Wrought magnesium alloy with high strength and high plasticity and preparation method thereof

Abstract

The invention discloses a wrought magnesium alloy with high strength and high plasticity and a preparation method thereof, and belongs to the technical field of magnesium alloys. According to the invention, the wrought magnesium alloy material with high strength and high plasticity is obtained by regulating and controlling the types and contents of alloying elements of the wrought magnesium alloy. Through alloying, hot extrusion and heat treatment, crystal grains and continuous needle-shaped or strip-shaped second phases in a magnesium alloy matrix structure are effectively crushed and refined, so that the crystal grains and the continuous needle-shaped or strip-shaped second phases are dispersed and distributed in the matrix structure, the stress concentration phenomenon generated when the material is subjected to external force is effectively avoided, and the resistance during dislocation slippage movement is improved; in addition, the magnesium alloy matrix structure is more compact through the hot extrusion process, the casting defects such as shrinkage porosity and cracks of the matrix structure are reduced, the uniformity of the matrix structure is further improved by combining heat treatment, and finally the wrought magnesium alloy material with high strength and high plasticity is obtained.

Description

Technical Field

[0001] The present invention belongs to the technical field of magnesium alloys, and in particular relates to a deformed magnesium alloy with high strength and high plasticity and a preparation method thereof. Background Art

[0002] Magnesium alloy is the lightest structural metal in industrial applications. The density of pure magnesium is 1.74 g cm -3 It is 2 / 3 of aluminum and 1 / 4 of steel. It has the advantages of high specific stiffness, good thermal conductivity and electrical conductivity, damping and vibration reduction, electromagnetic shielding, easy processing and forming, and easy recycling. It has increasingly important application value and broad application prospects in the fields of automobiles, 3C products, aerospace, national defense and military industry.

[0003] Deformed magnesium alloy refers to magnesium alloy that can be processed by plastic forming methods such as extrusion, rolling, forging and stamping. However, the crystal structure of magnesium is a close-packed hexagonal structure metal (hcp), which has only three independent basal slip systems at room temperature, which is far less than the number of slip systems in the face-centered cubic (fcc) and body-centered cubic (bcc) structures. After the basal slip is started, other slip systems are difficult to start, resulting in poor plastic deformation ability of magnesium alloy at room temperature and low temperature; and when the material is subjected to external force, dislocations are difficult to move and rearrange quickly to adapt to stress changes, and it is difficult to effectively release stress through slip when subjected to force, resulting in relatively low strength. In addition, the residual stress generated by the deformed magnesium alloy in the subsequent processing process will also weaken the strength of the magnesium alloy. If the residual stress is not effectively eliminated, it may cause premature failure of the material during subsequent use. The low strength and poor plasticity of magnesium alloys have become a bottleneck in the processing and application of deformed magnesium alloys. Improving the room temperature plasticity and strength of deformed magnesium alloys is a technical problem that needs to be solved urgently. Summary of the invention

[0004] In order to solve the above technical problems, the present invention proposes a deformable magnesium alloy having both high strength and high plasticity and a preparation method thereof.

[0005] To achieve the above object, the present invention provides the following technical solutions:

[0006] The present invention provides a deformable magnesium alloy with both high strength and high plasticity. The deformable magnesium alloy with both high strength and high plasticity comprises the following components in percentage by mass: 1.5-2.5% Zn, 0.2-1.0% Re, 0.3-1.2% Mn, 0.01-0.05% Al, impurity elements <0.2%, and the balance Mg; the Re is selected from one or more of La, Ce, Nd, Pr, and Y.

[0007] Preferably, the wrought magnesium alloy having both high strength and high plasticity comprises the following components, in percentage by mass: Zn 1.8-2.4%, Re 0.4-0.8%, Mn 0.5-0.9%, Al 0.02-0.04%, impurity elements <0.2%, and the balance being Mg.

[0008] The present invention also provides a method for preparing the deformed magnesium alloy with both high strength and high plasticity as described in the above technical solution, comprising the following steps: weighing raw materials according to mass percentage, and then preheating, melting and casting the raw materials to obtain a magnesium alloy casting rod; sequentially homogenizing, hot extruding and heat treating the magnesium alloy casting rod to obtain the deformed magnesium alloy with both high strength and high plasticity;

[0009] The heat treatment temperature is 300-330° C., and the heat preservation time is 2.5-5 hours.

[0010] Preferably, the raw materials include magnesium ingots, zinc ingots, magnesium-rare earth master alloys, anhydrous manganese chloride and aluminum ingots.

[0011] Preferably, the preheating temperature is 100±5° C., and the preheating time is 1.5 to 2 hours.

[0012] Preferably, the smelting includes melting and refining steps.

[0013] Preferably, the melting temperature is 710-740° C., and the melting atmosphere is a mixed gas of SF6 and CO2.

[0014] Preferably, the refining temperature is 710-740° C., and the refining time is 15-30 min.

[0015] Preferably, the temperature of the homogenization treatment is 300±2°C, and the time of the homogenization treatment is 12 hours.

[0016] Preferably, the casting temperature of the hot extrusion is 295-325°C, the temperature of the mold used for hot extrusion is 430±5°C, the extrusion ratio of hot extrusion is 13:1, the pressure of hot extrusion is 15-20MPa, and the extrusion speed of hot extrusion is 0.3-0.5mm / s.

[0017] Technical principle:

[0018] The present invention obtains a deformed magnesium alloy material with both high strength and high plasticity by regulating the type and content of alloying elements of the deformed magnesium alloy. The present invention also effectively breaks and refines the grains and continuous needle-shaped or strip-shaped second phase in the magnesium alloy matrix structure through alloying, hot extrusion and heat treatment, so that it is dispersed in the matrix structure, effectively avoiding the stress concentration phenomenon generated by the material when subjected to external force, and improving the resistance during dislocation slip movement; in addition, the hot extrusion process also makes the magnesium alloy matrix structure more compact, reduces casting defects such as shrinkage and cracks in the matrix structure, and further improves the uniformity of the matrix structure in combination with heat treatment, and finally obtains a deformed magnesium alloy material with both high strength and high plasticity, which solves the problems of low strength and poor plasticity existing in the current magnesium alloy materials, and has certain significance for broadening the application of magnesium alloy materials.

[0019] Compared with the prior art, the present invention has the following advantages and technical effects:

[0020] The deformed magnesium alloy with high strength and high plasticity prepared by the preparation method provided by the present invention has high strength and plasticity, and its tensile strength can reach 258.64MPa, its yield strength can reach 198.7MPa, and its elongation can reach 29.3%. The preparation method is simple, the process stability is good, and industrial production can be realized. It has broad application prospects in aerospace, military industry, 3C and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings:

[0022] Figure 1 This is a process flow chart of a method for preparing a deformed magnesium alloy having both high strength and high plasticity in Examples 1-3 of the present invention;

[0023] Figure 2 The metallographic structure diagrams of the magnesium alloy cast rod (ac) obtained in step (1) of Example 2 of the present invention and the deformed magnesium alloy plate (df) obtained in step (4). DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0025] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0026] An embodiment of the present invention provides a deformable magnesium alloy with high strength and high plasticity. The deformable magnesium alloy with high strength and high plasticity includes the following components, in mass percentage: Zn 1.5-2.5%, Re 0.2-1.0%, Mn 0.3-1.2%, Al 0.01-0.05%, impurity elements <0.2%, and the balance is Mg; the Re is selected from one or more of La, Ce, Nd, Pr, and Y.

[0027] In a preferred embodiment, the deformed magnesium alloy with both high strength and high plasticity includes 1.5-2.5% Zn, more preferably 1.8-2.4% Zn, in terms of mass percentage. The addition of Zn in the present invention can refine the grains and solid solution strengthen the magnesium alloy, thereby improving the strength and toughness of the alloy. Too little Zn will result in an insignificant grain refinement effect, and its strengthening and toughening effects cannot be fully exerted, and the strength and toughness of the alloy will be limited. Too much Zn may form coarse intermetallic compounds, which will become stress concentration points in the alloy matrix, thereby reducing the toughness of the alloy.

[0028] In a preferred embodiment, the deformable magnesium alloy with both high strength and high plasticity includes Re 0.2-1.0%, more preferably 0.4-0.8%, in terms of mass percentage. The addition of rare earth elements in the present invention can play a role in solid solution strengthening, improve the strength of the magnesium alloy, and can also refine the grains and weaken the texture of the magnesium alloy, thereby improving its plastic deformation ability. Too little rare earth element usage will weaken the grain refinement and solid solution strengthening effects on the magnesium alloy, and cannot fully change the crystal growth direction and preferred orientation of the magnesium alloy, and cannot well weaken the texture, so that the plastic deformation ability of the magnesium alloy is not significantly improved. Excessive use of rare earth elements will increase the alloy cost on the one hand, and easily form coarse intermetallic compounds, reducing the strength and plasticity of the alloy.

[0029] In a preferred embodiment, the deformable magnesium alloy with both high strength and high plasticity includes 0.3-1.2% Mn, and more preferably 0.5-0.9% Mn in percentage by mass. The Mn element in the present invention can refine the grains, and can also synergize with elements such as Al and Zn to increase the strength and toughness of the alloy. The Mn element can form complex compounds with Al and Zn elements, and these compounds can be dispersed in the alloy matrix to play a role in dispersion strengthening. When the Mn element is too little, the strength and toughness of the alloy cannot be effectively increased. When the Mn element is used in excessive amounts, coarse Mn-containing compounds may be formed, which then aggregate in the alloy matrix, causing stress concentration and reducing the toughness of the alloy.

[0030] In a preferred embodiment, the deformable magnesium alloy with both high strength and high plasticity includes 0.01-0.05% Al, more preferably 0.02-0.04% Al, by mass percentage. The addition of Al in the present invention can promote the refinement of magnesium alloy grains and improve the plasticity of the alloy. Too little Al will have limited strengthening effect on magnesium alloy, and too much Al will reduce the ductility and plastic deformation ability of magnesium alloy.

[0031] In a preferred embodiment, the wrought magnesium alloy having both high strength and high plasticity further includes a balance of Mg in terms of mass percentage.

[0032] The present invention also provides a method for preparing the deformed magnesium alloy with both high strength and high plasticity as described in the above technical solution, comprising the following steps: weighing raw materials according to mass percentage, and then preheating, melting and casting the raw materials to obtain a magnesium alloy casting rod; sequentially homogenizing, hot extruding and heat treating the magnesium alloy casting rod to obtain the deformed magnesium alloy with both high strength and high plasticity;

[0033] The heat treatment temperature is 300-330° C., and the heat preservation time is 2.5-5 hours.

[0034] In a preferred embodiment, the raw materials include magnesium ingots, zinc ingots, magnesium-rare earth master alloys, anhydrous manganese chloride and aluminum ingots; the magnesium-rare earth master alloy includes one or more of magnesium-lanthanum master alloys, magnesium-cerium master alloys, magnesium-neodymium master alloys, magnesium-praseodymium master alloys and magnesium-yttrium master alloys.

[0035] In a preferred embodiment, the preheating temperature is 100±5°C and the preheating time is 1.5 to 2 hours. The present invention removes moisture adsorbed by the raw material by preheating.

[0036] In a preferred embodiment, the smelting includes melting and refining steps.

[0037] In a preferred embodiment, the melting temperature is 710-740°C, the melting atmosphere is a mixed gas of SF6 and CO2, and the volume ratio of SF6 and CO2 is 0.5:99.5; the covering agent used for the melting is selected from RJ-2 flux; the amount of the covering agent is 0.05-0.10wt% of the mass of the deformed magnesium alloy, and the melt is covered and protected by adding the covering agent to avoid ignition of the magnesium alloy.

[0038] In a preferred embodiment, the refining temperature is 710-740°C, the refining time is 15-30 minutes; the refining agent used in the refining is selected from RJ-5 flux; the amount of the refining agent is 3.0-3.5wt% of the mass of the deformed magnesium alloy.

[0039] In a preferred embodiment, the casting is performed using a conventional casting process.

[0040] In a preferred embodiment, the temperature of the homogenization treatment is 300±2° C., and the homogenization treatment time is 12 hours. The present invention performs homogenization treatment under the above conditions, which is conducive to obtaining a more dense and uniform magnesium alloy matrix structure.

[0041] In a preferred embodiment, the cooling method of the homogenization treatment is air cooling.

[0042] In a preferred embodiment, the temperature of the hot extruded casting rod is 295-325°C, the temperature of the die used for hot extrusion is 430±5°C, the extrusion ratio of hot extrusion is 13:1, the pressure of hot extrusion is 15-20MPa, and the extrusion speed of hot extrusion is 0.3-0.5mm / s. The present invention performs hot extrusion under the above conditions, which is conducive to obtaining a denser magnesium alloy matrix structure and reducing casting defects such as shrinkage and cracks in the matrix structure.

[0043] In a preferred embodiment, the cooling method of the hot extrusion is air cooling.

[0044] In a preferred embodiment, the heat treatment temperature is 300-330°C, and the holding time is 2.5-5h. The present invention performs heat treatment under the above conditions, which is conducive to obtaining a matrix structure with good uniformity; too high a temperature or too long a time for heat treatment will lead to grain growth, overburning, excessive dissolution of the second phase and abnormal precipitation of the magnesium alloy, while too low a temperature or too short a time will lead to defects such as insufficient dissolution of the second phase, poor solid solution strengthening effect, and increased tissue inhomogeneity, which deteriorates the microstructure and mechanical properties of the magnesium alloy.

[0045] In a preferred embodiment, the cooling method of the heat treatment is water cooling.

[0046] The present invention also provides a deformable magnesium alloy having both high strength and high plasticity, which is prepared by the preparation method described in the above technical solution.

[0047] The room temperature in the embodiments of the present invention refers to "25±2°C".

[0048] In the following examples, the purity of the magnesium ingot is 99.99%; the purity of the zinc ingot is 99.99%; the magnesium-rare earth master alloy is Mg-30Re master alloy; the purity of the anhydrous manganese chloride is 99%; the purity of the aluminum ingot is 99.99%;

[0049] The alloying efficiency of magnesium ingots is about 100%, the alloying efficiency of zinc ingots is about 100%, the alloying efficiency of magnesium-rare earth master alloys is about 100%, the alloying efficiency of anhydrous manganese chloride is about 75%, and the alloying efficiency of aluminum ingots is about 100%.

[0050] Unless otherwise specified, the raw materials in the examples of the present invention were purchased from commercial sources.

[0051] Example 1

[0052] A wrought magnesium alloy with high strength and high plasticity consists of the following components by mass percentage: Mg 96.26%, Zn 2.30%, Ce 0.55%, Nd 0.12%, Y 0.05%, Mn 0.69% and Al 0.03%.

[0053] Preparation method of deformed magnesium alloy with high strength and high plasticity, the process flow is shown in Figure 1 , the specific steps are as follows:

[0054] (1) Preheat and dry a magnesium ingot, a zinc ingot, a magnesium-cerium master alloy, a magnesium-neodymium master alloy, a magnesium-yttrium master alloy, anhydrous manganese chloride, and an aluminum ingot at 100° C. for 1.5 h to remove moisture adsorbed by the raw materials; and place the preheated raw materials in a protective atmosphere (a mixed gas of SF6 and CO2, with a volume ratio of SF6 and CO2 of 0.5:99.5) according to the ratio of Mg:Zn:Ce:Nd:Y:Mn:Al=96.26:2.30:0.55:0.12:0.05:0.6 9:0.03 (mass percentage) and then melted. During the melting process, 0.05wt% of RJ-2 flux by weight of the deformed magnesium alloy was sprinkled to cover and protect the melt. The melting temperature was 740°C. After the raw materials were completely melted, 3.0wt% of RJ-5 flux by weight of the deformed magnesium alloy was added as a refining agent. The melt was refined by keeping it warm for 15 minutes. After the insulation was completed, the slag in the melt was skimmed off, and then casting was performed to obtain Mg-Zn-Re-Mn-Al magnesium alloy cast rods.

[0055] (2) The Mg-Zn-Re-Mn-Al magnesium alloy cast rod obtained in step (1) is placed in a resistance furnace and heated to 300±2° C., kept warm for 12 hours, and then air-cooled to room temperature after the insulation is completed to obtain a homogeneous Mg-Zn-Re-Mn-Al magnesium alloy cast rod.

[0056] (3) The homogeneous Mg-Zn-Re-Mn-Al magnesium alloy cast rod obtained in step (2) is placed in a resistance furnace and heated to 300±5°C, then placed in a mold preheated to 430±5°C for hot extrusion (extrusion ratio of 13:1, pressure of 15 MPa, extrusion speed of 0.3 mm / s), and then air-cooled to room temperature to obtain a Mg-Zn-Re-Mn-Al magnesium alloy sheet.

[0057] (4) The Mg-Zn-Re-Mn-Al magnesium alloy plate obtained in step (3) is placed in a heat treatment furnace for heat treatment at a temperature of (300±1°C)×5h. After the heat preservation is completed, the plate is cooled to room temperature with water to obtain a Mg-Zn-Re-Mn-Al deformable magnesium alloy plate with high strength and high plasticity.

[0058] Example 2

[0059] A wrought magnesium alloy having high strength and high plasticity consists of the following components by mass percentage: Mg 96.05%, Zn 2.40%, Ce 0.56%, La 0.20%, Y 0.07%, Mn 0.70% and Al 0.02%.

[0060] Preparation method of deformed magnesium alloy with high strength and high plasticity, the process flow is shown in Figure 1 , the specific steps are as follows:

[0061] (1) Preheating and drying a magnesium ingot, a zinc ingot, a magnesium-cerium master alloy, a magnesium-lanthanum master alloy, a magnesium-neodymium master alloy, anhydrous manganese chloride, and an aluminum ingot at 100° C. for 2 h to remove moisture adsorbed by the raw materials; and mixing the preheated raw materials in a protective atmosphere (a mixed gas of SF6 and CO2, with a volume ratio of SF6 and CO2 of 0.5:99.5) according to the ratio of Mg:Zn:Ce:La:Nd:Mn:Al=96.15:2.40:0.56:0.10:0.07:0.70 The raw materials are mixed in a ratio of ∶0.02 (mass percentage) and then melted. During the melting process, 0.06wt% of RJ-2 flux by weight of the deformed magnesium alloy is sprinkled to cover and protect the melt. The melting temperature is 735°C. After the raw materials are completely melted, 3.1wt% of RJ-5 flux by weight of the deformed magnesium alloy is added as a refining agent. The melt is refined by keeping the temperature for 20 minutes. After the insulation is completed, the slag in the melt is skimmed off, and then casting is performed to obtain Mg-Zn-Re-Mn-Al magnesium alloy cast rods.

[0062] (2) The Mg-Zn-Re-Mn-Al magnesium alloy cast rod obtained in step (1) is placed in a resistance furnace and heated to 300±2° C., kept warm for 12 hours, and then air-cooled to room temperature after the insulation is completed to obtain a homogeneous Mg-Zn-Re-Mn-Al magnesium alloy cast rod.

[0063] (3) The homogeneous Mg-Zn-Re-Mn-Al magnesium alloy cast rod obtained in step (2) is placed in a resistance furnace and heated to 315±5°C, then placed in a mold preheated to 430±5°C for hot extrusion (extrusion ratio of 13:1, pressure of 17 MPa, extrusion speed of 0.4 mm / s), and then air-cooled to room temperature to obtain a Mg-Zn-Re-Mn-Al magnesium alloy sheet.

[0064] (4) The Mg-Zn-Re-Mn-Al magnesium alloy plate obtained in step (3) is placed in a heat treatment furnace for heat treatment at a temperature of (320±1°C)×4h. After the heat preservation is completed, the plate is cooled to room temperature with water to obtain a Mg-Zn-Re-Mn-Al deformable magnesium alloy plate with high strength and high plasticity.

[0065] The metallographic structure of the magnesium alloy cast rod obtained in step (1) of Example 2 and the deformed magnesium alloy plate obtained in step (4) were observed. Figure 2 .

[0066] Figure 2 The metallographic structure diagrams of the magnesium alloy cast rod (ac) obtained in step (1) of Example 2 and the deformed magnesium alloy plate (df) obtained in step (4), wherein a is magnified 50 times, b is magnified 100 times, c is magnified 200 times, d is magnified 50 times, e is magnified 100 times, and f is magnified 200 times. Figure 2 It can be seen that magnesium alloys can effectively break up and refine the grains and continuous needle-shaped or strip-shaped second phases in the matrix structure of magnesium alloys through alloying, hot extrusion and heat treatment, so that they are dispersed in the matrix structure, effectively avoiding the stress concentration phenomenon caused by the material when subjected to external force, and increasing the resistance to dislocation slip movement; in addition, the hot extrusion process also makes the matrix structure of magnesium alloys denser, reduces casting defects such as shrinkage and cracks in the matrix structure, and subsequently heat treats the magnesium alloy sheet to further improve the uniformity of the matrix structure and improve its mechanical properties.

[0067] Example 3

[0068] A wrought magnesium alloy with high strength and high plasticity consists of the following components by mass percentage: Mg 96.23%, Zn 2.20%, Ce 0.60%, Nd 0.08%, Y 0.05%, Mn 0.80% and Al 0.04%.

[0069] Preparation method of deformed magnesium alloy with high strength and high plasticity, the process flow is shown in Figure 1 , the specific steps are as follows:

[0070] (1) Preheating and drying a magnesium ingot, a zinc ingot, a magnesium-cerium master alloy, a magnesium-yttrium master alloy, a magnesium-praseodymium master alloy, anhydrous manganese chloride, and an aluminum ingot at 100° C. for 1.5 h to remove moisture adsorbed by the raw materials; and mixing the preheated raw materials in a protective atmosphere (a mixed gas of SF6 and CO2, with a volume ratio of SF6 and CO2 of 0.5:99.5) according to the ratio of Mg:Zn:Ce:Y:Pr:Mn:Al=96.23:2.20:0.60:0.08:0.05: The raw materials are mixed in a ratio of 0.80:0.04 and then melted. During the melting process, 0.07wt% of RJ-2 flux by weight of the deformed magnesium alloy is sprinkled to cover and protect the melt. The melting temperature is 730°C. After the raw materials are completely melted, 3.2wt% of RJ-5 flux by weight of the deformed magnesium alloy is added as a refining agent. The melt is refined by keeping the temperature for 30 minutes. After the insulation is completed, the slag in the melt is skimmed off, and then casting is performed to obtain Mg-Zn-Re-Mn-Al magnesium alloy cast rods.

[0071] (2) The Mg-Zn-Re-Mn-Al magnesium alloy cast rod obtained in step (1) is placed in a resistance furnace and heated to 300±2° C., kept warm for 12 hours, and then air-cooled to room temperature after the insulation is completed to obtain a homogeneous Mg-Zn-Re-Mn-Al magnesium alloy cast rod.

[0072] (3) The homogeneous Mg-Zn-Re-Mn-Al magnesium alloy cast rod obtained in step (2) is placed in a resistance furnace and heated to 320±5°C, then placed in a mold preheated to 430±5°C for hot extrusion (extrusion ratio of 13:1, pressure of 20 MPa, extrusion speed of 0.5 mm / s), and then air-cooled to room temperature to obtain a Mg-Zn-Re-Mn-Al magnesium alloy sheet.

[0073] (4) The Mg-Zn-Re-Mn-Al magnesium alloy plate obtained in step (3) is placed in a heat treatment furnace for heat treatment at a temperature of (330±1°C)×2.5h. After the heat preservation is completed, the plate is cooled to room temperature with water to obtain a Mg-Zn-Re-Mn-Al deformable magnesium alloy plate with high strength and high plasticity.

[0074] Comparative Example 1

[0075] The difference from Example 2 is that steps (2) to (4) are omitted, that is, homogenization, hot extrusion and heat treatment are not performed.

[0076] Comparative Example 2

[0077] The difference from Example 2 is that step (4) is omitted, that is, no heat treatment is performed.

[0078] Comparative Example 3

[0079] Commercial AZ31B magnesium alloy extruded sheet that complies with the national standard "GB / T 5153-2016 Deformed magnesium and magnesium alloy grades and chemical composition".

[0080] Comparative Example 4

[0081] A wrought magnesium alloy, comprising, by mass percentage, the following components: Mg 96.15%, Zn 1.3%, Ce 0.1%, Nd 0.02%, Mn 0.3% and Al 0.01%;

[0082] The preparation method of the deformed magnesium alloy is the same as that of Example 2.

[0083] Comparative Example 5

[0084] A wrought magnesium alloy, comprising, by mass percentage, the following components: Mg 96.15%, Zn 4.1%, La 1.2%, Ce 2.3%, Mn 1.3% and Al 0.5%;

[0085] The preparation method of the deformed magnesium alloy is the same as that of Example 2.

[0086] Comparative Example 6

[0087] The difference from Example 2 is that in step (4), the heat treatment process is (280±1°C)×4h.

[0088] Comparative Example 7

[0089] The difference from Example 2 is that in step (4), the heat treatment process is (350±1°C)×4h.

[0090] Comparative Example 8

[0091] The difference from Example 2 is that in step (4), the heat treatment process is (320±1°C)×1.5h.

[0092] Comparative Example 9

[0093] The difference from Example 2 is that in step (4), the heat treatment process is (320±1°C)×6h.

[0094] The mechanical properties of the magnesium alloy plates in Examples 1-3 and Comparative Examples 1-9 were tested in accordance with the standard "GB / T 16865-2023 Specimens and methods for tensile testing of deformed aluminum, magnesium and their alloy products". The results are shown in Table 1.

[0095] Table 1 Mechanical properties of magnesium alloy sheets in Examples 1-3 and Comparative Examples 1-9

[0096]

[0097]

[0098] It can be seen from Table 1 that the tensile strength of the high-strength and high-plasticity deformable magnesium alloy prepared in the embodiment of the present invention can reach 258.64 MPa, the yield strength can reach 198.7 MPa, and the elongation can reach 29.3%.

[0099] The above are only preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by a person skilled in the art within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A deformable magnesium alloy having both high strength and high plasticity, characterized in that: The deformable magnesium alloy with high strength and high plasticity includes the following components in percentage by mass: Zn 1.5-2.5%, Re 0.2-1.0%, Mn 0.3-1.2%, Al 0.01-0.05%, impurity elements <0.2%, and the balance is Mg; the Re is selected from one or more of La, Ce, Nd, Pr, and Y.

2. The wrought magnesium alloy having both high strength and high plasticity according to claim 1, characterized in that: The deformable magnesium alloy with both high strength and high plasticity comprises the following components in percentage by mass: Zn 1.8-2.4%, Re 0.4-0.8%, Mn 0.5-0.9%, Al 0.02-0.04%, impurity elements <0.2%, and the balance Mg.

3. A method for preparing a deformed magnesium alloy having both high strength and high plasticity according to any one of claims 1 to 2, characterized in that: The method comprises the following steps: weighing raw materials according to mass percentage, and then preheating, melting and casting the raw materials to obtain magnesium alloy casting rods; sequentially homogenizing, hot extruding and heat treating the magnesium alloy casting rods to obtain the deformed magnesium alloy with high strength and high plasticity; The heat treatment temperature is 300-330° C., and the heat preservation time is 2.5-5 hours.

4. The method for preparing a deformed magnesium alloy having both high strength and high plasticity according to claim 3, characterized in that: The raw materials include magnesium ingots, zinc ingots, magnesium-rare earth master alloys, anhydrous manganese chloride and aluminum ingots.

5. The method for preparing a deformed magnesium alloy having both high strength and high plasticity according to claim 3, characterized in that: The preheating temperature is 100±5° C., and the preheating time is 1.5 to 2 hours.

6. The method for preparing a wrought magnesium alloy having both high strength and high plasticity according to claim 3, characterized in that: The smelting includes melting and refining steps.

7. The method for preparing a deformed magnesium alloy having both high strength and high plasticity according to claim 6, characterized in that: The melting temperature is 710-740° C., and the melting atmosphere is a mixed gas of SF6 and CO2.

8. The method for preparing a wrought magnesium alloy having both high strength and high plasticity according to claim 6, characterized in that: The refining temperature is 710-740° C., and the refining time is 15-30 minutes.

9. The method for preparing a wrought magnesium alloy having both high strength and high plasticity according to claim 3, characterized in that: The temperature of the homogenization treatment is 300±2°C, and the time of the homogenization treatment is 12h.

10. The method for preparing a wrought magnesium alloy having both high strength and high plasticity according to claim 3, characterized in that: The temperature of the hot extruded casting rod is 295-325° C., the temperature of the mold used for hot extrusion is 430±5° C., the extrusion ratio of hot extrusion is 13:1, the pressure of hot extrusion is 15-20 MPa, and the extrusion speed of hot extrusion is 0.3-0.5 mm / s.

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