A deformation-induced twinned aluminum-magnesium alloy composite material and preparation method thereof

Abstract

This invention relates to the field of aluminum alloy materials technology, and more specifically, to a deformation-induced twinned aluminum-magnesium alloy composite material and its preparation method. The composite material is an Hf2PbC particle-reinforced Al-Mg alloy composite material, wherein the Al-Mg alloy contains 2.0–6.5 wt% Mg, with the remainder being Al; the Hf2PbC particles have a size of 10 μm, and their addition amount accounts for 0.05–1.0% of the total mass of the composite material. This invention employs spark plasma sintering technology for preparation. Hf2PbC ceramic particles, as a high-melting-point, high-hardness reinforcing phase, can achieve particle composite reinforcement to improve the strength and hardness level of the Al-Mg alloy. By organically combining high-pressure torsion with Hopkinson bar dynamic loading technology, the synergistic effect of large plastic shear and high strain rate compression is achieved, which can induce continuous activation of multi-scale deformation mechanisms in the aluminum-magnesium alloy, effectively promoting the nucleation and expansion of high-density deformation twins.

Description

Technical Field

[0001] This invention relates to the field of aluminum alloy materials technology, and more specifically, to a deformation-induced twinned aluminum-magnesium alloy composite material and its preparation method. Background Technology

[0002] Aluminum-magnesium alloys, due to their lightweight, high specific strength, good corrosion resistance, and weldability, have broad application prospects in transportation, aerospace, and military industries. However, the mechanical properties of traditional aluminum-magnesium alloys still have significant shortcomings; their strength and ductility are often difficult to improve simultaneously, limiting their application in higher-performance scenarios. To improve alloy strength, researchers often use the addition of second-phase reinforcing particles (such as ceramic particles or intermetallic compounds) to achieve composite strengthening. However, this method often leads to a significant decrease in ductility while increasing hardness, affecting the material's formability and service reliability.

[0003] Recent research on nanostructured materials has shown that introducing twin boundaries can simultaneously optimize the strength and plasticity of materials. Twin boundaries can both promote plastic deformation as dislocation sources and hinder dislocation movement, thereby improving the strength-toughness balance of materials. However, aluminum and its alloys, as typical high stacking fault energy materials, exhibit dislocation slip dominating during conventional plastic deformation, making it difficult to spontaneously form deformation twins. This severely limits the application of twinning strengthening mechanisms in aluminum alloys. Although a small number of twins can be induced in aluminum through intense plastic deformation (such as constant diameter angular extrusion and high-pressure torsion) or extreme conditions (such as low-temperature deformation and high strain rate loading), the processes are complex and difficult to scale up. Therefore, developing novel processing technologies to promote the formation of deformation twins in aluminum-magnesium alloys under controllable conditions, breaking through the limitations of traditional strengthening mechanisms, and achieving a synergistic improvement in strength and plasticity has become a key scientific problem urgently needing to be solved in this field, and is of great significance for promoting the engineering application of high-performance aluminum-magnesium alloys. Summary of the Invention

[0004] The present invention aims to at least solve one of the technical problems existing in the prior art. To this end, one aspect of the present invention is to provide a deformation-induced twinned aluminum-magnesium alloy composite material, wherein the composite material is an Hf2PbC particle-reinforced Al-Mg alloy composite material, wherein the Al-Mg alloy composition by mass percentage is: Mg content of 2.0wt% to 6.5wt%, with the remainder being Al; the Hf2PbC particle size is 10μm, and its addition amount accounts for 0.05% to 1.0% of the total mass of the composite material.

[0005] Another objective of this invention is to provide a method for preparing a deformation-induced twinned aluminum-magnesium alloy composite material, the specific steps of which are as follows:

[0006] S1. Preparation of Al-Mg alloy spherical powder: Prepare raw materials with Mg content of 2.0wt% to 6.5wt% by mass percentage and Al as the remainder. Melt the material with qualified composition by induction melting device and maintain superheat. Then spray the melt into atomizing disk. Under the centrifugal action of high speed rotation of atomizing disk, the molten droplets are thrown out and fly, cool and solidify in atomizing chamber to form powder.

[0007] S2. Preparation of Hf2PbC particle-reinforced Al-Mg alloy composite powder: Al-Mg alloy powder with a particle size of less than 10μm was sieved out, and then Hf2PbC powder with a particle size of about 10μm was selected. The amount of Hf2PbC powder added accounted for 0.05% to 1.0% of the total mass. The two powders were put into a WC ball mill jar, and a dispersant was added. The mixture was then ball-milled using WC milling balls.

[0008] S3. Sintering Hf2PbC particle-reinforced Al-Mg alloy composite material bulk: The Hf2PbC particle-reinforced powder prepared in S2 is placed in a plasma discharge sintering furnace for discharge plasma hot pressing sintering;

[0009] S4. Processing raw specimens of Hf2PbC particle-reinforced Al-Mg alloy composite material: The material prepared in S3 is processed into circular specimens by wire cutting.

[0010] S5. High-pressure torsion treatment: Place the circular sample cut in S4 between the upper and lower molds of the high-pressure torsion device, ensuring that the sample is centered and fits tightly with the mold. First, apply axial preload and then apply pre-torsion at a constant speed. Then, increase the axial pressure and maintain it at a constant pressure. Under this high-pressure state, continue to apply the main torsion at a constant speed, causing the sample to undergo severe plastic shear deformation and gradually reduce its thickness.

[0011] S6. Hopkinson bar dynamic loading: The specimen after high-pressure torsion treatment in S5 is placed in the Hopkinson bar test device and clamped between the incident bar and the transmission bar. An axial high strain rate impact load is applied to the specimen. Through multiple dynamic deformations, the specimen thickness is further reduced to achieve plastic compression deformation, thereby inducing the formation of an ultrafine twinned structure.

[0012] Preferably, in step S1, the superheat is 50℃-150℃, and the melt is injected into the atomizing disc at a flow rate of 40Kg / h-100Kg / h.

[0013] Preferably, in S1, the atomizing disc has a diameter of 100mm, a rotation speed of 30000-80000r / min, and the atomizing chamber is filled with Ar protective gas.

[0014] Preferably, the dispersant in S2 is stearic acid powder.

[0015] Preferably, in S2, the WC grinding balls have a particle size of 3mm to 16mm and are subjected to ball milling; the ball milling speed is 350 to 450 rpm, the ball-to-material ratio is (15 to 20): 1, the ball milling time is 10 to 20 hours, and Ar protection is introduced throughout the ball milling process.

[0016] Preferably, the sintering temperature range in S3 is 350℃~450℃, the sintering pressure is 50MPa, and the holding time is 5min~10min.

[0017] Preferably, in step S4, the material prepared in step S3 is processed into a circular sample with a diameter of 20 mm and a thickness of 4 mm by wire cutting.

[0018] Preferably, in step S5, an axial preload of 2 GPa is first applied, followed by two pre-torsion rotations at a constant speed of 0.5 rpm. Then, the axial pressure is increased to 4 GPa to 6 GPa and kept constant. Under this high pressure, the main torsion is applied for another 10 rotations at a speed of 0.8 rpm, causing the sample to undergo severe plastic shear deformation and the thickness to gradually decrease to about 2 mm.

[0019] Preferably, in step S6, the pressure of the incident rod driving air is adjusted to 0.35 MPa to 0.55 MPa, the deformation temperature is controlled between -196°C and room temperature, and the corresponding strain rate range is 1500 s⁻¹ to 3000 s⁻¹. Through multiple dynamic deformations, the sample thickness is further reduced to 1 mm, and the corresponding axial true strain is 0.693, achieving approximately 50% plastic compressive deformation.

[0020] The beneficial effects of this invention are as follows:

[0021] 1. This invention uses spark plasma sintering (SPS) technology to prepare Hf2PbC particle-reinforced Al-Mg alloy composite materials. Hf2PbC ceramic particles, as a high-melting-point and high-hardness reinforcing phase, can achieve particle composite reinforcement to improve the strength and hardness of Al-Mg alloy materials.

[0022] 2. In this invention, the Mg content is precisely controlled within the mass percentage range of 2.0 wt% to 6.5 wt%, allowing Mg to be distributed in the aluminum matrix in a solid solution form. This effectively regulates the degree of lattice distortion and reduces the stacking fault energy of aluminum (based on relevant theoretical estimates, the stacking fault energy of pure Al is approximately 150 mJ / m). 2 After adding 6.5 wt% Mg, the stacking fault energy is approximately 60 mJ / m. 2 This process promotes the nucleation and propagation of twins under conditions of intense plastic deformation. Simultaneously, it avoids the precipitation of brittle second phases such as Al3Mg2 under high Mg content conditions, helping to maintain grain boundary integrity and twin boundary stability, ultimately resulting in an aluminum-magnesium alloy with a high-density, ultrafine twinned structure, balancing strength and plasticity.

[0023] 3. This invention organically combines high-pressure torsion (HPT) with Hopkinson bar dynamic loading technology, achieving a synergistic effect of high plastic shear and high strain rate compression. This enables the continuous activation of multi-scale deformation mechanisms in aluminum-magnesium alloys, effectively promoting the nucleation and expansion of high-density deformation twins. During high-pressure torsion, the combined effects of high pressure and torsion refine the grains, forming ultrafine or even nanocrystalline structures. Therefore, high-pressure torsion provides the material with an initial uniform and refined microstructure and high dislocation density. This method is often used to improve the strength, hardness, and other mechanical properties of materials while maintaining good ductility. It provides a structural basis for subsequent twin nucleation. Meanwhile, Hopkinson bar loading further drives the generation of a large number of twins under high strain rate and dynamic stress conditions, enhancing microstructure density and interface stability. The combination of these two methods not only improves the quantity and quality of deformation twins but also overcomes the limitations of a single deformation mode, significantly enhancing the material's comprehensive mechanical properties and microstructure control capabilities.

[0024] Additional aspects and advantages of the invention will become apparent from the description which follows, or may be learned by practice of the invention. Attached Figure Description

[0025] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0026] Figure 1 This is a schematic diagram of the high-pressure torsion process;

[0027] Figure 2 This is a schematic diagram of the microstructure transformation during high-pressure torsion;

[0028] Figure 3 These are images of 0.05wt% Hf2PbC / Al-5.5Mg plasma hot pressing sintering (SPS) after Example 1 of the present invention;

[0029] Figure 4 This is a TEM image of a 0.05wt% Hf2PbC / Al-5.5Mg matrix twin from Example 1 of this invention. Detailed Implementation

[0030] To better understand the above-mentioned objectives, features, and advantages of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0031] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the invention is not limited to the specific embodiments disclosed below.

[0032] like Figure 1 and 2 As shown, the high-pressure torsion process gradually achieves grain refinement through a series of processes, including dislocation accumulation, subgrain structure formation, and grain boundary evolution. Therefore, high-pressure torsion provides the material with an initial uniform and refined microstructure. According to the theory of grain refinement strengthening, smaller grain size is more conducive to strength, hardness, and maintaining good ductility, providing a structural basis for subsequent twin nucleation.

[0033] If the material has not undergone high-pressure torsion, the original grains are relatively coarse, and grain size is closely related to the material's plastic deformation capacity. With coarse grains, the grain boundary area decreases, reducing the resistance of grain boundaries to dislocation movement and leading to a decrease in the overall plasticity of the material. Simultaneously, the internal stress distribution of coarse-grained materials is extremely uneven, making localized stress concentrations more likely and increasing the probability of crack initiation and propagation. During the rapid deformation of the Hopkinson bar, this stress concentration effect is further aggravated, inducing rapid propagation of brittle cracks and ultimately leading to premature cracking or even fracture of the specimen. Therefore, coarse-grained materials exhibit more pronounced brittle characteristics in Hopkinson bar experiments, with a significantly increased tendency to crack. Therefore, it is essential to refine the grains through high-pressure torsion before conducting rapid deformation experiments on Hopkinson bars.

[0034] After high-pressure torsion, the grain size of the Hf2PbC particle-reinforced Al-Mg alloy composite material is tens of micrometers. Furthermore, the addition of appropriate Mg elements to the matrix significantly reduces the stacking fault energy, thus facilitating the initiation of a twinning deformation mechanism. During the rapid deformation of the Hopkinson bar, under high strain rate loading, dislocation movement and slip within the material are restricted, and local shear stress rapidly increases, prompting the material to undergo plastic deformation through a twinning mechanism. During high-speed impact, the probability of internal stress exceeding the critical shear stress for twinning increases significantly, thereby triggering the activation of the crystal twinning mechanism. Moreover, the local stress waves induced by high-speed deformation propagate rapidly within the grains, causing intense local strain concentration, intensifying the nucleation and rapid expansion of twins, and ultimately forming a twinned structure.

[0035] Example 1

[0036] Preparation of Al-Mg alloy spherical powder: The raw materials are prepared according to the following composition ratio: Mg content is 5.5wt%, and the remainder is Al. The raw materials are melted by induction melting device to obtain a melt with qualified composition and maintained at 100℃ superheat. Then, the melt is sprayed into an atomizing disk at a flow rate of 50Kg / h. Under the centrifugal action of the high-speed rotation of the atomizing disk, the molten droplets are thrown out and fly, cool, and solidify in the atomizing chamber to form powder. The diameter of the atomizing disk is 100mm and the rotation speed is 55000r / min. The atomizing chamber is filled with Ar protective gas.

[0037] Preparation of Hf2PbC particle-reinforced Al-Mg alloy composite powder: Al-Mg alloy powder with a particle size of less than 10μm was sieved out, and then Hf2PbC powder with a particle size of about 10μm was selected, accounting for 0.05% of the total mass. The two powders were put into a WC ball mill jar, and stearic acid powder was added as a dispersant. WC milling balls with a particle size of 3mm~16mm were used for ball milling. The ball milling speed was 400rpm, the ball-to-material ratio was 20:1, and the ball milling time was 15h. Ar protection was introduced throughout the ball milling process.

[0038] Sintered Hf2PbC particle-reinforced Al-Mg alloy composite material bulk: The prepared Hf2PbC particle-reinforced powder was placed in a plasma discharge sintering furnace for discharge plasma hot pressing sintering. The sintering temperature range was 380℃, the sintering pressure was 50MPa, and the holding time was 5min.

[0039] Processing raw sample of Hf2PbC particle-reinforced Al-Mg alloy composite material: The prepared material was processed into circular sample with a diameter of 20 mm and a thickness of 4 mm by wire cutting. Both sides of the sample were mechanically polished to ensure the surface was flat.

[0040] High-pressure torsion treatment: The circular sample is placed into the high-pressure torsion mold system, centered, and clamped. First, an axial preload of 2 GPa is applied, followed by two pre-torsion rotations at 0.5 rpm to activate dislocations and the initial micro-deformation mechanism. Then, the axial pressure is increased to 5 GPa and maintained at a constant pressure. Under this condition, the main torsion is continued at 0.8 rpm for 10 rotations. During this process, the sample thickness is gradually reduced from 4 mm to approximately 2 mm, forming a high-density dislocation structure and refining the grains.

[0041] Dynamic loading using the Hopkinson bar: The sample, after high-pressure torsion treatment, was clamped between the incident and transmission bars of a Φ14mm high-strength steel Hopkinson bar device, with insulating tape used for positioning. The device's driving air pressure was set to 0.45MPa, and the initial loading velocity was approximately 20m / s. The deformation temperature was controlled at room temperature, and the corresponding strain rate during the deformation process was approximately 2200s⁻¹. After one loading cycle, the sample thickness was compressed from 2mm to 1mm, with a true axial strain of 0.693, indicating sufficient plastic compressive deformation.

[0042] The deformed sample was observed using a transmission electron microscope (TEM), and a deformed twin structure was clearly visible within its grains, verifying the effectiveness of the method of this invention in forming twin structures. Figure 3 (Images of 0.05wt% Hf2PbC / Al-5.5Mg after plasma hot pressing (SPS)) and Figure 4 As shown in the TEM image of the 0.05wt%Hf2PbC / Al-5.5Mg matrix twins, distinct twinning characteristics are evident. These twins appear as a series of straight, regularly arranged fine bands that penetrate the grain interior. The twin interfaces are clear. The 0.05wt%Hf2PbC / Al-5.5Mg matrix material is an Al-5.5Mg alloy. Due to the addition of Mg, the matrix stacking fault energy is reduced. Under the high-speed impact load of the Hopkinson bar, rapid deformation triggers the twinning mechanism, inducing the formation of a twinned structure.

[0043] Example 2

[0044] Preparation of Al-Mg alloy spherical powder: The raw materials are prepared according to the following composition ratio: Mg content is 4.0wt%, and the remainder is Al. The raw materials are melted by induction melting device to obtain a melt with qualified composition and maintained at a superheat of 80°C. Then, the melt is sprayed into an atomizing disk at a flow rate of 50Kg / h. Under the centrifugal action of the high-speed rotation of the atomizing disk, the molten droplets are thrown out and fly, cool, and solidify in the atomizing chamber to form powder. The diameter of the atomizing disk is 100mm and the rotation speed is 55000r / min. The atomizing chamber is filled with Ar protective gas.

[0045] Preparation of Hf2PbC particle-reinforced Al-Mg alloy composite powder: Al-Mg alloy powder with a particle size of less than 10μm was sieved out, and then Hf2PbC powder with a particle size of about 10μm was selected, accounting for 0.1% of the total mass. The two powders were put into a WC ball mill jar, and stearic acid powder was added as a dispersant. WC milling balls with a particle size of 3mm~16mm were used for ball milling. The ball milling speed was 400rpm, the ball-to-material ratio was 15:1, and the ball milling time was 15h. Ar protection was introduced throughout the ball milling process.

[0046] Sintered Hf2PbC particle-reinforced Al-Mg alloy composite material bulk: The prepared Hf2PbC particle-reinforced powder was placed in a plasma discharge sintering furnace for discharge plasma hot pressing sintering. The sintering temperature range was 380℃, the sintering pressure was 50MPa, and the holding time was 5min.

[0047] Processing raw sample of Hf2PbC particle-reinforced Al-Mg alloy composite material: The prepared material was processed into circular sample with a diameter of 20 mm and a thickness of 4 mm by wire cutting. Both sides of the sample were mechanically polished to ensure the surface was flat.

[0048] High-pressure torsion treatment: The circular sample is placed into the high-pressure torsion mold system, centered, and clamped. First, an axial preload of 2 GPa is applied, followed by two pre-torsion rotations at 0.5 rpm to activate dislocations and the initial micro-deformation mechanism. Then, the axial pressure is increased to 4 GPa and maintained at a constant pressure. Under this condition, the main torsion is continued at 0.8 rpm for 10 rotations. During this process, the sample thickness is gradually reduced from 4 mm to approximately 2 mm, forming a high-density dislocation structure and refining the grains.

[0049] Dynamic loading using the Hopkinson bar: The sample, after high-pressure torsion treatment, was clamped between the incident and transmission bars of a Φ14mm high-strength steel Hopkinson bar device, with insulating tape used for positioning. The device's driving air pressure was set to 0.45MPa, and the initial loading velocity was approximately 20m / s. The deformation temperature was controlled at room temperature, and the corresponding strain rate during the deformation process was approximately 2200s⁻¹. After one loading cycle, the sample thickness was compressed from 2mm to 1mm, with a true axial strain of 0.693, indicating sufficient plastic compressive deformation.

[0050] The deformed sample was observed by transmission electron microscopy (TEM), and the deformed twin structure could be clearly observed inside its grains, verifying the effectiveness of the method of the present invention in the formation of twin structures.

[0051] Example 3

[0052] Preparation of Al-Mg alloy spherical powder: The raw materials are prepared according to the following composition ratio: Mg content is 4.5wt%, and the remainder is Al. The raw materials are melted by induction melting device to obtain a melt with qualified composition and maintained at a superheat of 70°C. Then, the melt is sprayed into an atomizing disk at a flow rate of 50Kg / h. Under the centrifugal action of the high-speed rotation of the atomizing disk, the molten droplets are thrown out and fly, cool, and solidify in the atomizing chamber to form powder. The diameter of the atomizing disk is 100mm and the rotation speed is 55000r / min. The atomizing chamber is filled with Ar protective gas.

[0053] Preparation of Hf2PbC particle-reinforced Al-Mg alloy composite powder: Al-Mg alloy powder with a particle size of less than 10μm was sieved out, and then Hf2PbC powder with a particle size of about 10μm was selected, accounting for 0.2% of the total mass. The two powders were put into a WC ball mill jar, and stearic acid powder was added as a dispersant. WC grinding balls with a particle size of 3mm~16mm were used for ball milling. The ball milling speed was 400rpm, the ball-to-material ratio was 15:1, and the ball milling time was 15h. Ar protection was introduced throughout the ball milling process.

[0054] Sintered Hf2PbC particle-reinforced Al-Mg alloy composite material bulk: The prepared Hf2PbC particle-reinforced powder was placed in a plasma discharge sintering furnace for discharge plasma hot pressing sintering. The sintering temperature range was 380℃, the sintering pressure was 50MPa, and the holding time was 5min.

[0055] Processing raw sample of Hf2PbC particle-reinforced Al-Mg alloy composite material: The prepared material was processed into circular sample with a diameter of 20 mm and a thickness of 4 mm by wire cutting. Both sides of the sample were mechanically polished to ensure the surface was flat.

[0056] High-pressure torsion treatment: The circular sample is placed into the high-pressure torsion mold system, centered, and clamped. First, an axial preload of 2 GPa is applied, followed by two pre-torsion rotations at 0.5 rpm to activate dislocations and the initial micro-deformation mechanism. Then, the axial pressure is increased to 5 GPa and maintained at a constant pressure. Under this condition, the main torsion is continued at 0.8 rpm for 10 rotations. During this process, the sample thickness is gradually reduced from 4 mm to approximately 2 mm, forming a high-density dislocation structure and refining the grains.

[0057] Dynamic loading using the Hopkinson bar: The sample, after high-pressure torsion treatment, was clamped between the incident and transmission bars of a Φ14mm high-strength steel Hopkinson bar device, with insulating tape used for positioning. The device's driving air pressure was set to 0.45MPa, and the initial loading velocity was approximately 20m / s. The deformation temperature was controlled at room temperature, and the corresponding strain rate during the deformation process was approximately 2200s⁻¹. After one loading cycle, the sample thickness was compressed from 2mm to 1mm, with a true axial strain of 0.693, indicating sufficient plastic compressive deformation.

[0058] The deformed sample was observed by transmission electron microscopy (TEM), and the deformed twin structure could be clearly observed inside its grains, verifying the effectiveness of the method of the present invention in the formation of twin structures.

[0059] The embodiments of the present invention demonstrate that by combining high-pressure torsion with dynamic loading of a Hopkinson bar, an ultrafine twinned structure can be constructed in aluminum-magnesium alloys, significantly improving the material's microstructure uniformity and mechanical properties, thus verifying the feasibility and superiority of the present invention.

[0060] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the invention by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A deformation-induced twinned aluminum-magnesium alloy composite material, characterized in that: The composite material is an Hf2PbC particle-reinforced Al-Mg alloy composite material, wherein the Al-Mg alloy composition by mass percentage is: Mg content of 2.0wt% to 6.5wt%, with the remainder being Al; the Hf2PbC particle size is 10μm, and its addition amount accounts for 0.05% to 1.0% of the total mass of the composite material; The specific steps for preparing composite materials are as follows: S1. Preparation of Al-Mg alloy spherical powder: Prepare raw materials with Mg content of 2.0wt% to 6.5wt% by mass percentage and Al as the remainder. Melt the material with qualified composition by induction melting device and maintain superheat. Then spray the melt into atomizing disk. Under the centrifugal action of high speed rotation of atomizing disk, the molten droplets are thrown out and fly, cool and solidify in atomizing chamber to form powder. S2. Preparation of Hf2PbC particle-reinforced Al-Mg alloy composite powder: Al-Mg alloy powder with a particle size of less than 10μm was sieved out, and then Hf2PbC powder with a particle size of 10μm was selected. The amount of Hf2PbC powder added accounted for 0.05% to 1.0% of the total mass. The two powders were put into a WC ball mill jar, and a dispersant was added. The mixture was then ball-milled using WC milling balls. S3. Sintering Hf2PbC particle-reinforced Al-Mg alloy composite material bulk: The Hf2PbC particle-reinforced powder prepared in S2 is placed in a plasma discharge sintering furnace for discharge plasma hot pressing sintering; S4. Processing raw specimens of Hf2PbC particle-reinforced Al-Mg alloy composite material: The material prepared in S3 is processed into circular specimens by wire cutting. S5. High-pressure torsion treatment: Place the circular sample cut in S4 between the upper and lower molds of the high-pressure torsion device, ensuring that the sample is centered and fits tightly with the mold. First, apply axial preload and apply pre-torsion at a constant speed. Then, increase the axial pressure and maintain it at a constant pressure. Continue to apply the main torsion under this high-pressure state to cause the sample to undergo severe plastic shear deformation and gradually reduce its thickness. S6. Hopkinson bar dynamic loading: The specimen after high-pressure torsion treatment in S5 is placed in the Hopkinson bar test device and clamped between the incident bar and the transmission bar. An axial high strain rate impact load is applied to the specimen. Through multiple dynamic deformations, the specimen thickness is further reduced to achieve plastic compression deformation, thereby inducing the formation of an ultrafine twinned structure.

2. The method for preparing a deformation-induced twinned aluminum-magnesium alloy composite material according to claim 1, characterized in that: The specific steps of the preparation method are as follows: S1. Preparation of Al-Mg alloy spherical powder: Prepare raw materials with Mg content of 2.0wt% to 6.5wt% by mass percentage and Al as the remainder. Melt the material with qualified composition by induction melting device and maintain superheat. Then spray the melt into atomizing disk. Under the centrifugal action of high speed rotation of atomizing disk, the molten droplets are thrown out and fly, cool and solidify in atomizing chamber to form powder. S2. Preparation of Hf2PbC particle-reinforced Al-Mg alloy composite powder: Al-Mg alloy powder with a particle size of less than 10μm was sieved out, and then Hf2PbC powder with a particle size of 10μm was selected. The amount of Hf2PbC powder added accounted for 0.05% to 1.0% of the total mass. The two powders were put into a WC ball mill jar, and a dispersant was added. The mixture was then ball-milled using WC milling balls. S3. Sintering Hf2PbC particle-reinforced Al-Mg alloy composite material bulk: The Hf2PbC particle-reinforced powder prepared in S2 is placed in a plasma discharge sintering furnace for discharge plasma hot pressing sintering; S4. Processing raw specimens of Hf2PbC particle-reinforced Al-Mg alloy composite material: The material prepared in S3 is processed into circular specimens by wire cutting. S5. High-pressure torsion treatment: Place the circular sample cut in S4 between the upper and lower molds of the high-pressure torsion device, ensuring that the sample is centered and fits tightly with the mold. First, apply axial preload and apply pre-torsion at a constant speed. Then, increase the axial pressure and maintain it at a constant pressure. Continue to apply the main torsion under this high-pressure state to cause the sample to undergo severe plastic shear deformation and gradually reduce its thickness. S6. Hopkinson bar dynamic loading: The specimen after high-pressure torsion treatment in S5 is placed in the Hopkinson bar test device and clamped between the incident bar and the transmission bar. An axial high strain rate impact load is applied to the specimen. Through multiple dynamic deformations, the specimen thickness is further reduced to achieve plastic compression deformation, thereby inducing the formation of an ultrafine twinned structure.

3. The method for preparing a deformation-induced twinned aluminum-magnesium alloy composite material according to claim 2, characterized in that: The superheat in S1 is 50℃-150℃, and the melt is injected into the atomizing disc at a flow rate of 40kg / h-100kg / h.

4. The method for preparing a deformation-induced twinned aluminum-magnesium alloy composite material according to claim 2, characterized in that: In S1, the atomizing disc has a diameter of 100mm, a rotation speed of 30,000-80,000 r / min, and the atomizing chamber is filled with Ar protective gas.

5. The method for preparing a deformation-induced twinned aluminum-magnesium alloy composite material according to claim 2, characterized in that: The dispersant in S2 is stearic acid powder.

6. The method for preparing a deformation-induced twinned aluminum-magnesium alloy composite material according to claim 2, characterized in that: In S2, the WC grinding balls have a particle size of 3mm to 16mm and are ball-milled; the ball milling speed is 350 to 450 rpm, the ball-to-material ratio is (15 to 20): 1, the ball milling time is 10 to 20 hours, and Ar protection is introduced throughout the ball milling process.

7. The method for preparing a deformation-induced twinned aluminum-magnesium alloy composite material according to claim 2, characterized in that: The sintering temperature range of S3 is 350℃~450℃, the sintering pressure is 50MPa, and the holding time is 5min~10min.

8. The method for preparing a deformation-induced twinned aluminum-magnesium alloy composite material according to claim 2, characterized in that: In step S4, the material prepared in step S3 is processed into a circular sample with a diameter of 20 mm and a thickness of 4 mm by wire cutting.

9. The method for preparing a deformation-induced twinned aluminum-magnesium alloy composite material according to claim 2, characterized in that: In step S5, an axial preload of 2 GPa is first applied, followed by two pre-torsion rotations at a constant speed of 0.5 rpm. Then, the axial pressure is increased to 4 GPa to 6 GPa and kept constant. Under this high pressure, the main torsion is applied for another 10 rotations at a speed of 0.8 rpm, causing the sample to undergo severe plastic shear deformation and gradually reduce its thickness to 2 mm.

10. The method for preparing a deformation-induced twinned aluminum-magnesium alloy composite material according to claim 2, characterized in that: In step S6, the air pressure of the incident rod is adjusted to 0.35MPa to 0.55MPa, and the deformation temperature is controlled between -196℃ and room temperature. The corresponding strain rate range is 1500s⁻¹ to 3000s⁻¹. Through multiple dynamic deformations, the sample thickness is further reduced to 1mm, and the corresponding axial true strain is 0.693, achieving 50% plastic compression deformation.

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