A method of manufacturing a magnesium-based composite component and a component

Abstract

The present application belongs to the field of metal composite material, and particularly relates to a preparation method of a magnesium-based composite component and the component. The preparation method comprises the following steps: preparing a blank body of magnesium matrix material and reinforcing material, to obtain a magnesium-based composite blank body; mechanically cutting the magnesium-based composite blank body, to obtain magnesium-based composite particles, wherein the size of the magnesium-based composite particles is 0.4mm-10.0mm; and injection molding the magnesium-based composite particles, to obtain a magnesium-based composite component, wherein the temperature of the barrel of the injection molding is lower than the melting point of the reinforcing material. In the injection molding process, the small gap between the screw and the screw barrel is not easy to be blocked, the injection molding process can be carried out smoothly, the reinforcing material is uniformly dispersed in the magnesium-based composite component, and the strength and plasticity of the component are significantly improved.

Description

Technical Field

[0001] This invention belongs to the field of metal composite materials technology, specifically, it relates to a method for preparing magnesium-based composite material components and the components themselves. Background Technology

[0002] Injection molding technology can be used to produce products with complex shapes, precise dimensions, or inserts. It has high production efficiency. The specific process is that after the material is plasticized in the heated barrel of the injection molding machine, it is injected into the mold cavity of the closed mold by the plunger or reciprocating screw to form the product.

[0003] Injection molding technology has been used to prepare metal-reinforced composite products, and the use of a mixture of matrix metal powder and reinforcement powder as feedstock for injection molding has been proposed. However, when using a mixture of matrix metal powder and reinforcement powder as feedstock, the small gap between the screw and barrel is easily blocked during injection molding, making it difficult for the screw to operate normally and hindering injection molding. When larger matrix metal particles are used instead of matrix metal powder as feedstock, the significant difference in particle size between the matrix metal and the reinforcement causes the reinforcement powder to agglomerate in the barrel, affecting the performance of the composite material. Furthermore, the problem of fine reinforcement powder blocking the small gap between the screw and barrel remains unresolved. Summary of the Invention

[0004] The purpose of this invention is to overcome the defects in the existing technology of injection molding for preparing magnesium-based reinforced composite material components, such as the small gap between the screw and the barrel being easily blocked and the reinforcing powder being easily agglomerated, which affects the performance of the composite material. This invention provides a method for preparing magnesium-based composite material components and the components themselves.

[0005] To achieve the above objectives, in a first aspect, the present invention provides a method for preparing a magnesium-based composite material component, comprising the following steps:

[0006] A preform in which magnesium matrix material and reinforcing material are uniformly mixed is prepared to obtain a magnesium matrix composite preform;

[0007] The magnesium-based composite material preform is mechanically cut to obtain magnesium-based composite material particles, the size of which is 0.4 mm to 10.0 mm.

[0008] The magnesium-based composite material particles are injection molded to obtain magnesium-based composite material components, wherein the temperature of the injection molding barrel is lower than the melting point of the reinforcing material.

[0009] In some preferred embodiments, the magnesium-based composite material particles are cuboid particles with a length of 1.0 mm to 6.0 mm and a width and height of 0.5 mm to 3.0 mm.

[0010] Preferably, the length of the cuboid particle is 5.0mm to 6.0mm, and the width and height are 1.5mm to 2.5mm.

[0011] Preferably, the ratios of the length to width and the length to height of the cuboid particles are 2 to 4, respectively.

[0012] Preferably, as determined by metallographic testing, the volume fraction of the reinforcing material in the magnesium-based composite material preform is 1.0% to 30.0%.

[0013] Preferably, the reinforcing material comprises whiskers and / or particles, wherein the length of the whiskers is not greater than 500 μm and the aspect ratio is 1:1 to 1:5, and the diameter of the particles is not greater than 100 μm.

[0014] Preferably, the injection molding conditions include: the barrel includes a heating section, a heat preservation section and an injection section arranged sequentially, the barrel temperature of the heating section gradually increases, the barrel temperature at the end of the heating section is 575℃~635℃, the barrel temperature of the heat preservation section is the same as the barrel temperature at the end of the heating section, and the barrel temperature of the injection section is 520℃~590℃.

[0015] Preferably, the injection molding conditions further include: an injection speed of 1.0 m / s to 3.5 m / s, a holding pressure of 100 MPa to 200 MPa, and a holding time of 0.1 s to 10 s.

[0016] Preferably, the injection molding conditions further include: preheating the molding die at a temperature of 200°C to 300°C.

[0017] In a second aspect, the present invention provides a magnesium-based composite material component prepared by the preparation method described in the first aspect.

[0018] The method for preparing magnesium-based composite material components of the present invention first involves preparing a preform by conventional methods, which uniformly mixes magnesium matrix material and reinforcing material. Next, the magnesium-based composite material preform is mechanically cut into millimeter-sized magnesium-based composite material particles with dimensions ranging from 0.4 mm to 10.0 mm, followed by injection molding. During injection molding, because the feed material consists of millimeter-sized magnesium-based composite material particles, the small gap between the screw and the screw barrel is less likely to be blocked, allowing the injection molding process to proceed smoothly. The barrel temperature of the injection molding process in this invention is lower than the melting point of the reinforcing material. During the injection molding heating process, the reinforcing material does not melt. The magnesium-based composite material particles of this invention exhibit uniform dispersion of the reinforcing material, resulting in uniform dispersion of the reinforcing material in the magnesium-based composite material component and improving the performance of the composite material. Attached Figure Description

[0019] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1 This is a microstructure photograph of the magnesium-based composite material component obtained in Example 1 of the present invention.

[0021] Figure 2 This is a micrograph of the magnesium-based composite material component obtained in Comparative Example 1 of the present invention.

[0022] Figure 3 This is a microstructure photograph of the magnesium-based composite material component obtained in Example 6 of the present invention.

[0023] Figure 4 This is a micrograph of the magnesium-based composite material component obtained in Comparative Example 2 of the present invention. Detailed Implementation

[0024] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0025] The inventors of this invention have discovered that in the prior art, when preparing magnesium-based reinforced composite material components by injection molding, the small gap between the screw and the barrel is easily blocked, and the reinforcing powder is easily agglomerated.

[0026] In this regard, firstly, the present invention provides a method for preparing a magnesium-based composite material component, comprising the following steps:

[0027] A preform in which magnesium matrix material and reinforcing material are uniformly mixed is prepared to obtain a magnesium matrix composite preform;

[0028] The magnesium-based composite material preform is mechanically cut to obtain magnesium-based composite material particles, the size of which is 0.4 mm to 10.0 mm.

[0029] The magnesium-based composite material particles are injection molded to obtain magnesium-based composite material components, wherein the temperature of the injection molding barrel is lower than the melting point of the reinforcing material.

[0030] In the preparation method of the magnesium-based composite material component of the present invention, firstly, a preform in which magnesium matrix material and reinforcing material are uniformly mixed is prepared; secondly, the magnesium-based composite material preform is mechanically cut to obtain magnesium-based composite material particles with a uniformly dispersed size of 0.4 mm to 10.0 mm. Then, the magnesium-based composite material particles are used as injection molding raw materials for injection molding to prepare the magnesium-based composite material component. The temperature of the injection molding barrel is lower than the melting point of the reinforcing material. During the heating process of injection molding, the reinforcing material will not melt. Since the size of the magnesium-based composite material particles is in the millimeter range, specifically not less than 0.4 mm, the plastic processing distortion energy and surface energy of the particles are limited. The magnesium matrix material in the composite material particles does not easily melt completely into a liquid state, which can prevent the reinforcing material from settling and agglomerating in the injection molding barrel. Based on the uniform dispersion of the reinforcing material in the magnesium-based composite material particles, the reinforcing material in the magnesium-based composite material component can be uniformly dispersed, improving the strength and plasticity properties of the composite material. The mechanically cut magnesium-based composite material particles are millimeter-sized, specifically no larger than 10.0 mm. These particles can store a certain amount of plastic deformation energy, promoting the melting of the eutectic phase in the matrix metal structure during injection molding heating. This results in the formation of fine matrix phase grains and a semi-solid melt, improving the flowability of the injection-molded material without increasing the injection molding barrel temperature. This, in turn, enhances the density and dimensional accuracy of the injection-molded metal-based composite material components. In this invention, the injection molding raw material is millimeter-sized magnesium-based composite material particles ranging from 0.4 mm to 10.0 mm. The small gap between the screw and the screw barrel is less prone to clogging, allowing the injection molding process to proceed smoothly.

[0031] The magnesium-based composite material particles of the present invention can be spherical particles, cuboid particles, columnar particles, etc. The size of the particles refers to the conventional geometric dimensions of the particles. For spherical particles, the size of the particles is the diameter; for cuboid particles, the size of the particles is the length, width, and height; and for columnar particles, the size of the particles is the height and the bottom diameter.

[0032] The magnesium matrix material of the present invention has a wide range of options. Preferably, the magnesium alloy matrix is ​​a Mg-Al, Mg-Zn and Mg-RE alloy, which can form a low melting point eutectic phase, which is more conducive to the formation of a semi-solid melt with non-Newtonian viscosity law, improves the fluidity of the material to be injected, is more conducive to injection molding, and improves the density and dimensional accuracy of the metal matrix composite component.

[0033] The present invention does not specifically limit the type of reinforcing material, which can be a non-metallic or metallic reinforcing material. Non-metallic materials can be, for example, SiC, Al2O3, TiC, etc., and metallic materials can be, for example, Ti, Cu, etc.

[0034] This invention does not specifically limit the method for preparing magnesium-based composite material billets; for example, it can be mechanical stirring casting. Preferred preparation conditions include pre-vacuuming and using a protective atmosphere to prevent oxidation of the magnesium melt, with a stirring temperature range of 550℃-750℃.

[0035] In some preferred embodiments, the magnesium-based composite material particles are cuboid particles with a length of 1.0 mm to 6.0 mm and a width and height of 0.5 mm to 3.0 mm. In this preferred embodiment, since the matrix metal is magnesium and the reinforcing material is uniformly dispersed in the magnesium-based composite particles, the use of cuboid magnesium-based composite particles, based on the plastic deformation generated by mechanical cutting, can increase the residual strain energy inside the magnesium-based composite particles. This is more conducive to the melting of the eutectic phase to form matrix solid particles during the injection molding heating stage, thereby improving the fluidity of the material to be injected. Furthermore, the length of the cuboid particles is no greater than 6.0 mm, and the width and height are no greater than 3.0 mm, which is more conducive to obtaining sufficient plastic deformation by mechanical cutting. This is more conducive to the rapid melting of the eutectic phase to form matrix solid particles during the injection molding heating stage, thereby improving the fluidity of the material to be injected. The length of the cuboid particles is no less than 1.0 mm, and the width and height are no less than 0.5 mm, which is more conducive to controlling and preventing the magnesium matrix material in the composite particles from melting into a liquid state, preventing the reinforcing material from settling and agglomerating in the injection molding barrel, and ensuring that the reinforcing material is uniformly dispersed in the composite component. The length of the cuboid particles can be, for example, 1.0mm, 2.0mm, 3.0mm, 4.0mm, 5.0mm and 6.0mm, and the width and height can be, for example, 0.5mm, 1mm, 1.5mm, 2.0mm, 2.5mm and 3.0mm.

[0036] The length of the cuboid particle in this invention refers to the length of the longest side of the cuboid particle, while the width and height refer to the lengths of the other two sides.

[0037] Preferably, the length of the cuboid particles is 5.0mm-6.0mm, and the width and height are 1.5mm-2.5mm. In this preferred embodiment, the length of the cuboid particles is not less than 5.0mm, and the width and height are 1.5mm-2.5mm, which is more conducive to maintaining a suitable particle size while ensuring that mechanical cutting produces a suitable amount of plastic deformation, thereby improving the efficiency of injection molding production.

[0038] Preferably, the ratios of the length to width and the length to height of the cuboid particles are 2 to 4. Since the matrix metal is magnesium, and the magnesium-based composite particles contain uniformly dispersed reinforcing materials, the composite particles are cuboids with a length of 1.0 mm to 6.0 mm and a width and height of 0.5 mm to 3.0 mm. This preferred configuration, where the ratios of the length to width and the length to height of the cuboid particles are 2 to 4, is more conducive to ensuring appropriate plastic deformation during mechanical cutting and maintaining suitable particle size. During the injection molding heating stage, the eutectic phase melts rapidly to generate solid matrix particles, improving the flowability of the material to be injected and increasing the efficiency of injection molding production. Specific ratios of the length to width and the length to height of the cuboid particles can be, for example, 2, 2.5, 3, 3.5, and 4.

[0039] Preferably, metallographic testing shows that the volume fraction of the reinforcing material in the magnesium-based composite preform is 1.0%-30.0%. Since the matrix metal is magnesium and the composite particles are cuboid particles with a length of 1.0mm-6.0mm, a width of 0.5mm-3.0mm, under this preferred embodiment, the volume fraction of the reinforcing material in the magnesium-based composite preform and the magnesium-based composite particles is no more than 30.0%. This is more conducive to avoiding agglomeration of the reinforcing material and improving the flowability of the material to be injected, thereby improving the density and dimensional accuracy of the component. Preferably, the volume fraction of the reinforcing material is 5%-15%, which is more conducive to the uniform dispersion of the reinforcing particles and improves the flowability of the material to be injected, thereby improving the comprehensive mechanical properties of the component and the density and dimensional accuracy of the component.

[0040] Preferably, the reinforcing material comprises whiskers and / or particles, wherein the length of the whiskers is not greater than 500 μm and the aspect ratio is 1:1-1:5, and the diameter of the particles is not greater than 100 μm. Since the matrix metal is magnesium, the composite material particles are cuboid particles with a length of 1.0 mm to 6.0 mm and a width and height of 0.5 mm to 3.0 mm. When whiskers are used as the reinforcing material, the length of the whiskers is no greater than 500 μm, and the aspect ratio of the whiskers is 1:1 to 1:5, which is more conducive to improving the fluidity of the melt, the density and dimensional accuracy of the component. When particles are used as the reinforcing material, the diameter of the particles is no greater than 100 μm, which is more conducive to improving the fluidity of the melt, the density and dimensional accuracy of the component. The length of the whiskers is preferably 100 μm to 300 μm, which is more conducive to obtaining both high melt fluidity and strong whisker reinforcement effect, improving the density, dimensional accuracy and comprehensive mechanical properties of the component. The diameter of the particles is preferably 1 μm to 20 μm, which is more conducive to obtaining both high melt fluidity and reinforcement effect, improving the density, dimensional accuracy and comprehensive mechanical properties of the component.

[0041] Preferably, the injection molding conditions include: the barrel includes a heating section, a heat preservation section and an injection section arranged sequentially, the barrel temperature of the heating section gradually increases, the barrel temperature at the end of the heating section is 575℃-635℃, the barrel temperature of the heat preservation section is the same as the barrel temperature at the end of the heating section, and the barrel temperature of the injection section is 520℃~590℃. The base metal is magnesium, and the raw material for injection molding is magnesium-based composite cuboid particles uniformly dispersed with reinforcing material. The length of the cuboid particles is 1.0 mm to 6.0 mm, and the width and height are 0.5 mm to 3.0 mm. In this preferred embodiment, the barrel temperature in the heating section gradually increases, with the temperature at the end of the heating section not lower than 575°C, which is more conducive to reducing the volume fraction of the solid phase in the matrix, obtaining high melt fluidity, and improving the density, dimensional accuracy, and comprehensive mechanical properties of the component. The temperature does not exceed 635°C, which avoids rapid wear and tear on the equipment due to high temperatures, thus extending the equipment's service life. The barrel temperature in the injection section is not lower than 520°C, which is more conducive to improving melt fluidity and injection molding. The temperature does not exceed 590°C, which is more conducive to ensuring a certain viscosity of the melt and preventing melt leakage upon completion of injection molding. Understandably, the barrel temperature can be adjusted within the above temperature range according to the type of magnesium-based alloy, etc. More preferably, the raw material is fed into the barrel by rotating the screw, with the screw speed ranging from 120 rpm to 200 rpm. This accelerates the collision between the matrix solid particles and the reinforcing particles, thereby refining and spherizing the matrix solid particles and the reinforcing material to disperse evenly. This is more conducive to improving the fluidity of the melt and the dispersion uniformity of the reinforcing material, thereby improving the efficiency of injection molding and enhancing the density, dimensional accuracy, and overall mechanical properties of the component.

[0042] More preferably, the injection molding conditions further include: an injection speed of 1.0 m / s to 3.5 m / s, a holding pressure of 100 MPa to 200 MPa, and a holding time of 0.1 s to 10 s. The base metal is magnesium, and reinforcing materials are dispersed in the semi-solid melt or near-liquid melt. The barrel temperature at the end of the heating section is 575℃ to 635℃, and the barrel temperature in the injection section is 520℃ to 590℃. Under this preferred scheme, an injection speed of 1.0 m / s to 3.5 m / s is more conducive to reducing the porosity of the component and improving its density and overall mechanical properties. Furthermore, a holding pressure of 100 MPa to 200 MPa and a holding time of 0.1 s to 10 s are more conducive to reducing the porosity of the component and improving its density and overall mechanical properties.

[0043] More preferably, the injection molding conditions further include: preheating the molding die to a temperature of 200℃-300℃. The base metal is magnesium, and reinforcing material is dispersed in the semi-solid melt or near-liquid melt. The barrel temperature at the end of the heating section is 575℃-635℃, and the barrel temperature of the injection section is 520℃~590℃. In this preferred embodiment, the preheating temperature of the molding die is not lower than 200℃, which helps to avoid excessively high cooling rates, reduce the porosity of the component, and improve the integrity and density of the molded component. The preheating temperature of the molding die is not higher than 300℃, which helps to avoid excessively low cooling rates, thereby achieving the effect of refining grains and improving the mechanical properties of the component.

[0044] In a second aspect, the present invention provides a magnesium-based composite material component prepared by the preparation method described in the first aspect.

[0045] The magnesium-based composite material component of the present invention has a uniformly dispersed reinforcing material, which significantly improves mechanical properties, density and dimensional accuracy.

[0046] The present invention will be further described in detail below with reference to specific embodiments.

[0047] Example 1

[0048] The preparation method of a magnesium-based composite material component includes the following steps:

[0049] Step 1: A blank uniformly mixed with magnesium matrix material and titanium particles is prepared using a vacuum induction casting furnace and a graphite crucible. AZ91D magnesium alloy ingots are loaded into the crucible, and preheated titanium particles (average particle size 10.0 μm) are loaded into the hopper. A pre-vacuum is applied to 0.1 Pa, followed by the introduction of high-purity Ar gas to standard atmospheric pressure. The mixture is then heated to 720℃ to melt AZ91D and held for 30 min. When the temperature is lowered to 600℃, a mechanical stirrer is placed in the furnace, and titanium particles are added while stirring at 550 rpm at a rate of 0.1 kg / min. After addition, the temperature is lowered to 585℃ and stirred for 30 min, then raised to 650℃ for casting to obtain a magnesium-based titanium particle composite blank. The volume fraction of spherical Ti particles in the magnesium-based titanium particle composite blank is 5%.

[0050] Step 2: Cut the magnesium-based titanium particle composite blank into magnesium-based titanium particle composite cuboid particles. The length of the cuboid particles is 5.0 mm, and the width and height are 2.0 mm. The ratio of the length to the width and the length to the height of the cuboid particles are 2.5 respectively.

[0051] Step 3: Injection molding the magnesium-based titanium particle composite cuboid particles. The injection molding machine barrel has seven zones: H1, H2, H3, H4, H5, H6, and H7. Zones H1-H4 are the heating zones, H5 and H6 are the heat preservation zones, and H7 is the injection zone. The barrel temperature is 500℃ for H1, 580℃ for H2, 590℃ for H3, 595℃ for H4, 595℃ for H5-H6, and 540℃ for H7. The raw material is added to the molding machine hopper by an automatic feeder. The screw continuously feeds the raw material into the barrel by rotating. After reaching the set amount, the screw stops rotating and feeding. The screw speed setting range is 150 rpm. The molding die is preheated with a mold temperature controller. The preheating temperature range is 280℃. After uniformly spraying the mold cavity surface with release agent, the mold is closed. The injection speed is set to 2.8 m / s, the holding pressure is 100 MPa, and the holding time is 1.0 s. Injection molding is performed and the pressure is held. The molded part is demolded and removed. It is then air-cooled to room temperature to obtain a magnesium-based composite material component.

[0052] Example 2

[0053] The preparation method of Example 1 was followed, and the barrel temperature of H7 was 500°C.

[0054] Example 3

[0055] The preparation method was carried out in accordance with Example 1, except that in step two, the length of the cuboid particle was 5.0 mm, the width and height were 1.0 mm, and the ratios of length to width and length to height were 5.0.

[0056] Example 4

[0057] The preparation method was carried out in accordance with Example 1, except that in step two, the length of the cuboid particles was 2.5 mm, and the width and height were 1.0 mm.

[0058] Example 5

[0059] The preparation method was carried out according to Example 1. In step two, the length of the cuboid particles was 10.0 mm, and the width and height were 4.0 mm.

[0060] Example 6

[0061] The preparation method was carried out according to Example 1, except that in step one, the reinforcing particles were non-spherical SiC particles with an average particle size of 10.0 μm. The stirring speed of the mechanical stirrer was 500 rpm, and the SiC particle addition rate was 0.2 kg / min. After addition, the temperature was lowered to 585°C and stirred for 30 min, then the temperature was raised to 680°C for casting. In the magnesium-based silicon carbide particle composite green body, the volume fraction of non-spherical SiC particles was 10%. In step two, the magnesium-based SiC particle composite green body was cut into magnesium-based SiC particle composite cuboid particles. The cuboid particles have a length of 6.0 mm, a width and a height of 2.0 mm, and length-to-width and length-to-height ratios of 3. In step three, the barrel temperature of H1 is 500℃, the barrel temperature of H2 is 590℃, the barrel temperature of H3 is 605℃, the barrel temperature of H4 is 605℃, the barrel temperatures of H5-H6 are 605℃, the barrel temperature of H7 is 540℃, the screw speed is set to 180 rpm, the preheating temperature of the molding die is 250℃, the injection speed is 2.5 m / s, the holding pressure is 120 MPa, and the holding time is 1.5 s.

[0062] Comparative Example 1

[0063] The preparation method was carried out in accordance with Example 1, except that AZ91D magnesium alloy particles with a length of 5.0 mm and a width and height of 2.0 mm were added to the hopper of the molding machine by an automatic feeding machine. The screw rotated and continuously fed the raw materials into the barrel. After the set amount was reached, the screw stopped rotating and feeding.

[0064] Comparative Example 2

[0065] The preparation method was carried out in accordance with Example 6, except that AZ91D magnesium alloy particles with a length of 6.0 mm and a width and height of 2.0 mm were added to the hopper of the molding machine by an automatic feeding and suction machine. The screw continuously fed the raw materials into the barrel by rotating. After the set amount was reached, the screw stopped rotating and feeding.

[0066] Test case

[0067] The density, dimensional accuracy, strength, and fracture plasticity of the magnesium-based composite components of Examples 1-6 and Comparative Examples 1-2 were tested, and the test results are shown in Table 1. The strength and fracture plasticity were tested according to GB / T228.1-2010. The microstructure of the composite components was characterized using metallographic methods. The microstructure of the component in Example 1 is shown in [Table 1]. Figure 1 The structure of the components in Comparative Example 1 is shown below. Figure 2 The organization of the components in Example 6 is shown in the figure. Figure 3 The structure of the components in Comparative Example 2 is shown below. Figure 4 .

[0068] Table 1

[0069]

[0070] Comparative examples and comparative examples show that magnesium-based composite material components prepared by injection molding of magnesium-based composite material particles according to the present invention have uniformly dispersed reinforcing materials, resulting in higher density, dimensional accuracy, strength, and plasticity. Comparative Examples 1 and 2 show that the barrel temperature in the injection section is not lower than 520°C, which is more conducive to improving melt flowability and increasing the density, dimensional accuracy, strength, and plasticity of the components. Comparative Examples 1 and 3 show that the length-to-width and length-to-height ratios of the cuboid particles are 2-4, which is more conducive to the rapid melting of the eutectic phase to generate matrix solid particles during the injection molding heating stage, improving the flowability of the material to be injection molded and increasing the density, dimensional accuracy, strength, and plasticity of the components. Compared with Examples 1 and 4, the length of the cuboid particles is not less than 5.0 mm, and the width and height are not less than 1.5 mm, which is more conducive to the uniform dispersion of the reinforcing material and improves the strength and plasticity of the component. Compared with Examples 1 and 5, the length of the cuboid particles is not greater than 6.0 mm, and the width and height are not greater than 3.0 mm, which is more conducive to improving the flowability of the material to be injected into the mold and improving the density, dimensional accuracy, strength and plasticity of the component.

Claims

1. A method for preparing a magnesium-based composite material component, characterized in that, Includes the following steps: A preform in which magnesium matrix material and reinforcing material are uniformly mixed is prepared to obtain a magnesium matrix composite preform; The magnesium-based composite material preform is mechanically cut to obtain magnesium-based composite material particles, the size of which is 0.4 mm to 10.0 mm. The magnesium-based composite material particles are injection molded to obtain magnesium-based composite material components, wherein the temperature of the injection molding barrel is lower than the melting point of the reinforcing material.

2. The preparation method according to claim 1, characterized in that, The magnesium-based composite material particles are cuboid particles with a length of 1.0 mm to 6.0 mm and a width and height of 0.5 mm to 3.0 mm.

3. The preparation method according to claim 2, characterized in that, The cuboid particles have a length of 5.0mm to 6.0mm and a width and height of 1.5mm to 2.5mm.

4. The preparation method according to claim 2, characterized in that, The ratios of the length to width and the length to height of the cuboid particles are 2 to 4, respectively.

5. The preparation method according to claim 2, characterized in that, Metallographic testing revealed that the volume fraction of the reinforcing material in the magnesium-based composite preform was 1.0% to 30.0%.

6. The preparation method according to claim 2, characterized in that, The reinforcing material includes whiskers and / or particles, wherein the length of the whiskers is no greater than 500 μm and the aspect ratio is 1:1 to 1:5, and the diameter of the particles is no greater than 100 μm.

7. The preparation method according to claim 2, characterized in that, The injection molding conditions include: the barrel includes a heating section, a heat preservation section and an injection section arranged sequentially; the barrel temperature in the heating section gradually increases; the barrel temperature at the end of the heating section is 575℃~635℃; the barrel temperature in the heat preservation section is the same as the barrel temperature at the end of the heating section; and the barrel temperature in the injection section is 520℃~590℃.

8. The preparation method according to claim 7, characterized in that, The injection molding conditions also include: an injection speed of 1.0 m / s to 3.5 m / s, a holding pressure of 100 MPa to 200 MPa, and a holding time of 0.1 s to 10 s.

9. The preparation method according to claim 7, characterized in that, The injection molding conditions also include: preheating the molding die at a temperature of 200℃~300℃.

10. A magnesium-based composite material component, characterized in that, It is prepared by the preparation method described in any one of claims 1 to 9.

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