Magnesium alloy and method for producing same, magnesium alloy member and method for producing same, vehicle

Abstract

The application provides a magnesium alloy and a preparation method thereof, a magnesium alloy component and a preparation method thereof, and a vehicle, and belongs to the technical field of vehicle parts, and the magnesium alloy comprises the following components in percentage by mass: 8.9%-9.4% of an aluminum element, 0.5%-1.4% of a zinc element, 0.1%-1.0% of a gadolinium element, and 0.1%-1.0% of a yttrium element, and the balance is a magnesium element. The magnesium alloy provided by the embodiment of the application can have good tensile strength, yield strength and elongation by adopting the above-mentioned component formula, and meanwhile, the magnesium alloy has excellent corrosion resistance, and the application prospect of the magnesium alloy is improved.

Description

Technical Field

[0001] This application relates to the field of vehicle parts technology, and in particular to a magnesium alloy and its preparation method, a magnesium alloy component and its preparation method, and a vehicle. Background Technology

[0002] Magnesium alloys, as important lightweight metallic structural materials, possess numerous advantages such as high specific strength, excellent electromagnetic shielding performance, and recyclability. In the context of lightweighting new energy vehicles, replacing aluminum with magnesium in electric drive housing components can theoretically achieve a 30% weight reduction, demonstrating significant application potential. Among related technologies, only AZ91D magnesium alloy is commercially available for manufacturing electric drive housing components. Its yield strength and elongation are essentially comparable to aluminum alloys, but its corrosion resistance is inferior, limiting its application in electric drive housings. Summary of the Invention

[0003] This application provides a magnesium alloy and its preparation method, a magnesium alloy component and its preparation method, and a vehicle. The magnesium alloy can have good corrosion resistance while ensuring yield strength and elongation.

[0004] To achieve the above objectives, according to a first aspect of this application, a magnesium alloy is provided, comprising the following components by mass percentage: 8.9%-9.4% aluminum, 0.5%-1.4% zinc, 0.1%-1.0% gadolinium, 0.1%-1.0% yttrium, and the balance being magnesium.

[0005] Optionally, the mass ratio of gadolinium to yttrium is (2-4):1.

[0006] Optionally, the mass ratio of gadolinium to yttrium is (2.8-3.2):1.

[0007] According to a second aspect of this application, a method for preparing a magnesium alloy is also provided, comprising:

[0008] According to the composition ratio of magnesium alloy, a mixture containing magnesium, aluminum, zinc, gadolinium and yttrium is prepared;

[0009] The mixture is smelted to obtain a molten liquid;

[0010] The molten liquid is poured into a mold to obtain a magnesium alloy.

[0011] Optionally, according to the composition ratio of the magnesium alloy, a mixture containing magnesium, aluminum, zinc, gadolinium, and yttrium is prepared, including:

[0012] According to the composition ratio of magnesium alloy, a mixture is prepared using pure magnesium, pure aluminum, pure zinc, pure gadolinium and pure yttrium.

[0013] Optionally, the mixture is smelted to obtain a molten liquid, comprising:

[0014] First, pure magnesium and pure aluminum are heated to 660℃-680℃ and melted to obtain the first molten metal.

[0015] Pure zinc, pure gadolinium, and pure yttrium are added to the first molten metal, and the mixture is refined at 680℃-700℃ to obtain a molten liquid.

[0016] According to a third aspect of this application, a magnesium alloy component is also provided, which is made of the magnesium alloy as described above;

[0017] And / or, the magnesium alloy is prepared by the method described above for preparing magnesium alloys.

[0018] Optionally, the magnesium alloy component includes at least one of the electric drive housing, the electric control box, and the battery pack housing.

[0019] According to a fourth aspect of this application, a method for preparing a magnesium alloy component is also provided, comprising:

[0020] Magnesium alloys are subjected to plastic deformation treatment and then processed into magnesium alloy particles;

[0021] Magnesium alloy particles are heated to obtain a semi-solid magnesium alloy slurry;

[0022] Magnesium alloy semi-solid slurry is injection molded to obtain magnesium alloy components.

[0023] Optionally, the magnesium alloy is subjected to plastic deformation treatment, including:

[0024] Magnesium alloys are deformed using one of the processes of forging, rolling, or extrusion to achieve an average grain size of ≤5μm.

[0025] Optionally, the magnesium alloy is deformed using one of the processes of forging, rolling, and extrusion, including:

[0026] Magnesium alloys are heated to 340℃-350℃ for free forging, which increases the axial plastic deformation of the magnesium alloy to more than 50% and refines the average grain size to less than 5μm.

[0027] Optionally, the magnesium alloy is deformed using one of the processes of forging, rolling, and extrusion, including:

[0028] The magnesium alloy is heated to 360℃-370℃ and rolled to achieve a plastic deformation of more than 70% in the thickness direction and refine the average grain size to below 3μm.

[0029] Optionally, the magnesium alloy is deformed using one of the processes of forging, rolling, and extrusion, including:

[0030] The magnesium alloy is heated to 340℃-350℃ and extruded in three passes to achieve a radial plastic deformation of more than 70% and refine the average grain size to below 2μm.

[0031] Optionally, heating the magnesium alloy particles includes:

[0032] Magnesium alloy particles are drawn into the screw slurry barrel under vacuum and then heated at a temperature of 580℃-650℃.

[0033] Optionally, the magnesium alloy semi-solid slurry is injection molded, including:

[0034] An injection molding device with a capacity of 1500t-3500t is used to inject magnesium alloy semi-solid slurry into a mold for molding under the conditions of injection volume of 3kg-25kg and injection speed of 2m / s-5m / s; wherein the mold is preheated to 200℃-320℃.

[0035] Optionally, after injection molding the magnesium alloy semi-solid slurry, the process further includes:

[0036] The formed castings are cleaned, surface treated and machined.

[0037] According to a fifth aspect of this application, a vehicle is also provided, comprising the magnesium alloy component as described above, and / or a magnesium alloy component prepared by the method described above.

[0038] The magnesium alloy provided in this application comprises the following components by mass percentage: 8.9%-9.4% aluminum, 0.5%-1.4% zinc, 0.1%-1.0% gadolinium, 0.1%-1.0% yttrium, with the balance being magnesium. By using the above-mentioned composition, the resulting magnesium alloy exhibits good tensile strength, yield strength, and elongation, as well as excellent corrosion resistance, thus improving the application prospects of magnesium alloys.

[0039] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0041] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0042] Figure 1 This is a schematic flowchart of the magnesium alloy preparation method provided in the embodiments of this application;

[0043] Figure 2 This is a schematic flowchart of the method for preparing magnesium alloy components provided in the embodiments of this application. Detailed Implementation

[0044] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0045] In a first aspect, embodiments of this application provide a magnesium alloy comprising the following components by mass percentage: 8.9%-9.4% aluminum (Al), 0.5%-1.4% zinc (Zn), 0.1%-1.0% gadolinium (Gd), and 0.1%-1.0% yttrium (Y), with the balance being magnesium (Mg). By employing the above-mentioned composition, the resulting magnesium alloy exhibits good tensile strength, yield strength, and elongation, while also possessing excellent corrosion resistance, thus improving the application prospects of magnesium alloys.

[0046] Setting the aluminum content to 8.9%-9.4% ensures that the solidus point of the magnesium alloy is located at the eutectic point of 438℃, resulting in better fluidity and filling performance during casting. Gadolinium and yttrium are rare earth elements; adding appropriate proportions of gadolinium and yttrium can improve the corrosion resistance of magnesium alloys, allowing them to maintain good performance in harsh environments such as humidity and corrosion. Furthermore, gadolinium and yttrium can significantly improve the strength of magnesium alloys through solid solution strengthening and precipitation strengthening.

[0047] In related technologies, the magnesium alloy with grade AZ91D has a yield strength of 160 MPa and an elongation of 3%, which is basically comparable to that of aluminum alloys, but its corrosion resistance is significantly worse than that of aluminum alloys. The magnesium alloy provided in this application, through the above-mentioned component formulation, can achieve a tensile strength of over 280 MPa, a yield strength of over 180 MPa, and an elongation of over 8%. Specifically, the yield strength is increased by 20 MPa compared to the magnesium alloy with grade AZ91D, and the elongation is increased by 5%, resulting in superior mechanical properties. Simultaneously, the magnesium alloy exhibits excellent corrosion resistance with a corrosion rate of less than 0.3 mm / y (0.3 mm per year) in a 3.5 wt% sodium chloride solution. Therefore, the magnesium alloy provided in this application can replace aluminum alloys, achieving lightweight while maintaining good mechanical properties and corrosion resistance.

[0048] In some embodiments, the mass ratio of gadolinium to yttrium is (2-4):1. By simultaneously adding gadolinium and yttrium to magnesium alloys, the solid solution strengthening and second-phase strengthening effects on the magnesium alloys can be improved. Setting the mass ratio of gadolinium (Gd) to yttrium (Y) to (2-4):1 ensures the strengthening effect, while the potential difference between the MgY5 precipitate and the magnesium (Mg) matrix is ​​close, which can improve the corrosion resistance of the magnesium alloy.

[0049] For example, the mass ratio of gadolinium to yttrium is 2:1, 2.2:1, 2.4:1, 2.6:1, 2.8:1, 3:1, 3.2:1, 3.4:1, 3.6:1, 3.8:1 or 4:1.

[0050] In some embodiments, the mass ratio of gadolinium to yttrium is (2.8-3.2):1. This ensures the strengthening effect and improves the corrosion resistance of magnesium alloys.

[0051] Secondly, embodiments of this application also provide a method for preparing a magnesium alloy, used to prepare the magnesium alloy as described above, such as... Figure 1 As shown, it includes:

[0052] Step 110: Prepare a mixture containing magnesium, aluminum, zinc, gadolinium and yttrium according to the composition ratio of the magnesium alloy.

[0053] Step 120: Melt the mixture to obtain a molten liquid;

[0054] Step 130: Cast the molten liquid into a shape to obtain a magnesium alloy.

[0055] First, prepare a suitable mixture according to the component ratio of magnesium alloy. Then, melt the mixture to form a molten liquid, so that the elements are mixed evenly. Finally, cast the molten liquid into a mold to obtain a uniform magnesium alloy.

[0056] In some embodiments, a mixture comprising magnesium, aluminum, zinc, gadolinium, and yttrium is prepared according to the component ratio of the magnesium alloy, including:

[0057] According to the composition ratio of magnesium alloy, a mixture is prepared using pure magnesium, pure aluminum, pure zinc, pure gadolinium and pure yttrium.

[0058] Among them, pure magnesium can be magnesium ingots with a purity of 99.9% or higher. Similarly, pure aluminum can be aluminum ingots with a purity of 99.9% or higher, pure zinc can be zinc blocks with a purity of 99.9% or higher, pure gadolinium can be gadolinium blocks with a purity of 99.9% or higher, and pure yttrium can be yttrium blocks with a purity of 99.9% or higher. By using pure magnesium, pure aluminum, pure zinc, pure gadolinium, and pure yttrium to formulate the mixture, the introduction of impurities can be reduced, and the formulation process can be simplified.

[0059] In some embodiments, the mixture is smelted to obtain a molten liquid, comprising:

[0060] First, pure magnesium and pure aluminum are heated to 660℃-680℃ and melted to obtain the first molten metal.

[0061] Pure zinc, pure gadolinium, and pure yttrium are added to the first molten metal, and the mixture is refined at 680℃-700℃ to obtain a molten liquid.

[0062] Magnesium and aluminum have low melting points. Melting pure magnesium and aluminum first allows for a faster attainment of the melting temperature, thus reducing the total melting time. Furthermore, magnesium and aluminum can form a limited solid solution with high protective solubility at the eutectic temperature. Melting pure magnesium and aluminum first helps achieve better fusion, providing a better alloying basis for the subsequent addition of other metals. After melting pure magnesium and aluminum to obtain the first molten metal, pure zinc, pure gadolinium, and pure yttrium are added, and the temperature is increased to form a molten liquid containing magnesium, aluminum, zinc, gadolinium, and yttrium.

[0063] Magnesium alloys are obtained by pouring molten metal into a mold and then cooling it to solidify. The resulting magnesium alloy can be either a cylindrical billet or a square billet.

[0064] Thirdly, embodiments of this application also provide a magnesium alloy component, which is made of the magnesium alloy as described above; and / or, which is made of the magnesium alloy prepared by the magnesium alloy preparation method described above.

[0065] The magnesium alloy components provided in this application are made using the magnesium alloy described above. They possess excellent mechanical properties such as tensile strength, yield strength, and elongation, as well as superior corrosion resistance. They can replace aluminum alloys and contribute to achieving the goal of lightweighting.

[0066] In some embodiments, the magnesium alloy component includes at least one of an electric drive housing, an electronic control enclosure, and a battery pack housing. The magnesium alloy component can be used in various applications, such as as an electric drive housing, an electronic control enclosure, and a battery pack housing.

[0067] In related technologies, the electric drive housing, electronic control box, and battery pack housing are typically made of aluminum alloy. The magnesium alloy component provided in this application is made of the magnesium alloy described above, exhibiting superior mechanical properties compared to aluminum alloy and excellent corrosion resistance. Replacing the aluminum alloy with aluminum alloy can significantly reduce weight, achieving a reduction of over 30%. The electric drive housing, electronic control box, and battery pack housing are crucial components of new energy vehicles. Using aluminum alloy components for these components can significantly reduce the weight of new energy vehicles.

[0068] In some embodiments, the magnesium alloy component has a tensile strength ≥270MPa, a yield strength ≥170MPa, an elongation ≥6%, and a corrosion rate ≤0.5mm / y.

[0069] The magnesium alloy components provided in this application have good tensile strength, yield strength and elongation, and excellent corrosion resistance. They can replace aluminum alloy components and help achieve lightweighting.

[0070] According to a fourth aspect of this application, a method for preparing a magnesium alloy component is also provided, such as... Figure 2 As shown, it includes:

[0071] Step 210: The magnesium alloy is subjected to plastic deformation treatment and then processed into magnesium alloy particles;

[0072] Step 220: Heat the magnesium alloy particles to obtain a semi-solid magnesium alloy slurry;

[0073] Step 230: Inject the magnesium alloy semi-solid slurry into shape to obtain a magnesium alloy component.

[0074] Plastic deformation treatment can refine the grain size of magnesium alloy gears, thereby achieving homogenization of microstructure and optimization of mechanical properties. The resulting magnesium alloy particles can have a diameter of 0.5cm-2cm. This particle size helps to shorten heating time and improve uniformity.

[0075] Magnesium alloy particles are heated to obtain a semi-solid magnesium alloy slurry. Compared to liquid casting, semi-solid forming requires a lower temperature, reducing energy consumption and production costs. Furthermore, the lower fluidity of the semi-solid slurry minimizes wear on the mold. In addition, the uniform distribution of solid components in the semi-solid slurry reduces defects such as porosity and shrinkage cavities.

[0076] Injection molding is a simple and efficient process. During the injection and propulsion process, the high shear rate and strength ensure uniform and fine grain spheroidization in the semi-solid slurry, thereby improving the microstructure of the magnesium alloy and resulting in magnesium alloy components with high mechanical properties. Furthermore, magnesium alloy components produced by injection molding have precise dimensions and small tolerances, reducing the amount of subsequent processing, increasing production efficiency, and lowering production costs.

[0077] In some embodiments, the magnesium alloy is subjected to plastic deformation treatment, including:

[0078] Magnesium alloys are deformed using one of the processes of forging, rolling, or extrusion to achieve an average grain size of ≤5μm.

[0079] Forging, rolling, and extrusion all achieve plastic deformation, which refines the grain size in magnesium alloys, resulting in an average grain size below 5 μm. When the average grain size of magnesium alloys is within this range, they exhibit excellent mechanical properties, thermal stability, and corrosion resistance, thereby improving the overall performance of magnesium alloy components.

[0080] In some embodiments, the magnesium alloy is deformed using one of the processes of forging, rolling, and extrusion, including:

[0081] Magnesium alloys are heated to 340℃-350℃ for free forging, which increases the axial plastic deformation of the magnesium alloy to more than 50% and refines the average grain size to less than 5μm.

[0082] Forging refers to the method of applying pressure to magnesium alloy billets using forging machinery to induce plastic deformation. Forging can improve plasticity, toughness, and other mechanical properties. Heating magnesium alloys to 340℃-350℃ allows them to reach a suitable state of plastic deformation, while reducing problems such as oxidation and excessive grain growth. During free forging, the axial plastic deformation of the magnesium alloy can reach more than 50%, ensuring the uniformity of plastic deformation, improving grain refinement, and ultimately refining the average grain size of the magnesium alloy to below 5μm.

[0083] In some embodiments, the magnesium alloy is deformed using one of the processes of forging, rolling, and extrusion, including:

[0084] The magnesium alloy is heated to 360℃-370℃ and rolled to achieve a plastic deformation of more than 70% in the thickness direction and refine the average grain size to below 3μm.

[0085] Rolling is a processing method that applies pressure to a magnesium alloy billet through the gap between a pair of rotating rolls, causing it to undergo plastic deformation and thus changing its shape. Heating the magnesium alloy to 360℃-370℃ facilitates plastic deformation and helps refine the grains. After rolling, the amount of plastic deformation in the thickness direction of the magnesium alloy reaches more than 70%, thereby making the plastic deformation of the magnesium alloy uniform and refining the grains, resulting in an average grain size of less than 3μm.

[0086] In some embodiments, the magnesium alloy is deformed using one of the processes of forging, rolling, and extrusion, including:

[0087] The magnesium alloy is heated to 340℃-350℃ and extruded in three passes to achieve a radial plastic deformation of more than 70% and refine the average grain size to below 2μm.

[0088] Extrusion is a method of applying pressure to magnesium alloy billets using a die to induce directional plastic deformation. By heating the magnesium alloy to 340℃-350℃, plastic deformation can occur, refining the grain size. Through three extrusion passes, the radial plastic deformation of the magnesium alloy reaches over 70%, ensuring uniform plastic deformation and improving grain refinement, thereby reducing the average grain size of the magnesium alloy to below 2μm.

[0089] In some embodiments, heating the magnesium alloy particles includes:

[0090] Magnesium alloy particles are drawn into the screw slurry barrel under vacuum and then heated at a temperature of 580℃-650℃.

[0091] By operating in a vacuum environment, oxidation and contamination of magnesium alloys during heating can be reduced. Setting the heating temperature to 580℃-650℃ allows the magnesium alloy to melt and mix uniformly. The screw slurry barrel mixes and homogenizes the magnesium alloy through a rotating screw, forming a semi-solid magnesium alloy slurry through shear force.

[0092] In some embodiments, injection molding of a magnesium alloy semi-solid slurry includes:

[0093] An injection molding device with a capacity of 1500t-3500t is used to inject magnesium alloy semi-solid slurry into a mold for molding under the conditions of injection volume of 3kg-25kg and injection speed of 2m / s-5m / s; wherein the mold is preheated to 200℃-320℃.

[0094] By adopting the above-mentioned injection molding setup, the efficiency and quality of injection molding can be guaranteed. Preheating the mold to the range of 200℃-320℃ can maintain the fluidity of the magnesium alloy semi-solid slurry in the mold, prolong the solidification time, and thus improve the dimensional accuracy and surface finish of the magnesium alloy components.

[0095] In some embodiments, after injection molding the magnesium alloy semi-solid slurry, the method further includes:

[0096] The formed castings are cleaned, surface treated and machined.

[0097] Cleaning removes defects such as risers, burrs, and surface flash. Surface treatment further ensures performance. Machining allows for the formation of specific shapes.

[0098] Surface treatment can include passivation and powder coating. Passivation involves forming a dense passivation film on the magnesium alloy surface using chemical or electrochemical methods, thereby improving its corrosion resistance and surface properties. Powder coating is a surface treatment technology that involves uniformly spraying powder coating onto the surface of magnesium alloy components and then curing it into a film through high-temperature baking, which can further improve the surface properties of magnesium alloy components.

[0099] Machining can shape magnesium alloys into specific shapes and create suitable holes, making them suitable for electric drive housings, control boxes, or battery pack housings.

[0100] According to a fifth aspect of this application, a vehicle is also provided, comprising the magnesium alloy component as described above, and / or a magnesium alloy component prepared by the method described above. The vehicle provided in this application's embodiments possesses all the beneficial effects of the magnesium alloy component as described above, which will not be repeated here.

[0101] The embodiments of this application are further illustrated below with reference to specific examples. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of this application. Experimental methods in the following embodiments that do not specify specific conditions are generally performed according to the conditions recommended by the manufacturer.

[0102] Example 1

[0103] In this embodiment, the magnesium alloy comprises the following components by mass percentage: 8.9% Al, 0.5% Zn, 0.3% Gd, 0.1% Y, and the balance being Mg.

[0104] (1) According to the composition ratio of magnesium alloy, a mixture is prepared by using pure magnesium ingots, pure aluminum ingots, pure zinc blocks, pure gadolinium blocks and pure yttrium blocks;

[0105] (2) First, add pure magnesium ingots and pure aluminum ingots into the smelting furnace and smelt them at 670°C to obtain the first molten metal. Then, add pure zinc blocks, pure gadolinium blocks and pure yttrium blocks and refine them at 690°C to obtain the molten liquid.

[0106] (3) The molten liquid is poured into the first mold to obtain magnesium alloy billet;

[0107] (4) The magnesium alloy is heated to 340°C and extruded three times to achieve a radial plastic deformation of more than 70% and a grain size of less than 2μm. Then, it is machined into magnesium alloy particles with a length of about 1cm by planing.

[0108] (5) Magnesium alloy particles are drawn into a screw slurry cylinder under vacuum and heated at 610°C and 30r / min to obtain a semi-solid magnesium alloy slurry.

[0109] (6) Using a 3200t injection molding device, under the conditions of injection volume of 10kg-15kg and injection speed of 5m / s, magnesium alloy semi-solid slurry is injected into the second mold to obtain magnesium alloy components; wherein, the second mold is preheated to 200℃.

[0110] (7) The gating system, risers, burrs and surface flash of the magnesium alloy components are cleaned, and then passivation and powder spraying are performed. The assembly end face is machined and bolt positioning holes are machined to obtain the motor housing.

[0111] Example 2

[0112] In this embodiment, the magnesium alloy comprises the following components by mass percentage: 9.4% Al, 1.4% Zn, 0.3% Gd, 0.1% Y, and the balance being Mg.

[0113] (1) According to the composition ratio of magnesium alloy, a mixture is prepared by using pure magnesium ingots, pure aluminum ingots, pure zinc blocks, pure gadolinium blocks and pure yttrium blocks;

[0114] (2) First, add pure magnesium ingots and pure aluminum ingots into the smelting furnace and smelt them at 670°C to obtain the first molten metal. Then, add pure zinc blocks, pure gadolinium blocks and pure yttrium blocks and refine them at 690°C to obtain the molten liquid.

[0115] (3) The molten liquid is poured into the first mold to obtain magnesium alloy billet;

[0116] (4) The magnesium alloy is heated to 340°C and extruded three times to achieve a radial plastic deformation of more than 70% and a grain size of less than 2μm. Then, it is machined into magnesium alloy particles with a length of about 1cm by planing.

[0117] (5) Magnesium alloy particles are drawn into a screw slurry cylinder under vacuum and heated at 610°C and 30r / min to obtain a semi-solid magnesium alloy slurry.

[0118] (6) Using a 1600t injection molding device, under the conditions of an injection volume of 5kg-8kg and an injection speed of 4m / s, magnesium alloy semi-solid slurry is injected into the second mold to obtain magnesium alloy components; wherein, the second mold is preheated to 200℃.

[0119] (7) The gating system, risers, burrs and surface flash of the magnesium alloy components are cleaned, and then passivation and powder spraying are performed. The assembly end face is machined and bolt positioning holes are machined to obtain the end cover shell.

[0120] Example 3

[0121] In this embodiment, the magnesium alloy comprises the following components by mass percentage: 9.0% Al, 1.0% Zn, 0.6% Gd, 0.2% Y, and the balance being Mg.

[0122] (1) According to the composition ratio of magnesium alloy, a mixture is prepared by using pure magnesium ingots, pure aluminum ingots, pure zinc blocks, pure gadolinium blocks and pure yttrium blocks;

[0123] (2) First, add pure magnesium ingots and pure aluminum ingots into the smelting furnace and smelt them at 670°C to obtain the first molten metal. Then, add pure zinc blocks, pure gadolinium blocks and pure yttrium blocks and refine them at 690°C to obtain the molten liquid.

[0124] (3) The molten liquid is poured into the first mold to obtain magnesium alloy billet;

[0125] (4) The magnesium alloy is heated to 340°C and extruded three times to achieve a radial plastic deformation of more than 70% and a grain size of less than 2μm. Then, it is machined into magnesium alloy particles with a length of about 1cm by planing.

[0126] (5) Magnesium alloy particles are drawn into a screw slurry cylinder under vacuum and heated at 610°C and 30r / min to obtain a semi-solid magnesium alloy slurry.

[0127] (6) Using a 2000t injection molding device, under the conditions of injection volume of 6kg-10kg and injection speed of 4.5m / s, magnesium alloy semi-solid slurry is injected into the second mold to obtain magnesium alloy components; wherein, the second mold is preheated to 200℃.

[0128] (7) The gating system, risers, burrs and surface flash of the magnesium alloy components are cleaned, and then passivation and powder spraying are performed. The assembly end face is machined and bolt positioning holes are machined to obtain the motor housing.

[0129] Example 4

[0130] In this embodiment, the magnesium alloy comprises the following components by mass percentage: 9.0% Al, 1.0% Zn, 0.9% Gd, 0.3% Y, and the balance being Mg.

[0131] (1) According to the composition ratio of magnesium alloy, a mixture is prepared by using pure magnesium ingots, pure aluminum ingots, pure zinc blocks, pure gadolinium blocks and pure yttrium blocks;

[0132] (2) First, add pure magnesium ingots and pure aluminum ingots into the smelting furnace and smelt them at 670°C to obtain the first molten metal. Then, add pure zinc blocks, pure gadolinium blocks and pure yttrium blocks and refine them at 690°C to obtain the molten liquid.

[0133] (3) The molten liquid is poured into the first mold to obtain magnesium alloy billet;

[0134] (4) The magnesium alloy is heated to 340°C and extruded three times to achieve a radial plastic deformation of more than 70% and a grain size of less than 2μm. Then, it is machined into magnesium alloy particles with a length of about 1cm by planing.

[0135] (5) Magnesium alloy particles are drawn into a screw slurry cylinder under vacuum and heated at 610°C and 30r / min to obtain a semi-solid magnesium alloy slurry.

[0136] (6) Using a 2000t injection molding device, under the conditions of injection volume of 6kg-10kg and injection speed of 4.2m / s, magnesium alloy semi-solid slurry is injected into the second mold to obtain magnesium alloy components; wherein, the second mold is preheated to 200℃.

[0137] (7) The gating system, risers, burrs and surface flash of the magnesium alloy components are cleaned, and then passivation and powder spraying are performed. The assembly end face is machined and bolt positioning holes are machined to obtain the electrical control box.

[0138] Comparative Example 1

[0139] In this comparative example, the magnesium alloy comprises the following components by mass percentage: 9.1% Al, 1.1% Zn, and the balance Mg, with the remaining conditions consistent with those in Example 1.

[0140] Comparative Example 2

[0141] In this comparative example, the magnesium alloy comprises the following components by mass percentage: 9.3% Al, 1.1% Zn, and the balance Mg;

[0142] Change the extrusion process in step (4) to the casting process;

[0143] In step (6), the injection molding method was changed to high pressure casting, the high pressure casting temperature was set to 670°C, and the other conditions remained the same as in Example 2.

[0144] Comparative Example 3

[0145] In this comparative example, the magnesium alloy comprises the following components by mass percentage: 8.9% Al, 0.8% Zn, and the balance Mg;

[0146] Change the extrusion process in step (4) to the casting process;

[0147] In step (6), the injection molding method was changed to high pressure casting, the high pressure casting temperature was set to 680°C, and the other conditions remained the same as in Example 3.

[0148] Comparative Example 4

[0149] In this comparative example, the magnesium alloy comprises the following components by mass percentage: 9.0% Al, 1.0% Zn, 1.0% Gd, 0.2% Y, with the balance being Mg, and the remaining conditions are consistent with those in Example 3.

[0150] The mechanical properties and corrosion resistance of the magnesium alloy components in Examples 1-4 and Comparative Examples 1-4 were tested. The mechanical property tests were conducted according to the methods specified in GB / T 228.1-2021, and the corrosion resistance tests were conducted according to the methods specified in GB / T 10125-2021. The results are shown in Table 1.

[0151] Table 1 Comparison of performance tests of magnesium alloy components in different embodiments and comparative examples.

[0152]

[0153] As can be seen from Table 1, the mechanical properties and corrosion resistance of the magnesium alloy components in Examples 1-4 of this application are superior to those in Prior Art Documents 1-4. This is mainly because the embodiments of this application use an improved magnesium alloy composition formula, which significantly improves corrosion resistance while ensuring mechanical properties.

[0154] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0155] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0156] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0157] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A magnesium alloy, characterized in that, It includes the following components by mass percentage: 8.9%-9.4% aluminum, 0.5%-1.4% zinc, 0.1%-1.0% gadolinium, 0.1%-1.0% yttrium, and the balance being magnesium.

2. The magnesium alloy according to claim 1, characterized in that, The mass ratio of gadolinium to yttrium is (2-4):

1.

3. The magnesium alloy according to claim 2, characterized in that, The mass ratio of gadolinium to yttrium is (2.8-3.2):

1.

4. A method for preparing a magnesium alloy, used to prepare the magnesium alloy as described in any one of claims 1-3, characterized in that, include: According to the composition ratio of magnesium alloy, a mixture containing magnesium, aluminum, zinc, gadolinium and yttrium is prepared; The mixture is smelted to obtain a molten liquid; The molten liquid is cast into a shape to obtain a magnesium alloy.

5. The method for preparing the magnesium alloy according to claim 4, characterized in that, The preparation of a mixture containing magnesium, aluminum, zinc, gadolinium, and yttrium according to the component ratio of the magnesium alloy includes: The mixture is prepared using pure magnesium, pure aluminum, pure zinc, pure gadolinium, and pure yttrium according to the composition ratio of the magnesium alloy.

6. The method for preparing magnesium alloy according to claim 5, characterized in that, The process of melting the mixture to obtain a molten liquid includes: First, the pure magnesium and the pure aluminum are heated to 660℃-680℃ and melted to obtain a first molten metal. The pure zinc, pure gadolinium, and pure yttrium are added to the first molten metal, and the mixture is refined at 680℃-700℃ to obtain the molten liquid.

7. A magnesium alloy component, characterized in that, It is prepared using the magnesium alloy as described in any one of claims 1-3; And / or, the magnesium alloy is prepared by the method for preparing magnesium alloy as described in any one of claims 4-6.

8. The magnesium alloy component according to claim 7, characterized in that, The magnesium alloy component includes at least one of an electric drive housing, an electric control box, and a battery pack housing.

9. A method for preparing a magnesium alloy component, used to prepare the magnesium alloy component as described in any one of claims 7-8, characterized in that, include: Magnesium alloys are subjected to plastic deformation treatment and then processed into magnesium alloy particles; The magnesium alloy particles are heated to obtain a magnesium alloy semi-solid slurry; The magnesium alloy semi-solid slurry is injection molded to obtain a magnesium alloy component.

10. The method for preparing magnesium alloy components according to claim 9, characterized in that, The process of plastic deformation treatment of the magnesium alloy includes: The magnesium alloy is deformed using one of the processes of forging, rolling, and extrusion, so that the average grain size of the magnesium alloy is ≤5μm.

11. The method for preparing magnesium alloy components according to claim 10, characterized in that, The deformation treatment of the magnesium alloy using one of the processes of forging, rolling, and extrusion includes: The magnesium alloy is heated to 340℃-350℃ for free forging, so that the axial plastic deformation of the magnesium alloy reaches more than 50% and the average grain size is refined to less than 5μm.

12. The method for preparing magnesium alloy components according to claim 10, characterized in that, The deformation treatment of the magnesium alloy using one of the processes of forging, rolling, and extrusion includes: The magnesium alloy is heated to 360℃-370℃ and rolled to achieve a plastic deformation of more than 70% in the thickness direction and refine the average grain size to less than 3μm.

13. The method for preparing magnesium alloy components according to claim 10, characterized in that, The deformation treatment of the magnesium alloy using one of the processes of forging, rolling, and extrusion includes: The magnesium alloy is heated to 340℃-350℃ and subjected to three extrusions to achieve a radial plastic deformation of more than 70% and refine the average grain size to below 2μm.

14. The method for preparing magnesium alloy components according to claim 9, characterized in that, The heating of the magnesium alloy particles includes: Under vacuum, the magnesium alloy particles are drawn into the screw slurry barrel and then heated at a temperature of 580℃-650℃.

15. The method for preparing magnesium alloy components according to claim 9, characterized in that, The injection molding of the magnesium alloy semi-solid slurry includes: An injection molding device with a capacity of 1500t-3500t is used to inject the magnesium alloy semi-solid slurry into a mold for molding under the conditions of injection volume of 3kg-25kg and injection speed of 2m / s-5m / s; wherein the mold is preheated to 200℃-320℃.

16. The method for preparing magnesium alloy components according to claim 9, characterized in that, After the magnesium alloy semi-solid slurry is injection molded, the process further includes: The formed castings are cleaned, surface treated and machined.

17. A vehicle, characterized in that, Includes magnesium alloy components as described in any one of claims 7-8, and / or magnesium alloy components prepared by the method described in any one of claims 9-16.

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