Magnesium-based composite material as well as preparation method and application thereof

Abstract

The invention belongs to the field of composite materials, and particularly discloses a magnesium-based composite material and a preparation method and application thereof.The preparation method comprises the following steps that S1, magnesium-based alloy particles are heated to be in a semi-solid state, then the magnesium-based alloy particles are mixed with metal reinforced particles, and semi-solid mixed slurry is obtained; and S2, the semi-solid mixed slurry is subjected to pressurized extrusion molding, and the magnesium-based composite material is prepared. According to the preparation method, the metal reinforced particles and the semi-solid magnesium-based alloy slurry are mixed, extrusion molding is conducted under pressurization, continuous production can be achieved through the whole preparation method, the production process is short, the efficiency is high, meanwhile, a semi-solid extrusion method is adopted, and the production cost is low. The prepared magnesium-based composite material has the advantages of compactness, no loose defect, uniform distribution of metal reinforced particles, high mechanical strength and the like.

Description

Technical Field

[0001] The invention belongs to the field of composite materials, and in particular relates to a magnesium-based composite material and a preparation method and application thereof. Background Art

[0002] Magnesium alloy is the most promising lightweight material at present, but its low strength, plasticity and poor corrosion resistance limit its wide application. By adding rare earth elements such as Y and Ga to rare earth, the strength of magnesium alloy can be significantly improved, but it is difficult to improve toughness, corrosion resistance and other properties at the same time. Magnesium-based composite materials prepared by using metal particles such as Ti and TC4 as reinforcements can combine the advantages of reinforcements and matrix magnesium alloys to obtain new materials with good comprehensive properties such as strength, toughness and corrosion resistance. Therefore, they have received extensive attention and research in the industry and have huge market potential.

[0003] The preparation methods of metal particle reinforced magnesium-based composite materials mainly include vacuum stirring casting and powder metallurgy. The equipment used in the vacuum stirring casting method is a vacuum stirring furnace. The reinforcement is added to the magnesium alloy melt under vacuum or inert gas protection, and the slurry is stirred evenly by mechanical or electromagnetic stirring before casting. The advantage of the stirring casting method is that the vacuum stirring furnace has a simple structure and low production cost. However, the rare earth magnesium alloy has a complex composition and a high melt viscosity. After adding reinforcing particles, the viscosity is further increased, and the ingot is prone to loose defects, which seriously affects the mechanical properties of the material.

[0004] The powder metallurgy method uses a powder mixer and a hot press to mix the reinforcement particles and magnesium alloy powder evenly and then sinter them to make composite materials. Its advantage is that the reinforcement is evenly distributed and the casting can be nearly net-shaped. However, the production efficiency is low and the manufacturing cost is high. In addition, the product structure is limited by the hot pressing equipment and molds. Summary of the invention

[0005] In order to overcome at least one of the problems existing in the above-mentioned prior art, one of the objectives of the present invention is to provide a method for preparing a magnesium-based composite material.

[0006] A second object of the present invention is to provide a magnesium-based composite material.

[0007] A third object of the present invention is to provide a screw extruder.

[0008] A fourth object of the present invention is to provide a method for preparing the above-mentioned magnesium-based composite material and / or the use of the above-mentioned magnesium-based composite material in the preparation of electronic equipment.

[0009] In order to achieve the above object, the technical solution adopted by the present invention is:

[0010] A first aspect of the present invention provides a method for preparing a magnesium-based composite material, comprising the following steps:

[0011] S1: heating magnesium-based alloy particles to a semi-solid state, and then mixing with metal reinforcement particles to obtain a semi-solid mixed slurry;

[0012] S2: Pressurizing and extruding the semi-solid mixed slurry to obtain the magnesium-based composite material.

[0013] Preferably, the step S1 comprises the following steps:

[0014] S11: heating the magnesium-based alloy particles to a semi-solid state in a screw extruder to obtain a semi-solid magnesium-based alloy;

[0015] S12: mixing the metal reinforcement particles with the semi-solid magnesium-based alloy in a screw extruder to obtain a semi-solid mixed slurry.

[0016] Preferably, the screw speed of the screw extruder is 300-500 r / min.

[0017] Preferably, the heating temperature in step S11 is 560-650°C.

[0018] Preferably, the step S2 specifically comprises: pressurizing and extruding the semi-solid mixed slurry, and solidifying and molding it through an extrusion die to obtain the magnesium-based composite material.

[0019] Preferably, the extrusion speed in the pressurized extrusion step is 10 to 100 mm / min.

[0020] Preferably, the extrusion pressure in the pressurized extrusion step is 60-100 MPa.

[0021] Preferably, the temperature of the extrusion die is 350-420°C.

[0022] Preferably, the metal reinforcement particles include at least one of Ti, TC4, Mn, titanium metal compounds, and manganese metal compounds.

[0023] Preferably, the particle size of the metal reinforcement particles is 0.5-30 μm.

[0024] Preferably, the magnesium-based alloy particles are irregularly shaped or cuboid.

[0025] Preferably, the length of the magnesium-based alloy particles is 0.5-10 mm, and the cross-sectional size is 0.25-4 mm. 2 .

[0026] Preferably, the magnesium-based alloy is at least one of a cast magnesium alloy and a deformed magnesium alloy. The present invention can use either a cast magnesium alloy or a deformed magnesium alloy as a matrix, and can achieve continuous production of composite materials of different shapes.

[0027] The second aspect of the present invention provides a magnesium-based composite material, which is prepared by the preparation method described in the first aspect of the present invention, wherein the mass percentage of metal reinforcement particles in the magnesium-based composite material is 0.5-35%.

[0028] The third aspect of the present invention provides a screw extruder for realizing the preparation method of the magnesium-based composite material described in the first aspect of the present invention, wherein the screw extruder comprises a screw rotating mechanism, a screw, a barrel, an extrusion pad, a hopper A, a hopper B, a pressure system, a heater, and an extrusion die; the output end of the screw rotating mechanism is connected to the screw; the screw and the extrusion pad are both located in the barrel, and the extrusion die is arranged at the outlet of the barrel; the hopper A and the hopper B are arranged on the barrel; the distance between the hopper A and the extrusion die is smaller than the distance between the hopper B and the extrusion die; the barrel is provided with a heater; and the pressure system provides pressure for the extrusion pad.

[0029] Preferably, the heater is a segmented electric heater. The heater in the present invention adopts a segmented electric heater to achieve segmented control of the barrel temperature, thereby adjusting the barrel temperature in segments according to extrusion requirements.

[0030] The fourth aspect of the present invention provides a method for preparing the magnesium-based composite material described in the first aspect of the present invention and / or use of the magnesium-based composite material described in the second aspect of the present invention in preparing electronic equipment.

[0031] Preferably, the electronic equipment includes 3C electronic products, drones, cars, ships, aerospace equipment, marine equipment or engineering equipment.

[0032] The beneficial effects of the present invention are as follows: the preparation method of the present invention is to mix metal reinforcement particles with semi-solid magnesium-based alloy slurry and extrude them under pressure. The entire preparation method can be produced continuously, with a short production process and high efficiency. At the same time, the semi-solid extrusion method is adopted, so that the prepared magnesium-based composite material has the advantages of being dense, free of loose defects, uniform distribution of metal reinforcement particles, and high mechanical strength.

[0033] Specifically, the preparation method of the present invention realizes the online addition of metal reinforcement particles to the semi-solid magnesium-based alloy slurry, uniform mixing under the shearing and stirring action of the screw, and extrusion molding under pressure. The production process is short, the efficiency is high, and continuous production can be achieved. The prepared magnesium-based composite material has a dense structure, has both the characteristics of casting structure and deformation structure, and the metal reinforcement particles are evenly distributed. The mechanical properties are significantly higher than those of the composite material prepared by stirring casting. In addition, the preparation method of the present invention does not require inert gas protection throughout the preparation process, and belongs to a short-process green manufacturing technology. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 This is a schematic structural diagram of the semi-solid extrusion casting device used in Example 1.

[0035] Figure 2 This is a physical picture of the Mg-9Gd-4Y-1Zn magnesium alloy particles in Example 1.

[0036] Figure 3 This is a cross-sectional SEM image of the magnesium-based composite material in Example 1.

[0037] Figure 4 This is the longitudinal cross-sectional SEM image of the magnesium-based composite material in Example 1. DETAILED DESCRIPTION

[0038] The specific implementation of the present invention is further described in detail below in conjunction with the accompanying drawings and examples, but the implementation and protection of the present invention are not limited thereto. It should be noted that if there are processes that are not particularly described in detail below, they can be implemented or understood by those skilled in the art with reference to the prior art. The reagents or instruments used that do not indicate the manufacturer are all conventional products that can be purchased commercially.

[0039] In some embodiments of the present invention, the present invention provides a method for preparing a magnesium-based composite material, comprising the following steps:

[0040] The magnesium-based alloy particles are heated to a semi-solid state, and then mixed with metal reinforcement particles to obtain a semi-solid mixed slurry;

[0041] The semi-solid mixed slurry is pressurized and extruded to form a magnesium-based composite material.

[0042] In some embodiments of the present invention, the method for preparing the magnesium-based composite material provided by the present invention comprises the following steps:

[0043] The magnesium-based alloy particles are heated in a screw extruder to a semi-solid state to obtain a semi-solid magnesium-based alloy;

[0044] Mixing the metal reinforcement particles with the semi-solid magnesium-based alloy in a screw extruder to obtain a semi-solid mixed slurry;

[0045] The semi-solid mixed slurry is extruded under pressure and solidified and formed through an extrusion die to obtain the magnesium-based composite material.

[0046] In some embodiments of the present invention, the magnesium-based alloy particles are formed by processing a magnesium-based alloy ingot into a granular material using a granulator.

[0047] In some embodiments of the present invention, the screw speed of the screw extruder is 300-500r / min. In some specific embodiments of the present invention, the screw speed of the screw extruder can be 310r / min, 320r / min, 330r / min, 340r / min, 350r / min, 360r / min, 370r / min, 380r / min, 390r / min, 400r / min, 410r / min, 420r / min, 430r / min, 440r / min, 450r / min, 460r / min, 470r / min, 480r / min, 490r / min, 500r / min. The present invention uses a screw extruder with the above speed to mix the metal reinforcement particles and the semi-solid magnesium alloy matrix. Under the rotational stirring and shearing action of the screw, the mixing effect is better, and the uniform dispersion of the metal reinforcement particles can be achieved. If the screw rotates too slowly, the shear force is small and the stirring effect is poor, which is not conducive to the uniform distribution of metal reinforcement particles. If the screw rotates too fast, the material, rigidity, power and stability of the screw are high, and the production cost increases.

[0048] In some embodiments of the present invention, the heating temperature for heating the magnesium-based alloy particles to a semi-solid state is 560-650° C.; in some specific embodiments of the present invention, the heating temperature may be 560° C., 570° C., 580° C., 590° C., 600° C., 610° C., 620° C., 630° C., 640° C., 650° C. If the heating temperature is too low, the melt viscosity is too high, which is not conducive to extrusion molding; if the heating temperature is too high, the metal reinforcement particles are prone to sedimentation, affecting the distribution uniformity of the metal reinforcement particles.

[0049] In some embodiments of the present invention, the extrusion speed of the pressurized extrusion step is 10 to 100 mm / min; in some specific embodiments of the present invention, the extrusion speed can be 10 mm / min, 15 mm / min, 20 mm / min, 25 mm / min, 30 mm / min, 35 mm / min, 40 mm / min, 45 mm / min, 50 mm / min, 55 mm / min, 60 mm / min, 65 mm / min, 70 mm / min, 75 mm / min, 80 mm / min, 85 mm / min, 90 mm / min, 95 mm / min, 100 mm / min. If the extrusion speed is too slow, the production efficiency is low, and the semi-solid mixed slurry is easy to solidify at the entrance of the extrusion die, resulting in extrusion failure; if the extrusion speed is too fast, the obtained magnesium-based composite material is prone to hole defects, which reduces the mechanical properties of the material, and at the same time, cracks and other defects are easy to occur on the surface.

[0050] In some embodiments of the present invention, the extrusion pressure of the pressurized extrusion step is 60-100MPa; in some specific embodiments of the present invention, the extrusion pressure can be 60MPa, 65MPa, 70MPa, 75MPa, 80MPa, 85MPa, 90MPa, 95MPa, 100MPa. If the extrusion pressure is too small, the extrusion speed is slow, and the density of the obtained magnesium-based composite material decreases; if the extrusion pressure is too large, it is easy to cause the solidification position of the semi-solid mixed slurry to move outward to the outlet of the extrusion die, resulting in extrusion failure, or insufficient extrusion deformation of the magnesium-based composite material, and the product shape consistency of the obtained magnesium-based composite material is poor.

[0051] In some embodiments of the present invention, the temperature of the extrusion die is 350-420°C; in some specific embodiments of the present invention, the temperature of the extrusion die can be 350°C, 355°C, 360°C, 365°C, 370°C, 375°C, 380°C, 385°C, 390°C, 395°C, 400°C, 405°C, 410°C, 415°C, 420°C. If the temperature of the extrusion die is too low, extrusion failure is likely to occur, and the composite material is difficult to form; if the temperature of the extrusion die is too high, the composite material is prone to transverse cracks and poor surface quality.

[0052] In some embodiments of the present invention, the shape of the extrusion die may be a rod, a tube, a plate, a strip or other irregular shapes.

[0053] In some embodiments of the present invention, the metal reinforcement particles include at least one of Ti, TC4, Mn, titanium metal compounds, and manganese metal compounds. In some embodiments of the present invention, the titanium metal compound includes at least one of titanium oxide, titanium nitride, and titanium boride; in some embodiments of the present invention, the manganese metal compound includes at least one of manganese oxide and manganese nitride. The metal reinforcement particles in the present invention do not chemically react with the magnesium-based alloy matrix, and have a very small solid solubility in the magnesium-based alloy matrix.

[0054] In some embodiments of the present invention, the particle size of the metal reinforced particles is 0.5-30μm. In some specific embodiments of the present invention, the particle size of the metal reinforced particles can be 0.5μm, 1μm, 2μm, 3μm, 4μm, 5μm, 6μm, 7μm, 8μm, 9μm, 10μm, 11μm, 12μm, 13μm, 14μm, 15μm, 16μm, 17μm, 18μm, 19μm, 20μm, 21μm, 22μm, 23μm, 24μm, 25μm, 26μm, 27μm, 28μm, 29μm, or 30μm.

[0055] In some embodiments of the present invention, the metal reinforcement particles are spherical or quasi-spherical.

[0056] In some embodiments of the present invention, the magnesium-based alloy particles are irregularly shaped or cuboid; in some embodiments of the present invention, the length of the magnesium-based alloy particles is 0.5-10 mm, and the cross-sectional size is 0.25-4 mm. 2 In some embodiments of the present invention, the length of the magnesium-based alloy particles may be 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm; In some embodiments of the present invention, the cross-sectional size of the magnesium-based alloy particles may be 0.25 mm 2 , 1mm 2 , 2mm 2 , 3mm 2 , 4mm 2 .

[0057] In some embodiments of the present invention, the magnesium-based alloy is at least one of a cast magnesium alloy and a deformed magnesium alloy. The present invention can use either a cast magnesium alloy or a deformed magnesium alloy as a matrix, and can achieve continuous production of composite materials of different shapes.

[0058] In some embodiments of the present invention, the present invention further provides a magnesium-based composite material obtained by the above preparation method, wherein the mass percentage of metal reinforcement particles in the magnesium-based composite material is 0.5-35%.

[0059] In some embodiments of the present invention, the present invention further provides a screw extruder, the structural schematic diagram of which is as follows: Figure 1 As shown, it includes a pressure system 1, a hopper B2, a heater 3, a hopper A4, an extrusion die 5, an extruded composite material 6, a semi-solid mixed slurry 7, an extrusion pad 8, a barrel 9, a screw 10, and a screw rotating mechanism 11; the output end of the screw rotating mechanism 11 is connected to the screw 10; the screw 10 and the extrusion pad 8 are both arranged in the barrel 9, and the barrel 9 is filled with the semi-solid mixed slurry 7, and the inlet of the barrel 9 is connected to the hopper B2 and the hopper A4 respectively; the hopper A4 is located between the hopper B2 and the extrusion die 5, and the outside of the barrel 9 is provided with a heater 3, and the heater 3 can be heated in sections. The outlet of the barrel 9 is provided with an extrusion die 5, and a pressure system 1 is provided on the semi-solid extrusion casting device, and the pressure system 1 is used to provide pressure for the extrusion pad 8. The extrusion pad 8 extrude the semi-solid mixed slurry 7 under the pressure provided by the pressure system 1, so that the semi-solid mixed slurry 7 is extruded through the extrusion die 5 and cooled to form an extruded composite material 6.

[0060] The screw 10 in the present invention can rotate, but does not move in the horizontal direction. When in use, the screw 10 pushes the magnesium alloy particles to the area where the metal reinforcement particles are added, and the semi-solid temperature has been reached. With the addition of the metal reinforcement particles, if the melt temperature drops significantly, the temperature needs to be readjusted to ensure that the slurry is in a semi-solid state and has good fluidity to facilitate extrusion molding. The pressure system 1 can continuously apply pressure to the extrusion pad 8, and the slurry is squeezed into the extrusion die 5 under the pressure of the extrusion pad 8. The semi-solid mixed slurry 7 is solidified and formed under the combined action of the pressure provided by the pressure system 1 and the deformation pressure of the extrusion die 5, avoiding the generation of loose and other hole defects, so that the obtained magnesium-based composite material has a higher density and mechanical strength.

[0061] In some embodiments of the present invention, the method for preparing the magnesium-based composite material provided by the present invention comprises the following steps:

[0062] 1) Processing the magnesium-based alloy ingot into magnesium-based alloy particles using a granulator;

[0063] 2) The magnesium-based alloy particles are fed into the barrel 9 through the hopper B2 and transported toward the extrusion die 5 by the screw 10. The barrel 9 is heated by the heater 3 to heat the magnesium-based alloy particles to a semi-solid state, thereby obtaining a semi-solid magnesium alloy matrix;

[0064] 3) The heterogeneous metal reinforcement particles enter the barrel 9 through the hopper A4, and are fully mixed with the semi-solid magnesium alloy matrix under the rotating stirring action of the screw 10 to obtain a semi-solid mixed slurry 7 with uniform particle distribution; the rotation of the screw 10 squeezes the particles, and the particles move in the barrel 9 to obtain mixing.

[0065] 4) The pressure system 1 provides pressure, and the semi-solid mixed slurry 7 is shaped by the extrusion die 5 under the pressure of the extrusion pad 8 to achieve continuous extrusion.

[0066] The implementation of the present invention is further described in detail below with reference to specific embodiments:

[0067] Example 1

[0068] This example provides a semi-solid extrusion preparation method of a magnesium-based composite material, which comprises the following steps:

[0069] (1) Using a granulator, the commercially available Mg-9Gd-4Y-1Zn ingot is processed into irregular long strips of Mg-9Gd-4Y-1Zn magnesium alloy particles (the actual picture is as shown in FIG. Figure 2As shown), the particles are added into the barrel 9 through the hopper B2 and are transported toward the extrusion die 5 under the action of the screw 10. The rotation speed of the screw 10 is 350 r / min. The particles are heated to a semi-solid temperature range of 585-600°C by the heater 3 outside the barrel 9 to obtain a semi-solid Mg-9Gd-4Y-1Zn slurry.

[0070] (2) Dry Ti particles with an average particle size of 10 μm are pre-loaded into hopper A4. During the preparation process, the valve below hopper A4 is opened, and the adding speed is adjusted to add the Ti particles into the semi-solid Mg-9Gd-4Y-1Zn slurry. The mixture is evenly mixed under the shearing and stirring action of screw 10 to form a semi-solid mixed slurry.

[0071] (3) The extrusion die 5 is preheated to 400° C., and the semi-solid mixed slurry is extruded at an extrusion speed of 60 mm / min and an extrusion pressure of 70 MPa to obtain the magnesium-based composite material in this example, that is, the Ti particle reinforced Mg-9Gd-4Y-1Zn rod-shaped composite material profile.

[0072] The mass percentage of Ti particles in the magnesium-based composite material of this example is 5wt%, and the magnesium-based composite material is a rod-shaped composite material with a diameter of 40mm.

[0073] Example 2

[0074] This example provides a semi-solid extrusion preparation method of a magnesium-based composite material, which comprises the following steps:

[0075] (1) A granulator is used to process commercially available AZ91D ingots into irregular long strips of AZ91D magnesium alloy particles. The particles are added into a barrel 9 through a hopper B2 and transported toward an extrusion die 5 under the action of a screw 10. The screw rotates at a speed of 400 r / min and is heated to a semi-solid temperature range of 580-590°C by a heater outside the barrel.

[0076] (2) Dry TC4 particles with an average particle size of 15 μm are pre-loaded into hopper A4. During the preparation process, the valve below hopper A4 is opened, and the adding speed is adjusted to add TC4 particles into the semi-solid AZ91D slurry, and the mixture is evenly mixed under the shearing and stirring action of screw 10 to form a semi-solid mixed slurry.

[0077] (3) Preheat the extrusion die 5 to 380° C. The semi-solid mixed slurry is extruded at an extrusion speed of 50 mm / min and an extrusion pressure of 70 MPa to obtain the magnesium-based composite material in this example, that is, the Ti particle reinforced AZ91D rod-shaped composite material.

[0078] Comparative Example 1

[0079] This example provides a method for preparing a magnesium-based composite material by extrusion, which comprises the following steps:

[0080] (1) Irregular long strips of Mg-9Gd-4Y-1Zn magnesium alloy particles are added into a barrel 9 through a hopper B2 and transported toward an extrusion die 5 under the action of a screw 10. The rotation speed of the screw 10 is 350 r / min. The particles are heated to a temperature range of 640-650° C. by a heater 3 outside the barrel 9 to obtain a liquid Mg-9Gd-4Y-1Zn slurry.

[0081] (2) Dry Ti particles with an average particle size of 10 μm are pre-loaded into hopper A4. During the preparation process, the valve below hopper A4 is opened, and the adding speed is adjusted to add the Ti particles into the above-mentioned liquid Mg-9Gd-4Y-1Zn slurry. The mixture is evenly mixed under the shearing and stirring action of the screw 10 to form a molten composite material slurry.

[0082] (3) The extrusion die 5 is preheated to 400° C. The molten composite material slurry is extruded at an extrusion speed of 60 mm / min and an extrusion pressure of 70 MPa to obtain the magnesium-based composite material in this example, that is, the Ti particle reinforced Mg-9Gd-4Y-1Zn rod-shaped composite material.

[0083] In the magnesium-based composite material of this example, the amount of Ti particles added is 5wt% of the mass of the Mg-9Gd-4Y-1Zn magnesium alloy particles, and the magnesium-based composite material is a rod-shaped composite material with a diameter of 40 mm.

[0084] Comparative Example 2

[0085] The extrusion preparation method of the magnesium-based composite material in this example is different from that in Example 1 only in that the rotation speed of the screw 10 in step (1) of this example is 200 r / min.

[0086] Comparative Example 3

[0087] The extrusion preparation method of the magnesium-based composite material in this example is different from that in Example 1 only in that the extrusion speed of the semi-solid mixed slurry in step (3) of this example is 110 mm / min.

[0088] Comparative Example 4

[0089] The extrusion preparation method of the magnesium-based composite material in this example is different from that in Example 1 only in that in step (1) of this example, the irregular long strip Mg-9Gd-4Y-1Zn magnesium alloy particles are heated to a liquid temperature range of 660-670°C by a heater outside the barrel.

[0090] Comparative Example 5

[0091] The extrusion preparation method of the magnesium-based composite material in this example is different from that in Example 1 only in that the extrusion pressure of the semi-solid mixed slurry in step (3) of this example is 50 MPa.

[0092] Comparative Example 6

[0093] The extrusion preparation method of the magnesium-based composite material in this example is different from that in Example 2 only in that in step (1) of this example, the irregular long strip AZ91D magnesium alloy particles are heated to a liquid temperature range of 620-630° C. by a heater outside the barrel.

[0094] Comparative Example 7

[0095] The extrusion preparation method of the magnesium-based composite material in this example is different from that in Example 2 only in that in step (3) of this example, the extrusion die 5 is preheated to 450°C.

[0096] Comparative Example 8

[0097] The extrusion preparation method of the magnesium-based composite material in this example is different from that in Example 2 only in that in step (3) of this example, the extrusion die 5 is preheated to 300°C.

[0098] The magnesium-based composite materials prepared in the examples and comparative examples were subjected to performance tests, wherein the room temperature tensile strength and yield strength test standards refer to GB / T16865-2013, and the elongation after fracture test standards refer to GB / T16865-2013, and the test results are shown in Table 1 below.

[0099] Table 1 Room temperature performance test results of magnesium-based composites

[0100]

[0101] As can be seen from Table 1, the present invention adopts a semi-solid extrusion method to prepare the magnesium-based composite material, which can improve the tensile strength and yield strength of the magnesium-based composite material at room temperature.

[0102] The SEM images of the cross section and longitudinal section of the magnesium-based composite material prepared in Example 1 were respectively tested using a scanning electron microscope. The specific test results are as follows: Figure 3 and Figure 4 As shown. Figure 3 and Figure 4 It can be seen that the Ti particles are evenly distributed in the Mg-9Gd-4Y-1Zn matrix. Under the action of the extrusion pressure, the Ti particles are distributed along the fiber structure in the extrusion casting direction.

[0103] The above is a detailed description of the embodiments of the present invention, but the present invention is not limited to the above embodiments. Various changes can be made within the knowledge of ordinary technicians in the relevant technical field without departing from the purpose of the present invention. In addition, the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

Claims

1. A method for preparing a magnesium-based composite material, characterized in that: The following steps are involved: S1: heating magnesium-based alloy particles to a semi-solid state, and then mixing with metal reinforcement particles to obtain a semi-solid mixed slurry; S2: Pressurizing and extruding the semi-solid mixed slurry to obtain the magnesium-based composite material.

2. The method for preparing the magnesium-based composite material according to claim 1, characterized in that: The step S1 comprises the following steps: S11: heating the magnesium-based alloy particles to a semi-solid state in a screw extruder to obtain a semi-solid magnesium-based alloy; S12: mixing the metal reinforcement particles with the semi-solid magnesium-based alloy in a screw extruder to obtain a semi-solid mixed slurry.

3. The method for preparing the magnesium-based composite material according to claim 2, characterized in that: The screw speed of the screw extruder is 300-500 r / min; And / or, the heating temperature in step S11 is 560-650°C.

4. The method for preparing the magnesium-based composite material according to claim 1, characterized in that: The step S2 specifically includes: pressurizing and extruding the semi-solid mixed slurry, and solidifying and forming it through an extrusion die to obtain the magnesium-based composite material.

5. The method for preparing the magnesium-based composite material according to claim 4, characterized in that: The extrusion speed of the pressurized extrusion step is 10 to 100 mm / min; And / or, the extrusion pressure in the pressurized extrusion step is 60 to 100 MPa; And / or, the temperature of the extrusion die is 350-420°C.

6. The method for preparing the magnesium-based composite material according to claim 1, characterized in that: The metal reinforcement particles include at least one of Ti, TC4, Mn, titanium metal compounds, and manganese metal compounds; and / or, the particle size of the metal reinforcement particles is 0.5 to 30 μm; And / or, the length of the magnesium-based alloy particles is 0.5 to 10 mm, and the cross-sectional size is 0.25 to 4 mm 2 ; And / or, the magnesium-based alloy is at least one of a cast magnesium alloy and a deformable magnesium alloy.

7. A magnesium-based composite material, characterized in that: The magnesium-based composite material is prepared by the preparation method according to any one of claims 1 to 6, wherein the mass percentage of metal reinforcement particles in the magnesium-based composite material is 0.5 to 35%.

8. A screw extruder for implementing the method for preparing the magnesium-based composite material according to any one of claims 1 to 6, characterized in that: The screw extruder comprises a screw rotating mechanism, a screw, a barrel, an extrusion pad, a hopper A, a hopper B, a pressure system, a heater, and an extrusion die; the output end of the screw rotating mechanism is connected to the screw; the screw and the extrusion pad are both located in the barrel, and the extrusion die is arranged at the outlet of the barrel; the hopper A and the hopper B are arranged on the barrel; the distance between the hopper A and the extrusion die is smaller than the distance between the hopper B and the extrusion die; A heater is arranged on the barrel; and the pressure system provides pressure for the extrusion pad.

9. A method for preparing the magnesium-based composite material according to any one of claims 1 to 6 and / or use of the magnesium-based composite material according to claim 7 in preparing electronic equipment.

10. The use according to claim 9, characterized in that: The electronic equipment includes 3C electronic products, drones, automobiles, ships, aerospace equipment, marine equipment or engineering equipment.

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