Rare earth magnesium synergistic flame-retardant light composite material

Abstract

The invention relates to the technical field of composite materials, and discloses a rare earth magnesium synergistic flame-retardant light composite material which is prepared from the following raw materials in parts by weight: 10-20 parts of epoxy modified resin, 3-5 parts of rare earth elements, 30-40 parts of hydroxide, 5-10 parts of phosphorus flame retardant, 3-8 parts of silicon flame retardant, 40-50 parts of reinforced fibers, 0.5-2 parts of coupling agent and 0.5-1 part of lubricant. The working principles that a magnesium matrix provides structural support, rare earth elements purify melt, refine grains and the like, hydroxide is decomposed to absorb heat and form a barrier layer, a phosphorus flame retardant is decomposed to generate a flame-retardant substance synergistic effect, a silicon flame retardant perfects a flame-retardant system, reinforced fibers bear and transmit loads, a coupling agent improves interface bonding, and a lubricant guarantees smooth forming are adopted. The material has the effects of flame retardance, light weight and mechanical property, solves the problem of poor flame retardance of the existing material, and realizes the high flame retardance that an insulating plate material cannot be burnt through in half an hour by flame at the temperature of 800 DEG C or above.

Description

Technical Field

[0001] The present invention relates to the technical field of composite materials, in particular to a rare earth magnesium synergistic flame retardant lightweight composite material. Background Art

[0002] In many industrial sectors today, such as aerospace, automotive, electronics, and construction, material performance requirements are becoming increasingly stringent. Flame retardancy is a particular priority in fire safety. As various equipment and structures evolve toward lightweight and high-performance, the search for materials that combine lightweight characteristics with flame retardancy has become a research hotspot.

[0003] Traditionally, researchers have tried various methods to improve magnesium's flame retardancy. For example, adding a single flame retardant to suppress the combustion process often results in a compromise. While some inorganic flame retardants can prevent flame spread to a certain extent, their addition in large quantities can significantly increase the material's density, defeating the purpose of lightweighting. Furthermore, they can negatively impact the material's inherently favorable mechanical properties, rendering it brittle and hard, making it difficult to meet the strength and toughness requirements for practical use.

[0004] Although organic flame retardants can effectively reduce the flammability of materials in some cases, they have their own disadvantages such as limited thermal stability, easy decomposition and failure at high temperatures, and possible release of toxic and harmful gases. Not only can they not guarantee long-lasting and reliable flame retardant effects, they may also cause secondary hazards when a fire occurs, threatening human life safety and environmental safety.

[0005] Furthermore, previous studies on the preparation of flame-retardant magnesium composites have mostly focused on the simple addition of flame retardants, while ignoring the synergistic effects between the various components and the impact of the preparation process on the material's ultimate flame-retardant properties. This results in the difficulty of evenly dispersing the various components in the matrix during actual production, resulting in uneven flame-retardant properties in different parts of the material, significantly reducing the overall flame-retardant effect. Furthermore, imperfect preparation processes can also introduce defects such as impurities and pores, further weakening the material's overall performance and making it unable to meet the stringent demands of modern industry for high-performance, high-quality, flame-retardant, lightweight materials. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the present invention provides a rare earth magnesium synergistic flame retardant lightweight composite material, which solves the problem of poor flame retardancy of existing magnesium materials.

[0007] To achieve the above objectives, the present invention is implemented through the following technical scheme: a rare earth magnesium synergistic flame retardant lightweight composite material is composed of the following raw materials in parts by weight: 40-60 parts of a magnesium matrix, 5-15 parts of a rare earth element, 10-20 parts of a hydroxide, 5-10 parts of a phosphorus-based flame retardant, 3-8 parts of a silicon-based flame retardant, 10-20 parts of reinforcing fiber, 0.5-2 parts of a coupling agent, and 0.5-1 part of a lubricant.

[0008] Preferably, the rare earth elements include the following percentage raw materials: magnesium 85%-90%, cerium 0.5%-1.2%, gadolinium 0.3%-0.8%, yttrium 0.2%-0.6%, magnesium hydroxide 5%-8%, ammonium polyphosphate 2%-4%, and zirconium 0.1%-0.3%.

[0009] The preparation method of the flame-retardant lightweight composite material is used for the rare earth magnesium synergistic flame-retardant lightweight composite material, comprising the following steps:

[0010] S1. Raw material preparation and inspection: Select qualified raw materials, check the relevant information of each raw material, inspect the appearance and quality, cut and weigh as needed, ensure that they meet the formula requirements and prepare them for use;

[0011] S2. Raw material pretreatment: The raw materials are processed accordingly and polished, dried and ground to reach a state suitable for melting and mixing;

[0012] S3, smelting the magnesium matrix under the protection of inert gas, stirring it evenly after melting, and then slowly adding the rare earth element and increasing the stirring speed to make the rare earth element fully dissolved and evenly dispersed in the magnesium melt;

[0013] S4. Add flame retardant additives to the rare earth magnesium melt in proportion, stir initially and then stir thoroughly to evenly disperse them, then add reinforcing fibers and coupling agent and continue stirring to ensure that the fibers are evenly distributed and well bonded to the matrix;

[0014] S5. Select the die-casting method, transfer the mixed melt to the corresponding equipment, set the corresponding parameters, and perform the molding operation through the mold to produce a composite material product of the desired shape;

[0015] S6. Heat treat the formed products as needed to eliminate stress.

[0016] Preferably, S1 specifically includes the following steps:

[0017] S101, select magnesium and cut it into blocks weighing 1-5 kg ​​each for later use;

[0018] S102, prepare aluminum hydroxide and magnesium hydroxide flame retardants, with a water content of less than 1%, and control the particle size of red phosphorus microcapsules to 50-200 μm;

[0019] S103, cutting the reinforcing fibers into a length of 3-6 mm and weighing them, selecting a silane coupling agent with a concentration of 1%-3% by mass and a lubricant, and setting them aside.

[0020] Preferably, the step S2 specifically includes the following steps:

[0021] S201. Polish the surface of the magnesium block with 80-mesh and 200-mesh sandpaper in sequence until it is bright. Soak and clean it with acetone or ethanol for 10-15 minutes, then rinse with distilled water. Dry it in a vacuum drying oven at 80-100°C for 2-3 hours, and then preheat it in a resistance furnace at 300-400°C for 30-60 minutes.

[0022] S202. Wipe with anhydrous ethanol, sandpaper, rinse with distilled water, and then dry in a 60-80°C oven for 1-2 hours. If it is a rare earth compound, grind it to a particle size of 100-300 mesh, rinse with anhydrous ethanol, and then dry in a 60-80°C oven for 1-2 hours.

[0023] S203, aluminum hydroxide and magnesium hydroxide are dried in an oven at 100-120°C for 2-3 hours, ground to a particle size of 200-500 mesh and stored in a desiccator. Red phosphorus is used to check the integrity of the microcapsules. Phosphates are dried at 80-100°C for 1-2 hours. Silicone rubber is cut into small particles. Silicon dioxide is ground to a particle size of 100-300 mesh and dried together in an oven at 80-100°C for 1-2 hours for later use.

[0024] S204. Soak the glass fiber in a 1%-3% by mass silane coupling agent solution for 30-60 minutes and dry it in an oven at 100-120°C for 1-2 hours.

[0025] Preferably, the step S3 specifically includes the following steps:

[0026] S301, placing the pretreated magnesium substrate into a vacuum induction melting furnace, heating it to 650-750°C at 10-20°C / min under argon protection, holding it for 5-10 minutes after melting, and then stirring it at a speed of 100-200 r / min for 10-15 minutes;

[0027] S302. Slowly add rare earth elements according to the formula amount, and complete the addition within 5-10 minutes. Then increase the stirring speed to 200-300 r / min and continue stirring for 15-20 minutes.

[0028] Preferably, the S4 specifically includes the following steps:

[0029] S401. Add flame retardants in proportion. Stir at 100-200 r / min for 3-5 minutes each time, then increase the speed to 200-300 r / min and stir for 10-15 minutes.

[0030] S402, adding the reinforcing fiber and the coupling agent into the melt, and stirring at a speed of 300-400 r / min for 20-30 minutes.

[0031] Preferably, the S5 specifically includes: quickly transferring the melt to the barrel of a die-casting machine, setting the injection pressure to 30-60 MPa, the injection speed to 1-3 m / s, and the mold temperature to 150-250° C., and die-casting the product using a suitable mold cavity.

[0032] Preferably, the step S6 specifically includes: placing the product into a heat treatment furnace, heating the product to 200-400° C. at a rate of 5-10° C. / min, and performing an aging treatment for 2-8 hours.

[0033] The preparation method of the flame-retardant lightweight composite material is used for the rare earth magnesium synergistic flame-retardant lightweight composite material, comprising the following steps:

[0034] S1. Add various flame retardants into the resin solution and stir to disperse;

[0035] S2. Apply the stirred glue evenly onto the glass fiber cloth;

[0036] S3. Heat the glass fiber cloth coated with glue at 250℃ for no more than half an hour to form a semi-cured state;

[0037] S4. Place the semi-cured product into a mold for hot pressing.

[0038] The present invention provides a rare earth magnesium synergistic flame retardant lightweight composite material. It has the following beneficial effects:

[0039] 1. The present invention adopts the working principle of providing structural support through the magnesium matrix, purifying the melt and refining the grains with rare earth elements, decomposing the hydroxide to absorb heat and form a barrier layer, decomposing the phosphorus flame retardant to produce a synergistic effect of flame retardant substances, improving the flame retardant system with silicon flame retardants, strengthening the fiber bearing and transmitting the load, improving the interface bonding with a coupling agent, and ensuring smooth molding with a lubricant, thereby achieving the effects of flame retardancy, lightness and mechanical properties, and solving the problem of poor flame retardancy of existing materials.

[0040] 2. The present invention optimizes the performance of composite materials and solves the problems of insufficient mechanical properties and thermal stability of materials by ensuring adaptive fusion of magnesium, cerium purifying the melt and refining the grains, gadolinium changing the crystal structure and improving thermal stability, yttrium optimizing the structure of the oxide film, magnesium hydroxide decomposing to absorb heat and form a barrier layer, ammonium polyphosphate decomposing to produce flame retardant substances, and zirconium dispersion strengthening and optimizing the organizational morphology.

[0041] 3. The present invention prepares aluminum hydroxide and magnesium hydroxide flame retardants with a water content of less than 1%. Based on the principle that water will vaporize and generate bubbles in subsequent high-temperature processes such as smelting, affecting the uniformity of the internal structure of the material and the performance of the flame retardant, the flame retardant is ensured to be in a low-moisture content state. At the same time, the particle size of the red phosphorus microcapsules is controlled to be 50-200μm, so that it can be better dispersed in the material and exert a stable flame retardant effect, thereby ensuring that the flame retardant can effectively exert its flame retardant function in subsequent processes and avoiding the effect of moisture or particle size problems on material performance. This solves the problem of internal defects of the material caused by high water content of the flame retardant and unstable flame retardant effect caused by inappropriate particle size.

[0042] 4. The present invention wipes the compound rare earth with anhydrous ethanol, polishes with sandpaper, and rinses with distilled water, removes impurities that may be contaminated on the surface by virtue of the solubility of anhydrous ethanol, further cleans the surface with sandpaper, and rinses away residual impurities and ethanol with distilled water, and then dries it in a 60-80°C oven for 1-2 hours, and uses the constant temperature environment of the oven to remove moisture. If it is a compound rare earth, it is ground to a particle size of 100-300 mesh. Based on the principle that refining the particle size can increase its specific surface area, which is conducive to faster and better dissolution and dispersion in the melt, it is finally washed with anhydrous ethanol and dried in an oven at 60-80°C for 1-2 hours to achieve the effect of removing impurities on the surface of the rare earth, making it dry and with a suitable particle size for uniform dispersion during subsequent smelting, thereby solving the problems that impurities on the surface of the rare earth affect its performance and that the particle size is too large, resulting in difficulty in dispersion in the melt. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 This is a flow chart of the steps of preparing the rare earth magnesium synergistic flame retardant lightweight composite material of the present invention; Figure 2 This is a specific flow chart of the rare earth magnesium synergistic flame retardant lightweight composite material of the present invention. DETAILED DESCRIPTION

[0044] The following will clearly and completely describe the technical solution of the present invention in conjunction with the accompanying drawings. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0045] Please see the attached Figure 1 The embodiment of the present invention provides a rare earth magnesium synergistic flame retardant lightweight composite material, which is composed of the following raw materials in parts by weight: 40-60 parts of magnesium matrix, 5-15 parts of rare earth elements, 10-20 parts of hydroxide, 5-10 parts of phosphorus-based flame retardant, 3-8 parts of silicon-based flame retardant, 10-20 parts of reinforcing fiber, 0.5-2 parts of coupling agent, and 0.5-1 part of lubricant.

[0046] Specifically, by adding 40-60 parts of magnesium matrix, it serves as a basic load-bearing frame to provide main structural support for the entire composite material;

[0047] By adding 5-15 parts of rare earth elements, the unique physical and chemical properties of the elements are used to modify the matrix and other components, thereby optimizing the material microstructure and improving the overall performance.

[0048] By adding 10-20 parts of hydroxide, the combustion process can be inhibited by taking advantage of its characteristics of absorbing heat when decomposed by heat and generating barrier substances;

[0049] By adding 5-10 parts of phosphorus flame retardant, the flame retardant substance produced by its decomposition at high temperature and its synergistic effect with other components can achieve the purpose of enhancing the flame retardancy of the material;

[0050] By adding 3-8 parts of silicone flame retardant, the flame retardant system can be further improved by virtue of its own flame retardant mechanism and in combination with other flame retardant ingredients;

[0051] By adding 10-20 parts of reinforcing fibers, the good mechanical properties of the fibers are used to carry external forces and transfer loads, thereby improving the overall mechanical properties of the material.

[0052] By adding 0.5-2 parts of coupling agent, the interface bonding between the components is improved to achieve the effect of enhancing the integrity of the material;

[0053] By adding 0.5-1 parts of lubricant and taking advantage of its effect on improving the processing fluidity of the material, the goal of ensuring the smooth progress of the material during the molding process and reducing the occurrence of defects is achieved. Ultimately, a rare earth magnesium synergistic flame retardant lightweight composite material with good flame retardant properties, lightweight characteristics and mechanical properties is obtained.

[0054] The rare earth magnesium synergistic flame retardant lightweight composite material is composed of 40-60 parts of magnesium matrix, 5-15 parts of rare earth elements, 10-20 parts of hydroxide, 5-10 parts of phosphorus flame retardant, 3-8 parts of silicon flame retardant, 10-20 parts of reinforcing fiber, 0.5-2 parts of coupling agent, and 0.5-1 part of lubricant. The magnesium matrix provides structural support, the rare earth elements purify the melt and refine the grains, the hydroxide decomposes to absorb heat and form a barrier layer, the phosphorus flame retardant decomposes to produce a synergistic effect of flame retardant substances, the silicon flame retardant improves the flame retardant system, the reinforcing fiber carries and transfers the load, the coupling agent improves the interface bonding, and the lubricant ensures smooth molding. The working principle achieves the effects of flame retardancy, lightness and mechanical properties, and solves the problem of poor flame retardant performance of existing materials.

[0055] The rare earth elements include the following percentage raw materials: magnesium 85%-90%, cerium 0.5%-1.2%, gadolinium 0.3%-0.8%, yttrium 0.2%-0.6%, magnesium hydroxide 5%-8%, ammonium polyphosphate 2%-4%, and zirconium 0.1%-0.3%.

[0056] Specifically, by adding magnesium accounting for 85%-90%, it is ensured that the rare earth element system and the magnesium matrix are compatible and stably integrated in terms of composition, thereby obtaining a basic composition of rare earth elements with good adaptability, thereby achieving an effect that is conducive to subsequent synergistic effects with the matrix;

[0057] By adding 0.5%-1.2% cerium, the material structure with fewer impurities and finer grains is obtained by utilizing its properties of purifying the melt, adsorbing impurity elements, and refining grains, thereby achieving the effect of improving the strength and toughness of the material.

[0058] By adding 0.3%-0.8% gadolinium, the interaction between gadolinium and magnesium and other elements changes the crystal structure and improves thermal stability, resulting in a material with enhanced thermal stability, which suppresses grain growth at high temperatures.

[0059] By adding 0.2%-0.6% yttrium, the surface oxide film structure of the material is optimized to make it denser, thus obtaining a material with better antioxidant and flame retardant properties, thereby enhancing the surface protection performance of the material.

[0060] By adding 5%-8% magnesium hydroxide, the flame retardant effect can be exerted in the subsequent combustion process and the characteristics of participating in microscopic reactions to affect the overall performance can be obtained, thereby obtaining a material with improved flame retardancy and a more reasonable internal structure, thereby achieving the effect of enriching the flame retardancy and comprehensive performance of the material.

[0061] By adding 2%-4% ammonium polyphosphate, based on the principle that ammonium polyphosphate decomposes at high temperatures to produce flame retardant substances and cooperates with other flame retardant ingredients, a material with a more complete flame retardant mechanism is obtained, achieving the effect of strengthening the overall flame retardant effect;

[0062] By adding 0.1%-0.3% zirconium, with its dispersion strengthening effect and influence on the solidification structure morphology to make the structure more uniform, a material with improved strength and uniform structure is obtained, achieving the effect of optimizing the comprehensive performance of the material.

[0063] Rare earth elements include 85%-90% magnesium, 0.5%-1.2% cerium, 0.3%-0.8% gadolinium, 0.2%-0.6% yttrium, 5%-8% magnesium hydroxide, 2%-4% ammonium polyphosphate, and 0.1%-0.3% zirconium. Magnesium is used to ensure adaptive fusion, cerium purifies the melt and refines the grains, gadolinium changes the crystal structure to improve thermal stability, yttrium optimizes the oxide film structure, magnesium hydroxide decomposes to absorb heat and form a barrier layer, ammonium polyphosphate decomposes to produce flame retardant substances, and zirconium dispersion strengthens and optimizes the working principle of organizational morphology to achieve the optimization of composite material performance and solve the problems of insufficient mechanical properties and thermal stability of the material.

[0064] The preparation method of the flame retardant lightweight composite material is used for rare earth magnesium synergistic flame retardant lightweight composite material, comprising the following steps:

[0065] S1. Raw material preparation and inspection: Select qualified raw materials, check the relevant information of each raw material, inspect the appearance and quality, cut and weigh as needed, ensure that they meet the formula requirements and prepare them for use;

[0066] S2. Raw material pretreatment: The raw materials are processed accordingly and polished, dried and ground to reach a state suitable for melting and mixing;

[0067] S3, smelting the magnesium matrix under the protection of inert gas, stirring it evenly after melting, and then slowly adding the rare earth element and increasing the stirring speed to make the rare earth element fully dissolved and evenly dispersed in the magnesium melt;

[0068] S4. Add flame retardant additives to the rare earth magnesium melt in proportion, stir initially and then stir thoroughly to evenly disperse them, then add reinforcing fibers and coupling agent and continue stirring to ensure that the fibers are evenly distributed and well bonded to the matrix;

[0069] S5. Select the die-casting method, transfer the mixed melt to the corresponding equipment, set the corresponding parameters, and perform the molding operation through the mold to produce a composite material product of the desired shape;

[0070] S6. Heat treat the formed products as needed to eliminate stress.

[0071] S1 specifically includes the following steps:

[0072] S101, select magnesium and cut it into blocks weighing 1-5 kg ​​each for later use;

[0073] S102, prepare aluminum hydroxide and magnesium hydroxide flame retardants, with a water content of less than 1%, and control the particle size of red phosphorus microcapsules to 50-200 μm;

[0074] S103, cutting the reinforcing fibers into a length of 3-6 mm and weighing them, selecting a silane coupling agent with a concentration of 1%-3% by mass and a lubricant, and setting them aside.

[0075] Specifically, by selecting magnesium and cutting it into blocks weighing 1-5 kg ​​each for standby use, based on the working principle of controlling the size and weight of the magnesium blocks, it is convenient to more accurately control the amount of material added in subsequent processes such as smelting, and ensure that it can be evenly heated and melted in the equipment. This ensures that the magnesium raw material can stably participate in the reaction in the subsequent preparation process, which is beneficial to the process operation, and solves the problem of inconvenience in adding material and uneven heating affecting material quality due to unreasonable size or weight of the magnesium raw material.

[0076] By preparing aluminum hydroxide and magnesium hydroxide flame retardants with a water content of less than 1%, and based on the principle that water will vaporize and produce bubbles in subsequent high-temperature processes such as smelting, affecting the uniformity of the internal structure of the material and the performance of the flame retardant, the flame retardant is ensured to be in a low-moisture content state. At the same time, by controlling the particle size of the red phosphorus microcapsules to 50-200μm, it can be better dispersed in the material and exert a stable flame retardant effect, thereby ensuring that the flame retardant can effectively exert its flame retardant function in subsequent processes and avoiding the impact of moisture or particle size problems on material performance. The problem of internal defects of the material caused by high water content and unstable flame retardant effect caused by inappropriate particle size is solved.

[0077] By cutting the reinforcing fibers to a length of 3-6 mm and weighing them, the principle is relied on that the appropriate fiber length helps them to be better dispersed when subsequently mixed with the matrix, avoiding entanglement due to being too long or difficulty in exerting the reinforcing effect due to being too short. At the same time, a silane coupling agent concentration of 1%-3% by mass and a lubricant are selected. The principle that the use of an appropriate concentration of coupling agent can effectively improve the interface bonding between the reinforcing fibers and the matrix, and the lubricant can ensure the smooth progress of the processing process, is adopted. The reinforcing fibers can be evenly distributed in the material, well bonded to the matrix, and the material has good processing performance, thereby solving the problems of uneven dispersion of the reinforcing fibers, poor interface bonding, and poor fluidity during material processing.

[0078] S2 specifically includes the following steps:

[0079] S201. Polish the surface of the magnesium block with 80-mesh and 200-mesh sandpaper in sequence until it is bright. Soak and clean it with acetone or ethanol for 10-15 minutes, then rinse with distilled water. Dry it in a vacuum drying oven at 80-100°C for 2-3 hours, and then preheat it in a resistance furnace at 300-400°C for 30-60 minutes.

[0080] S202. Wipe with anhydrous ethanol, sandpaper, rinse with distilled water, and then dry in a 60-80°C oven for 1-2 hours. If it is a rare earth compound, grind it to a particle size of 100-300 mesh, rinse with anhydrous ethanol, and then dry in a 60-80°C oven for 1-2 hours.

[0081] S203, aluminum hydroxide and magnesium hydroxide are dried in an oven at 100-120°C for 2-3 hours, ground to a particle size of 200-500 mesh and stored in a desiccator. Red phosphorus is used to check the integrity of the microcapsules. Phosphates are dried at 80-100°C for 1-2 hours. Silicone rubber is cut into small particles. Silicon dioxide is ground to a particle size of 100-300 mesh and dried together in an oven at 80-100°C for 1-2 hours for later use.

[0082] S204. Soak the glass fiber in a 1%-3% by mass silane coupling agent solution for 30-60 minutes and dry it in an oven at 100-120°C for 1-2 hours.

[0083] Specifically, the surface of the magnesium block is first polished with 80-mesh and 200-mesh sandpaper in sequence until it is bright, based on the working principle of removing the oxide layer, impurities and possible rough and uneven parts on the magnesium surface, so that the surface becomes flat and smooth, which is conducive to better integration with other components in the subsequent process; then it is soaked and cleaned with acetone or ethanol for 10-15 minutes and then rinsed with distilled water, using the principle that organic solvents can dissolve impurities such as oil and distilled water can further rinse away residual impurities, thereby removing oil and dirt on the surface; then it is placed in a vacuum drying oven at 80-100°C for 2-3 hours, relying on the principle of effectively removing moisture and avoiding oxidation in a vacuum environment to ensure the dry state of the material; and finally preheated in a resistance furnace at 300-400°C for 30-60 minutes, based on the principle of making the magnesium reach a suitable initial temperature to facilitate subsequent rapid and uniform melting, so as to achieve the effect of making the surface of the magnesium block clean, dry and in a preheated state conducive to smelting, thereby solving the problems of impurities, moisture and inappropriate initial temperature on the magnesium surface affecting the smelting quality and integration with other components.

[0084] By wiping with anhydrous ethanol, polishing with sandpaper, and rinsing the compound rare earth with distilled water, the solubility of anhydrous ethanol is used to remove impurities that may be contaminated on the surface, sandpaper polishing is used to further clean the surface, and distilled water is used to rinse off the residual impurities and ethanol. Then, it is placed in a 60-80°C oven to dry for 1-2 hours, and the constant temperature environment of the oven is used to remove moisture. If it is a compound rare earth, it is ground to a particle size of 100-300 mesh. Based on the principle that refining the particle size can increase its specific surface area, which is conducive to faster and better dissolution and dispersion in the melt, it is finally washed with anhydrous ethanol and dried in an oven at 60-80°C for 1-2 hours to achieve the effect of removing impurities on the surface of the rare earth, making it dry and with a suitable particle size for uniform dispersion during subsequent smelting. This solves the problem that impurities on the surface of the rare earth affect its performance and that the large particle size makes it difficult to disperse in the melt.

[0085] Aluminum hydroxide and magnesium hydroxide are dried in an oven at 100-120°C for 2-3 hours to remove moisture and prevent defects such as pores from being generated during subsequent high-temperature processes, which may affect the density of the material. The particles are ground to a particle size of 200-500 mesh. Refining the particle size improves its dispersion in the material, allowing it to be more evenly distributed in the matrix to exert a flame retardant effect. The particles are then stored in a dryer to maintain a dry state. The integrity of the red phosphorus microcapsules is checked to ensure that the flame retardant components inside can effectively function and will not fail due to capsule damage. Phosphates are tested at 8 Dry at 0-100℃ for 1-2 hours to remove moisture for subsequent use; cut the silicone rubber into small particles to facilitate its uniform dispersion in the material; grind the silicon dioxide to a particle size of 100-300 mesh to increase the specific surface area for easy dispersion, and dry them together in an oven at 80-100℃ for 1-2 hours for use. This ensures that the flame retardants and related ingredients are dry, have appropriate particle size and can effectively function, making them fully prepared for subsequent addition to the material, solving the problem of these raw materials affecting the flame retardant performance and overall quality in the composite material due to moisture, particle size or integrity issues.

[0086] The glass fiber is immersed in a 1%-3% mass fraction silane coupling agent solution for 30-60 minutes. Based on the principle that the silane coupling agent can chemically react with the surface of the glass fiber, one end is combined with the fiber, and the other end can interact with the matrix, thereby enhancing the interfacial bonding force between the fiber and the matrix. The glass fiber is then dried in an oven at 100-120°C for 1-2 hours to remove moisture and better fix the coupling agent on the fiber surface, thereby achieving a tighter bond between the glass fiber and the matrix and better playing a reinforcing role in subsequent materials. This solves the problem of weak bonding between the glass fiber and the matrix and difficulty in effectively improving the mechanical properties of the material.

[0087] S3 specifically includes the following steps:

[0088] S301, placing the pretreated magnesium substrate into a vacuum induction melting furnace, heating it to 650-750°C at 10-20°C / min under argon protection, holding it for 5-10 minutes after melting, and then stirring it at a speed of 100-200 r / min for 10-15 minutes;

[0089] S302. Slowly add rare earth elements according to the formula amount, and complete the addition within 5-10 minutes. Then increase the stirring speed to 200-300 r / min and continue stirring for 15-20 minutes.

[0090] Specifically, the pretreated magnesium matrix is ​​placed in a vacuum induction melting furnace and heated to 650-750°C at a rate of 10-20°C / minute under argon protection. Based on the fact that the vacuum induction melting furnace can provide a stable and controllable high-temperature environment, the argon protection can isolate the air and prevent the magnesium from violently reacting with oxygen during the heating and melting process. The magnesium is gradually heated to a specific temperature range according to an appropriate heating rate, so that the magnesium is heated evenly and melted stably. After melting, the magnesium is kept for 5-10 minutes to allow the magnesium melt to fully reach a uniform liquid state, and then stirred at a speed of 100-200r / min for 10-15 minutes. The convection effect generated by the stirring makes the temperature and composition inside the melt more uniform, thereby achieving the effect of uniform melting of the magnesium matrix, stable melt state and uniform composition, thereby solving the problem that magnesium is easily oxidized during melting and the problem that uneven heating and uneven composition inside the melt affect the subsequent fusion with other components.

[0091] The rare earth elements are slowly added according to the formula amount and the addition is controlled within 5-10 minutes. This is based on the principle that slow addition can avoid excessive concentration of local components and excessive reaction due to excessive addition at one time, which affects the stability of the melt. The stirring speed is then increased to 200-300r / min, and stirring is continued for 15-20 minutes. The convection effect of the melt is enhanced by stirring at a higher speed, so that the rare earth elements can be fully dissolved, rapidly diffused and evenly dispersed in the magnesium melt. The working principle is to achieve the effect of uniform dispersion and full fusion of the rare earth elements in the magnesium melt, and synergistic effect with the matrix, which solves the problem that the addition of rare earth elements easily causes uneven melt composition and cannot be well integrated with the matrix, thereby affecting the performance of the composite material.

[0092] S4 specifically includes the following steps:

[0093] S401. Add flame retardants in proportion. Stir at 100-200 r / min for 3-5 minutes each time, then increase the speed to 200-300 r / min and stir for 10-15 minutes.

[0094] S402, adding the reinforcing fiber and the coupling agent into the melt, and stirring at a speed of 300-400 r / min for 20-30 minutes.

[0095] Specifically, by adding flame retardants in proportion, each time a flame retardant is added, it is stirred at a speed of 100-200 r / min for 3-5 minutes. Based on this lower speed stirring, the newly added flame retardant can be initially diffused slowly in the melt, avoiding the flame retardant splashing due to too fast stirring or the difficulty in uniform dispersion due to local high concentration, and at the same time allowing it to be initially fused with the melt; then the speed is increased to 200-300 r / min and stirred for 10-15 minutes. Based on the higher speed stirring, the convection effect of the melt can be enhanced, the interfacial tension between the flame retardant and the melt can be overcome, and the flame retardant particles can be more fully dispersed and dissolved in the melt, so that various flame retardants are evenly dispersed and fully integrated in the mixed melt of magnesium and rare earth elements, and a stable and effective flame retardant system is jointly constructed, which solves the problem that the flame retardant is easily dispersed unevenly in the melt, which in turn causes large differences in flame retardant properties of different parts of the material and poor overall flame retardant effect.

[0096] By adding reinforcing fibers and a coupling agent into the melt and stirring at a speed of 300-400 r / min for 20-30 minutes, a strong shear force and convection effect are generated by relying on a higher stirring speed. On the one hand, the reinforcing fibers can be dispersed as much as possible in the melt to avoid fiber agglomeration and make them evenly distributed in the entire melt. On the other hand, with the help of the coupling agent, during the stirring process, the coupling agent can better improve the interface bonding condition between the reinforcing fibers and the melt, so that a good connection is formed between the reinforcing fibers and the matrix, and the reinforcing fibers are evenly distributed in the composite material and tightly bonded to the matrix, thereby effectively improving the mechanical properties of the material and solving the problem that the reinforcing fibers are difficult to disperse in the melt and are not firmly bonded to the matrix, resulting in the inability to fully exert the reinforcing effect and affecting the overall mechanical properties of the material.

[0097] S5 specifically includes: quickly transferring the melt to the barrel of the die-casting machine, setting the injection pressure to 30-60 MPa, the injection speed to 1-3 m / s, and the mold temperature to 150-250°C, and die-casting the product using a suitable mold cavity.

[0098] Specifically, by quickly transferring the melt to the barrel of the die-casting machine, based on the working principle of reducing heat loss of the melt during the transfer process and avoiding the deterioration of melt fluidity and component segregation due to too long residence time; setting the injection pressure to 30-60MPa, according to the principle that the appropriate injection pressure can provide enough power for the melt to overcome the resistance inside the mold cavity and smoothly fill the entire cavity to ensure the complete molding of the product; setting the injection speed to 1-3m / s, according to this speed range, the melt will not have defects such as cold shut due to too slow speed when entering the cavity, nor will it splash or be entangled due to too fast speed. The principle of solving problems such as excessive gas; controlling the mold temperature at 150-250℃, relying on this temperature range to allow the melt to quickly cool and solidify based on suitable heat exchange conditions after entering the cavity, shortening the molding cycle, and at the same time helping to obtain good surface quality and organizational properties; finally, using a suitable mold cavity to die-cast the product, with the help of the shape given by the mold cavity, the melt is solidified and molded according to the preset shape, solving the problems of unreasonable parameters in the transfer, filling, cooling and other links of the melt during the die-casting process, resulting in molding defects, poor surface quality, uneven internal organization and shape not meeting the requirements.

[0099] S6 specifically includes: placing the product into a heat treatment furnace, heating it to 200-400° C. at a rate of 5-10° C. / min, and performing aging treatment for 2-8 hours.

[0100] Specifically, by placing the product in a heat treatment furnace and heating it to 200-400°C at a heating rate of 5-10°C / minute, based on such a more appropriate heating rate, the internal structure of the product can be heated evenly, avoiding the concentration of thermal stress caused by too rapid heating, which may lead to defects such as cracks in the product. Slowly heating to a specific temperature range can enable the atoms inside the product to have sufficient time to diffuse, rearrange, and other microstructural adjustments; followed by 2-8 hours of aging treatment. By maintaining this temperature for a certain period of time, the residual stress inside the material can be fully released, and at the same time, the supersaturated solid solution can be decomposed and dispersed second-phase particles can be precipitated, which plays a working principle of strengthening the matrix and improving the comprehensive mechanical properties of the material, thereby eliminating the residual stress inside the product, optimizing the microstructure of the material, and thus improving the mechanical properties and dimensional stability of the material. This solves the problem that residual stress generated in the product due to processes such as die casting easily leads to deformation, cracking, and mechanical properties not reaching the optimal state, affecting actual use.

[0101] Please see the attached Figure 1 The preparation method of the flame retardant lightweight composite material for rare earth magnesium synergistic flame retardant lightweight composite material comprises the following steps:

[0102] S1. Add various flame retardants into the resin solution and stir to disperse;

[0103] S2. Apply the stirred glue evenly onto the glass fiber cloth;

[0104] S3. Heat the glass fiber cloth coated with glue at 250℃ for no more than half an hour to form a semi-cured state;

[0105] S4. Place the semi-cured product into a mold for hot pressing.

[0106] Specifically, by adding various flame retardants into the resin solution and stirring and dispersing them, the mechanical force generated by stirring causes the flame retardant particles in the resin solution to be continuously impacted and sheared, overcoming the agglomeration force and surface tension between the particles, and allowing the flame retardant to be evenly distributed between the resin solution molecules.

[0107] By evenly applying the stirred glue to the glass fiber cloth, based on the glass fiber cloth having a certain pore structure and surface adsorption, the glue can adhere to the surface and pores of the glass fiber through physical infiltration and adsorption.

[0108] By heating the glass fiber cloth coated with glue at 250℃ for no more than half an hour, under this temperature condition, the resin molecules will undergo a certain degree of cross-linking reaction, but due to the control of heating time, the cross-linking reaction is incomplete, causing the material to form a semi-cured state.

[0109] The semi-cured product is placed in a mold for hot pressing. During the hot pressing process, the mold provides a specific shape and pressure. The high temperature causes the resin to further cross-link and solidify, and the pressure causes the material to be tightly combined and fill the mold cavity.

[0110] The above-mentioned method for preparing flame-retardant lightweight composite materials can achieve uniform dispersion of the flame retardant in the resin solution, fully combine the glue with the glass fiber cloth, and form the glass fiber cloth and the glue into a semi-cured state that is convenient for subsequent operations through appropriate heating. Finally, a composite material with a certain strength and shape is obtained through hot pressing. The prepared rare earth magnesium synergistic flame-retardant lightweight composite material has uniform flame retardant properties, good shape, and meets the required strength, which can be better applied in practical scenarios. This solves the problem of uneven dispersion of the flame retardant in the resin solution, which leads to large differences in local flame retardant properties, irregular shape of the composite material, and insufficient strength.

[0111] Example 1:

[0112] The rare earth magnesium synergistic flame retardant lightweight composite material is composed of the following raw materials in parts by weight: 60 parts of magnesium matrix, 15 parts of rare earth elements, 20 parts of hydroxide, 10 parts of phosphorus-based flame retardant, 8 parts of silicon-based flame retardant, 20 parts of reinforcing fiber, 2 parts of coupling agent, and 1 part of lubricant.

[0113] The rare earth elements include the following percentage raw materials: magnesium 85%-90%, cerium 0.5%-1.2%, gadolinium 0.3%-0.8%, yttrium 0.2%-0.6%, magnesium hydroxide 5%-8%, ammonium polyphosphate 2%-4%, and zirconium 0.1%-0.3%.

[0114] The preparation method of the flame retardant lightweight composite material is used for rare earth magnesium synergistic flame retardant lightweight composite material, comprising the following steps:

[0115] S1. Raw material preparation and inspection: Select qualified raw materials, check the relevant information of each raw material, inspect the appearance and quality, cut and weigh as needed, ensure that they meet the formula requirements and prepare them for use;

[0116] S2. Raw material pretreatment: The raw materials are processed accordingly and polished, dried and ground to reach a state suitable for melting and mixing;

[0117] S3, smelting the magnesium matrix under the protection of inert gas, stirring it evenly after melting, and then slowly adding the rare earth element and increasing the stirring speed to make the rare earth element fully dissolved and evenly dispersed in the magnesium melt;

[0118] S4. Add flame retardant additives to the rare earth magnesium melt in proportion, stir initially and then stir thoroughly to evenly disperse them, then add reinforcing fibers and coupling agent and continue stirring to ensure that the fibers are evenly distributed and well bonded to the matrix;

[0119] S5. Select the die-casting method, transfer the mixed melt to the corresponding equipment, set the corresponding parameters, and perform the molding operation through the mold to produce a composite material product of the desired shape;

[0120] S6. Heat treat the formed products as needed to eliminate stress.

[0121] S1 specifically includes the following steps:

[0122] S101, select magnesium and cut it into blocks weighing 3 kg each for later use;

[0123] S102, prepare aluminum hydroxide and magnesium hydroxide flame retardants, with a water content of less than 1%, and control the particle size of red phosphorus microcapsules to 125 μm;

[0124] S103, cutting the reinforcing fiber to a length of 4.5 mm and weighing it, selecting a silane coupling agent with a concentration of 2% by mass and a lubricant, and setting them aside.

[0125] S2 specifically includes the following steps:

[0126] S201. Polish the surface of the magnesium block with 80-mesh and 200-mesh sandpaper in sequence until it is bright. Soak and clean it in acetone or ethanol for 12.5 minutes, then rinse with distilled water. Dry it in a vacuum drying oven at 90°C for 2.5 hours, and then preheat it in a resistance furnace at 350°C for 45 minutes.

[0127] S202. Wipe with anhydrous ethanol, sandpaper, rinse with distilled water, and then dry in a 70°C oven for 1.5 hours. If it is a rare earth compound, grind it to a particle size of 200 mesh, rinse with anhydrous ethanol, and then dry in a 70°C oven for 1.5 hours.

[0128] S203, aluminum hydroxide and magnesium hydroxide were dried in an oven at 110°C for 2.5 hours, ground to a particle size of 350 mesh and stored in a desiccator. Red phosphorus was used to check the integrity of the microcapsules. Phosphate esters were dried at 90°C for 1.5 hours. Silicone rubber was cut into small particles. Silicon dioxide was ground to a particle size of 200 mesh and dried in an oven at 90°C for 1.5 hours for later use.

[0129] S204. Soak the glass fiber in a 2% by mass silane coupling agent solution for 45 minutes and then dry it in an oven at 110° C. for 1.5 hours.

[0130] S3 specifically includes the following steps:

[0131] S301, placing the pretreated magnesium substrate into a vacuum induction melting furnace, heating it to 700°C at a rate of 15°C / min under argon protection, holding it for 7.5 minutes after melting, and then stirring it at a speed of 150 r / min for 12.5 minutes;

[0132] S302. Slowly add rare earth elements according to the formula amount and complete the addition within 7.5 minutes. Then increase the stirring speed to 250 r / min and continue stirring for 17.5 minutes.

[0133] S4 specifically includes the following steps:

[0134] S401. Add flame retardants in proportion. Stir at 150 r / min for 4 minutes each time, then increase the speed to 250 r / min and stir for 12.5 minutes.

[0135] S402, adding the reinforcing fiber and the coupling agent into the melt, and stirring at a speed of 350 r / min for 25 minutes.

[0136] S5 specifically includes: quickly transferring the melt to the barrel of the die-casting machine, setting the injection pressure to 45 MPa, the injection speed to 2 m / s, and the mold temperature to 200°C, and die-casting the product using a suitable mold cavity.

[0137] S6 specifically includes: placing the product into a heat treatment furnace, heating it to 300° C. at a rate of 7.5° C. / min, and performing an aging treatment for 5 hours.

[0138] Example 2:

[0139] This embodiment differs from the above-mentioned embodiment 1 in that:

[0140] The rare earth magnesium synergistic flame retardant lightweight composite material is characterized in that it is composed of the following raw materials in parts by weight: 40 parts of magnesium matrix, 5 parts of rare earth elements, 10 parts of hydroxide, 5 parts of phosphorus-based flame retardant, 3 parts of silicon-based flame retardant, 10 parts of reinforcing fiber, 0.5 part of coupling agent, and 0.5 part of lubricant.

[0141] Example 3:

[0142] This embodiment differs from the above-mentioned embodiment 1 in that:

[0143] The rare earth magnesium synergistic flame retardant lightweight composite material is characterized in that it is composed of the following raw materials in parts by weight: 50 parts of magnesium matrix, 10 parts of rare earth elements, 15 parts of hydroxide, 7.5 parts of phosphorus-based flame retardant, 5.5 parts of silicon-based flame retardant, 15 parts of reinforcing fiber, 1.25 parts of coupling agent, and 0.75 parts of lubricant.

[0144] contrast Existing materials Example 1 Example 2 Example 3 density <![CDATA[1.9g / cm 3 ]]> <![CDATA[1.7g / cm 3 ]]> <![CDATA[1.8g / cm 3 ]]> <![CDATA[1.75g / cm 3 ]]> tensile strength 200MPa 280MPa 220MPa 250MPa Limiting oxygen index 22％ 30％ 25％ 28％

[0145] The comparison in the above table is for existing materials. It can be seen from the above table that compared with existing rare earth magnesium related materials, the rare earth magnesium synergistic flame retardant lightweight composite material of the present invention has obvious advantages in key performance indicators such as density, tensile strength and limiting oxygen index under different raw material ratios (minimum value, intermediate value, maximum value). Specifically, in terms of density, the density value of the material of the present invention is lower, reflecting better lightweight characteristics; in terms of tensile strength, the values ​​under each ratio are higher than those of existing materials, which means that it has better mechanical properties and can withstand greater external forces; and in terms of limiting oxygen index, an indicator for measuring flame retardant performance, the values ​​achieved by the material of the present invention are also significantly higher than those of existing materials, indicating that its flame retardant effect is more prominent.

[0146] The preparation of a rare earth magnesium synergistic flame retardant lightweight composite material that simultaneously takes into account light weight, high-strength mechanical properties and good flame retardant properties has been achieved. By rationally adjusting the dosage ratio of each raw material (magnesium matrix, rare earth elements, hydroxides, phosphorus flame retardants, silicon flame retardants, reinforcing fibers, coupling agents, and lubricants), the tensile strength of the material is effectively improved while reducing its density, and its flame retardant ability is enhanced. This enables the material to better meet the application requirements of lightweight, safety, and structural strength in fields such as aerospace, electronics, and automobiles that have strict requirements on the comprehensive performance of materials. This solves the problem that existing rare earth magnesium-related materials are difficult to simultaneously meet the requirements of light weight, high strength, and high flame retardant properties.

[0147] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. Rare earth magnesium synergistic flame retardant lightweight composite material, characterized in that: The invention is composed of the following raw materials in parts by weight: 40-60 parts of magnesium matrix, 5-15 parts of rare earth elements, 10-20 parts of hydroxide, 5-10 parts of phosphorus flame retardant, 3-8 parts of silicon flame retardant, 10-20 parts of reinforcing fiber, 0.5-2 parts of coupling agent and 0.5-1 part of lubricant.

2. The rare earth magnesium synergistic flame retardant lightweight composite material according to claim 1, characterized in that: The rare earth elements include the following percentage raw materials: magnesium 85%-90%, cerium 0.5%-1.2%, gadolinium 0.3%-0.8%, yttrium 0.2%-0.6%, magnesium hydroxide 5%-8%, ammonium polyphosphate 2%-4%, and zirconium 0.1%-0.3%.

3. A method for preparing a flame retardant lightweight composite material, characterized in that: The rare earth magnesium synergistic flame retardant lightweight composite material according to any one of claims 1 to 2 comprises the following steps: S1. Raw material preparation and inspection: Select qualified raw materials, check the relevant information of each raw material, inspect the appearance and quality, cut and weigh as needed, ensure that they meet the formula requirements and prepare them for use; S2. Raw material pretreatment: The raw materials are processed accordingly and polished, dried and ground to reach a state suitable for melting and mixing; S3, melting and gasification: melting the magnesium matrix under the protection of inert gas, stirring it evenly after melting, and then slowly adding the rare earth element and increasing the stirring speed to make the rare earth element fully dissolved and evenly dispersed in the magnesium melt; S4. Stirring and mixing: Add the flame retardant additive to the rare earth magnesium melt in proportion, stir it preliminarily and then stir it thoroughly to make it evenly dispersed, then add the reinforcing fiber and coupling agent and continue stirring to ensure that the fiber is evenly distributed and well bonded to the matrix; S5. Die casting: Select the die casting method, transfer the mixed melt to the corresponding equipment, set the corresponding parameters, and perform the molding operation through the mold to produce the composite material product of the desired shape; S6. Post-processing: Heat treat the formed products as required to eliminate stress.

4. The method for preparing a flame-retardant lightweight composite material according to claim 3, wherein: The S1 specifically includes the following steps: S101, select magnesium and cut it into blocks weighing 1-5 kg ​​each for later use; S102, prepare aluminum hydroxide and magnesium hydroxide flame retardants, with a water content of less than 1%, and control the particle size of red phosphorus microcapsules to 50-200 μm; S103, cutting the reinforcing fibers into a length of 3-6 mm and weighing them, selecting a silane coupling agent with a concentration of 1%-3% by mass and a lubricant, and setting them aside.

5. The method for preparing a flame-retardant lightweight composite material according to claim 3, wherein: The S2 specifically includes the following steps: S201. Polish the surface of the magnesium block with 80-mesh and 200-mesh sandpaper in sequence until it is bright. Soak and clean it with acetone or ethanol for 10-15 minutes, then rinse with distilled water. Dry it in a vacuum drying oven at 80-100°C for 2-3 hours, and then preheat it in a resistance furnace at 300-400°C for 30-60 minutes. S202. Wipe with anhydrous ethanol, sandpaper, rinse with distilled water, and then dry in a 60-80°C oven for 1-2 hours. If it is a rare earth compound, grind it to a particle size of 100-300 mesh, rinse with anhydrous ethanol, and then dry in a 60-80°C oven for 1-2 hours. S203, aluminum hydroxide and magnesium hydroxide are dried in an oven at 100-120°C for 2-3 hours, ground to a particle size of 200-500 mesh and stored in a desiccator. Red phosphorus is used to check the integrity of the microcapsules. Phosphates are dried at 80-100°C for 1-2 hours. Silicone rubber is cut into small particles. Silicon dioxide is ground to a particle size of 100-300 mesh and dried together in an oven at 80-100°C for 1-2 hours for later use. S204. Soak the glass fiber in a 1%-3% by mass silane coupling agent solution for 30-60 minutes and dry it in an oven at 100-120°C for 1-2 hours.

6. The method for preparing a flame-retardant lightweight composite material according to claim 3, wherein: The S3 specifically includes the following steps: S301, placing the pretreated magnesium substrate into a vacuum induction melting furnace, heating it to 650-750°C at 10-20°C / min under argon protection, holding it for 5-10 minutes after melting, and then stirring it at a speed of 100-200 r / min for 10-15 minutes; S302. Slowly add rare earth elements according to the formula amount, and complete the addition within 5-10 minutes. Then increase the stirring speed to 200-300 r / min and continue stirring for 15-20 minutes.

7. The method for preparing a flame-retardant lightweight composite material according to claim 3, wherein: The S4 specifically includes the following steps: S401. Add flame retardants in proportion. Stir at 100-200 r / min for 3-5 minutes each time, then increase the speed to 200-300 r / min and stir for 10-15 minutes. S402, adding the reinforcing fiber and the coupling agent into the melt, and stirring at a speed of 300-400 r / min for 20-30 minutes.

8. The method for preparing a flame-retardant lightweight composite material according to claim 3, wherein: The S5 specifically includes: quickly transferring the melt to the barrel of the die-casting machine, setting the injection pressure to 30-60 MPa, the injection speed to 1-3 m / s, and the mold temperature to 150-250° C., and die-casting the product using a suitable mold cavity.

9. The method for preparing a flame-retardant lightweight composite material according to claim 3, wherein: The S6 specifically includes: placing the product into a heat treatment furnace, heating it to 200-400° C. at a rate of 5-10° C. / min, and performing aging treatment for 2-8 hours.

10. A method for preparing a flame retardant lightweight composite material, characterized in that: The rare earth magnesium synergistic flame retardant lightweight composite material according to any one of claims 1 to 2 comprises the following steps: S1. Add various flame retardants into the resin solution and stir to disperse; S2. Apply the stirred glue evenly onto the glass fiber cloth; S3. Heat the glass fiber cloth coated with glue at 250℃ for no more than half an hour to form a semi-cured state; S4. Place the semi-cured product into a mold for hot pressing.

Images