Preparation method of iron-based amorphous particle reinforced magnesium-rare earth-based composite material and composite material

Abstract

The application provides a preparation method of an iron-based amorphous particle reinforced magnesium-rare earth-based composite material, and belongs to the technical field of magnesium alloy materials; the preparation method comprises the following steps: S1, semi-solid state stirring casting forming: placing a base alloy in a crucible, heating to form a magnesium melt under the condition of passing protection gas, reducing the temperature of the magnesium melt to a semi-solid state temperature by using a stage type temperature reduction method, adding preheated iron-based amorphous particles into the magnesium melt and stirring, then heating and stirring, and then rapidly cooling to obtain a cast composite material after heat preservation and standing; and S2, solid solution treatment; the application provides a preparation method of an iron-based amorphous particle reinforced magnesium-rare earth-based composite material, and the influence of the content of the iron-based amorphous particles, heat treatment and hot extrusion on the structure and performance of the composite material is studied, so as to prepare an iron-based amorphous particle reinforced magnesium-rare earth-based composite material with good comprehensive performance.

Description

Technical Field

[0001] This invention relates to the field of magnesium alloy materials technology, specifically to a method for preparing an iron-based amorphous particle-reinforced magnesium rare earth-based composite material, and the iron-based amorphous particle magnesium rare earth-based composite material obtained by the method. Background Technology

[0002] Magnesium and magnesium alloys, as lightweight materials, are widely used in aerospace, 3C (computers, communications, and consumer electronics), defense, and automotive industries. Despite their advantages in certain aspects, magnesium alloys suffer from drawbacks such as relatively low absolute strength, poor high-temperature creep resistance, and a high coefficient of thermal expansion, which limit their development and utilization. Adding rare earth elements to magnesium alloys can purify the melt, refine the grain size, and improve the room-temperature and high-temperature mechanical properties. While the emergence of rare earth magnesium alloys has expanded their application areas, they still fall short in applications requiring high strength, hardness, wear resistance, and corrosion resistance, especially when the mechanical properties of magnesium alloys are nearing their limits. To further improve the performance of magnesium alloys, composite materials offer a new design approach. By adding appropriate amounts of ceramic or metallic materials as reinforcements to magnesium alloys, magnesium-based composite materials can be prepared, thereby improving and optimizing the strength, modulus, stiffness, and wear resistance of the magnesium matrix.

[0003] In magnesium-based composites, the choice of matrix and reinforcement plays a crucial role in the final performance of the composite. The improvement in composite performance by reinforcement has certain limitations; therefore, the choice of matrix determines the performance level of the final composite. Using pure magnesium as the matrix is ​​advantageous because it facilitates observation of the reinforcement effect and exploration of the reinforcement mechanism between the reinforcement and the magnesium matrix. However, due to the poor mechanical properties of pure magnesium, the performance of the resulting composite is limited. If a magnesium-based composite with excellent mechanical properties is desired, pure magnesium is not suitable as a direct matrix; a magnesium alloy must be selected. Studies have shown that adding rare earth elements such as Gd, Y, Er, Sm, and Ce to magnesium alloys can improve their mechanical properties and creep resistance. Compared to ordinary magnesium alloys, rare earth magnesium alloys not only have higher strength, better high-temperature resistance and corrosion resistance, but also have the advantages of easy processing and recycling. Therefore, using rare earth magnesium alloys as the matrix of composites may lead to the preparation of magnesium-based composites with even higher mechanical properties.

[0004] The reinforcing agent is key to achieving strengthening in composite materials. Commonly used reinforcing phases in magnesium matrix composites include ceramic particles and heterostructured metal particles. These reinforcing phases play an important role in improving the mechanical properties and heat resistance of magnesium matrix composites. Ceramic particles, as a commonly used reinforcing phase in magnesium matrix composites, have advantages such as high hardness, wear resistance, and corrosion resistance, effectively improving the strength and rigidity of the composite material. Although ceramic particle-reinforced magnesium matrix composites have many advantages, they also present some challenges. Specifically, the limited fracture strain of the ceramic particles themselves and the poor interface between them and the matrix lead to a decrease in the fracture toughness of the composite material, thereby reducing the impact toughness. Given the contradiction between strength and toughness in ceramic particle-reinforced magnesium matrix composites, researchers have begun to explore the use of heterostructured metals to reinforce magnesium matrix composites to improve the overall performance of magnesium alloy composites. Heterostructured metal-reinforced magnesium matrix composites enhance the mechanical and heat resistance properties of magnesium matrix materials while retaining good plasticity by embedding heterostructured metal particles into the magnesium matrix.

[0005] Amorphous materials possess the properties of general metals and glasses. Thanks to their unique atomic arrangement, amorphous materials exhibit high strength, high hardness, good corrosion resistance, a large elastic strain limit, and excellent wear resistance. Among various amorphous materials, iron-based amorphous materials have attracted widespread attention from researchers due to their excellent soft magnetic properties, high corrosion resistance, high strength, high hardness, and high wear resistance. Compared with traditional crystalline materials, amorphous materials have significantly different structures and properties. They can form metallic bonds at interfaces and have a low coefficient of thermal expansion, thus serving as a better alternative to traditional ceramic reinforcement materials. By organically combining the high strength and high wear resistance of amorphous materials with the fracture toughness and plasticity of crystalline metal compounds, the amorphous materials and metal matrix mutually reinforce each other, ultimately resulting in metal matrix composites with excellent properties. Amorphous particle-reinforced metal matrix composites are an emerging research field. Using amorphous materials as reinforcement, their high strength and high elastic strain limit can provide excellent mechanical properties for composite materials.

[0006] Semi-solid stirring casting is a common method for preparing magnesium matrix composites reinforced with metal particles. This method involves melting a magnesium alloy into a molten magnesium mass, adding metal particle reinforcement to the molten magnesium mass, stirring, and then cooling to obtain the as-cast composite material. In traditional magnesium matrix composite preparation processes, the reinforcing particles tend to settle or aggregate due to the density difference between them and the matrix metal, resulting in uneven particle distribution within the matrix. This uneven distribution can cause localized instability in the composite material's properties, affecting its overall mechanical properties. Summary of the Invention

[0007] This invention provides a method for preparing iron-based amorphous particle-reinforced magnesium rare earth-based composite materials. By studying the effects of iron-based amorphous particle content, heat treatment, and hot extrusion on the microstructure and properties of the composite material, the aim is to obtain iron-based amorphous particle-reinforced magnesium rare earth-based composite materials with excellent comprehensive performance.

[0008] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A method for preparing an iron-based amorphous particle-reinforced magnesium rare earth-based composite material, using a magnesium rare earth alloy as the matrix alloy and iron-based amorphous particles as the reinforcing phase, the preparation method includes the following steps: S1. Semi-solid stirring casting: The matrix alloy is placed in a crucible and heated to form a magnesium melt under the condition of a protective gas. The temperature of the magnesium melt is reduced to a semi-solid temperature by a staged cooling method. The preheated iron-based amorphous particles are added to the magnesium melt and stirred. Then the temperature is raised and stirred. After holding at the temperature and standing, the mixture is rapidly cooled to obtain the as-cast composite material. S2, Solution treatment: The as-cast composite material prepared in S1 was solution treated at 520℃ for 7 hours; S3. Hot extrusion molding: The composite material in S2 that has undergone solution treatment is subjected to isothermal hot extrusion deformation to obtain iron-based amorphous particle magnesium rare earth-based composite material.

[0009] Preferably, the preparation method further includes an aging treatment step for the composite material, wherein the aging treatment conditions are: aging treatment at 250°C for 16 hours.

[0010] Preferably, the mass ratio of the iron-based amorphous particles to the composite material is (2% to 6%): 1.

[0011] Preferably, in S1, an angle grinder is used to remove the oxide film on the surface of the base alloy before placing it in the crucible.

[0012] Preferably, the protective gas in S1 is a mixture of carbon dioxide and sulfur hexafluoride in a volume fraction ratio of 99:1.

[0013] Preferably, the temperature at which magnesium melt is formed in S1 is 730°C; the semi-solid temperature is 635°C.

[0014] Preferably, the matrix parameters for stirring in S1 are as follows: using a stirrer, the initial stirring speed is 350 r·min. -1 The stirring time is 2 minutes; when the magnesium melt reaches a slurry state, the stirring speed is increased to 950 rpm. -1 The stirring time was 6 minutes. During stirring, a combination of up-and-down stirring and tilting was used, ensuring the stirring head remained immersed in the magnesium melt throughout the process. After the stirring was completed, the magnesium melt was heated. When the temperature reached 645°C, the stirring was repeated at 350 rpm.-1 After stirring the magnesium melt at a certain speed for 30 seconds, remove the stirrer and use a slotted spoon to remove slag and impurities from the composite material melt.

[0015] Preferably, the preheating conditions for the iron-based amorphous particles in S1 are: preheating in a drying oven at 200°C for 1 hour.

[0016] Preferably, the hot extrusion molding conditions in S3 are: isothermal hot extrusion deformation at 450°C, with an extrusion ratio of 25:1.

[0017] The iron-based amorphous particle magnesium rare earth-based composite material prepared according to the aforementioned preparation method has yield strength YS, ultimate tensile strength UTS, elongation EL, and Young's modulus E of 4wt.% and 157MPa, 266MPa, 6%, and 49.16GPa, respectively.

[0018] As can be seen from the above technical solutions, the present invention has the following beneficial effects: 1. In this invention, a semi-solid stirring casting technique is used to prepare iron-based amorphous particle-reinforced magnesium rare-earth matrix composites. The semi-solid stirring casting method effectively improves the dispersibility of the reinforcing particles. Specifically, the iron-based amorphous particles are preheated and added to the magnesium melt, and stirred under semi-solid conditions. Semi-solid stirring helps reduce the tendency of particle aggregation and improves the dispersion effect. The stirring process ensures that the particles are uniformly distributed in the magnesium matrix, thereby overcoming the problem of poor dispersion of the reinforcing particles and achieving a uniform distribution of the iron-based amorphous particles in the matrix. The addition of iron-based amorphous particles does not affect the type of the second phase in the composite material and also has a grain refinement effect. Furthermore, the composite material exhibits the best overall performance when the amount of iron-based amorphous particles added is 4 wt.%.

[0019] 2. In this invention, the as-cast composite material prepared by semi-solid stirring casting technology is subjected to heat treatment. During the solution treatment process, the composite material is heated to 520℃ and held for 7 hours, which promotes atomic diffusion between the matrix and the reinforcement, and enhances the interfacial bonding. The solution treatment improves the interaction between the iron-based amorphous particles and the magnesium rare earth matrix, improves the interfacial properties, and thus improves the strength and toughness of the composite material. This solves the problem that due to the physical and chemical differences between the iron-based amorphous particles and the magnesium matrix, the interfacial bonding between them is easily poor, and interfacial delamination easily occurs during use, resulting in poor strength and toughness of the material. After the solution treatment, the Mg5 (Gd, Y, Zn) phase distributed along the grain boundaries basically disappears, and different contents of iron-based amorphous particles do not have a significant impact on the solution effect of the composite material. The strength and plasticity of the composite material are improved, especially the plasticity is improved most significantly; after aging treatment, the strength of the composite material is improved most significantly.

[0020] 3. In this invention, compared with the as-cast and heat-treated iron-based amorphous particle-reinforced magnesium rare earth matrix composites, the iron-based amorphous particles are more uniformly dispersed in the matrix alloy after hot extrusion, effectively improving casting defects in the microstructure. The addition of iron-based amorphous particles increases the degree of recrystallization, refines the grains, and weakens the texture strength of the alloy, which helps to reduce stress concentration, increase elongation, and improve the plasticity of the composite material. At the same time, the mechanical properties of the hot-extruded composite material are improved compared with the matrix alloy, achieving a synergistic improvement in the strength, stiffness, and plasticity of the composite material.

[0021] 4. In this invention, the extruded iron-based amorphous particle-reinforced magnesium rare earth-based composite material is subjected to aging treatment. After aging treatment, the composite material achieves higher yield strength and strength through precipitation strengthening, grain boundary strengthening and solid solution strengthening, while retaining a certain elongation, so as to further improve the strength of the composite material through plastic replacement strength.

[0022] 5. In this invention, the semi-solid stirring casting technology employs a combination of low-speed stirring, high-speed stirring, short-time stirring, and long-time stirring. Low-speed stirring is used to initially mix the iron-based reinforcing particles with the matrix alloy melt, avoiding particle agglomeration or floating caused by violent particle movement during the initial high-speed stirring, reducing the generation of bubbles and eddies, and preventing bubbles from entering the melt. This allows the reinforcing particles to disperse in the melt, which helps to evenly distribute the particles and improve the overall uniformity of the material. Meanwhile, short-term initial stirring is used to initially mix the particles and avoid particle aggregation. At the same time, short-term stirring can reduce the drop in melt temperature, thereby controlling the initial distribution of reinforcing particles. High-speed stirring is carried out after the initial dispersion of reinforcing particles. It is used to further break up particle agglomerates, enhance the uniformity of particle distribution, improve the bonding quality between reinforcing particles and matrix, and improve the microscopic uniformity of the material. High-speed stirring is specifically manifested in breaking up particle agglomerates through strong shear force, while increasing the kinetic energy of particles in the melt, enhancing the interaction between particles and matrix, and promoting uniform particle dispersion. Meanwhile, prolonged stirring can fully and evenly disperse the particles, enhancing the uniform distribution of the particles. Attached Figure Description

[0023] Figure 1 This is a design diagram of the composite material melt stirring parameters in this invention; Figure 2 Metallographic images of matrix alloy VW103 and FMGp-reinforced VW103 magnesium matrix composites; Figure 3 Scanning electron microscope (SEM) images of VW103 matrix alloy and FMGp-reinforced VW103 magnesium matrix composite at the 100 μm scale; Figure 4 Scanning electron microscope (SEM) images of VW103 matrix alloy and FMGp-reinforced VW103 magnesium matrix composite at the 10 μm scale; Figure 5 Engineering stress-strain curves and mechanical property statistics of matrix alloy VW103 and FMGp-reinforced VW103 magnesium matrix composites; Figure 6 Metallographic images and grain size distribution diagrams of the matrix alloy VW103 and the FMGp-reinforced VW103 magnesium matrix composite after solution treatment; Figure 7 The images are scanning electron microscope (SEM) images of the matrix alloy VW103 and the FMGp-reinforced VW103 magnesium matrix composite after solution treatment at the 100 μm scale. Figure 8 The images are scanning electron microscope (SEM) images of the matrix alloy VW103 and the FMGp-reinforced VW103 magnesium matrix composite after solution treatment at the 10 μm scale. Figure 9 The engineering stress-strain curves and mechanical property statistics of VW103 matrix alloy and FMGp reinforced VW103 magnesium matrix composite material after solution treatment; Figure 10 Metallographic images of the matrix alloy VW103 and the FMGp-reinforced VW103 magnesium matrix composite after solution treatment and aging treatment; Figure 11 The images are scanning electron microscope (SEM) images of the matrix alloy VW103 and the FMGp-reinforced VW103 magnesium matrix composite after solution treatment and aging treatment at the 100 μm scale. Figure 12 The engineering stress-strain curves and mechanical property statistics of matrix alloy VW103 and FMGp-reinforced VW103 magnesium matrix composite after solution treatment and aging treatment are shown. Figure 13 Metallographic and scanning electron microscope images of the matrix alloy VW103 and the FMGp-reinforced VW103 magnesium matrix composite after solution treatment and hot extrusion. Figure 14 The engineering stress-strain curves and mechanical property statistics of matrix alloy VW103 and FMGp-reinforced VW103 magnesium matrix composite after solution treatment and hot extrusion treatment are shown. Figure 15 Metallographic and scanning electron microscope images of 4wt.%FMGp-reinforced VW103 magnesium matrix composites after solution treatment, hot extrusion, and aging. Figure 16The engineering stress-strain curves and mechanical property statistics of 4wt.% FMGp / VW103 composite material after solution treatment and hot extrusion, and 4wt.% FMGp reinforced VW103 magnesium matrix composite material after solution treatment, hot extrusion and aging treatment; Figure 17 The flowchart illustrates the preparation method provided by this invention. Detailed Implementation

[0024] A preferred embodiment of the present invention will now be described in detail with reference to the accompanying drawings.

[0025] In the following embodiments, the matrix alloy used is VW103 (Mg-10Gd-3Y-1Zn-0.5Zr), a rare earth magnesium alloy manufactured by Chongqing Yuhua New Material Technology Co., Ltd., China. Compared with other low-cost magnesium alloys, VW103 magnesium alloy exhibits better overall performance. The reinforcement used is iron-based amorphous particles FMGp, purchased from AME Corporation, USA. The average particle size of this iron-based amorphous reinforcement is approximately 30.8 μm.

[0026] Example 1: Reference Figure 17 This invention provides a method for preparing iron-based amorphous particle-reinforced magnesium rare earth-based composite materials, comprising the following steps: S1. Semi-solid stirring casting: First, use an angle grinder to remove the oxide film on the surface of VW103 alloy. Then, use an electronic weighing scale to weigh 1.5 kg of the base alloy and place it in a clean and dried stainless steel crucible. Under the condition of introducing CO2 and SF6 with a volume fraction ratio of 99:1, place the crucible in a resistance furnace at 730°C to melt the base alloy. At the same time, weigh out 2% FMGp of the composite material and preheat it in a drying oven at 200°C for 1 hour. After the alloy was completely melted into a metallic molten metal, the temperature of the magnesium molten metal was measured using a handheld thermocouple. A staged cooling method was then used to lower the molten metal temperature to slightly above the semi-solid temperature of 635°C. Preheated iron-based amorphous particles were then added, and stirring was initiated using a mechanical stirrer. The matrix parameters for stirring were as follows: Figure 1 The initial stirring speed was 350 r·min. -1 The stirring time is 2 minutes; when the melt reaches a slurry state, the stirring speed is increased to 950 r / min. -1 The stirring time is 6 minutes. During stirring, the stirring method is up and down reciprocating and tilting. During the stirring process, the stirring head of the stirrer is always kept in the magnesium melt to avoid the generation of eddies that introduce gas and form impurities. After stirring, the melt temperature was increased. When the melt temperature reached 645℃, it was heated again at 350 rpm. -1After stirring the melt at low speed for 30 seconds, the stirrer was removed, and the composite material melt was slag-removed and impurities were removed using a slotted spoon. Then, the melt was kept at a constant temperature for 5 minutes and then rapidly cooled to obtain the FMGp / VW103 magnesium-based composite material.

[0027] Example 2: Reference Figure 17 This invention provides a method for preparing iron-based amorphous particle-reinforced magnesium rare earth-based composite materials, comprising the following steps: S1. Semi-solid stirring casting: First, use an angle grinder to remove the oxide film on the surface of VW103 alloy. Then, use an electronic weighing scale to weigh 1.5 kg of the base alloy and place it in a clean and dried stainless steel crucible. Under the condition of introducing CO2 and SF6 with a volume fraction ratio of 99:1, place the crucible in a resistance furnace at 730°C to melt the base alloy. At the same time, weigh out 4% FMGp of the composite material and preheat it in a drying oven at 200°C for 1 hour. After the alloy was completely melted into a metallic molten metal, the temperature of the magnesium molten metal was measured using a handheld thermocouple. A staged cooling method was then used to lower the molten metal temperature to slightly above the semi-solid temperature of 635°C. Preheated iron-based amorphous particles were then added, and stirring was initiated using a mechanical stirrer. The matrix parameters for stirring were as follows: Figure 1 The initial stirring speed was 350 r·min. -1 The stirring time is 2 minutes; when the melt reaches a slurry state, the stirring speed is increased to 950 r / min. -1 The stirring time is 6 minutes. During stirring, the stirring method is up and down reciprocating and tilting. During the stirring process, the stirring head of the stirrer is always kept in the magnesium melt to avoid the generation of eddies that introduce gas and form impurities. After stirring, the melt temperature was increased. When the melt temperature reached 645℃, it was heated again at 350 rpm. -1 After stirring the melt at low speed for 30 seconds, the stirrer was removed, and the composite material melt was slag-removed and impurities were removed using a slotted spoon. Then, the melt was kept at a constant temperature for 5 minutes and then rapidly cooled to obtain the FMGp / VW103 magnesium-based composite material.

[0028] Example 3: Reference Figure 17 This invention provides a method for preparing iron-based amorphous particle-reinforced magnesium rare earth-based composite materials, comprising the following steps: S1. Semi-solid stirring casting: First, use an angle grinder to remove the oxide film on the surface of VW103 alloy. Then, use an electronic weighing scale to weigh 1.5 kg of the base alloy and place it in a clean and dried stainless steel crucible. Under the condition of introducing CO2 and SF6 with a volume fraction ratio of 99:1, place the crucible in a resistance furnace at 730°C to melt the base alloy. At the same time, weigh out 6% FMGp of the composite material and preheat it in a drying oven at 200°C for 1 hour. After the alloy was completely melted into a metallic molten metal, the temperature of the magnesium molten metal was measured using a handheld thermocouple. A staged cooling method was then used to lower the molten metal temperature to slightly above the semi-solid temperature of 635°C. Preheated iron-based amorphous particles were then added, and stirring was initiated using a mechanical stirrer. The matrix parameters for stirring were as follows: Figure 1 The initial stirring speed was 350 r·min. -1 The stirring time is 2 minutes; when the melt reaches a slurry state, the stirring speed is increased to 950 r / min. -1 The stirring time is 6 minutes. During stirring, the stirring method is up and down reciprocating and tilting. During the stirring process, the stirring head of the stirrer is always kept in the magnesium melt to avoid the generation of eddies that introduce gas and form impurities. After stirring, the melt temperature was increased. When the melt temperature reached 645℃, it was heated again at 350 r / min. -1 After stirring the melt at low speed for 30 seconds, the stirrer was removed, and the composite material melt was slag-removed and impurities were removed using a slotted spoon. Then, the melt was kept at a constant temperature for 5 minutes and then rapidly cooled to obtain the FMGp / VW103 magnesium-based composite material.

[0029] Comparative Example 1: This invention provides a method for preparing a magnesium rare earth alloy, comprising the following steps: S1. Semi-solid stirring casting: First, use an angle grinder to remove the oxide film on the surface of VW103 alloy. Then, use an electronic weighing scale to weigh 1.5 kg of the base alloy and place it in a clean and dried stainless steel crucible. Under the condition of introducing CO2 and SF6 with a volume fraction ratio of 99:1, place the crucible in a resistance furnace at 730°C to melt the base alloy. After the alloy was completely melted into a metallic molten metal, the temperature of the magnesium molten metal was measured using a handheld thermocouple. A staged cooling method was then used to lower the molten metal temperature to slightly above the semi-solid temperature of 635°C. Stirring was then initiated, with the following matrix parameters for stirring: Figure 1 The initial stirring speed was 350 r·min. -1 The stirring time is 2 minutes; when the melt reaches a slurry state, the stirring speed is increased to 950 r / min. -1The stirring time is 6 minutes. During stirring, the stirring method is up and down reciprocating and tilting. During the stirring process, the stirring head of the stirrer is always kept in the magnesium melt to avoid the generation of eddies that introduce gas and form impurities. After stirring, the melt temperature was increased. When the melt temperature reached 645℃, it was heated again at 350 r / min. -1 After stirring the melt at low speed for 30 seconds, the stirrer was removed, and the composite material melt was slag-removed and impurities were removed using a slotted spoon. Then, it was kept at a constant temperature for 5 minutes and then removed and rapidly cooled to obtain a magnesium rare earth alloy.

[0030] Example 4: Reference Figure 17 This invention provides a method for preparing iron-based amorphous particle-reinforced magnesium rare earth-based composite materials, comprising the following steps: S1. Semi-solid stirring casting: First, use an angle grinder to remove the oxide film on the surface of VW103 alloy. Then, use an electronic weighing scale to weigh 1.5 kg of the base alloy and place it in a clean and dried stainless steel crucible. Under the condition of introducing CO2 and SF6 with a volume fraction ratio of 99:1, place the crucible in a resistance furnace at 730°C to melt the base alloy. At the same time, weigh out 2% FMGp of the composite material and preheat it in a drying oven at 200°C for 1 hour. After the alloy was completely melted into a metallic molten metal, the temperature of the magnesium molten metal was measured using a handheld thermocouple. A staged cooling method was then used to lower the molten metal temperature to slightly above the semi-solid temperature of 635°C. Preheated iron-based amorphous particles were then added, and stirring was initiated using a mechanical stirrer. The matrix parameters for stirring were as follows: Figure 1 The initial stirring speed was 350 r·min. -1 The stirring time is 2 minutes; when the melt reaches a slurry state, the stirring speed is increased to 950 r / min. -1 The stirring time is 6 minutes. During stirring, the stirring method is up and down reciprocating and tilting. During the stirring process, the stirring head of the stirrer is always kept in the magnesium melt to avoid the generation of eddies that introduce gas and form impurities. After stirring, the melt temperature was increased. When the melt temperature reached 645℃, it was heated again at 350 r / min. -1 After stirring the melt at low speed for 30 seconds, the stirrer was removed, and the composite material melt was slag-removed and impurities were removed using a slotted spoon. Then, the melt was kept at a constant temperature for 5 minutes and then rapidly cooled to obtain the FMGp / VW103 magnesium-based composite material.

[0031] S2, Solution treatment: The as-cast composite material prepared in S1 was solution treated at 520℃ for 7 hours.

[0032] Example 5: Reference Figure 17This invention provides a method for preparing iron-based amorphous particle-reinforced magnesium rare earth-based composite materials, comprising the following steps: S1. Semi-solid stirring casting: First, use an angle grinder to remove the oxide film on the surface of VW103 alloy. Then, use an electronic weighing scale to weigh 1.5 kg of the base alloy and place it in a clean and dried stainless steel crucible. Under the condition of introducing CO2 and SF6 with a volume fraction ratio of 99:1, place the crucible in a resistance furnace at 730°C to melt the base alloy. At the same time, weigh out 4% FMGp of the composite material and preheat it in a drying oven at 200°C for 1 hour. After the alloy was completely melted into a metallic molten metal, the temperature of the magnesium molten metal was measured using a handheld thermocouple. A staged cooling method was then used to lower the molten metal temperature to slightly above the semi-solid temperature of 635°C. Preheated iron-based amorphous particles were then added, and stirring was initiated using a mechanical stirrer. The matrix parameters for stirring were as follows: Figure 1 The initial stirring speed was 350 r·min. -1 The stirring time is 2 minutes; when the melt reaches a slurry state, the stirring speed is increased to 950 r / min. -1 The stirring time is 6 minutes. During stirring, the stirring method is up and down reciprocating and tilting. During the stirring process, the stirring head of the stirrer is always kept in the magnesium melt to avoid the generation of eddies that introduce gas and form impurities. After stirring, the melt temperature was increased. When the melt temperature reached 645℃, it was heated again at 350 rpm. -1 After stirring the melt at low speed for 30 seconds, the stirrer was removed, and the composite material melt was slag-removed and impurities were removed using a slotted spoon. Then, the melt was kept at a constant temperature for 5 minutes and then rapidly cooled to obtain the FMGp / VW103 magnesium-based composite material.

[0033] S2, Solution treatment: The as-cast composite material prepared in S1 was solution treated at 520℃ for 7 hours.

[0034] Example 6: Reference Figure 17 This invention provides a method for preparing iron-based amorphous particle-reinforced magnesium rare earth-based composite materials, comprising the following steps: S1. Semi-solid stirring casting: First, use an angle grinder to remove the oxide film on the surface of VW103 alloy. Then, use an electronic weighing scale to weigh 1.5 kg of the base alloy and place it in a clean and dried stainless steel crucible. Under the condition of introducing CO2 and SF6 with a volume fraction ratio of 99:1, place the crucible in a resistance furnace at 730°C to melt the base alloy. At the same time, weigh out 6% FMGp of the composite material and preheat it in a drying oven at 200°C for 1 hour. After the alloy was completely melted into a metallic molten metal, the temperature of the magnesium molten metal was measured using a handheld thermocouple. A staged cooling method was then used to lower the molten metal temperature to slightly above the semi-solid temperature of 635°C. Preheated iron-based amorphous particles were then added, and stirring was initiated using a mechanical stirrer. The matrix parameters for stirring were as follows: Figure 1 The initial stirring speed was 350 r·min. -1 The stirring time is 2 minutes; when the melt reaches a slurry state, the stirring speed is increased to 950 r / min. -1 The stirring time is 6 minutes. During stirring, the stirring method is up and down reciprocating and tilting. During the stirring process, the stirring head of the stirrer is always kept in the magnesium melt to avoid the generation of eddies that introduce gas and form impurities. After stirring, the melt temperature was increased. When the melt temperature reached 645℃, it was heated again at 350 rpm. -1 After stirring the melt at low speed for 30 seconds, the stirrer was removed, and the composite material melt was slag-removed and impurities were removed using a slotted spoon. Then, the melt was kept at a constant temperature for 5 minutes and then rapidly cooled to obtain the FMGp / VW103 magnesium-based composite material.

[0035] S2, Solution treatment: The as-cast composite material prepared in S1 was solution treated at 520℃ for 7 hours.

[0036] Comparative Example 2: This invention provides a method for preparing a magnesium rare earth alloy, comprising the following steps: S1. Semi-solid stirring casting: First, use an angle grinder to remove the oxide film on the surface of VW103 alloy. Then, use an electronic weighing scale to weigh 1.5 kg of the base alloy and place it in a clean and dried stainless steel crucible. Under the condition of introducing CO2 and SF6 with a volume fraction ratio of 99:1, place the crucible in a resistance furnace at 730°C to melt the base alloy. After the alloy was completely melted into a metallic molten metal, the temperature of the magnesium molten metal was measured using a handheld thermocouple. A staged cooling method was then used to lower the molten metal temperature to slightly above the semi-solid temperature of 635°C. Stirring was then initiated, with the following matrix parameters for stirring: Figure 1 The initial stirring speed was 350 r·min. -1 The stirring time is 2 minutes; when the melt reaches a slurry state, the stirring speed is increased to 950 r / min. -1 The stirring time is 6 minutes. During stirring, the stirring method is up and down reciprocating and tilting. During the stirring process, the stirring head of the stirrer is always kept in the magnesium melt to avoid the generation of eddies that introduce gas and form impurities. After stirring, the melt temperature was increased. When the melt temperature reached 645℃, it was heated again at 350 rpm. -1After stirring the melt at low speed for 30 seconds, the stirrer was removed, and the composite material melt was slag-removed and impurities were removed using a slotted spoon. Then, it was kept at a constant temperature for 5 minutes and then removed and rapidly cooled to obtain a magnesium rare earth alloy. S2, Solution treatment: The magnesium rare earth alloy prepared in S1 was solution treated at 520℃ for 7 hours.

[0037] Example 7: Reference Figure 17 This invention provides a method for preparing iron-based amorphous particle-reinforced magnesium rare earth-based composite materials, comprising the following steps: S1. Semi-solid stirring casting: First, use an angle grinder to remove the oxide film on the surface of VW103 alloy. Then, use an electronic weighing scale to weigh 1.5 kg of the base alloy and place it in a clean and dried stainless steel crucible. Under the condition of introducing CO2 and SF6 with a volume fraction ratio of 99:1, place the crucible in a resistance furnace at 730°C to melt the base alloy. At the same time, weigh out 2% FMGp of the composite material and preheat it in a drying oven at 200°C for 1 hour. After the alloy was completely melted into a metallic molten metal, the temperature of the magnesium molten metal was measured using a handheld thermocouple. A staged cooling method was then used to lower the molten metal temperature to slightly above the semi-solid temperature of 635°C. Preheated iron-based amorphous particles were then added, and stirring was initiated using a mechanical stirrer. The matrix parameters for stirring were as follows: Figure 1 The initial stirring speed was 350 r·min. -1 The stirring time is 2 minutes; when the melt reaches a slurry state, the stirring speed is increased to 950 r / min. -1 The stirring time is 6 minutes. During stirring, the stirring method is up and down reciprocating and tilting. During the stirring process, the stirring head of the stirrer is always kept in the magnesium melt to avoid the generation of eddies that introduce gas and form impurities. After stirring, the melt temperature was increased. When the melt temperature reached 645℃, it was heated again at 350 rpm. -1 After stirring the melt at low speed for 30 seconds, the stirrer was removed, and the composite material melt was slag-removed and impurities were removed using a slotted spoon. Then, the melt was kept at a constant temperature for 5 minutes and then rapidly cooled to obtain the FMGp / VW103 magnesium-based composite material.

[0038] S2, Solution treatment: The as-cast composite material prepared in S1 was solution treated at 520℃ for 7 hours; S2-1, Aging treatment: The composite material prepared by S2 is aged at 250℃ for 16h.

[0039] Example 8: Reference Figure 17 This invention provides a method for preparing iron-based amorphous particle-reinforced magnesium rare earth-based composite materials, comprising the following steps: S1. Semi-solid stirring casting: First, use an angle grinder to remove the oxide film on the surface of VW103 alloy. Then, use an electronic weighing scale to weigh 1.5 kg of the base alloy and place it in a clean and dried stainless steel crucible. Under the condition of introducing CO2 and SF6 with a volume fraction ratio of 99:1, place the crucible in a resistance furnace at 730°C to melt the base alloy. At the same time, weigh out 4% FMGp of the composite material and preheat it in a drying oven at 200°C for 1 hour. After the alloy was completely melted into a metallic molten metal, the temperature of the magnesium molten metal was measured using a handheld thermocouple. A staged cooling method was then used to lower the molten metal temperature to slightly above the semi-solid temperature of 635°C. Preheated iron-based amorphous particles were then added, and stirring was initiated using a mechanical stirrer. The matrix parameters for stirring were as follows: Figure 1 The initial stirring speed was 350 r·min. -1 The stirring time is 2 minutes; when the melt reaches a slurry state, the stirring speed is increased to 950 r / min. -1 The stirring time is 6 minutes. During stirring, the stirring method is up and down reciprocating and tilting. During the stirring process, the stirring head of the stirrer is always kept in the magnesium melt to avoid the generation of eddies that introduce gas and form impurities. After stirring, the melt temperature was increased. When the melt temperature reached 645℃, it was heated again at 350 rpm. -1 After stirring the melt at low speed for 30 seconds, the stirrer was removed, and the composite material melt was slag-removed and impurities were removed using a slotted spoon. Then, the melt was kept at a constant temperature for 5 minutes and then rapidly cooled to obtain the FMGp / VW103 magnesium-based composite material.

[0040] S2, Solution treatment: The as-cast composite material prepared in S1 was solution treated at 520℃ for 7 hours; S2-1, Aging Treatment: The composite material prepared in S2 is aged at 250℃ for 16 hours. Example 9: Reference Figure 17 This invention provides a method for preparing iron-based amorphous particle-reinforced magnesium rare earth-based composite materials, comprising the following steps: S1. Semi-solid stirring casting: First, use an angle grinder to remove the oxide film on the surface of VW103 alloy. Then, use an electronic weighing scale to weigh 1.5 kg of the base alloy and place it in a clean and dried stainless steel crucible. Under the condition of introducing CO2 and SF6 with a volume fraction ratio of 99:1, place the crucible in a resistance furnace at 730°C to melt the base alloy. At the same time, weigh out 6% FMGp of the composite material and preheat it in a drying oven at 200°C for 1 hour. After the alloy was completely melted into a metallic molten metal, the temperature of the magnesium molten metal was measured using a handheld thermocouple. A staged cooling method was then used to lower the molten metal temperature to slightly above the semi-solid temperature of 635°C. Preheated iron-based amorphous particles were then added, and stirring was initiated using a mechanical stirrer. The matrix parameters for stirring were as follows: Figure 1 The initial stirring speed was 350 r·min. -1 The stirring time is 2 minutes; when the melt reaches a slurry state, the stirring speed is increased to 950 r / min. -1 The stirring time is 6 minutes. During stirring, the stirring method is up and down reciprocating and tilting. During the stirring process, the stirring head of the stirrer is always kept in the magnesium melt to avoid the generation of eddies that introduce gas and form impurities. After stirring, the melt temperature was increased. When the melt temperature reached 645℃, it was heated again at 350 rpm. -1 After stirring the melt at low speed for 30 seconds, the stirrer was removed, and the composite material melt was slag-removed and impurities were removed using a slotted spoon. Then, the melt was kept at a constant temperature for 5 minutes and then rapidly cooled to obtain the FMGp / VW103 magnesium-based composite material.

[0041] S2, Solution treatment: The as-cast composite material prepared in S1 was solution treated at 520℃ for 7 hours; S2-1, Aging treatment: The composite material prepared by S2 is aged at 250℃ for 16h.

[0042] Comparative Example 3: This invention provides a method for preparing a magnesium rare earth alloy, comprising the following steps: S1. Semi-solid stirring casting: First, use an angle grinder to remove the oxide film on the surface of VW103 alloy. Then, use an electronic weighing scale to weigh 1.5 kg of the base alloy and place it in a clean and dried stainless steel crucible. Under the condition of introducing CO2 and SF6 with a volume fraction ratio of 99:1, place the crucible in a resistance furnace at 730°C to melt the base alloy. After the alloy was completely melted into a metallic molten metal, the temperature of the magnesium molten metal was measured using a handheld thermocouple. A staged cooling method was then used to lower the molten metal temperature to slightly above the semi-solid temperature of 635°C. Stirring was then initiated, with the following matrix parameters for stirring: Figure 1 The initial stirring speed was 350 r·min. -1 The stirring time is 2 minutes; when the melt reaches a slurry state, the stirring speed is increased to 950 r / min. -1 The stirring time is 6 minutes. During stirring, the stirring method is up and down reciprocating and tilting. During the stirring process, the stirring head of the stirrer is always kept in the magnesium melt to avoid the generation of eddies that introduce gas and form impurities. After stirring, the melt temperature was increased. When the melt temperature reached 645℃, it was heated again at 350 rpm. -1 After stirring the melt at low speed for 30 seconds, the stirrer was removed, and the composite material melt was slag-removed and impurities were removed using a slotted spoon. Then, it was kept at a constant temperature for 5 minutes and then removed and rapidly cooled to obtain a magnesium rare earth alloy. S2, Solution treatment: The magnesium rare earth alloy prepared in S1 was solution treated at 520℃ for 7 hours.

[0043] S2-1, Aging treatment: The magnesium rare earth alloy prepared by S2 is aged at 250℃ for 16h.

[0044] Example 10: Reference Figure 17 This invention provides a method for preparing iron-based amorphous particle-reinforced magnesium rare earth-based composite materials, comprising the following steps: S1. Semi-solid stirring casting: First, use an angle grinder to remove the oxide film on the surface of VW103 alloy. Then, use an electronic weighing scale to weigh 1.5 kg of the base alloy and place it in a clean and dried stainless steel crucible. Under the condition of introducing CO2 and SF6 with a volume fraction ratio of 99:1, place the crucible in a resistance furnace at 730°C to melt the base alloy. At the same time, weigh out 4% FMGp of the composite material and preheat it in a drying oven at 200°C for 1 hour. After the alloy was completely melted into a metallic molten metal, the temperature of the magnesium molten metal was measured using a handheld thermocouple. A staged cooling method was then used to lower the molten metal temperature to slightly above the semi-solid temperature of 635°C. Preheated iron-based amorphous particles were then added, and stirring was initiated using a mechanical stirrer. The matrix parameters for stirring were as follows: Figure 1 The initial stirring speed was 350 r·min. -1 The stirring time is 2 minutes; when the melt reaches a slurry state, the stirring speed is increased to 950 r / min. -1 The stirring time is 6 minutes. During stirring, the stirring method is up and down reciprocating and tilting. During the stirring process, the stirring head of the stirrer is always kept in the magnesium melt to avoid the generation of eddies that introduce gas and form impurities. After stirring, the melt temperature was increased. When the melt temperature reached 645℃, it was heated again at 350 rpm. -1 After stirring the melt at low speed for 30 seconds, the stirrer was removed, and the composite material melt was slag-removed and impurities were removed using a slotted spoon. Then, the melt was kept at a constant temperature for 5 minutes and then rapidly cooled to obtain the FMGp / VW103 magnesium-based composite material.

[0045] S2, Solution treatment: The as-cast composite material prepared in S1 was solution treated at 520℃ for 7 hours; S3. Hot extrusion molding: The composite material in S2 that has undergone solution treatment is subjected to isothermal hot extrusion deformation at 450℃ with an extrusion ratio of 25:1 to obtain an iron-based amorphous particle magnesium rare earth-based composite material.

[0046] Comparative Example 4: This invention provides a method for preparing a magnesium rare earth alloy, comprising the following steps: S1. Semi-solid stirring casting: First, use an angle grinder to remove the oxide film on the surface of VW103 alloy. Then, use an electronic weighing scale to weigh 1.5 kg of the base alloy and place it in a clean and dried stainless steel crucible. Under the condition of introducing CO2 and SF6 with a volume fraction ratio of 99:1, place the crucible in a resistance furnace at 730°C to melt the base alloy. After the alloy was completely melted into a metallic molten metal, the temperature of the magnesium molten metal was measured using a handheld thermocouple. A staged cooling method was then used to lower the molten metal temperature to slightly above the semi-solid temperature of 635°C. Stirring was then initiated, with the following matrix parameters for stirring: Figure 1 The initial stirring speed was 350 r·min. -1 The stirring time is 2 minutes; when the melt reaches a slurry state, the stirring speed is increased to 950 r / min. -1 The stirring time is 6 minutes. During stirring, the stirring method is up and down reciprocating and tilting. During the stirring process, the stirring head of the stirrer is always kept in the magnesium melt to avoid the generation of eddies that introduce gas and form impurities. After stirring, the melt temperature was increased. When the melt temperature reached 645℃, it was heated again at 350 rpm. -1 After stirring the melt at low speed for 30 seconds, the stirrer was removed, and the composite material melt was slag-removed and impurities were removed using a slotted spoon. Then, it was kept at a constant temperature for 5 minutes and then removed and rapidly cooled to obtain a magnesium rare earth alloy. S2, Solution treatment: The magnesium rare earth alloy prepared in S1 was solution treated at 520℃ for 7 hours; S3. Hot extrusion forming: The magnesium rare earth alloy that has undergone solid solution treatment in S2 is subjected to isothermal hot extrusion deformation at 450℃ with an extrusion ratio of 25:1 to obtain the magnesium rare earth alloy.

[0047] Example 11: Reference Figure 17 This invention provides a method for preparing iron-based amorphous particle-reinforced magnesium rare earth-based composite materials, comprising the following steps: S1. Semi-solid stirring casting: First, use an angle grinder to remove the oxide film on the surface of VW103 alloy. Then, use an electronic weighing scale to weigh 1.5 kg of the base alloy and place it in a clean and dried stainless steel crucible. Under the condition of introducing CO2 and SF6 with a volume fraction ratio of 99:1, place the crucible in a resistance furnace at 730°C to melt the base alloy. At the same time, weigh out 4% FMGp of the composite material and preheat it in a drying oven at 200°C for 1 hour. After the alloy was completely melted into a metallic molten metal, the temperature of the magnesium molten metal was measured using a handheld thermocouple. A staged cooling method was then used to lower the molten metal temperature to slightly above the semi-solid temperature of 635°C. Preheated iron-based amorphous particles were then added, and stirring was initiated using a mechanical stirrer. The matrix parameters for stirring were as follows: Figure 1 The initial stirring speed was 350 r·min. -1 The stirring time is 2 minutes; when the melt reaches a slurry state, the stirring speed is increased to 950 r / min. -1 The stirring time is 6 minutes. During stirring, the stirring method is up and down reciprocating and tilting. During the stirring process, the stirring head of the stirrer is always kept in the magnesium melt to avoid the generation of eddies that introduce gas and form impurities. After stirring, the melt temperature was increased. When the melt temperature reached 645℃, it was heated again at 350 rpm. -1 After stirring the melt at low speed for 30 seconds, the stirrer was removed, and the composite material melt was slag-removed and impurities were removed using a slotted spoon. Then, the melt was kept at a constant temperature for 5 minutes and then rapidly cooled to obtain the FMGp / VW103 magnesium-based composite material.

[0048] S2, Solution treatment: The as-cast composite material prepared in S1 was solution treated at 520℃ for 7 hours; S3. Hot extrusion molding: The composite material in S2 that has been solution treated is subjected to isothermal hot extrusion deformation at 450℃ with an extrusion ratio of 25:1 to obtain iron-based amorphous particle magnesium rare earth-based composite material. S3-1, Aging Treatment: The composite material prepared by hot extrusion molding of S3 is aged at 250℃ for 16h.

[0049] Table 1 - Room temperature mechanical properties of alloy materials prepared in Examples 1-11 and Comparative Examples 1-4

[0050] Referring to Table 1, the iron-based amorphous particle-reinforced magnesium rare earth-based composite material prepared by the method provided in this application exhibits superior strength and elongation compared to other rare earth magnesium alloys and magnesium-based composite materials. Specifically: Reference Figure 2 , Figure 2 Image (a) is a metallographic image of the matrix alloy VW103. Figure 2 Figures (b), (c), and (d) show the metallographic structures of VW103 magnesium matrix composites reinforced with 2wt.%, 4wt.%, and 6wt.%, respectively. Macroscopically, when the amount of FMGp added is low, it is relatively uniformly distributed in the VW103 matrix alloy. When the amount of FMGp added reaches 6wt.%, localized particle clustering of FMGp appears in the VW103 matrix. This localized clustering can be attributed to the difference in thermal conductivity between the reinforcement FMGp and the VW103 alloy during solidification, leading to a disordered temperature field at the solidification interface, causing FMGp to agglomerate at grain boundaries. Furthermore, it was found that the grains near FMGp are finer. This is because, as heterogeneous metal particles, the surface of FMGp can act as nucleation sites, promoting heterogeneous grain nucleation and inhibiting further grain growth. The composite material exhibits the finest grain size when the amount of FMGp added reaches 4wt.%.

[0051] To clearly observe the morphology of the precipitated phase and FMGp in the composite material, refer to Figure 3 , Figure 3 Image (a) in the image is a scanning electron microscope image of the matrix alloy VW103 at the 100 μm scale. Figure 3 Images (b), (c), and (d) show scanning electron microscope (SEM) images at the 100 μm scale of VW103 magnesium matrix composites reinforced with 2 wt.%, 4 wt.%, and 6 wt.%, respectively. The images reveal that FMGp is ​​relatively uniformly distributed along the grain boundaries in the matrix, with intact particle morphology and no obvious fracture or deformation. Furthermore, no defects such as oxide inclusions were observed during the composite material preparation process. In addition, with increasing FMGp content, the second phase, continuously distributed along the grain boundaries, gradually transforms into a discontinuous network structure.

[0052] To further confirm the phase composition and characteristics of the second phase in the composite material, EDS energy dispersive spectroscopy analysis was performed on composite materials with different contents of reinforcing particles, referring to... Figure 4 , Figure 4 (a) is a scanning electron microscope image of the matrix alloy VW103 at the 10 μm scale. Figure 4 Images (b), (c), and (d) are scanning electron microscope (SEM) images of VW103 magnesium-based composites reinforced with 2 wt.%, 4 wt.%, and 6 wt.% FMGp, respectively, at the 10 μm scale. EDS analysis data are listed in Table 2. Analysis revealed that the atomic ratio of Mg to (Gd, Y, Zn) in the second phase distributed along the grain boundaries in the VW103 alloy is 5:1. Figure 4 Based on the midpoints B, C, and D, determine that the second phase is the Mg5(Gd, Y, Zn) phase. Figure 4(b), (c), and (d) show the EDS spectra of the composite material reinforced with FMGp. With increasing FMGp content, the type and composition of the second phase in the composite material remained unchanged. Based on the atomic ratio of Mg:(Gd, Y, Zn) in the second phase, it can be determined that the second phase is the Mg5(Gd, Y, Zn) phase. Spot scanning of FMGp shows that it mainly contains Fe, Cr, and Mo. B and C elements are not accurately detected by SEM and are therefore not listed.

[0053] Table 2 - EDS spot scan results of FMGP / VW103 composite material

[0054] Reference Figure 5 In conjunction with Examples 1-3 and Comparative Example 1 in Table 1, Figure 5 (a) shows the stress-strain curve, and (b) shows the mechanical property statistics. With the increase of FMGp addition, the ultimate tensile strength and elongation of the composite material first increase and then decrease, while the yield strength gradually increases, increasing from 142 MPa to 162 MPa compared with the matrix alloy. Furthermore, when the FMGp addition in the composite material is 4 wt.%, the overall mechanical properties of the FMGp / VW103 composite material reach their optimal level, with yield strength, ultimate tensile strength, and elongation of 157 MPa, 266 MPa, and 6.0%, respectively, representing increases of 10.5%, 14.6%, and 39.5% compared with the matrix alloy. This indicates that the FMGp / VW103 composite material prepared using semi-solid casting technology effectively prevents the sedimentation of FMGp particles, achieves uniform distribution of FMGp particles in the matrix, and the addition of FMGp does not affect the type of the second phase in the composite material. Moreover, it has a grain-refining effect, contributing to the improvement of the composite material's performance.

[0055] Reference Figure 6 , Figure 6 (a) shows the metallographic diagram and grain size distribution of the matrix alloy VW103 after solution treatment. Figure 6Figures (b), (c), and (d) show the metallographic images and grain size distribution diagrams of VW103 magnesium-based composites reinforced with 2wt.%, 4wt.%, and 6wt.%, respectively, after solution treatment. The figures reveal that under these solution treatment parameters, the eutectic phase Mg5(Gd, Y, Zn) distributed along the grain boundaries in the composite material essentially disappears, and the grain size shows no significant increase compared to the as-cast state. Furthermore, compared to the VW103 alloy, the composite material with added FMGp exhibits a finer grain size. Observation of the amorphous grains reveals that the grain size around FMGp is ​​significantly smaller. This is because FMGp provides more heterogeneous nucleation sites, effectively promoting grain nucleation. Simultaneously, FMGp, as heterogeneous metal particles distributed at grain boundaries, has the effect of pinning grain boundaries and inhibiting grain growth; therefore, the addition of FMGp refines the grain size of the composite material.

[0056] Reference Figure 7 , Figure 7 Image (a) in the image is a scanning electron microscope (SEM) image of the VW103 matrix alloy after solution treatment at a scale of 100 μm. Figure 7 Images (b), (c), and (d) are scanning electron microscope (SEM) images at a 100 μm scale of VW103 magnesium matrix composites reinforced with 2 wt.%, 4 wt.%, and 6 wt.% FMGp, respectively, after solution treatment. Observations show that the Mg5(Gd, Y, Zn) phase distributed along the grain boundaries in both the VW103 alloy and the composite material is largely dissolved into the matrix, indicating that the addition of FMGp did not affect the phase composition of the composite material after solution treatment. However, a small amount of bulk phase and a large amount of cubic phase were still observed at the grain boundaries. Point scan analysis was performed, as shown... Figure 8 As shown in Table 3. Figure 8 (a) is a SEM-EDS analysis of the solid solution VW103 alloy. The analysis revealed that the bulk phase at the grain boundaries is the LPSO phase (Point B, C), and the large amount of cubic phase is the rare earth-rich phase (Point D). Figure 8 (b) SEM-EDS of the 4wt.% FMGP / VW103 composite material in solid solution state. Compared with the matrix alloy, except for FMGp (Point E), the bulk phases located at the grain boundaries (Points F and G) and the dispersed cubic phases (Point H) are the same as in the matrix alloy, both being LPSO phase and rare earth-rich phase. This indicates that the addition of FMGp did not affect the phase composition of the composite material after solid solution treatment.

[0057] Table 3 - EDS spot scan results of solution-treated VW103 alloy and FMGP / VW103 composite material

[0058] Reference Figure 9 In conjunction with Examples 4-6 and Comparative Example 2 in Table 1, Figure 9(a) shows the stress-strain curve, and (b) shows the mechanical property statistics. Analysis shows that the mechanical properties of the iron-based amorphous particle-reinforced magnesium rare earth composite material are improved after solution treatment, demonstrating that the composite material can achieve relatively better mechanical properties after solution treatment at 520℃ for 7 hours. When the amount of FMGp added is 4 wt.%, the yield strength, ultimate tensile strength, and elongation of the composite material are 162 MPa, 280 MPa, and 14.2%, respectively, with the elongation increasing by 136% compared to the as-cast state. Compared to the as-cast alloy, the plasticity of the solution-treated composite material is most significantly improved. This is mainly because solution treatment causes the eutectic phase to disappear, the microstructure to become homogenized, and some LPSO phase to form, which contributes to the improvement of the composite material's plasticity.

[0059] Reference Figure 10 , Figure 10 Image (a) is the metallographic diagram of the base alloy VW103 after solution treatment and aging. Figure 10 (b), (c), and (d) are metallographic images of VW103 magnesium-based composites reinforced with 2wt.%, 4wt.%, and 6wt.%, respectively, after solution treatment and aging. Compared with the microstructure in the solution state, the microstructure of the composites after aging treatment did not change significantly. Except for FMGp, it still consists of Mg12(Gd,Y)Zn phase distributed along the grain boundaries and a large number of rare earth-rich phases. Analyzing the grain size of the composites after aging, the grain size did not change significantly compared with the solution state. This is because FMGp located at the grain boundaries has a pinning effect on the grain boundaries, which restricts the movement of the grain boundaries and thus hinders grain growth.

[0060] Reference Figure 11 , Figure 11 Image (a) shows a scanning electron microscope (SEM) image of the matrix alloy VW103 after solution treatment and aging at a scale of 100 μm. Figure 11 Images (b), (c), and (d) show scanning electron microscope (SEM) images at a 100 μm scale of VW103 magnesium-based composites reinforced with 2 wt.%, 4 wt.%, and 6 wt.% FMGp, respectively, after solution treatment and aging. The images show no significant difference in morphology between the VW103 alloy and the composite material. Furthermore, the microstructure remains largely unchanged compared to the solution-treated composite. Aside from a small amount of Mg12(Gd,Y)Zn phase and a large amount of rare-earth-rich phases observed along the grain boundaries, no fine, dispersed aging precipitates were observed.

[0061] Reference Figure 12 Referring to Examples 7-9 and Comparative Example 3 in Table 1, Figure 12(a) shows the stress-strain curve, and (b) shows the mechanical property statistics. Analysis reveals that the strength improvement of the aged composite material is most significant compared to the solution-treated composite. The mechanical properties of the composite material do not change with the amount of FMGp added after aging treatment. The yield strength increases with increasing FMGp content, while the tensile strength and elongation show a trend of first increasing and then decreasing with increasing FMGp content. When the FMGp addition is 4 wt.%, its strength and plasticity reach their optimal levels. At this point, the yield strength, ultimate tensile strength, and elongation of the composite material are 234 MPa, 350 MPa, and 5.8%, respectively. These represent increases of 8.8%, 10.4%, and 61.1% compared to the matrix alloy. In conclusion, solution treatment followed by aging treatment further enhances the strength of the composite material, achieving a synergistic improvement in strength and plasticity compared to the matrix alloy.

[0062] Reference Figure 13 , Figure 13 Images (a) and (b) are metallographic diagrams of the VW103 matrix alloy after solution treatment and hot extrusion. Figure 13 Image (c) in the image is a scanning electron microscope (SEM) image of the base alloy VW103 after solution treatment and hot extrusion. Figure 13 Images (d) and (e) are metallographic images of the 4wt.%FMGp reinforced VW103 magnesium matrix composite material after solution treatment and hot extrusion. Figure 13Image (f) shows a scanning electron microscope (SEM) image of the 4wt.% FMGp-reinforced VW103 magnesium matrix composite after solution treatment and hot extrusion. Both the metallographic and SEM images clearly show that incomplete dynamic recrystallization occurred in the matrix alloy during hot extrusion. Some grains are deformed grains that remain elongated along the extrusion direction, while others are fine recrystallized grains formed during dynamic recrystallization. After hot extrusion, FMGp is ​​more uniformly dispersed in the matrix alloy, effectively improving casting defects in the microstructure. Compared to the matrix alloy, the addition of FMGp increases the degree of recrystallization, refines the grains, and weakens the texture strength, indicating that FMGp helps alleviate stress concentration and improve fracture elongation. Observation of the 4wt.% FMGp / VW103 composite reveals that the microstructure of the composite also consists of deformed grains elongated along the extrusion direction and small grains formed by dynamic recrystallization. Compared to the matrix alloy, the deformed grains are smaller and fewer, and the recrystallized grains are also finer. This is because the addition of FMGp to the VW103 magnesium alloy can influence the dynamic recrystallization process of the VW103 alloy by introducing heterogeneous nucleation sites (PSN mechanism) and increasing grain boundary area, thereby improving the recrystallization degree of the composite material. Furthermore, both the matrix alloy and the extruded composite samples contained fragmented second phases distributed along the extrusion direction. EDS spot scan analysis (as shown in Table 4) revealed that the residual second phases in the VW103 matrix alloy were Mg5(Gd, Y, Zn) phase and α-Zr phase. In the composite material, except for FMGp, the residual second phases were consistent with those in the matrix alloy.

[0063] Table 4 - EDS spot scan results of extruded FMGP / VW103 composite materials

[0064] Reference Figure 14 In conjunction with Table 1, Example 10 and Comparative Example 4, Figure 14(a) shows the stress-strain curve, and (b) shows the mechanical property statistics. It can be seen that after hot extrusion at 450℃, the yield strength, ultimate tensile strength, and elongation of the VW103 matrix alloy are 299 MPa, 367 MPa, and 9.3%, respectively, showing a certain improvement compared to the as-cast alloy. Compared to the VW103 matrix alloy, the 4wt.%FMGp / VW103 composite material exhibits higher strength and plasticity after hot extrusion. Its yield strength, ultimate tensile strength, and elongation are 354 MPa, 417 MPa, and 16.3%, respectively, representing increases of 18.4%, 13.6%, and 74.9% compared to the matrix alloy, achieving a synergistic improvement in the strength and plasticity of the composite material. The improvement in strength and plasticity of the composite material indicates that the addition of FMGp has an impact on the grain size, texture, dislocation slip, etc. The huge improvement in plasticity can be attributed to the weakening of texture strength caused by FMGp and the joint activation of non-basal plane slip and twinning. In addition, the good interfacial bonding between FMGp and VW103 matrix alloy can alleviate stress concentration through load transfer during deformation, which also contributes to the improvement of plasticity.

[0065] Reference Figure 15 , Figure 15 (a) is the metallographic image of the 4wt.%FMGp / VW103 composite material after solution treatment, hot extrusion, and aging. Figure 15 Image (b) is a scanning electron microscope (SEM) image of the 4wt.% FMGp / VW103 composite material after solution treatment, hot extrusion, and aging. (The image is combined with...) Figure 13 (a), (c) and Figure 13 As shown in figures (d) and (f), the aging treatment did not change the microstructure of the composite material; it still consists of coarse deformed grains and fine dynamic recrystallization, similar to... Figure 13 Compared to the microstructure, there was no significant difference in morphology, and no fine, dispersed precipitate phase was observed.

[0066] Reference Figure 16 In conjunction with Examples 11 and 10 in Table 1, Figure 16(a) shows the stress-strain curve, and (b) shows the mechanical property statistics. After hot extrusion and aging, the composite material's microstructure remained unchanged, still consisting of coarse deformed grains and fine dynamic recrystallization. Aging also had no significant effect on the grain size and dimensions, indicating that aging does not cause significant grain growth or dynamic recrystallization. The composite material achieved not only higher yield strength and tensile strength but also retained a certain elongation. Its yield strength, ultimate tensile strength, and elongation were 390 MPa, 450 MPa, and 7.7%, respectively. Compared to the extruded composite material, the hardness was significantly improved, with yield strength and ultimate tensile strength increasing by 36 MPa and 33 MPa, respectively, while the elongation decreased by 8.5%. The significant increase in strength is due to the precipitation strengthening effect brought about by the large amount of nanoscale phases precipitated during the aging process. The decrease in elongation may be due to the brittle and hard eutectic phase remaining during extrusion causing cracks during tensile deformation, thus leading to a decrease in elongation. The increase in strength and decrease in plasticity is a typical result of aging precipitation strengthening.

[0067] The above-described embodiments are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for preparing an iron-based amorphous particle-reinforced magnesium rare earth-based composite material, characterized in that, Using a magnesium rare earth alloy as the matrix alloy and iron-based amorphous particles as the reinforcing phase, the magnesium rare earth alloy has the chemical composition of Mg-10Gd-3Y-1Zn-0.5Zr, and the iron-based amorphous particles are FMGp. The mass ratio of the iron-based amorphous particles to the composite material is (2%~6%):

1. The preparation method includes the following steps: S1. Semi-solid stirring casting: The matrix alloy is placed in a crucible and heated to form a magnesium melt under the condition of a protective gas. The temperature of the magnesium melt is reduced to a semi-solid temperature by a staged cooling method. The preheated iron-based amorphous particles are added to the magnesium melt and stirred. Then the temperature is raised and stirred. After holding at the temperature and standing, the mixture is rapidly cooled to obtain the as-cast composite material. The stirring process parameters in S1 are as follows: stirring is performed using a stirrer, and the initial stirring speed is 350 r / min. -1 The stirring time is 2 minutes; when the magnesium melt reaches a slurry state, the stirring speed is increased to 950 rpm. -1 The stirring time was 6 minutes. During stirring, a combination of up-and-down stirring and tilting was used, ensuring the stirring head remained immersed in the magnesium melt throughout the process. After the stirring was completed, the magnesium melt was heated. When the temperature reached 645°C, the stirring was repeated at 350 rpm. -1 After stirring the magnesium melt at a certain stirring speed for 30 seconds, remove the stirrer and use a slotted spoon to remove slag and impurities from the composite material melt. S2, Solution treatment: The as-cast composite material prepared in S1 was solution treated at 520℃ for 7 hours; S3. Hot extrusion molding: The composite material in S2 that has undergone solution treatment is subjected to isothermal hot extrusion deformation to obtain iron-based amorphous particle magnesium rare earth-based composite material.

2. The preparation method according to claim 1, characterized in that, The preparation method further includes an aging treatment step for the composite material, wherein the aging treatment conditions are: aging treatment at 250°C for 16 hours.

3. The preparation method according to claim 2, characterized in that, In S1, an angle grinder is used to remove the oxide film on the surface of the base alloy before placing it in the crucible.

4. The preparation method according to claim 2, characterized in that, The protective gas in S1 is a mixture of carbon dioxide and sulfur hexafluoride in a volume fraction ratio of 99:

1.

5. The preparation method according to claim 2, characterized in that, The temperature at which magnesium melt forms in S1 is 730℃; the semi-solid temperature is 635℃.

6. The preparation method according to claim 1, characterized in that, The preheating conditions for the iron-based amorphous particles in S1 are: preheating in a drying oven at 200℃ for 1 hour.

7. The preparation method according to claim 1, characterized in that, The hot extrusion molding conditions in S3 are: isothermal hot extrusion deformation at 450℃, with an extrusion ratio of 25:

1.

8. The iron-based amorphous particulate magnesium rare earth-based composite material prepared by the preparation method according to any one of claims 1-7, characterized in that, When the amount of iron-based amorphous particles added is 4 wt.%, the yield strength YS, ultimate tensile strength UTS, elongation EL and Young's modulus E of the cast composite material are 157 MPa, 266 MPa, 6% and 49.16 GPa, respectively.

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