Preparation device and preparation method of particle reinforced magnesium-based composite material

Abstract

The invention discloses a particle reinforced magnesium-based composite material preparation device and method, and the particle reinforced magnesium-based composite material preparation device comprises a melting mechanism used for melting a magnesium alloy matrix to form a magnesium alloy melt; the stirring mechanism is used for stirring the magnesium alloy melt and the reinforced particles; the conveying mechanism comprises a charging barrel, a hopper, a feeding screw, a first heating device and a first driving device, the charging barrel is divided into a first section and a second section in the conveying direction, a feeding port communicated with the melting mechanism is formed in the end, away from the second section, of the first section, and a discharging port communicated with the stirring mechanism is formed in the end, away from the first section, of the second section; the discharging end of the hopper is communicated with the end, close to the first section, of the second section, the hopper is used for feeding reinforced particles, the feeding screw is arranged in the charging barrel, the first heating device is arranged on the charging barrel, and the first driving device is used for driving the feeding screw to rotate. By means of the structure, the particle reinforced magnesium-based composite material with the ideal mechanical property can be prepared.

Description

Technical Field

[0001] The present application relates to the technical field of preparation of particle-reinforced magnesium-based composite materials, and in particular to a preparation device and a preparation method of a particle-reinforced magnesium-based composite material. Background Art

[0002] Heterogeneous particle reinforced magnesium-based composites not only have the characteristics of high specific strength, high specific modulus and low density of magnesium alloys, but also have the characteristics of high strength and high modulus of reinforced particles. They have great application potential and have received widespread attention.

[0003] In the related art, the stirring casting method is a commonly used method for preparing particle-reinforced magnesium-based composite materials. When the stirring casting method is used to prepare particle-reinforced magnesium-based composite materials, a vacuum furnace or an inert gas protection furnace is generally used. When the magnesium alloy matrix is ​​melted to form a magnesium alloy melt and is in a semi-solid or liquid state, the reinforcing particles are added while stirring. Since the particle size of the reinforcing particles is generally in the micrometer or nanometer range, the tendency to agglomerate is relatively large. In order to reduce the agglomeration phenomenon of the reinforcing particles, long-term stirring (usually 30min to 40min) is required. However, the density of the reinforcing particles is generally greater than the density of the magnesium alloy melt. During stirring, the reinforcing particles tend to move to the outside of the crucible under the action of centrifugal force, resulting in uneven macroscopic distribution of the reinforcing particles in the crucible. The longer the stirring time, the more serious this uneven phenomenon, resulting in poor consistency of the mechanical properties of the prepared particle-reinforced magnesium-based composite material. At the same time, the traditional stirring casting method is carried out under low vacuum or inert gas protection. Long-term high-speed stirring is prone to air entrainment, so that pores are formed inside the prepared particle-reinforced magnesium-based composite material, thereby deteriorating the mechanical properties of the particle-reinforced magnesium-based composite material.

[0004] In addition, when the stirring casting method is used to prepare particle-reinforced magnesium-based composites, the slag content in the magnesium alloy melt is relatively high due to the influence of equipment and process, resulting in a high slag content in the prepared particle-reinforced magnesium-based composites, thereby affecting the mechanical properties of the particle-reinforced magnesium-based composites. Summary of the invention

[0005] The present application aims to solve at least one of the technical problems existing in the prior art. To this end, the present application proposes a particle-reinforced magnesium-based composite material preparation device, which can shorten the stirring time on the basis of reducing the agglomeration phenomenon of the reinforcing particles when preparing the particle-reinforced magnesium-based composite material, which is not only conducive to reducing the phenomenon of uneven macroscopic distribution of the reinforcing particles, but also conducive to reducing the pores formed by air entrainment, thereby preparing a particle-reinforced magnesium-based composite material with relatively ideal mechanical properties.

[0006] The present application also proposes a preparation method applied to the above-mentioned particle-reinforced magnesium-based composite material preparation device.

[0007] According to the first aspect of the present application, a particle-reinforced magnesium-based composite material preparation device includes: a melting mechanism for melting a magnesium alloy matrix to form a magnesium alloy melt; a stirring mechanism for stirring the magnesium alloy melt and reinforced particles; a conveying mechanism, including a barrel, a hopper, a feeding screw, a first heating device and a first driving device, the barrel is divided into a first section and a second section along the conveying direction, the first section is provided with a feed port connected to the melting mechanism at one end away from the second section, the second section is provided with a discharge port connected to the stirring mechanism at one end away from the first section, the discharge end of the hopper is connected to an end of the second section close to the first section, the hopper is used to put in reinforced particles, the feeding screw is arranged in the barrel and is used to convey the magnesium alloy melt and reinforced particles, the first heating device is arranged on the barrel, and the first driving device is used to drive the feeding screw to rotate.

[0008] According to the particle-reinforced magnesium-based composite material preparation device of the embodiment of the present application, at least the following beneficial effects are achieved: when preparing the particle-reinforced magnesium-based composite material, the magnesium alloy matrix is ​​first melted by a melting mechanism to form a magnesium alloy melt, and then the magnesium alloy melt is transported to a stirring mechanism by a conveying mechanism. In the process of conveying the magnesium alloy melt by the conveying mechanism, reinforcing particles are put into the barrel through a hopper, so that the magnesium alloy melt and the reinforced particles can be preliminarily mixed in the second section of the barrel under the stirring and shearing action of the feeding screw, and the stirring time of the magnesium alloy melt and the reinforced particles by the stirring mechanism can be shortened on the basis of reducing the agglomeration of the reinforced particles, which is not only beneficial to reducing the uneven macroscopic distribution of the reinforced particles, but also beneficial to reducing the pores formed by air entrainment, thereby preparing a particle-reinforced magnesium-based composite material with relatively ideal mechanical properties.

[0009] According to some embodiments of the present application, the first heating device includes a first heating element and a second heating element that are independent of each other, the first heating element is arranged in the first section, and the second heating element is arranged in the second section.

[0010] According to some embodiments of the present application, both the first heating element and the second heating element are electric heating belts.

[0011] According to some embodiments of the present application, the melting mechanism includes a melting furnace, the melting furnace includes a first furnace body, a first crucible, a second heating device and a protective gas system, the first crucible is arranged in the first furnace body and is used to accommodate a magnesium alloy matrix, the second heating device is arranged in the first furnace body and is used to heat the first crucible, and the protective gas system is used to introduce protective gas into the first furnace body.

[0012] According to some embodiments of the present application, a first conveying pipeline is connected to the upper portion of the first crucible, a first valve for controlling the on-off of the flow path is provided on the first conveying pipeline, a second conveying pipeline is connected to the lower portion of the first crucible, a second valve for controlling the on-off of the flow path is provided on the second conveying pipeline, and an end of the second conveying pipeline away from the first crucible is connected to the feed port.

[0013] According to some embodiments of the present application, a third delivery pipeline is connected to the bottom of the first crucible, and a third valve for controlling the on-off of the flow path is provided on the third delivery pipeline.

[0014] According to some embodiments of the present application, the stirring mechanism includes a vacuum stirring furnace, which includes a second furnace body, a second crucible, a third heating device, a stirring system, a vacuum system and a second driving device. The second crucible is arranged in the second furnace body and is used to accommodate magnesium alloy melt and reinforcing particles. The third heating device is arranged in the second furnace body and is used to heat the second crucible. The stirring system is used to stir the contents in the second crucible. The vacuum system is used to form a vacuum environment in the second furnace body. The second driving device is used to drive the second crucible to tilt to pour out the contents in the second crucible.

[0015] According to some embodiments of the present application, a filtering device is provided between the first conveying pipeline and the feed port.

[0016] According to some embodiments of the present application, the filtering device includes a filter box with a heat preservation function and a filter net or a porous filter plate arranged in the filter box.

[0017] According to the preparation method of the second aspect of the present application, which is applied to the particle-reinforced magnesium-based composite material preparation device according to the first aspect of the present application, the preparation method comprises the following steps:

[0018] The magnesium alloy matrix is ​​loaded into a first crucible of a melting furnace, and the magnesium alloy matrix in the first crucible is heated and melted by a second heating device under the protection of a protective gas to form a magnesium alloy melt. After reaching a set temperature, the magnesium alloy melt is refined and slag removed, and then the first valve is opened to discharge the magnesium alloy melt with a high impurity content located at the upper part of the first crucible through a first conveying pipeline;

[0019] Open the second valve, and deliver the magnesium alloy melt with a relatively high purity located in the middle and lower part of the first crucible into the filtering device through the second delivery pipeline. After being filtered by the filtering device, the magnesium alloy melt enters the feed port of the barrel;

[0020] The temperature of the magnesium alloy melt in the barrel is controlled by the first heating device, and the temperature of the first section is adjusted to a preset temperature so that the magnesium alloy melt in the first section is in a semi-solid state. Reinforcement particles are quantitatively and uniformly added into the barrel through the hopper. The semi-solid magnesium alloy melt and the reinforcement particles are mixed in the second section to form a semi-solid composite material slurry and transported to the second crucible of the vacuum stirring furnace through the discharge port of the barrel.

[0021] The second furnace body is evacuated in advance by a vacuum system, and the vacuum degree in the second furnace body is ensured to be no higher than 10Pa, and the temperature in the second furnace body is adjusted by a third heating device so that the semi-solid composite material slurry remains semi-solid after entering the second crucible;

[0022] After all the semi-solid composite material slurry enters the second crucible, the semi-solid composite material slurry in the second crucible is stirred by a stirring system, the stirring time is 1 min to 3 min, and the stirring speed is 50 r / min to 300 r / min;

[0023] Opening the third valve to discharge the magnesium alloy melt with a high impurity content at the bottom of the first crucible through the third delivery pipeline;

[0024] The temperature of the semi-solid composite material slurry in the second crucible is heated to 30°C to 50°C above the liquidus line of the magnesium alloy matrix by a third heating device, and then the second crucible is tilted by a second driving device to pour the semi-solid composite material slurry in the second crucible into a mold to form a particle-reinforced magnesium-based composite ingot.

[0025] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0027] Figure 1 It is a schematic structural diagram of a device for preparing a particle-reinforced magnesium-based composite material according to an embodiment of the present application;

[0028] Figure 2 yes Figure 1 A schematic diagram of another view of the structure shown;

[0029] Figure 3 is a cross-sectional schematic diagram of a device for preparing a particle-reinforced magnesium-based composite material according to an embodiment of the present application;

[0030] Figure 4 yes Figure 3 A partial enlarged schematic diagram in the middle;

[0031] Figure 5 is a SEM photograph of the titanium particle reinforced AZ91 magnesium alloy composite material prepared in Example 1 of the present application;

[0032] Figure 6 This is a SEM photograph of the titanium particle reinforced VW94 magnesium alloy composite material prepared in Example 2 of the present application.

[0033] Reference numerals:

[0034] Barrel 110, first section 111, second section 112, hopper 120, feeding screw 130, first driving device 140, first heating element 150, second heating element 160;

[0035] Melting furnace 200, first furnace body 210, first crucible 220, second heating device 230;

[0036] A first delivery pipeline 300 and a first valve 310;

[0037] A second delivery pipeline 400 and a second valve 410;

[0038] A third delivery pipeline 500 and a third valve 510;

[0039] Collection box 600;

[0040] A vacuum stirring furnace 700, a second furnace body 710, a second crucible 720, a rotating shaft 730, a stirring shaft 740, and a stirring blade 750;

[0041] Filter box 810 and filter net 820 . DETAILED DESCRIPTION

[0042] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be understood as limiting the present application.

[0043] In the description of the present application, it should be understood that if orientation descriptions are involved, the orientations or positional relationships indicated, such as up, down, front, back, left, and right, are based on the orientations or positional relationships shown in the accompanying drawings. This is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be understood as a limitation on the present application.

[0044] In the description of this application, if the words "some", "greater than", "less than", "exceed", "above", "below", "within" etc. appear, "some" means one or more, "more" means more than two, "greater than", "less than", "exceed", etc. are understood to exclude the number, and "above", "below", "within", etc. are understood to include the number.

[0045] In the description of this application, if the words "first", "second", etc. appear, they are only used to distinguish technical features and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features or implicitly indicating the order of the indicated technical features.

[0046] In the description of this application, unless otherwise clearly defined, terms such as setting, installing, connecting, etc. should be understood in a broad sense, and technicians in the relevant technical field can reasonably determine the specific meanings of the above terms in this application based on the specific content of the technical solution.

[0047] Reference Figures 1 to 4 According to an embodiment of the present application, a device for preparing a particle-reinforced magnesium-based composite material includes a melting mechanism, a stirring mechanism and a conveying mechanism.

[0048] Specifically, the melting mechanism is used to melt the magnesium alloy matrix to form a magnesium alloy melt, the stirring mechanism is used to stir the magnesium alloy melt and the reinforced particles, the conveying mechanism includes a barrel 110, a hopper 120, a feeding screw 130, a first heating device and a first driving device 140, the barrel 110 is divided into a first section 111 and a second section 112 along the conveying direction, the first section 111 is provided with a feeding port connected to the melting mechanism at one end away from the second section 112, the second section 112 is provided with a discharging port connected to the stirring mechanism at one end away from the first section 111, the discharging end of the hopper 120 is connected to an end of the second section 112 close to the first section 111, the hopper 120 is used to feed the reinforced particles, the feeding screw 130 is arranged in the barrel 110 and is used to convey the magnesium alloy melt and the reinforced particles, the first heating device is arranged on the barrel 110, and the first driving device 140 is used to drive the feeding screw 130 to rotate.

[0049] Specifically, the first driving device 140 includes a driving motor, and the feeding screw 130 is driven to rotate by the driving motor.

[0050] When preparing a particle-reinforced magnesium-based composite material, a magnesium alloy matrix is ​​first melted by a melting mechanism to form a magnesium alloy melt, and then the magnesium alloy melt is transported to a stirring mechanism by a conveying mechanism. In the process of conveying the magnesium alloy melt by the conveying mechanism, reinforcing particles are put into the barrel 110 through the hopper 120, so that the magnesium alloy melt and the reinforced particles can be preliminarily mixed under the stirring and shearing action of the feeding screw 130 in the second section 112 of the barrel 110, which can shorten the stirring time of the magnesium alloy melt and the reinforced particles by the stirring mechanism on the basis of reducing the agglomeration of the reinforced particles, which is not only conducive to reducing the uneven macroscopic distribution of the reinforced particles, but also conducive to reducing the pores formed by air entrainment, thereby preparing a particle-reinforced magnesium-based composite material with relatively ideal mechanical properties.

[0051] Reference Figures 1 to 4 In some embodiments, the first heating device includes a first heating element 150 and a second heating element 160 which are independent of each other. The first heating element 150 is arranged in the first section 111, and the second heating element 160 is arranged in the second section 112, so that the temperatures of the first section 111 and the second section 112 can be controlled respectively, thereby better meeting the preparation requirements.

[0052] In some embodiments, the first heating element 150 and the second heating element 160 are both electric heating belts.

[0053] It should be noted that, in some other embodiments, the first heating element 150 and the second heating element 160 may also be resistance wires or other heating structures, which are not limited here.

[0054] Reference Figures 1 to 3 In some embodiments, the melting mechanism includes a melting furnace 200, the melting furnace 200 includes a first furnace body 210, a first crucible 220, a second heating device 230 and a protective gas system, the first crucible 220 is arranged in the first furnace body 210 and is used to accommodate the magnesium alloy matrix, the second heating device 230 is arranged in the first furnace body 210 and is used to heat the first crucible 220, and the protective gas system is used to introduce protective gas into the first furnace body 210.

[0055] In some embodiments, the second heating device 230 is a resistance wire.

[0056] It should be noted that, in some other embodiments, the second heating device 230 may also be an electromagnetic induction heating structure or other heating structures, which are not limited here.

[0057] Specifically, the material of the first crucible 220 is graphite. Of course, the first crucible 220 may also be an iron crucible, which is not limited here.

[0058] It should be noted that the specific structure and working principle of each part of the melting furnace 200 are not the improvements of the present application and will not be described in detail here.

[0059] Reference Figures 1 to 3 In some embodiments, the upper portion of the first crucible 220 is connected to a first delivery pipeline 300, and a first valve 310 for controlling the on-off of the flow path is provided on the first delivery pipeline 300; the lower portion of the first crucible 220 is connected to a second delivery pipeline 400, and a second valve 410 for controlling the on-off of the flow path is provided on the second delivery pipeline 400; and one end of the second delivery pipeline 400 away from the first crucible 220 is connected to the feed port of the barrel 110. Since the slag content of the magnesium alloy melt located at the top and bottom of the first crucible 220 is relatively high, by providing a first conveying pipeline 300 having a first valve 310 and a second conveying pipeline 400 having a second valve 410, before the magnesium alloy melt in the first crucible 220 is fed into the barrel 110, the magnesium alloy melt with a relatively high impurity content located at the top of the first crucible 220 can be discharged through the first conveying pipeline 300, and then the magnesium alloy melt with a relatively high purity located in the middle and lower part of the first crucible 220 can be fed into the barrel 110 through the second conveying pipeline 400, which is beneficial to further improve the mechanical properties of the prepared particle-reinforced magnesium-based composite material.

[0060] It should be noted that the upper portion of the first crucible 220 and the lower portion of the first crucible 220 are both regions located between the top of the first crucible 220 and the bottom of the first crucible 220 , wherein the upper portion of the first crucible 220 is located above the lower portion of the first crucible 220 .

[0061] Reference Figure 1 and Figure 2 In some embodiments, a third delivery pipeline 500 is connected to the bottom of the first crucible 220, and a third valve 510 for controlling the on-off of the flow path is provided on the third delivery pipeline 500. When the magnesium alloy melt with higher purity located in the middle and lower part of the first crucible 220 is fed into the barrel 110, the magnesium alloy melt with higher impurity content located at the bottom of the first crucible 220 can be discharged through the third delivery pipeline 500.

[0062] Specifically, the first valve 310 , the second valve 410 , and the third valve 510 are all cone-plug valves. Of course, the first valve 310 , the second valve 410 , and the third valve 510 may also be other types of valves, which are not limited here.

[0063] Reference Figures 1 to 3In some embodiments, one end of the first conveying pipeline 300 away from the first crucible 220 is connected to a collecting box 600, and the collecting box 600 is used to collect the discharged magnesium alloy melt for recycling, wherein one end of the third conveying pipeline 500 away from the first crucible 220 is also connected to the collecting box 600.

[0064] Reference Figures 1 to 3 In some embodiments, the stirring mechanism includes a vacuum stirring furnace 700, which includes a second furnace body 710, a second crucible 720, a third heating device, a stirring system, a vacuum system, and a second driving device. The second crucible 720 is disposed in the second furnace body 710 and is used to accommodate the magnesium alloy melt and the reinforcement particles. The third heating device is disposed in the second furnace body 710 and is used to heat the second crucible 720. The stirring system is used to stir the contents in the second crucible 720. The vacuum system is used to form a vacuum environment in the second furnace body 710. The second driving device is used to drive the second crucible 720 to tilt to pour out the contents in the second crucible 720. When in use, the stirring system stirs under vacuum conditions, which is conducive to reducing pores formed by entrained gas compared to stirring under protective gas.

[0065] Specifically, the second driving device includes a rotating shaft 730 disposed on the second furnace body 710 and connected to the second crucible 720, and a driving member for driving the rotating shaft 730 to rotate, wherein the driving member can be a driving motor or a hand wheel, which is not limited here.

[0066] Specifically, the stirring system includes a driving motor, a stirring shaft 740 and a stirring blade 750 . The stirring system can be raised and lowered so that the stirring shaft 740 and the stirring blade 750 will not hinder the tilting of the second crucible 720 .

[0067] Among them, the specific structure and working principle of each part of the vacuum stirring furnace 700 are not the improvements of this application and will not be repeated here.

[0068] In some of the embodiments, a filtering device is provided between the first conveying pipeline 300 and the feed port of the barrel 110. When in use, the magnesium alloy melt to be fed into the barrel 110 can be filtered, thereby facilitating further improving the mechanical properties of the prepared particle-reinforced magnesium-based composite material.

[0069] Reference Figures 1 to 4 In some embodiments, the filtering device includes a filter box 810 with a heat preservation function and a filter screen 820 disposed in the filter box 810, and the structure is simple and easy to implement. The filter box 810 has a heat preservation function, so as to ensure the fluidity of the magnesium alloy melt in the filter box 810.

[0070] Specifically, the filter screen 820 may be made of a stainless steel wire mesh.

[0071] It should be noted that, in some other embodiments, the filter screen 820 may also be replaced by a porous filter plate, which is not limited here. Specifically, the porous filter plate may be made of stainless steel.

[0072] Specifically, the body of the filter box 810 may be made of a heat-insulating material, or a heat-insulating structure may be disposed outside the filter box 810 , which is not limited herein.

[0073] According to the preparation method of the embodiment of the present application, which is applied to the above-mentioned particle-reinforced magnesium-based composite material preparation device, the following steps are included:

[0074] The magnesium alloy matrix is ​​loaded into the first crucible 220 of the melting furnace 200, and the magnesium alloy matrix in the first crucible 220 is heated and melted by the second heating device 230 under the protection of the protective gas to form a magnesium alloy melt. After reaching the set temperature, the magnesium alloy melt is refined and slag-removed, and then the first valve 310 is opened to discharge the magnesium alloy melt with a high impurity content located at the upper part of the first crucible 220 through the first conveying pipeline 300;

[0075] Open the second valve 410, and deliver the magnesium alloy melt with high purity located in the middle and lower part of the first crucible 220 to the filtering device through the second delivery pipeline 400. After being filtered by the filtering device, the magnesium alloy melt enters the feed port of the barrel 110;

[0076] The temperature of the magnesium alloy melt in the barrel 110 is controlled by the first heating device, and the temperature of the first section 111 is adjusted to a preset temperature so that the magnesium alloy melt in the first section 111 is in a semi-solid state. Reinforcement particles are quantitatively and uniformly added into the barrel 110 through the hopper 120. The semi-solid magnesium alloy melt and the reinforcement particles are mixed in the second section 112 to form a semi-solid composite material slurry and are transported to the second crucible 720 of the vacuum stirring furnace 700 through the discharge port of the barrel 110. Specifically, the semi-solid magnesium alloy melt and the reinforcement particles are fully sheared and mixed by the feeding screw 130 during the forward transportation in the second section 112 to form a partially melted semi-solid composite material slurry containing a matrix liquid phase, a matrix spherical solid phase and a reinforcement solid phase. The slurry has good fluidity. At the end of the barrel 110 (i.e., the end of the barrel 110 close to the discharge port), the semi-solid composite material slurry enters the second crucible 720 under the shear thrust of the feeding screw 130 and the negative pressure in the second furnace body 710;

[0077] The second furnace body 710 is evacuated in advance by a vacuum system, and the vacuum degree in the second furnace body 710 is ensured to be no higher than 10 Pa, and the temperature in the second furnace body 710 is adjusted by a third heating device so that the semi-solid composite material slurry remains semi-solid after entering the second crucible 720;

[0078] After all the semi-solid composite material slurry enters the second crucible 720, the semi-solid composite material slurry in the second crucible 720 is stirred by a stirring system, the stirring time is 1 min to 3 min, and the stirring speed is 50 r / min to 300 r / min;

[0079] Open the third valve 510 to drain the magnesium alloy melt with a high impurity content at the bottom of the first crucible 220 through the third delivery pipeline 500;

[0080] The temperature of the semi-solid composite material slurry in the second crucible 720 is heated to 30°C to 50°C above the liquidus line of the magnesium alloy matrix by a third heating device, and then the second crucible 720 is driven to tilt by a second driving device to pour the semi-solid composite material slurry in the second crucible 720 into a mold to form a particle-reinforced magnesium-based composite ingot.

[0081] When the particle-reinforced magnesium-based composite material is prepared by the above-mentioned preparation method, all technical effects of the above-mentioned particle-reinforced magnesium-based composite material preparation device are obtained. In addition, during the preparation process, the vacuum degree in the second furnace body 710 is not higher than 10Pa, that is, the vacuum degree in the second furnace body 710 is relatively high, which is conducive to further reducing the pores formed by air entrainment.

[0082] Example 1

[0083] This embodiment provides a titanium particle reinforced AZ91 magnesium alloy composite material, the average particle size of the titanium particles is 20 μm, and the volume fraction is 45%. The preparation process is as follows:

[0084] The AZ91 magnesium alloy matrix is ​​loaded into the first crucible 220 of the melting furnace 200, and the AZ91 magnesium alloy matrix in the first crucible 220 is heated and melted by the second heating device 230 under argon protection to form a magnesium alloy melt. When the temperature reaches 680° C., a refining agent is used for refining, and the slag is removed after being kept at the temperature for 15 minutes. The temperature is adjusted to 620° C., and then the first valve 310 is opened to discharge 15% of the magnesium alloy melt located at the upper part of the first crucible 220 through the first conveying pipeline 300;

[0085] The second valve 410 is opened, and the magnesium alloy melt with a high purity located in the middle and lower part of the first crucible 220 is fed into the filtering device through the second conveying pipeline 400. After being filtered by the filtering device, the magnesium alloy melt enters the feed port of the barrel 110, and the first driving device 140 is started to drive the feeding screw 130 in the barrel 110 to rotate at a speed of 200 r / min.

[0086] The heating power of the first heating element 150 is adjusted so that the temperature of the magnesium alloy melt in the first section 111 is maintained at 595° C. to 605° C. Titanium particles are quantitatively and uniformly added into the barrel 110 through the hopper 120. The magnesium alloy melt and the titanium particles are mixed in the second section 112 to form a semi-solid composite material slurry and transported to the second crucible 720 of the vacuum stirring furnace 700 through the discharge port of the barrel 110. The heating power of the second heating element 160 is adjusted so that the temperature of the semi-solid composite material slurry in the second section 112 is maintained at 585° C. to 595° C.;

[0087] The second furnace body 710 is pre-evacuated by a vacuum system to a vacuum degree of 5 Pa, and the temperature in the second furnace body 710 is preheated to 585° C. to 595° C. by a third heating device. The semi-solid composite material slurry enters the second crucible 720 under the shear thrust of the feeding screw 130 and the negative pressure in the second furnace body 710;

[0088] Open the third valve 510 to drain the magnesium alloy melt with a high impurity content at the bottom of the first crucible 220 through the third delivery pipeline 500;

[0089] The stirring system is turned on to stir the semi-solid composite material slurry in the second crucible 720 at a stirring speed of 200 r / min. After stirring for 2 minutes, the temperature of the semi-solid composite material slurry is raised to 620° C. by a third heating device and then cast to obtain a metal titanium particle reinforced AZ91 magnesium alloy composite material.

[0090] The obtained titanium particle reinforced AZ91 magnesium alloy composite material was microstructured. Figure 5 As shown, it was observed that metallic titanium particles were uniformly distributed in the AZ91 magnesium alloy.

[0091] Example 2

[0092] This embodiment provides a titanium particle reinforced VW94 magnesium alloy composite material, the average particle size of the titanium particles is 10 μm, and the volume fraction is 3%. The preparation process is as follows:

[0093] The VW94 magnesium alloy matrix is ​​loaded into the first crucible 220 of the melting furnace 200, and the VW94 magnesium alloy matrix in the first crucible 220 is heated and melted by the second heating device 230 under the protection of argon gas to form a magnesium alloy melt. When the temperature reaches 720°C, a refining agent is used for refining, and the slag is removed after being kept at the temperature for 15 minutes. The temperature is adjusted to 650°C, and then the first valve 310 is opened to discharge 20% of the magnesium alloy melt located at the upper part of the first crucible 220 through the first conveying pipeline 300;

[0094] The second valve 410 is opened, and the magnesium alloy melt with a high purity located in the middle and lower part of the first crucible 220 is fed into the filtering device through the second conveying pipeline 400. After being filtered by the filtering device, the magnesium alloy melt enters the feed port of the barrel 110, and the first driving device 140 is started to drive the feeding screw 130 in the barrel 110 to rotate at a speed of 150 r / min.

[0095] The heating power of the first heating element 150 is adjusted so that the temperature of the magnesium alloy melt in the first section 111 is maintained at 620° C. to 630° C. Titanium particles are quantitatively and uniformly added into the barrel 110 through the hopper 120. The magnesium alloy melt and the titanium particles are mixed in the second section 112 to form a semi-solid composite material slurry and transported to the second crucible 720 of the vacuum stirring furnace 700 through the discharge port of the barrel 110. The heating power of the second heating element 160 is adjusted so that the temperature of the semi-solid composite material slurry in the second section 112 is maintained at 610° C. to 620° C.;

[0096] The second furnace body 710 is pre-evacuated by a vacuum system, and the vacuum degree is 10 Pa. The temperature in the second furnace body 710 is preheated to 610° C. to 620° C. by a third heating device. The semi-solid composite material slurry enters the second crucible 720 under the shear thrust of the feeding screw 130 and the negative pressure in the second furnace body 710.

[0097] Open the third valve 510 to drain the magnesium alloy melt with a high impurity content at the bottom of the first crucible 220 through the third delivery pipeline 500;

[0098] The stirring system is turned on to stir the semi-solid composite material slurry in the second crucible 720 at a stirring speed of 100 r / min. After stirring for 1 minute, the temperature of the semi-solid composite material slurry is raised to 660° C. by a third heating device and then cast to obtain a metal titanium particle reinforced VW94 magnesium alloy composite material.

[0099] The obtained titanium particle reinforced VW94 magnesium alloy composite material was subjected to microstructural observation. Figure 6 As shown, it is observed that the metallic titanium particles are uniformly distributed in the VW94 magnesium alloy.

[0100] In the description of this specification, if the description involves reference terms such as "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples" and "some examples", it means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0101] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. A device for preparing a particle-reinforced magnesium-based composite material, characterized in that: include: A melting mechanism, used for melting the magnesium alloy matrix to form a magnesium alloy melt; A stirring mechanism, used for stirring the magnesium alloy melt and the reinforcement particles; A conveying mechanism comprises a barrel, a hopper, a feeding screw, a first heating device and a first driving device, wherein the barrel is divided into a first section and a second section along a conveying direction, an end of the first section away from the second section is provided with a feeding port connected to the melting mechanism, an end of the second section away from the first section is provided with a discharging port connected to the stirring mechanism, a discharging end of the hopper is connected to an end of the second section close to the first section, the hopper is used for feeding reinforced particles, the feeding screw is arranged in the barrel and is used for conveying magnesium alloy melt and reinforced particles, the first heating device is arranged on the barrel, and the first driving device is used for driving the feeding screw to rotate.

2. The device for preparing a particle-reinforced magnesium-based composite material according to claim 1, characterized in that: The first heating device includes a first heating element and a second heating element that are independent of each other. The first heating element is disposed in the first section, and the second heating element is disposed in the second section.

3. The device for preparing a particle-reinforced magnesium-based composite material according to claim 2, characterized in that: The first heating element and the second heating element are both electric heating belts.

4. The device for preparing a particle-reinforced magnesium-based composite material according to any one of claims 1 to 3, characterized in that: The melting mechanism includes a melting furnace, which includes a first furnace body, a first crucible, a second heating device and a protective gas system. The first crucible is arranged in the first furnace body and is used to accommodate a magnesium alloy substrate. The second heating device is arranged in the first furnace body and is used to heat the first crucible. The protective gas system is used to introduce protective gas into the first furnace body.

5. The device for preparing a particle-reinforced magnesium-based composite material according to claim 4, characterized in that: A first conveying pipeline is connected to the upper portion of the first crucible, a first valve for controlling the on-off of the flow path is arranged on the first conveying pipeline, a second conveying pipeline is connected to the lower portion of the first crucible, a second valve for controlling the on-off of the flow path is arranged on the second conveying pipeline, and an end of the second conveying pipeline away from the first crucible is connected to the feed port.

6. The device for preparing a particle-reinforced magnesium-based composite material according to claim 5, characterized in that: The bottom of the first crucible is connected to a third delivery pipeline, and the third delivery pipeline is provided with a third valve for controlling the on-off of the flow path.

7. The device for preparing a particle-reinforced magnesium-based composite material according to claim 6, characterized in that: The stirring mechanism includes a vacuum stirring furnace, which includes a second furnace body, a second crucible, a third heating device, a stirring system, a vacuum system and a second driving device. The second crucible is arranged in the second furnace body and is used to accommodate magnesium alloy melt and reinforcement particles. The third heating device is arranged in the second furnace body and is used to heat the second crucible. The stirring system is used to stir the contents in the second crucible. The vacuum system is used to form a vacuum environment in the second furnace body. The second driving device is used to drive the second crucible to tilt so as to pour out the contents in the second crucible.

8. The device for preparing a particle-reinforced magnesium-based composite material according to claim 7, characterized in that: A filtering device is provided between the first conveying pipeline and the feed inlet.

9. The device for preparing a particle-reinforced magnesium-based composite material according to claim 8, characterized in that: The filtering device comprises a filtering box with a heat preservation function and a filtering net or a porous filtering plate arranged in the filtering box.

10. A preparation method, characterized in that: The device for preparing a particle-reinforced magnesium-based composite material as claimed in claim 8 or 9 comprises the following steps: The magnesium alloy matrix is ​​loaded into a first crucible of a melting furnace, and the magnesium alloy matrix in the first crucible is heated and melted by a second heating device under the protection of a protective gas to form a magnesium alloy melt. After reaching a set temperature, the magnesium alloy melt is refined and slag removed, and then the first valve is opened to discharge the magnesium alloy melt with a high impurity content located at the upper part of the first crucible through a first conveying pipeline; Open the second valve, and deliver the magnesium alloy melt with a relatively high purity located in the middle and lower part of the first crucible into the filtering device through the second delivery pipeline. After being filtered by the filtering device, the magnesium alloy melt enters the feed port of the barrel; The temperature of the magnesium alloy melt in the barrel is controlled by the first heating device, and the temperature of the first section is adjusted to a preset temperature so that the magnesium alloy melt in the first section is in a semi-solid state. Reinforcement particles are quantitatively and uniformly added into the barrel through the hopper. The semi-solid magnesium alloy melt and the reinforcement particles are mixed in the second section to form a semi-solid composite material slurry and transported to the second crucible of the vacuum stirring furnace through the discharge port of the barrel. The second furnace body is evacuated in advance by a vacuum system, and the vacuum degree in the second furnace body is ensured to be no higher than 10Pa, and the temperature in the second furnace body is adjusted by a third heating device so that the semi-solid composite material slurry remains semi-solid after entering the second crucible; After all the semi-solid composite material slurry enters the second crucible, the semi-solid composite material slurry in the second crucible is stirred by a stirring system, the stirring time is 1 min to 3 min, and the stirring speed is 50 r / min to 300 r / min; Opening the third valve to discharge the magnesium alloy melt with a high impurity content at the bottom of the first crucible through the third delivery pipeline; The temperature of the semi-solid composite material slurry in the second crucible is heated to 30°C to 50°C above the liquidus line of the magnesium alloy matrix by a third heating device, and then the second crucible is tilted by a second driving device to pour the semi-solid composite material slurry in the second crucible into a mold to form a particle-reinforced magnesium-based composite ingot.

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