Preparation method of an intermediate alloy of a nanoparticle-reinforced magnesium-based material

Abstract

The present invention discloses a preparation method of a nanoparticle-reinforced magnesium-based material master alloy, comprising the following steps: (1) performing surface modification on the nanoparticles, dispersing the surface-modified nanoparticles into a low-melting-point metal to form a mixture; (2) dispersing the mixture into a nano suspension, adding micron-sized pure magnesium powder to the nano suspension, and assisting with ultrasonic dispersion; (3) cutting a circular hole in a pure magnesium ingot, quickly cooling the obtained mixture into a solid, placing it into the circular hole of the magnesium ingot, and plugging the circular hole of the magnesium ingot with a magnesium plug; (4) sealing the above pure magnesium ingot into an iron crucible, placing it in an induction heating furnace for heating, quickly heating it to 690-710 °C at a rate of 25 °C / min, holding for 30-60 min, and then placing the crucible in a high-energy vibration device to assist electromagnetic stirring; (5) quickly water-cooling the sealed iron crucible, and cutting to obtain a nanoparticle magnesium ingot; (6) performing extrusion processing on the nanoparticle magnesium ingot to obtain a deformed nanoparticle-reinforced magnesium-based material master alloy.

Description

Technical Field

[0001] The present invention relates to a preparation method of an intermediate alloy of a nanoparticle-reinforced magnesium-based material, belonging to the field of industrial magnesium alloys. Background Art

[0002] As the lightest metallic structural material, magnesium alloys have important potential application values in the fields of aerospace and weaponry. Moreover, in recent years, their application amounts have been gradually increasing, becoming an important alternative material for structural weight reduction.

[0003] Although magnesium alloys have significant advantages, their intrinsic property problems have restricted the expansion of their applications. Among them, the most prominent one is the relatively low elastic modulus of magnesium alloys. During the design process of components, it is often necessary to increase the volume to achieve the improvement of stiffness, resulting in the weakening of the lightweight advantage of magnesium alloys themselves. Therefore, researching high-modulus magnesium alloy systems and related preparation and processing methods will be one of the effective ways to promote the in-depth development of magnesium materials.

[0004] Adding reinforcements is an effective means to improve the elastic modulus of magnesium alloys. The addition methods of reinforcements include the external addition method and the in-situ generation method, among which the external addition of reinforcements is the mainstream method for current magnesium-based composites. As an excellent reinforcement phase, nano-reinforced phases can enhance the elastic modulus of alloys. However, nano-reinforced phases have an extremely high specific surface energy. Under the action of intermolecular forces such as van der Waals forces and electrostatic forces, they are prone to agglomeration phenomena, and there is a lack of effective industrialized dispersion methods. Therefore, how to avoid the segregation of nano-reinforced phases has become the focus of current work. In addition, in addition to being prone to agglomeration themselves, nano-reinforced phases also have the problem of a large diameter difference from the matrix. Nano-particles are extremely prone to segregate in the gaps between the matrices, and there are also natural problems of being difficult to disperse.

[0005] Therefore, exploring methods to effectively disperse nano-particles and improve their comprehensive utilization efficiency is a key problem that urgently needs to be solved. The method of adding intermediate alloys can effectively improve the recovery rate of valuable substances, especially for refractory second phases or solute elements. Summary of the Invention

[0006] The purpose of the present invention is to provide a preparation method of an intermediate alloy of a nanoparticle-reinforced magnesium-based material, which improves the dispersion ability of the reinforcement phase and further improves the recovery rate of nano-reinforced phases by prefabricating the intermediate alloy.

[0007] To achieve the above purpose, the present invention adopts the following technical solutions:

[0008] A preparation method of an intermediate alloy of a nanoparticle-reinforced magnesium-based material, comprising the following steps:

[0009] (1) Modify the surface of the nanoparticles to form a lipophilic and hydrophobic surface film layer;

[0010] (2) Disperse the surface-modified nanoparticles into a low-melting-point metal to form a mixture;

[0011] (3) Disperse the mixture to obtain a nano-suspension, and then add micron-sized pure magnesium powder to the nano-suspension, and stir while adding with the assistance of ultrasonic waves until there is no obvious liquid left;

[0012] (4) Cut a round hole in the pure magnesium ingot, quickly cool the obtained mixture into a solid, then put the solid into the round hole of the magnesium ingot, and seal the round hole of the magnesium ingot with a magnesium plug;

[0013] (5) Seal the above-mentioned pure magnesium ingot into an iron crucible, place it in an induction heating furnace for heating, quickly heat it to 690 - 710 °C at a rate of 25 °C / min, keep it warm for 30 - 60 min, and then place the crucible in a high-energy vibration device to assist electromagnetic stirring;

[0014] (6) Quickly water-cool the sealed iron crucible, and cut it to obtain a nano-particle magnesium ingot;

[0015] (7) Heat the nano-particle magnesium ingot to between 250 - 350 °C, keep it warm for 1 - 2 h, and perform extrusion after uniform temperature. Control the extrusion ratio between 20 - 25 to obtain a deformed nano-particle reinforced magnesium-based material master alloy.

[0016] Preferably, the nanoparticles are one or more of SiO2, TiC, TiB2, and SiC. The size of the nanoparticles is D50 = 5 - 30 nm. The surface of the nanoparticles is modified by the esterification method, surface grafting reaction method, or coupling agent method.

[0017] Preferably, in step (2), the low-melting-point metal is one or more of Ga, In, Hg, and Sn. Melt the low-melting-point metal into a liquid state, and then add 3 - 10% of the surface-modified nanoparticles by volume percentage to disperse and form a mixture.

[0018] Preferably, in step (3), the mixture is first ultrasonically dispersed and then dispersed in a high-shear mixer. The ultrasonic dispersion time is controlled within 20 - 30 min.

[0019] Preferably, in step (4), the diameter of the round hole is 30 - 50 mm.

[0020] The beneficial effects of the present invention:

[0021] 1. Due to the extremely high specific surface area of the nanoparticles, surface modification can be used to achieve depolymerization and improve the dispersion ability of the particles.

[0022] 2. Since most of the surface modification film layers of nanoparticles are organic substances, carbonization or failure will occur at high temperatures. Therefore, during the preparation of the master alloy, low-melting-point metals are introduced as auxiliary dispersants. On the one hand, it can prevent the agglomeration of particles. At the same time, it can also avoid the failure of surface modification caused by high-temperature problems. Most importantly, these low-melting-point metals can also be used as components of magnesium alloys during subsequent use.

[0023] 3. By adding micron-sized magnesium powder during the auxiliary dispersion process, the liquid metal can be better dispersed into the magnesium powder, and at the same time, it can also play an isolation role to form a local closed-loop morphology.

[0024] 4. By applying ultrasonic stirring and a high-shear mixer to the liquid metal in sequence, the depolymerization effect can be further achieved, and the dispersion effect of nanoparticles can be accelerated.

[0025] 5. Extruding the master alloy can further improve the element recovery rate of the master alloy as an auxiliary additive. Specific Embodiments

[0026] The following further describes the present invention with reference to embodiments. It should be emphasized that the following description is merely exemplary and not intended to limit the scope and application of the present invention.

[0027] The specific scheme of the method for preparing the master alloy of the nanoparticle-reinforced magnesium-based material provided by the present invention includes the following steps:

[0028] (1) Select one or more of nano-sized SiO2, TiC, TiB2, and SiC, control the particle size between 5 and 30 nm, and modify the particle surface by esterification method, surface grafting reaction method or coupling agent method to form a lipophilic and hydrophobic surface film layer.

[0029] (2) Disperse the surface-modified nanoparticles into low-melting-point metals, where the low-melting-point metals include one or more of metals Ga, In, Hg, and Sn. Melt the metal into a liquid state, and then add 3 to 10% of the surface-modified nanoparticles to form a mixture.

[0030] (3) Place the mixture in an ultrasonic field to accelerate the dispersion of nanoparticles in the mixture. Control the dispersion time within 20 to 30 minutes. After taking out the particles, continue to put them into a high-shear mixer to further reduce the specific surface energy and accelerate the dispersion effect of the particles to construct a nano-suspension. Then add micron-sized pure magnesium powder to the suspension and stir while adding in an auxiliary ultrasonic way until there is no obvious liquid.

[0031] (4) Cut a round hole with a diameter of 30 - 50 mm in the pure magnesium ingot. Rapidly cool the nano - suspension + magnesium powder mixture into a solid, and then put the solid into the round hole of the magnesium ingot prepared in advance. Ensure that the mixture does not liquefy throughout the process. Subsequently, plug the round hole on the pure magnesium ingot with a magnesium plug.

[0032] (5) Seal the above - mentioned pure magnesium ingot in an iron crucible, place it in an induction heating furnace for heating, rapidly heat it to 690 - 710 °C at a rate of 25 °C / min, hold for 30 - 60 min, and then place the crucible in a high - energy vibration device to assist electromagnetic stirring to accelerate the movement of the melt and achieve rapid dispersion of the nano - particles therein.

[0033] (6) Quench the sealed iron crucible rapidly with water to prevent the settlement of nano - particles, and obtain a magnesium + nano - particle ingot with good surface quality after cutting.

[0034] (7) Heat the magnesium + nano - particle ingot to 250 - 350 °C, hold for 1 - 2 h, and perform extrusion after temperature equalization. Control the extrusion ratio between 20 - 25 to obtain a deformed intermediate alloy of magnesium + nano - particles.

[0035] Example 1

[0036] Select 20 - nm SiO₂ nano - particles and clean them with acetone to remove surface impurities and organic pollutants. Disperse the cleaned SiO₂ nano - particles in isopropanol to form a uniform suspension. After adding an appropriate amount of silane coupling agent to the suspension, heat it under nitrogen protection. After reacting for 24 h, use ethanol to remove the unreacted silane coupling agent and by - products to obtain SiO₂ particles with a lipophilic and hydrophobic surface film layer. Use water - bath heating to melt metallic Ga into a liquid state, and then add 5% of the surface - modified SiO₂ nano - particles to form a mixture. Place the mixture in an ultrasonic field for ultrasonic dispersion treatment for 22 min. Continue to put the dispersed particles into a high - shear mixer, select a rotation speed of 2000 r / min, and the treatment time is 1 h to construct a nano - suspension. Then add micron - sized pure magnesium powder to the suspension and stir it while adding with the assistance of ultrasonic waves until there is no obvious liquid. Cut a round hole with a diameter of 40 mm in the pure magnesium ingot. Rapidly cool the nano - suspension + magnesium powder mixture into a solid, and then put the solid into the round hole of the magnesium ingot prepared in advance. Ensure that the mixture does not liquefy throughout the process. Subsequently, plug the round hole on the pure magnesium ingot with a magnesium plug.

[0037] Seal the above-mentioned pure magnesium ingots in an iron crucible and place it in an induction heating furnace for heating. Rapidly heat it to 705 °C at a rate of 25 °C / min, hold for 55 min, then place the crucible in a high-energy vibration device and assist with electromagnetic stirring. After quickly water-cooling the sealed iron crucible to 25 °C, perform cutting treatment to obtain a magnesium + SiO2 nanoparticle ingot with good surface quality. Finally, heat the magnesium + SiO2 nanoparticle ingot to 330 °C, hold for 2 h, and perform extrusion after uniform temperature is reached. The extrusion ratio is 22 to obtain a deformed intermediate alloy of magnesium + SiO2 nanoparticles. Observe the prepared alloy by TEM. After statistics, it is found that the average diameter of the SiO2 particles is about 26 nm. The yield of the SiO2 nanoparticles is calculated to be about 91% through ICP testing.

[0038] Example 2

[0039] Select 10 nm SiC nanoparticles and clean them with acetone to remove surface impurities and organic contaminants. Disperse the cleaned SiC nanoparticles in isopropanol to form a uniform suspension. After adding an appropriate amount of silane coupling agent to the suspension, heat it under nitrogen protection. After reacting for 20 h, use ethanol to remove the unreacted silane coupling agent and by-products to obtain SiC nanoparticles with a lipophilic and hydrophobic surface film layer. Use water bath heating to melt metallic In into a liquid state, and then add 10% of the surface-modified SiC nanoparticles to form a mixture. Place the mixture in an ultrasonic field for ultrasonic dispersion treatment for 25 min. Continue to place the dispersed particles in a high-shear mixer with a rotation speed of 2200 r / min and a treatment time of 1.5 h to construct a nano-suspension. Then add micron-sized pure magnesium powder to the suspension and use auxiliary ultrasound to stir while adding until there is no obvious liquid. Cut a round hole with a diameter of 35 mm in the pure magnesium ingot, quickly cool the nano-suspension + magnesium powder mixture into a solid, and then place the solid into the round hole of the magnesium ingot prepared in advance, ensuring that the mixture does not liquefy throughout the process. Subsequently, plug the round hole on the pure magnesium ingot with a magnesium plug.

[0040] Seal the above pure magnesium ingot in an iron crucible, place it in an induction heating furnace for heating, rapidly heat it to 710 °C at a rate of 25 °C / min, hold for 40 min, then place the crucible in a high-energy vibration device and assist with electromagnetic stirring. After rapidly water-cooling the sealed iron crucible to 20 °C, perform cutting treatment to obtain a magnesium + SiC nanoparticle ingot with good surface quality. Finally, heat the magnesium + SiC nanoparticle ingot to 340 °C, hold for 2 h, and perform extrusion after uniform temperature is achieved. The extrusion ratio is 25 to obtain a deformed intermediate alloy of magnesium + SiC nanoparticles. Observe the prepared alloy by TEM. After statistics, it is found that the average diameter of the SiC particles is about 16 nm. The yield of the SiC nanoparticles is calculated to be about 90% through ICP testing.

[0041] Example 3

[0042] Select 15 nm TiC nanoparticles and clean them with acetone to remove surface impurities and organic pollutants. Disperse the cleaned TiC nanoparticles in isopropanol to form a uniform suspension. After adding an appropriate amount of silane coupling agent to the suspension, heat it under nitrogen protection. After reacting for 24 h, use ethanol to remove the unreacted silane coupling agent and by-products to obtain TiC nanoparticles with a lipophilic and hydrophobic surface film layer. Use water bath heating to melt metallic Ga into a liquid state, and then add 5% of the surface-modified TiC nanoparticles to form a mixture. Place the mixture in an ultrasonic field for ultrasonic dispersion treatment for 30 min. Continue to place the dispersed particles in a high-shear mixer, select a rotation speed of 1900 r / min, and the treatment time is 2 h to construct a nano-suspension. Then add micron-sized pure magnesium powder to the suspension and use auxiliary ultrasound to add and stir until there is no obvious liquid. Cut a round hole with a diameter of 50 mm in the pure magnesium ingot, quickly cool the nano-suspension + magnesium powder mixture into a solid, and then place the solid into the round hole of the pre-made magnesium ingot, ensuring that the mixture does not liquefy throughout the process. Subsequently, plug the round hole in the pure magnesium ingot with a magnesium plug.

[0043] Seal the above pure magnesium ingots in an iron crucible, place it in an induction heating furnace for heating, rapidly heat it to 690 °C at a rate of 25 °C / min, hold for 30 min, then place the crucible in a high-energy vibration device and assist with electromagnetic stirring. After rapidly water-cooling the sealed iron crucible to 23 °C, perform cutting treatment to obtain a magnesium + TiC nanoparticle ingot with good surface quality. Finally, heat the magnesium + TiC nanoparticle ingot to 300 °C, hold for 1.5 h, and perform extrusion after uniform temperature. The extrusion ratio is 20 to obtain a deformed intermediate alloy of magnesium + TiC nanoparticles. Observe the prepared alloy by TEM. After statistics, it is found that the average diameter of TiC particles is about 21 nm. The yield of TiC nanoparticles is calculated to be about 88% through ICP testing.

[0044] Example 4

[0045] Select two kinds of nanoparticles of 20 nm TiC and SiC, and clean them with acetone to remove surface impurities and organic pollutants. Disperse the cleaned TiC and SiC nanoparticles in isopropanol to form a uniform suspension. After adding an appropriate amount of silane coupling agent to the suspension, heat it under nitrogen protection. After reacting for 18 h, use ethanol to remove the unreacted silane coupling agent and by-products to obtain TiC and SiC nanoparticles with a lipophilic and hydrophobic surface film layer. Use water bath heating to melt metallic In into a liquid state, and then add 10% of the surface-modified TiC and SiC nanoparticles to form a mixture. Place the mixture in an ultrasonic field for ultrasonic dispersion treatment for 30 min. Continue to put the dispersed particles into a high-shear mixer, select a rotation speed of 2500 r / min, and the treatment time is 1 h to construct a nano-suspension. Then add micron-sized pure magnesium powder to the suspension and use auxiliary ultrasound to add and stir until there is no obvious liquid. Cut a round hole with a diameter of 45 mm in the pure magnesium ingot, quickly cool the nano-suspension + magnesium powder mixture into a solid, and then put the solid into the round hole of the pre-made magnesium ingot, ensuring that the mixture does not liquefy throughout the process. Subsequently, plug the round hole in the pure magnesium ingot with a magnesium plug.

[0046] Seal the above pure magnesium ingots in an iron crucible, place it in an induction heating furnace for heating, rapidly heat it to 700 °C at a rate of 25 °C / min, hold for 40 min, then place the crucible in a high-energy vibration device and assist with electromagnetic stirring. After quickly water-cooling the sealed iron crucible to 25 °C, perform cutting treatment to obtain magnesium + TiC and SiC nanoparticle ingots with good surface quality. Finally, heat the magnesium + TiC and SiC nanoparticle ingots to 320 °C, hold for 1 h, and perform extrusion after uniform temperature. The extrusion ratio is 24 to obtain a deformed intermediate alloy of magnesium + TiC and SiC nanoparticles. Observe the prepared alloy by TEM. After statistics, it is found that the average diameter of TiC and SiC nanoparticles is about 26 nm. The yield of TiC and SiC nanoparticles is calculated to be about 92% through ICP testing.

[0047] Example 5

[0048] Select 30-nm SiO2 nanoparticles and clean them with acetone to remove surface impurities and organic contaminants. Disperse the cleaned SiO2 nanoparticles in isopropanol to form a uniform suspension. After adding an appropriate amount of silane coupling agent to the suspension, heat it under nitrogen protection. After reacting for 18 h, use ethanol to remove the unreacted silane coupling agent and by-products to obtain SiO2 nanoparticles with a lipophilic and hydrophobic surface film layer. Use water bath heating to melt metallic Sn into a liquid state, and then add 10% of the surface-modified SiO2 nanoparticles to form a mixture. Place the mixture in an ultrasonic field for ultrasonic dispersion treatment for 30 min. Continue to put the dispersed particles into a high-shear mixer, select a rotation speed of 2200 r / min, and the treatment time is 1.2 h to construct a nano-suspension. Then add micron-scale pure magnesium powder to the suspension and use auxiliary ultrasound to add and stir simultaneously until there is no obvious liquid. Cut a round hole with a diameter of 45 mm in the pure magnesium ingot, quickly cool the nano-suspension + magnesium powder mixture into a solid, and then put the solid into the round hole of the pre-prepared magnesium ingot, ensuring that the mixture does not liquefy throughout the process. Subsequently, plug the round hole in the pure magnesium ingot with a magnesium plug.

[0049] Seal the above-mentioned pure magnesium ingots in an iron crucible, place it in an induction heating furnace for heating, rapidly heat it to 700 °C at a rate of 25 °C / min, hold for 50 min, then place the crucible in a high-energy vibration device and assist with electromagnetic stirring. After quickly water-cooling the sealed iron crucible to 25 °C, perform cutting treatment to obtain a magnesium + SiO2 nanoparticle ingot with good surface quality. Finally, heat the magnesium + SiO2 nanoparticle ingot to 280 °C, hold for 1 h, and perform extrusion after uniform temperature. The extrusion ratio is 25 to obtain an intermediate alloy of deformed magnesium + SiO2 nanoparticles. Observe the prepared alloy by TEM. After statistics, it is found that the average diameter of SiO2 particles is about 34 nm. The yield of SiO2 nanoparticles is calculated to be about 90% through ICP testing.

[0050] Example 6

[0051] Select 10 nm TiB2 nanoparticles and clean them with acetone to remove surface impurities and organic contaminants. Disperse the cleaned nano-TiB2 in isopropanol to form a uniform suspension. After adding an appropriate amount of silane coupling agent to the suspension, heat it under nitrogen protection. After reacting for 24 h, use ethanol to remove the unreacted silane coupling agent and by-products to obtain nano-TiB2 particles with a lipophilic and hydrophobic surface film layer. Use water bath heating to melt metallic In into a liquid state, and then add 8% of the surface-modified TiB2 nanoparticles to form a mixture. Place the mixture in an ultrasonic field for ultrasonic dispersion treatment for 25 min. Continue to put the dispersed particles into a high-shear mixer, select a rotation speed of 1800 r / min, and the treatment time is 2 h to construct a nano-suspension. Then add micron-sized pure magnesium powder to the suspension and stir while adding with the assistance of ultrasonic waves until there is no obvious liquid. Cut a round hole with a diameter of 40 mm in the pure magnesium ingot, quickly cool the nano-suspension + magnesium powder mixture into a solid, and then put the solid into the round hole of the pre-made magnesium ingot, ensuring that the mixture does not liquefy throughout the process. Subsequently, plug the round hole in the pure magnesium ingot with a magnesium plug.

[0052] Seal the above-mentioned pure magnesium ingot in an iron crucible and place it in an induction heating furnace for heating. Rapidly heat it to 710 °C at a rate of 25 °C / min, hold for 60 min, then place the crucible in a high-energy vibration device and assist with electromagnetic stirring. After rapidly water-cooling the sealed iron crucible to 25 °C, perform cutting treatment to obtain a magnesium + TiB2 nanoparticle ingot with good surface quality. Finally, heat the magnesium + TiB2 nanoparticle ingot to 350 °C, hold for 1 h, and perform extrusion after uniform temperature is reached. The extrusion ratio is 20 to obtain an intermediate alloy of deformed magnesium + TiB2 nanoparticles. Observe the prepared alloy by TEM. After statistics, it is found that the average diameter of TiB2 particles is about 17 nm. The yield of TiB2 nanoparticles is calculated to be about 90% through ICP testing.

[0053] Example 7

[0054] Select 25 nm SiC nanoparticles and clean them with acetone to remove surface impurities and organic contaminants. Disperse the cleaned nano-SiC in isopropanol to form a uniform suspension. After adding an appropriate amount of silane coupling agent to the suspension, heat it under nitrogen protection. After reacting for 18 h, use ethanol to remove the unreacted silane coupling agent and by-products to obtain SiC nanoparticles with a lipophilic and hydrophobic surface film layer. Use water bath heating to melt metallic Sn into a liquid state, and then add 10% of the surface-modified SiC nanoparticles to form a mixture. Place the mixture in an ultrasonic field for ultrasonic dispersion treatment for 20 min. Continue to place the dispersed particles in a high-shear mixer, select a rotation speed of 2000 r / min, and the treatment time is 1.5 h to construct a nano-suspension. Then add micron-sized pure magnesium powder to the suspension and use auxiliary ultrasonic waves to stir while adding until there is no obvious liquid. Cut a round hole with a diameter of 40 mm in the pure magnesium ingot, quickly cool the nano-suspension + magnesium powder mixture into a solid, and then place the solid into the round hole of the pre-prepared magnesium ingot, ensuring that the mixture does not liquefy throughout the process. Subsequently, plug the round hole in the pure magnesium ingot with a magnesium plug.

[0055] Seal the above pure magnesium ingots in an iron crucible and place it in an induction heating furnace for heating. Rapidly heat it to 700 °C at a rate of 25 °C / min, hold for 55 min, then place the crucible in a high-energy vibration device and assist with electromagnetic stirring. After rapidly water-cooling the sealed iron crucible to 25 °C, perform cutting treatment to obtain a magnesium + SiC nanoparticle ingot with good surface quality. Finally, heat the magnesium + SiC nanoparticle ingot to 290 °C, hold for 1.5 h, and perform extrusion after uniform temperature is reached. The extrusion ratio is 25 to obtain a deformed intermediate alloy of magnesium + SiC nanoparticles. Observe the prepared alloy by TEM. After statistics, it is found that the average diameter of the SiC particles is about 30 nm. The yield of the SiC nanoparticles is calculated to be about 87% through ICP testing.

[0056] Example 8

[0057] Select 20 nm TiC, SiO2, and SiC nanoparticles and clean them with acetone to remove surface impurities and organic contaminants. Disperse the cleaned TiC, SiO2, and SiC nanoparticles in isopropanol to form a uniform suspension. After adding an appropriate amount of silane coupling agent to the suspension, heat it under nitrogen protection. After reacting for 20 h, use ethanol to remove the unreacted silane coupling agent and by-products to obtain TiC, SiO2, and SiC nanoparticles with a lipophilic and hydrophobic surface film layer. Use water bath heating to melt the metal Sn into a liquid state, and then add 5% of the surface-modified TiC, SiO2, and SiC nanoparticles to form a mixture. Place the mixture in an ultrasonic field and perform ultrasonic dispersion treatment for 25 min. Continue to place the dispersed particles in a high-shear mixer, select a rotation speed of 2300 r / min, and the treatment time is 1.5 h to construct a nano-suspension. Then add micron-sized pure magnesium powder to the suspension and stir while adding with the assistance of ultrasonic waves until there is no obvious liquid. Cut a round hole with a diameter of 50 mm in the pure magnesium ingot, quickly cool the nano-suspension + magnesium powder mixture into a solid, and then place the solid into the round hole of the pre-prepared magnesium ingot, ensuring that the mixture does not liquefy throughout the process. Subsequently, plug the round hole on the pure magnesium ingot with a magnesium plug.

[0058] Seal the above pure magnesium ingots in an iron crucible, place it in an induction heating furnace for heating, rapidly heat it to 710 °C at a rate of 25 °C / min, hold for 60 min, then place the crucible in a high-energy vibration device and assist with electromagnetic stirring. After rapidly water-cooling the sealed iron crucible to 25 °C, perform cutting treatment to obtain magnesium + TiC, SiO2, and SiC nanoparticle ingots with good surface quality. Finally, heat the magnesium + TiC, SiO2, and SiC nanoparticle ingots to 250 °C, hold for 2 h, and perform extrusion after uniform temperature is reached. The extrusion ratio is 25 to obtain a deformed intermediate alloy of magnesium + TiC, SiO2, and SiC nanoparticles. Observe the prepared alloy by TEM. After statistics, it is found that the average diameters of TiC, SiO2, and SiC particles are about 26 nm. Calculate the yield of TiC, SiO2, and SiC nanoparticles to be about 91% through ICP testing.

[0059] Example 9

[0060] Select 30 nm TiB2 nanoparticles and clean them with acetone to remove surface impurities and organic contaminants. Disperse the cleaned TiB2 nanoparticles in isopropanol to form a uniform suspension. After adding an appropriate amount of silane coupling agent to the suspension, heat it under nitrogen protection. After reacting for 24 h, use ethanol to remove the unreacted silane coupling agent and by-products to obtain TiB2 nanoparticles with a lipophilic and hydrophobic surface film layer. Use water bath heating to melt metallic Hg into a liquid state, and then add 5% of the surface-modified TiB2 nanoparticles to form a mixture. Place the mixture in an ultrasonic field for ultrasonic dispersion treatment for 20 min. Continue to place the dispersed particles in a high-shear mixer with a rotation speed of 2500 r / min and a treatment time of 0.5 h to construct a nano-suspension. Then add micron-sized pure magnesium powder to the suspension and use auxiliary ultrasound to add and stir until there is no obvious liquid. Cut a round hole with a diameter of 40 mm in the pure magnesium ingot, quickly cool the nano-suspension + magnesium powder mixture into a solid, and then place the solid into the round hole of the pre-prepared magnesium ingot, ensuring that the mixture does not liquefy throughout the process. Subsequently, plug the round hole in the pure magnesium ingot with a magnesium plug.

[0061] Seal the above-mentioned pure magnesium ingot in an iron crucible, place it in an induction heating furnace for heating, rapidly heat it to 710 °C at a rate of 25 °C / min, hold for 30 min, then place the crucible in a high-energy vibration device and assist with electromagnetic stirring. After quickly water-cooling the sealed iron crucible to 20 °C, perform cutting treatment to obtain a magnesium + TiB2 nanoparticle ingot with good surface quality. Finally, heat the magnesium + TiB2 nanoparticle ingot to 330 °C, hold for 1 h, and perform extrusion after temperature equilibration. The extrusion ratio is 21 to obtain a deformed intermediate alloy of magnesium + TiB2 nanoparticles. Observe the prepared alloy by TEM. After statistics, it is found that the average diameter of TiB2 particles is about 36 nm. The yield of TiB2 nanoparticles is calculated to be about 90% through ICP testing.

[0062] Example 10

[0063] Select 15 nm SiC nanoparticles and clean them with acetone to remove surface impurities and organic contaminants. Disperse the cleaned nano-SiC in isopropanol to form a uniform suspension. After adding an appropriate amount of silane coupling agent to the suspension, heat it under nitrogen protection. After reacting for 24 h, use ethanol to remove the unreacted silane coupling agent and by-products to obtain SiC nanoparticles with a lipophilic and hydrophobic surface film layer. Use water bath heating to melt the GaIn alloy into a liquid state, and then add 8% of the surface-modified SiC nanoparticles to form a mixture. Place the mixture in an ultrasonic field for ultrasonic dispersion treatment for 30 min. Continue to put the dispersed particles into a high-shear mixer, select a rotation speed of 1800 r / min, and the treatment time is 2 h to construct a nano-suspension. Then add micron-scale pure magnesium powder to the suspension and use auxiliary ultrasound to stir while adding until there is no obvious liquid. Cut a round hole with a diameter of 50 mm in the pure magnesium ingot, quickly cool the nano-suspension + magnesium powder mixture into a solid, and then put the solid into the round hole of the magnesium ingot prepared in advance, ensuring that the mixture does not liquefy throughout the process. Subsequently, plug the round hole on the pure magnesium ingot with a magnesium plug.

[0064] Seal the above-mentioned pure magnesium ingots in an iron crucible and place it in an induction heating furnace for heating. Rapidly heat it to 710 °C at a rate of 25 °C / min, hold for 40 min, then place the crucible in a high-energy vibration device and assist with electromagnetic stirring. After quickly water-cooling the sealed iron crucible to 20 °C, perform cutting treatment to obtain a magnesium + SiC nanoparticle ingot with good surface quality. Finally, heat the magnesium + SiC nanoparticle ingot to 350 °C, hold for 1 h, and perform extrusion after uniform temperature is reached. The extrusion ratio is 20 to obtain a deformed intermediate alloy of magnesium + SiC nanoparticles. Observe the prepared alloy by TEM. After statistics, it is found that the average diameter of the SiC particles is about 21 nm. The yield of the SiC nanoparticles is calculated to be about 91% through ICP testing.

Claims

1. A preparation method of an intermediate alloy of a nanoparticle-reinforced magnesium-based material, characterized in that, It includes the following steps: (1) Modify the surface of the nanoparticles to form a lipophilic and hydrophobic surface film layer; (2) Disperse the surface-modified nanoparticles into a low-melting-point metal to form a mixture; (3) Disperse the mixture to obtain a nano-suspension, and then add micron-sized pure magnesium powder to the nano-suspension, stirring while adding by means of assisting ultrasonic waves until there is no obvious liquid left; (4) Cut a round hole in the pure magnesium ingot, quickly cool the obtained mixture into a solid, then put the solid into the round hole of the magnesium ingot, and plug the round hole of the magnesium ingot with a magnesium plug; (5) Seal the above-mentioned pure magnesium ingot into an iron crucible, place it in an induction heating furnace for heating, quickly raise the temperature to 690 - 710 °C at a rate of 25 °C / min, hold for 30 - 60 min, and then place the crucible in a high-energy vibration device to assist electromagnetic stirring; (6) Quickly water-cool the sealed iron crucible, and machine it to obtain a nano-particle magnesium ingot; (7) Heat the nano-particle magnesium ingot to between 250 - 350 °C, hold for 1 - 2 h, and perform extrusion after the temperature is evenly distributed, with the extrusion ratio controlled between 20 - 25 to obtain a deformed nano-particle reinforced magnesium-based material master alloy.

2. The preparation method of the nanoparticle-reinforced magnesium-based material master alloy according to claim 1, wherein The nanoparticles are one or more of SiO2, TiC, TiB2, and SiC.

3. The preparation method of the nanoparticle-reinforced magnesium-based material master alloy according to claim 2, characterized in that, The size of the nanoparticles is D50 = 5 - 30 nm.

4. The preparation method of the master alloy of the nanoparticle-reinforced magnesium-based material according to claim 1, wherein The surface of the nanoparticles is modified by an esterification method, a surface grafting reaction method, or a coupling agent method.

5. The preparation method of the master alloy of the nanoparticle-reinforced magnesium-based material according to claim 1, characterized in that, The low-melting-point metal is one or more of Ga, In, Hg, and Sn.

6. The preparation method of the nanoparticle-reinforced magnesium-based material master alloy according to claim 1, characterized in that, In the step (2), melt the low-melting-point metal into a liquid state, and then add 3 - 10% of the surface-modified nanoparticles by volume percentage to disperse and form a mixture.

7. The preparation method of the nano-particle reinforced magnesium-based master alloy according to claim 1, characterized in that, In the step (3), first ultrasonically disperse the mixture, and then disperse it in a high-shear mixer, with the ultrasonic dispersion time controlled within 20 - 30 min.

8. The preparation method of the master alloy of the nanoparticle-reinforced magnesium-based material according to claim 1, characterized in that, In the step (4), the diameter of the round hole is 30 - 50 mm.