heat to room temperature, it is removed from the ball mill to obtain evenly mixed alloy powder;

Step 2, Compression Sintering:

(1) Pour the evenly mixed alloy powder into a pressing mold under the protection of argon gas, use a 0.5MN double-column manual hydraulic press, hold the pressure at 240 MPa for 5 minutes, and demold to obtain a massive sintered billet;

(2) vacuum sintering the block sintered billet in a vacuum hot pressing sintering furnace, the sintering temperature is 560 ℃, and after 2 hours of sintering time, it is cooled to room temperature with the furnace to obtain the sintered billet;

Step 3, subsequent heat treatment:

(1) The sintered billet is quenched with a resistance furnace, the quenching temperature is 500°C, the holding time is 2h (it can be determined according to the size of the sintered part), and then water-cooled;

(2) Tempering the quenched billet with a tempering temperature of 180° C. and air-cooling after a holding time of 2h to obtain a graphene-reinforced high-silicon-aluminum-based composite material; its microstructure is shown in accompanying drawing 1, in the figure The dark particles are Si particles, and the off-white areas are mostly Al ₂ Cu phases.

Example 2

A graphene-enhanced high-silicon-aluminum-based composite material, which contains the following components by mass percentage: silicon: 16.0%, copper: 3.5%, magnesium: 1.0%, titanium: 0.06%, boron: 0.03%, graphene: 0.3% , and aluminum is the remainder.

The preparation method of the above-mentioned graphene-enhanced high-silicon aluminum-based composite material specifically comprises the following steps:

Step 1, Mixing:

The composition of the graphene-reinforced high-silicon-aluminum-based composite material is calculated by mass percentage as silicon 16.0%, copper 3.5%, magnesium 1.0%, titanium 0.06%, boron 0.03%, graphene 0.3%, and aluminum is the balance.

In the glove isolation box under the protection of argon gas, the various raw material powders of 700 mesh were batched according to the above mass percentages and put into the mixing tank, and then the mixing tank was assembled on the ball mill, and then moved in the three-dimensional space mixing ball mill. , Mixing at a speed of 40r/min for 30h, after standing for 1h, the purpose is to prevent the temperature of the mixing tank from rising due to long-term continuous rotation, causing cold welding of the powder in the tank, repeat the continuous rotation and mixing for 30h, and let it stand After dissipating heat to room temperature, it is removed from the ball mill to obtain evenly mixed alloy powder;

Step 2, Compression Sintering:

(1) Pour the evenly mixed alloy powder into a pressing mold under the protection of argon gas, use a 0.5MN double-column manual hydraulic press, hold the pressure at 240 MPa for 5 minutes, and demold to obtain a massive sintered billet;

(2) vacuum sintering the block sintered billet in a vacuum hot-pressing sintering furnace, the sintering temperature is 575°C, and the sintering time is 1.52h, followed by cooling to room temperature in the furnace to obtain a sintered billet;

Step 3, subsequent heat treatment:

(1) The sintered billet is quenched with a resistance furnace, the quenching temperature is 500°C, the holding time is 2h (it can be determined according to the size of the sintered part), and then water-cooled;

(2) Tempering the quenched billet with a tempering temperature of 180° C. and air-cooling after a holding time of 2 hours to obtain a graphene-reinforced high-silicon-aluminum matrix composite material; its microstructure is shown in Figure 2.

Example 3

A graphene-enhanced high-silicon-aluminum-based composite material, which contains the following components by mass percentage: silicon: 20.0%, copper: 2.0%, magnesium: 1.0%, titanium: 0.07%, boron: 0.04%, graphene: 0.6% , and aluminum is the remainder.

The preparation method of the above-mentioned graphene-enhanced high-silicon aluminum-based composite material specifically comprises the following steps:

Step 1, Mixing:

The composition of the graphene-reinforced high-silicon aluminum-based composite material is calculated by mass percentage, silicon 20.0%, copper 2.0%, magnesium 1.0%, titanium 0.07%, boron 0.04%, graphene 0.6%, and aluminum is the balance.

In the glove isolation box under the protection of argon gas, the various raw material powders of 700 mesh were batched according to the above mass percentages and put into the mixing tank, and then the mixing tank was assembled on the ball mill, and then moved in the three-dimensional space mixing ball mill. , Mixing at a speed of 40r/min for 30h, after standing for 1h, the purpose is to prevent the temperature of the mixing tank from rising due to long-term continuous rotation, causing cold welding of the powder in the tank, repeat the continuous rotation and mixing for 30h, and let it stand After dissipating heat to room temperature, it is removed from the ball mill to obtain evenly mixed alloy powder;

Step 2, Compression Sintering:

(1) Pour the evenly mixed alloy powder into a pressing mold under the protection of argon gas, use a 0.5MN double-column manual hydraulic press, hold the pressure at 240 MPa for 5 minutes, and demold to obtain a massive sintered billet;

(2) vacuum sintering the block sintered billet in a vacuum hot pressing sintering furnace, the sintering temperature is 565°C, and after 1.8h sintering time, the sintered billet is obtained by cooling to room temperature with the furnace;

Step 3, subsequent heat treatment:

(1) A double-column manual hydraulic press is used to perform multi-directional forging on the sintered billet. A total of 5 forging passes are carried out. The forging temperature is 490 ° C, the deformation speed is 3 mm/s, and the forging deformation direction is changed for each forging pass;

(2) The forged billet is annealed, the annealing temperature is 200°C, and the annealing time is 2h, to obtain a graphene-reinforced high-silicon-aluminum-based composite material. Its microstructure is shown in Figure 3.

Example 4

A graphene-enhanced high-silicon-aluminum-based composite material, which contains components by mass percentage: silicon: 19.0%, copper: 2.5%, magnesium: 1.0%, titanium: 0.06%, boron: 0.04%, graphene: 0.5% , and aluminum is the remainder.

The preparation method of the above-mentioned graphene-enhanced high-silicon aluminum-based composite material specifically comprises the following steps:

Step 1, Mixing:

The composition of the graphene-enhanced high-silicon-aluminum-based composite material is calculated by mass percentage as silicon 19.0%, copper 2.5%, magnesium 1.0%, titanium 0.06%, boron 0.04%, graphene 0.5%, and aluminum is the balance.

In the glove isolation box under the protection of argon gas, the various raw material powders of 700 mesh were batched according to the above mass percentages and put into the mixing tank, and then the mixing tank was assembled on the ball mill, and then moved in the three-dimensional space mixing ball mill. , Mixing at a speed of 40r/min for 30h, after standing for 1h, the purpose is to prevent the temperature of the mixing tank from rising due to long-term continuous rotation, causing cold welding of the powder in the tank, repeat the continuous rotation and mixing for 30h, and let it stand After dissipating heat to room temperature, it is removed from the ball mill to obtain evenly mixed alloy powder;

Step 2, Compression Sintering:

(1) Pour the evenly mixed alloy powder into a pressing mold under the protection of argon gas, use a 0.5MN double-column manual hydraulic press, hold the pressure at 240 MPa for 5 minutes, and demold to obtain a massive sintered billet;

(2) vacuum sintering the block sintered billet in a vacuum hot-pressing sintering furnace, the sintering temperature is 570°C, and the sintering time is 1.5 to 2 hours, followed by cooling to room temperature with the furnace to obtain the sintered billet;

Step 3, subsequent heat treatment:

(1) A double-column manual hydraulic press is used to perform multi-directional forging on the sintered billet. A total of 10 forging passes are carried out, the forging temperature is 490 °C, the deformation speed is 3 mm/s, and the forging deformation direction is changed for each forging pass;

(2) The forged billet is annealed, the annealing temperature is 200°C, and the annealing time is 2h, to obtain a graphene-reinforced high-silicon-aluminum-based composite material. Its microstructure is shown in Figure 4.

Claims (6)

1. a preparation method of a graphene-enhanced high-silicon-aluminum-based composite material, is characterized in that, the described graphene-enhanced high-silicon aluminum-based composite material contains composition by mass percent: silicon: 15.0～20.0%, copper : 2.0 ~ 4.0%, magnesium: 0.5 ~ 1.0%, titanium: 0.05 ~ 0.07%, boron: 0.02 ~ 0.05%, graphene: 0.3 ~ 0.6%, the balance is aluminum; The method specifically includes the following steps: Step 1, Mixing: After batching according to the mass percentage of the graphene-enhanced high-silicon-aluminum-based composite material, under the protection of inert gas or nitrogen, put it into a mixing tank, mix at a speed of 30~50r/min for 24~36h, and let it stand for 1~2h After that, mix the material at a speed of 30~40r/min for 24~36h, and let it stand to dissipate heat to room temperature to obtain a uniformly mixed alloy powder; Step 2, Compression Sintering: (1) Pour the evenly mixed alloy powder into a pressing mold under the protection of an inert gas, hold the pressure at 220-250 MPa for 5-8 min, and demold it to obtain a massive sintered billet; (2) vacuum sintering the block sintered billet, the sintering temperature is 560~575 ℃, and the sintering time is 1.5~2 h, and then cooled to room temperature with the furnace to obtain the sintered billet; Step 3, subsequent heat treatment: For the composition ratio of the graphene-reinforced high-silicon-aluminum-based composite material in step 1, when 15.0%≤silicon mass percentage <18%, the following treatments (a) and (b) are used: (a) quenching the sintered billet, the quenching temperature is 500°C, and the holding time is 1~3h and then water-cooled; (b) Tempering the quenched billet at a tempering temperature of 150-200° C. and air-cooling for a holding time of 1-3 hours to obtain a graphene-reinforced high-silicon-aluminum matrix composite material; For the composition ratio of the graphene-reinforced high-silicon aluminum-based composite material in step 1, when 18.0%≤silicon mass percentage≤20.0%, the following treatments (c) and (d) are used: (c) Multi-directional forging is performed on the sintered billet, the forging temperature is 480~500 °C, the deformation speed is 2~4 mm/s, and the forging deformation direction is changed for each forging pass; (d) The forged billet is annealed, the annealing temperature is 180-200 °C, and the annealing time is 1-3 h to obtain a graphene-reinforced high-silicon-aluminum matrix composite material. 2. the preparation method of graphene-enhanced high-silicon aluminum-based composite material according to claim 1, is characterized in that, described graphene-enhanced high-silicon aluminum-based composite material contains composition by mass percentage: silicon: 15.0 ~ 18.0%, Copper: 3.0 ~ 4.0%, Magnesium: 0.5 ~ 1.0%, Titanium: 0.05 ~ 0.06%, Boron: 0.02 ~ 0.03%, Graphene: 0.3 ~ 0.6%, and the balance is Aluminum. 3. the preparation method of graphene-enhanced high-silicon aluminum-based composite material according to claim 1, is characterized in that, described graphene-enhanced high-silicon aluminum-based composite material contains composition by mass percentage: silicon: 18.0 ~ 20.0%, copper: 2.0 ~ 3.0 %, magnesium: 0.5 ~ 1.0%, titanium: 0.06 ~ 0.07 %, boron: 0.03 ~ 0.05%, graphene: 0.3 ~ 0.6%, the balance is aluminum. 4. the preparation method of the high-silicon-aluminum-based composite material reinforced by graphene according to claim 1, is characterized in that, in described step 1, loading into mixing tank is to carry out in gas protection glove isolation box; It is carried out in a three-dimensional space motion mixing ball mill; in step 2, a 0.5MN double-column manual hydraulic press is used for molding, and a vacuum hot pressing sintering furnace is used for vacuum sintering; in step 3, resistance furnace is used for quenching treatment, and multi-directional forging adopts Double column manual hydraulic press. 5. The preparation method of graphene-enhanced high-silicon-aluminum-based composite material according to claim 1, wherein in the step 1, the inert gas is argon. 6. The preparation method of graphene-enhanced high-silicon-aluminum-based composite material according to claim 1, characterized in that, in the step 3, a total of 5～10 passes of forging are carried out.

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