An ultra-high-strength corrosion-resistant low-alloyed Mg-Al-Mn-Y-Zr alloy and a preparation method thereof

Abstract

The application provides a kind of superhigh strength corrosion-resistant low alloyed Mg-Al-Mn-Y-Zr alloy and its preparation method, belongs to magnesium alloy technical field.The application uses magnesium, aluminum, magnesium manganese intermediate alloy, magnesium yttrium intermediate alloy, magnesium zirconium intermediate alloy as raw material, is prepared into high-strength corrosion-resistant magnesium alloy after melting casting, solid solution treatment, low-temperature extrusion, the components of the alloy are Al:0.1%;Mn:0.1%;Y:0.1%;Zr:0.1%, the rest is magnesium and unavoidable impurities.The alloy prepared by the application has elongation of 5%, tensile strength of 501.3MPa, yield strength of 400.9MPa, corrosion rate in simulated body fluid of 0.07mm / a, and the preparation method has the advantages of low cost, simple process, short process, etc.

Description

Technical Field

[0001] This invention belongs to the field of magnesium alloy technology, specifically relating to an ultra-high strength, corrosion-resistant, low-alloy Mg-Al-Mn-Y-Zr alloy and its preparation method. Background Technology

[0002] Magnesium and magnesium alloys possess high specific strength and specific stiffness, along with excellent machinability, making them promising candidates for applications in aerospace, automotive, and military industries. Furthermore, as functional metals, magnesium alloys exhibit biodegradability, offering significant potential for applications in the biomedical field. However, the relatively low absolute strength and poor corrosion resistance of magnesium alloys limit their application in high-load, corrosive environments. Therefore, it is necessary to develop novel high-strength, corrosion-resistant magnesium alloys to expand their application.

[0003] To improve the corrosion resistance of magnesium alloys, for example, adding trace amounts of rare earth elements to AM60 can significantly enhance corrosion resistance. Several magnesium alloy materials have been developed and industrialized, but their strength is generally below 380 MPa, limiting their application. Improving the strength of magnesium and magnesium alloys has become a bottleneck restricting their widespread use. Designing the microstructure and alloying are among the most effective ways to increase the strength of magnesium alloys. Due to the high solid solubility of rare earth elements in magnesium, they exhibit significant age-hardening characteristics and can form nanoscale second-phase precipitates, thereby increasing alloy strength. Pan Hucheng et al. studied a Mg-13Gd alloy, achieving a tensile strength (UTS) and yield strength (YS) of 493 MPa and 458 MPa, respectively. Liu Ke et al. studied a Mg-8Dy-5Cu-2Sn alloy, which, after homogenization and hot extrusion, achieved a tensile strength of 420 MPa and a yield strength of 390 MPa. Although rare earth magnesium alloys possess excellent high strength, the high price of rare earth elements limits their industrial application.

[0004] Therefore, improving the low-alloying process and related preparation techniques to obtain magnesium alloys with high strength, good plasticity, and excellent intrinsic corrosion resistance is of great significance for expanding the application range of magnesium alloys. Summary of the Invention

[0005] In view of this, the purpose of this invention is to provide an ultra-high strength, corrosion-resistant, low-alloyed Mg-Al-Mn-Y-Zr alloy and its preparation method. The resulting alloy has low preparation cost and high tensile strength, yield strength and corrosion resistance.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] In a first aspect, the present invention provides an ultra-high strength, corrosion-resistant, low-alloy Mg-Al-Mn-Y-Zr alloy, comprising the following components by weight percentage:

[0008] Al: 0.1%; Mn: 0.1%; Y: 0.1%; Zr: 0.1%, with the remainder being magnesium and unavoidable impurities.

[0009] Preferably, the high-strength, corrosion-resistant, low-alloy magnesium-aluminum-manganese-yttrium-zirconium alloy is made from the following parts by weight of metallic raw materials:

[0010] Mg 509.5-514.5 parts, Al 0.5-0.6 parts, magnesium-manganese master alloy 5.5-6.0 parts, magnesium-yttrium master alloy 1.8-2.0 parts, magnesium-zirconium master alloy 1.8-2.0 parts

[0011] The magnesium-manganese master alloy has a magnesium-manganese mass ratio of 9:1;

[0012] The magnesium-yttrium mass ratio of the magnesium-yttrium master alloy is 7:3;

[0013] The magnesium-zirconium mass ratio of the magnesium-zirconium master alloy is 7:3.

[0014] Secondly, the present invention provides a method for preparing the above-mentioned high-strength, corrosion-resistant, low-alloyed magnesium-aluminum-manganese-zirconium alloy, comprising the following steps:

[0015] 1) Remove the oxide layer from the metal raw material and dry it, then weigh the metal raw material according to the stated weight proportions;

[0016] 2) Place Mg metal into the melting furnace under a protective atmosphere, then hold it at the first temperature, then place Al metal into the furnace, then hold it at the second temperature, then place magnesium-manganese master alloy into the furnace, then hold it at the third temperature, then place magnesium-yttrium master alloy into the furnace, then hold it at the fourth temperature, then place magnesium-zirconium master alloy into the furnace, and finally hold it at the fifth temperature to obtain the alloy liquid.

[0017] 3) After the alloy liquid undergoes a first cooling process, a refining agent is added, and the mixture is stirred, kept warm, cooled a second time, and then cast to obtain an ingot.

[0018] 4) The ingot is subjected to solution treatment to obtain a solution-treated ingot;

[0019] 5) After removing the oxide layer from the solution-treated ingot, it is subjected to extrusion treatment to obtain a high-strength, corrosion-resistant, low-alloyed magnesium-aluminum-manganese-yttrium-zirconium alloy.

[0020] Preferably, the protective atmosphere in step 2) is a mixture of SF6 and CO2 in a volume ratio of 40:1.

[0021] Preferably, in step 2), the first temperature is 710-715℃ and the holding time is 25-30 min; the second temperature is 720-725℃ and the holding time is 20-25 min; the third temperature is 720-725℃ and the holding time is 20-25 min; the fourth temperature is 720-725℃ and the holding time is 20-25 min; and the fifth temperature is 750-755℃ and the holding time is 20-25 min.

[0022] In this invention, Mg, Al, Mn, Y, and Zr undergo an alloying reaction throughout the smelting process. The reaction equations are as follows:

[0023] Mg + Al + Mn + Y + Zr → α-Mg + Mg 17 Al 12 ;

[0024] In the formula, α-Mg represents the α-magnesium phase, and Mg... 17 Al 12 It is a magnesium-aluminum phase.

[0025] Preferably, the amount of refining agent used in step 3) is 1-2 wt% of the alloy liquid.

[0026] Preferably, the refining agent in step 3) is composed of the following raw materials by weight percentage: MgCl2 46%, KCl 40%, BaCl2 8%, and CaF2 5%.

[0027] Preferably, in step 3), the first cooling temperature is 740-745℃; the stirring time is 2-5 minutes; the holding temperature is 750-755℃, and the holding time is 20-25 minutes; the second cooling temperature is 710-715℃.

[0028] Preferably, the solution treatment method in step 4) is as follows: first, perform a primary solution treatment, then a secondary solution treatment, and finally perform water quenching.

[0029] The primary solution treatment temperature is 320℃, and the holding time is 1 hour;

[0030] The secondary solution treatment temperature is 500℃, and the holding time is 3 hours. By adopting the above technical solution through a two-stage solution treatment, the difference between the two holding temperatures is reduced, which is beneficial for temperature stability control. On the other hand, the alloy in this design contains a second phase, and this solution treatment method allows as much of the second phase as possible to melt into the magnesium matrix.

[0031] Preferably, the extrusion treatment in step 5) is performed by heating the extrusion die to 225-230°C, placing the sample in the die and keeping it warm for 55-60 minutes, and then extruding at an extrusion temperature of 225°C, an extrusion rate of 0.1 mm / s, and an extrusion ratio of 16:1.

[0032] Preferably, during the preparation process, a protective coating is uniformly applied to the surface of the crucible, crucible tongs, and stirring rod; the protective coating is made by mixing talc powder, water, and water glass in a mass-volume ratio of 80g:250mL:20g.

[0033] It contains at least the following beneficial technical effects:

[0034] This invention uses magnesium, aluminum, magnesium-manganese master alloys, magnesium-yttrium master alloys, and magnesium-zirconium master alloys as raw materials, and prepares high-strength, corrosion-resistant magnesium alloys through melting and casting, solution treatment, and low-temperature extrusion. During hot extrusion, the second phase is broken into fine particles and uniformly distributed in the magnesium matrix, thereby strengthening the matrix and promoting dynamic recrystallization, resulting in a finer microstructure. The heterogeneous structure composed of deformed grains and fine grains provides additional strain hardening capacity, enhancing the tensile strength and yield strength of the magnesium alloy. Furthermore, compared to rare-earth magnesium alloys and complex and expensive large plastic deformation techniques, this invention offers advantages such as low cost, simple process, and short process flow, making it economically viable and possessing significant application potential. Attached Figure Description

[0035] Figure 1 The X-ray diffraction intensity pattern of the magnesium-aluminum-manganese-yttrium-zirconium alloy prepared in Example 1;

[0036] Figure 2 The image shows the electron backscatter diffraction (EBSD) grain boundary pattern of the magnesium-aluminum-manganese-yttrium-zirconium alloy prepared in Example 1.

[0037] Figure 3 The potentiodynamic polarization curve of the magnesium-aluminum-manganese-yttrium-zirconium alloy prepared in Example 1 is shown.

[0038] Figure 4 The tensile properties of the magnesium-aluminum-manganese-yttrium-zirconium alloy prepared in Example 1 are shown in the figure. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0040] The terms “comprising” or “including” in this invention are open-ended descriptions that include the specified ingredients or steps described, as well as other specified ingredients or steps that do not materially affect them.

[0041] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0042] Where specific techniques or conditions are not specified in the examples, they shall be performed in accordance with the techniques or conditions described in the literature in this field, or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased through legitimate channels.

[0043] The protective coating used in the following embodiments of the present invention is a mixture of talc, water, and water glass in a mass-volume ratio of 80g:250mL:20g. Before preparation, the protective coating is uniformly applied to the surfaces of the crucible, crucible tongs, and stirring rod. The magnesium-manganese master alloy used has a magnesium-to-manganese mass ratio of 9:1; the magnesium-yttrium master alloy has a magnesium-to-yttrium mass ratio of 7:3; the magnesium-zirconium master alloy has a magnesium-to-zirconium mass ratio of 7:3; and the purity of each metal raw material used is greater than 99.99%.

[0044] Example 1

[0045] This embodiment provides an ultra-high strength, corrosion-resistant, low-alloyed Mg-Al-Mn-Y-Zr alloy, comprising the following preparation steps:

[0046] 1) Remove the oxide layer from the metal raw materials and dry them. Weigh out 514.5 parts of Mg, 0.55 parts of Al, 5.5 parts of magnesium-manganese master alloy, 1.83 parts of magnesium-yttrium master alloy, and 1.83 parts of magnesium-zirconium master alloy.

[0047] 2) Preheat the crucible to 300℃, place the magnesium metal block in the crucible, and then put them into the resistance furnace together. Introduce a protective gas consisting of a mixture of SF6 and CO2 in a volume ratio of 40:1. When the temperature reaches 710℃, hold for 25 minutes. Then, place the Al metal block in the furnace and raise the furnace temperature to 720℃, hold for 20 minutes. Next, add the magnesium-manganese master alloy to the crucible and raise the furnace temperature to 720℃, hold for 20 minutes. Then, add the magnesium-yttrium master alloy to the crucible and raise the furnace temperature to 720℃, hold for 20 minutes. Finally, add the magnesium-zirconium master alloy to the crucible and raise the furnace temperature to 750℃, hold for 20 minutes. This allows the four alloying elements, Al, Mn, Y, and Zr, to have sufficient time to diffuse fully in the molten magnesium alloy, thus homogenizing the alloy composition and obtaining the alloy liquid.

[0048] 3) After the holding period is over, adjust the furnace temperature to 740℃, stir the alloy liquid vigorously, and slowly add the refining agent at the same time. Maintain this process for 1-2 minutes until the surface of the alloy liquid becomes mirror-like. The refining agent is composed of the following raw materials by weight percentage: MgCl2 46%, KCl 40%, BaCl2 8%, CaF2 5%. After refining is completed, heat the furnace temperature to 740℃ and hold for 20 minutes. After the holding period is over, wait for the furnace temperature to drop to 710℃, and then start casting into the preheated and dried metal mold (the mold preheating temperature is 180℃) to finally cast a cylindrical ingot.

[0049] 4) Cut off the shrinkage cavity and bottom of the cylindrical ingot with wire cutting. Machining is performed before solution treatment. Then, a first-stage solution treatment is performed, followed by a second-stage solution treatment, and then water quenching is performed to obtain a solution-treated ingot.

[0050] The primary solution treatment temperature is 320℃, and the holding time is 1 hour;

[0051] The secondary solution treatment temperature is 500℃, and the holding time is 3 hours.

[0052] 5) First, the oxide scale on the surface of the solution-treated ingot is removed by turning to make the surface bright; then the extrusion temperature is set to 225℃. After the temperature is reached, the polished sample is placed in the resistance furnace and kept warm for 30 minutes. After the warming is completed, the warmed sample is placed in the mold for extrusion. The extrusion temperature is 225℃, the extrusion rate is 0.1mm / s, and the extrusion ratio is 16:1. Finally, a high-strength, corrosion-resistant, low-alloyed magnesium-aluminum-manganese-zirconium alloy is obtained.

[0053] The high-strength, corrosion-resistant, low-alloy magnesium-aluminum-manganese-zirconium alloy obtained after testing includes Al: 0.1%; Mn: 0.1%; Y: 0.1%; Zr: 0.1%, unavoidable impurities <0.05%, and the remainder is magnesium.

[0054] Example 2

[0055] 1) Remove the oxide layer from the metal raw materials and dry them. Weigh out 509.5 parts of Mg, 0.5 parts of Al, 5.5 parts of magnesium-manganese master alloy, 1.8 parts of magnesium-yttrium master alloy, and 1.8 parts of magnesium-zirconium master alloy.

[0056] 2) Preheat the crucible to 300℃, place the magnesium metal block in the crucible, and then put them into the resistance furnace together. Introduce a protective gas consisting of a mixture of SF6 and CO2 in a volume ratio of 40:1. When the temperature reaches 710℃, hold for 25 minutes. Then, place the Al metal block in the furnace and raise the furnace temperature to 720℃, hold for 20 minutes. Next, add the magnesium-manganese master alloy to the crucible and raise the furnace temperature to 720℃, hold for 20 minutes. Then, add the magnesium-yttrium master alloy to the crucible and raise the furnace temperature to 720℃, hold for 20 minutes. Finally, add the magnesium-zirconium master alloy to the crucible and raise the furnace temperature to 750℃, hold for 20 minutes. This allows the four alloying elements, Al, Mn, Y, and Zr, to have sufficient time to diffuse fully in the molten magnesium alloy, thus homogenizing the alloy composition and obtaining the alloy liquid.

[0057] 3) After the heat preservation is completed, adjust the furnace temperature to 740℃. Stir the alloy liquid up and down with a stirring rod while slowly adding the refining agent. Maintain this process for 1 minute until the surface of the alloy liquid becomes mirror-like. The refining agent consists of the following raw materials in weight percentage: MgCl2 38%, KCl 32%, BaCl2 5%, CaF2 3%. After refining is completed, heat the furnace temperature to 740℃ and hold for 20 minutes. After holding, wait for the furnace temperature to drop to 710℃, and then start casting into the preheated and dried metal mold (the mold preheating temperature is 180℃) to finally cast a cylindrical ingot.

[0058] 4) Cut off the shrinkage cavity and bottom of the cylindrical ingot with wire cutting. Machining is performed before solution treatment. Then, a first-stage solution treatment is performed, followed by a second-stage solution treatment, and then water quenching is performed to obtain a solution-treated ingot.

[0059] The primary solution treatment temperature is 320℃, and the holding time is 1 hour;

[0060] The secondary solution treatment temperature is 500℃, and the holding time is 3 hours.

[0061] 5) First, the oxide scale on the surface of the solution-treated ingot is removed by turning to make the surface bright; then the extrusion temperature is set to 225℃. After the temperature is reached, the polished sample is placed in the resistance furnace and kept warm for 30 minutes. After the warming is completed, the warmed sample is placed in the mold for extrusion. The extrusion temperature is 225℃, the extrusion rate is 0.1mm / s, and the extrusion ratio is 16:1. Finally, a high-strength, corrosion-resistant, low-alloyed magnesium-aluminum-manganese-zirconium alloy is obtained.

[0062] The high-strength, corrosion-resistant, low-alloy magnesium-aluminum-manganese-zirconium alloy obtained after testing includes Al: 0.1%; Mn: 0.1%; Y: 0.1%; Zr: 0.1%, unavoidable impurities <0.05%, and the remainder is magnesium.

[0063] Example 3

[0064] 1) Remove the oxide layer from the metal raw materials and dry them. Weigh out 514.5 parts of Mg, 0.6 parts of Al, 6.0 parts of magnesium-manganese master alloy, 2.0 parts of magnesium-yttrium master alloy, and 2.0 parts of magnesium-zirconium master alloy.

[0065] 2) Preheat the crucible to 300℃, place the magnesium metal block in the crucible, and then put them into the resistance furnace together. Introduce a protective gas consisting of a mixture of SF6 and CO2 in a volume ratio of 40:1. When the temperature reaches 715℃, hold for 30 minutes. Then, place the Al metal block in the furnace and raise the furnace temperature to 725℃, hold for 25 minutes. Next, add the magnesium-manganese master alloy to the crucible and raise the furnace temperature to 725℃, hold for 25 minutes. Then, add the magnesium-yttrium master alloy to the crucible and raise the furnace temperature to 725℃, hold for 25 minutes. Finally, add the magnesium-zirconium master alloy to the crucible and raise the furnace temperature to 755℃, hold for 25 minutes. This allows the four alloying elements, Al, Mn, Y, and Zr, to have sufficient time to diffuse fully in the molten magnesium alloy, thus homogenizing the alloy composition and obtaining the alloy liquid.

[0066] 3) After the heat preservation is completed, adjust the furnace temperature to 745℃. Stir the alloy liquid up and down with a stirring rod while slowly adding the refining agent. Maintain this process for 2 minutes until the surface of the alloy liquid becomes mirror-like. The refining agent consists of the following raw materials by weight percentage: MgCl2 46%, KCl 40%, BaCl2 8%, and CaF2 5%. After refining is completed, heat the furnace temperature to 745℃ and hold for 25 minutes. After holding, wait for the furnace temperature to drop to 715℃, and then begin casting into the preheated and dried metal mold (the mold preheating temperature is 200℃) to finally cast a cylindrical ingot.

[0067] 4) Cut off the shrinkage cavity and bottom of the cylindrical ingot with wire cutting. Machining is performed before solution treatment. Then, a first-stage solution treatment is performed, followed by a second-stage solution treatment, and then water quenching is performed to obtain a solution-treated ingot.

[0068] The primary solution treatment temperature is 320℃, and the holding time is 1 hour;

[0069] The secondary solution treatment temperature is 500℃, and the holding time is 3 hours.

[0070] 5) First, the oxide scale on the surface of the solution-treated ingot is removed by turning to make the surface bright; then the extrusion temperature is set to 225℃. After the temperature is reached, the polished sample is placed in the resistance furnace and kept warm for 30 minutes. After the warming is completed, the warmed sample is placed in the mold for extrusion. The extrusion temperature is 225℃, the extrusion rate is 0.1mm / s, and the extrusion ratio is 16:1. Finally, a high-strength, corrosion-resistant, low-alloyed magnesium-aluminum-manganese-zirconium alloy is obtained.

[0071] The high-strength, corrosion-resistant, low-alloy magnesium-aluminum-manganese-zirconium alloy obtained after testing includes Al: 0.1%; Mn: 0.1%; Y: 0.1%; Zr: 0.1%, unavoidable impurities <0.05%, and the remainder is magnesium.

[0072] Comparative Example 1

[0073] The preparation method of this comparative example is the same as that of Example 1, except that the raw materials are 514.5 parts of Mg, 0.275 parts of Al, 5.5 parts of magnesium-manganese master alloy, 1.83 parts of magnesium-yttrium master alloy, and 1.83 parts of magnesium-zirconium master alloy.

[0074] Comparative Example 2

[0075] The preparation method of this comparative example is the same as that of Example 1, except that the raw materials are 514.5 parts of Mg, 1.1 parts of Al, 5.5 parts of magnesium-manganese master alloy, 1.83 parts of magnesium-yttrium master alloy, and 1.83 parts of magnesium-zirconium master alloy.

[0076] Experimental Example 1

[0077] Table 1 Mechanical and electrochemical properties of each experimental alloy

[0078]

[0079] Experimental Example 2

[0080] 1. The high-strength, high-toughness, and corrosion-resistant magnesium alloy prepared in Example 1 was subjected to XRD analysis, such as... Figure 1 As shown, the vertical axis represents diffraction intensity, and the horizontal axis represents the diffraction angle 2θ. Ultra-high strength, toughness, and corrosion-resistant magnesium alloys are mainly composed of α-Mg and Mg... 17 Al 12 The phase composition was determined, and no diffraction peaks of other phases were observed.

[0081] 2. The high-strength, high-toughness, and corrosion-resistant magnesium alloy prepared in Example 1 was subjected to microstructural analysis, such as... Figure 2 As shown, the microstructure of the high-strength, high-toughness, and corrosion-resistant magnesium alloy can be observed to consist of elongated deformed grains and smaller equiaxed grains.

[0082] 3. The high-strength, high-toughness, and corrosion-resistant magnesium alloy prepared in Example 1 was subjected to tensile property testing, such as... Figure 3As shown, the high-strength, high-toughness, and corrosion-resistant magnesium alloy has a room temperature tensile yield strength of 400.9 MPa, a tensile strength of 501.3 MPa, and an elongation of 5%.

[0083] 4. The corrosion resistance of the high-strength, tough, and corrosion-resistant magnesium alloy prepared in Example 1 was tested, such as... Figure 4 As shown, the potentiodynamic polarization curves of the high-strength, tough, and corrosion-resistant magnesium alloy were fitted using the CorShow software with Tafel data for the cathode branch. The results showed that the corrosion potential of the alloy was -1.44 V, the cathode branch slope was approximately 132.5 mV, and the corrosion current was 3.08 μA / cm². 2 The corrosion rate is approximately 0.07 mm / a.

[0084] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A high-strength, corrosion-resistant, low-alloy magnesium-aluminum-manganese-yttrium-zirconium alloy, characterized in that, Includes the following components by weight percentage: Al: 0.1%; Mn: 0.1%; Y：0.1％； Zr: 0.1%, the remainder being magnesium and unavoidable impurities; The alloy consists of α-Mg and Mg 17 Al 12 Phase composition; the microstructure of the alloy consists of elongated deformed grains and smaller equiaxed grains; The alloy has a room temperature tensile yield strength of 400.9 MPa, a tensile strength of 501.3 MPa, and an elongation of 5%. The alloy has a corrosion potential of -1.44V, a cathode branch slope of approximately 132.5mV, and a corrosion current of 3.08μA / cm. 2 The corrosion rate is 0.07 mm / a.

2. The ultra-high strength, corrosion-resistant, low-alloy magnesium-aluminum-manganese-yttrium-zirconium alloy according to claim 1, characterized in that, The ultra-high strength, corrosion-resistant, low-alloy magnesium-aluminum-manganese-yttrium-zirconium alloy is made from the following parts by weight of metallic raw materials: Mg 509.5-514.5 parts, Al 0.5-0.6 parts, magnesium-manganese master alloy 5.5-6.0 parts, magnesium-yttrium master alloy 1.8-2.0 parts, magnesium-zirconium master alloy 1.8-2.0 parts; The magnesium-manganese master alloy has a magnesium-manganese mass ratio of 9:1; The magnesium-yttrium mass ratio of the magnesium-yttrium master alloy is 7:3; The magnesium-zirconium mass ratio of the magnesium-zirconium master alloy is 7:

3.

3. The preparation method of the ultra-high strength corrosion-resistant low-alloyed magnesium-aluminum-manganese-yttrium-zirconium alloy according to claim 2, characterized in that, Includes the following steps: 1) Remove the oxide layer from the metal raw material and dry it, then weigh the metal raw material according to the stated weight proportions; 2) Place Mg metal into the melting furnace under a protective atmosphere, then hold it at the first temperature and then place Al metal in it, then hold it at the second temperature and then place magnesium-manganese master alloy in it, then hold it at the third temperature and then place magnesium-yttrium master alloy in it, then hold it at the fourth temperature and then place magnesium-zirconium master alloy in it, and finally hold it at the fifth temperature to obtain the alloy liquid. 3) After the alloy liquid undergoes a first cooling process, a refining agent is added, and the mixture is stirred, kept warm, cooled a second time, and then cast to obtain an ingot. 4) The ingot is subjected to solution treatment to obtain a solution-treated ingot; 5) After removing the oxide layer from the solution-treated ingot, it is subjected to extrusion treatment to obtain a high-strength, corrosion-resistant, low-alloyed magnesium-aluminum-manganese-yttrium-zirconium alloy.

4. The preparation method according to claim 2, characterized in that, In step 2), the protective atmosphere is a mixture of SF6 and CO2 at a volume ratio of 40:

1.

5. The preparation method according to claim 2, characterized in that, In step 2), the first temperature is 710-715℃, and the holding time is 25-30 min; the second temperature is 720-725℃, and the holding time is 20-25 min; the third temperature is 720-725℃, and the holding time is 20-25 min; the fourth temperature is 720-725℃, and the holding time is 20-25 min; and the fifth temperature is 750-755℃, and the holding time is 20-25 min.

6. The preparation method according to claim 2, characterized in that, In step 3), the amount of refining agent used is 1-2 wt% of the alloy liquid.

7. The preparation method according to claim 2, characterized in that, The refining agent in step 3) consists of the following raw materials in weight percentage: MgCl2 38-46%, KCl 32-40%, BaCl2 5-8%, and CaF2 3-5%.

8. The preparation method according to claim 2, characterized in that, In step 3), the first cooling temperature is 740-745℃; the stirring time is 2-5 min; the holding temperature is 750-755℃ and the holding time is 20-25 min; the second cooling temperature is 710-715℃.

9. The preparation method according to claim 2, characterized in that, The solution treatment method in step 4) is as follows: first, perform a primary solution treatment, then a secondary solution treatment, and finally water quenching. The primary solution treatment temperature is 320℃, and the holding time is 1 hour; The secondary solution treatment temperature is 500℃, and the holding time is 3 hours.

10. The preparation method according to claim 2, characterized in that, The extrusion treatment method in step 5) is as follows: heat the extrusion die to 225-230℃, place the sample in and keep it at the temperature for 55-60 minutes, and then extrude at an extrusion temperature of 225℃, an extrusion rate of 0.1mm / s, and an extrusion ratio of 16:1.

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