A high-strength, high-damping magnesium rare-earth alloy, its preparation method and application

Abstract

This invention discloses a high-strength, high-damping magnesium rare-earth alloy, its preparation method, and its applications, belonging to the field of metallic materials and lightweight structural materials preparation technology. The alloy uses magnesium as the matrix, with yttrium, zinc, aluminum, and silicon as the main alloying elements. By controlling the content and proportion of each element, a multi-scale microstructure is formed, dominated by an α-Mg matrix, reinforced by LPSO phase, and with Al / Si-Y phase synergistic distribution. The preparation method includes steps such as batching, smelting, casting, solution treatment, and hot deformation. This invention, through quaternary synergistic alloying of Y, Zn, Al, and Si and process control, improves the tensile strength and yield strength of the alloy while retaining necessary dislocation and interface energy dissipation capabilities, achieving a synergistic match between high strength and high damping performance. It is suitable for lightweight load-bearing and vibration-damping structural components in the automotive, aerospace, and other fields.

Description

Technical Field

[0001] This invention belongs to the field of metal materials and lightweight structural materials preparation technology, and particularly relates to a high-strength, high-damping magnesium rare earth alloy, its preparation method and application. Background Technology

[0002] Magnesium alloys possess advantages such as low density, high specific strength, high specific stiffness, good damping performance, and recyclability, making them important lightweight metallic structural materials. Compared to aluminum alloys and steel, magnesium alloys have potential advantages in weight reduction, vibration reduction, and noise reduction, making them suitable for structural components that withstand vibration, impact, or have high noise control requirements.

[0003] However, traditional magnesium alloys often suffer from insufficient strength and difficulty in simultaneously improving damping performance. High-damping magnesium alloys typically rely on a high density of mobile dislocations, but simply increasing dislocation mobility may lead to a decrease in strength; while increasing strength through a large amount of second phase or strong texture may inhibit dislocation mobility and reduce damping capacity. Therefore, achieving a synergistic match between "high strength and high damping" in magnesium alloys remains a significant technical challenge.

[0004] Mg-Y magnesium alloys possess good potential for solid solution strengthening and precipitation strengthening. Adding Zn is beneficial for forming long-period stacked ordered phase structures. Al can participate in grain refinement, recrystallization regulation, and the formation of Al-Y intermetallic compounds. Si can form high-melting-point strengthening phases such as the Si-Y phase, which positively impacts hardness, thermal stability, and interfacial energy dissipation. However, excessively high Al and Si contents may lead to excessive consumption of Y, inhibited LPSO structure formation, or the formation of coarse, continuous, and brittle Al / Si-Y phases, thereby impairing plasticity and damping properties.

[0005] Existing Mg-RE-Zn alloy schemes mostly focus on strength, heat resistance, or casting performance. There is still room for further optimization regarding the competitive and synergistic relationship between the LPSO phase and the Al / Si-Y multiphase system, as well as technical solutions that achieve both high strength and high damping through composition ratios and process routes. Summary of the Invention

[0006] To address the aforementioned technical problems, this invention proposes a high-strength, high-damping magnesium rare-earth alloy, its preparation method, and its applications. Using magnesium as the matrix and yttrium (Y), zinc (Zn), aluminum (Al), and silicon (Si) as the main alloying elements, a Mg-Y-Zn-Al-Si magnesium rare-earth alloy with both high strength and high damping capabilities is prepared. This alloy can be used in automobiles, aerospace, rail transportation, electronic equipment, instrumentation, and structural components requiring a combination of lightweighting, load-bearing capacity, and vibration and noise reduction.

[0007] To achieve the above objectives, the present invention provides the following technical solution: A high-strength, high-damping magnesium rare-earth alloy, comprising the following components by mass percentage: Y: 2.0–10.0%; Zn: 0.5–5.0%; Al: 0.1–2.0%; Si: 0.05–1.5%; balance is Mg and unavoidable impurities.

[0008] This invention successfully constructed a unique multi-scale microstructure in a magnesium alloy matrix by precisely controlling the content and ratio of four elements: yttrium (Y), zinc (Zn), aluminum (Al), and silicon (Si). This microstructure uses α-Mg as the matrix and cleverly introduces two key strengthening phases: a long-period stacked ordered (LPSO) phase formed by the synergistic effect of Y and Zn, and an Al / Si-Y phase formed by the participation of Al and Si. These two strengthening phases are synergistically distributed in the matrix and work together to significantly improve the tensile strength and yield strength of the alloy while retaining the necessary dislocation movement and interfacial slip capabilities, thus ensuring the material's excellent energy dissipation characteristics and ultimately achieving a synergistic match between high strength and high damping performance.

[0009] Optionally, the high-strength, high-damping magnesium rare-earth alloy comprises the following components by weight percentage: Y: 2.0–8.0%; Zn: 1.0–3.0%; Al: 0.1–0.5%; Si: 0.05–0.50%; balance is Mg and unavoidable impurities.

[0010] Furthermore, the high-strength, high-damping magnesium rare-earth alloy comprises the following components by weight percentage: Y: 3.5%; Zn: 1.5%; Al: 0.1%; Si: 0.1%; balance is Mg and unavoidable impurities.

[0011] Furthermore, the high-strength, high-damping magnesium rare-earth alloy comprises the following components by weight percentage: Y: 5%; Zn: 2.0%; Al: 0.2%; Si: 0.1%; balance is Mg and unavoidable impurities.

[0012] Furthermore, the high-strength, high-damping magnesium rare-earth alloy comprises the following components by weight percentage: Y: 7%; Zn: 2.5%; Al: 0.2%; Si: 0.2%; balance is Mg and unavoidable impurities.

[0013] Optionally, the alloy has a tensile strength of 268 MPa to 340 MPa, a yield strength of 185 MPa to 243 MPa, and a room temperature damping performance of 0.017 to 0.028.

[0014] A method for preparing the high-strength, high-damping magnesium rare-earth alloy as described above includes the following steps: (1) Batching: Weigh the raw materials according to the target alloy composition. The raw materials include pure Mg, Mg-Y master alloy, pure Zn, pure Al and Mg-Si master alloy. (2) Melting: Pure Mg is melted under a protective atmosphere, and then preheated Mg-Y master alloy, pure Al, pure Zn and Mg-Si master alloy are added in sequence. After complete melting, magnesium alloy melt is obtained. (3) Settling and casting: The magnesium alloy melt is settling and then cast into a preheated mold to cool, thus obtaining a cast magnesium alloy ingot; (4) Heat treatment and deformation: The cast magnesium alloy ingot is subjected to solution treatment and then hot deformation treatment to obtain a high-strength and high-damping magnesium rare earth alloy.

[0015] This invention provides a complete and reproducible preparation process, covering the entire process from batching, melting, casting to solution treatment and hot deformation. This process is not only suitable for precise laboratory preparation but also lays a solid foundation for subsequent industrial-scale production. Specifically, by systematically optimizing the order of adding the intermediate alloy, melting temperature, heat treatment regime, and hot deformation parameters, this process effectively suppresses the formation of coarse, brittle phases and continuous network second phases in the alloy. This precise microstructure control significantly improves the uniformity and consistency of the alloy's internal structure, thereby ensuring the high stability of the final product's mechanical and damping properties.

[0016] Optionally, in step (1), the Y content in the Mg-Y master alloy is 20-30 wt.%, and the Si content in the Mg-Si master alloy is 5-10 wt.%.

[0017] Optionally, in step (2), the protective atmosphere is a mixture of CO2 and SF6; during the smelting process, pure Mg is first heated to 720°C to melt, and Mg-Y master alloy, pure Al and pure Zn are added. After all are melted, the temperature is raised to 760°C and Mg-Si master alloy is added. After the addition is completed, the temperature is lowered to 720°C.

[0018] Optionally, in step (3), the settling time is 15 to 20 minutes; the temperature of the preheated mold is 250°C.

[0019] Optionally, in step (4), the temperature of the solution treatment is 480-520°C, and water cooling is performed after the solution treatment is completed.

[0020] Optionally, in step (4), the heat deformation treatment is hot extrusion, that is, first heat preservation at 420-450 ℃ for 2 h, and then hot extrusion under the conditions of extrusion temperature of 350-450 ℃ and extrusion ratio ≤20∶1.

[0021] Optionally, the hot extrusion temperature is 420°C and the extrusion ratio is 16:1.

[0022] Application of the above-mentioned high-strength, high-damping magnesium rare earth alloy in the preparation of lightweight load-bearing and vibration-damping noise-reducing structural components for automobiles, aerospace, rail transportation, electronic equipment, and instruments.

[0023] Compared with the prior art, the present invention has the following advantages and technical effects: 1. This invention innovatively employs a quaternary synergistic alloying strategy of Y, Zn, Al, and Si. By precisely controlling the alloy composition, a multi-scale strengthening structure composed of LPSO phase and Al / Si-Y phase composite is successfully constructed in the matrix. This unique microstructure design provides a solid material basis for simultaneously improving the strength and damping properties of the alloy, achieving synergistic optimization of the two properties.

[0024] 2. This invention significantly reduces the risk of excessive consumption of Y element by Al / Si by strictly limiting the amount of Al and Si added and optimizing the Y / Zn ratio. This precise composition control strategy effectively promotes the uniformity of the alloy structure and improves the plastic stability of the material, avoiding performance degradation caused by excessive brittle phases.

[0025] 3. The subsequent hot deformation process in the preparation of this invention can effectively break up the coarse second phase in the as-cast structure, significantly refine the grains, and introduce an appropriate amount of dislocations and interfaces. This process achieves an ideal balance between the dislocation strengthening and grain refinement mechanisms and the damping energy dissipation mechanisms such as dislocation motion and interface slip, thus realizing a reasonable match between strengthening and damping.

[0026] 4. The preparation route of this invention is clear and well-defined, and can be completed entirely using conventional magnesium alloy smelting, casting, solution treatment, and extrusion equipment. This process route not only facilitates repeated verification in a laboratory environment but also possesses good scalability, providing convenient conditions for subsequent transition from laboratory research to large-scale industrial production.

[0027] 5. The high-strength, high-damping magnesium rare earth alloy disclosed in this invention, with its excellent comprehensive performance, shows great potential in terms of lightweighting, load-bearing capacity, and vibration and noise reduction, and is very suitable for manufacturing high-performance structural components in the fields of automobiles, aerospace, rail transportation, electronic equipment, and instruments. Attached Figure Description

[0028] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings: Figure 1 The images shown are (a) and (b) of the metallographic image of the high-strength, high-damping magnesium rare earth alloy Mg-Y-Zn-Al-Si prepared in Example 3 of this invention. Detailed Implementation

[0029] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0030] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0031] Unless otherwise stated, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. While only preferred methods and materials have been described herein, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this invention. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0032] Various modifications and variations can be made to the specific embodiments described in this specification without departing from the scope or spirit of the invention, as will be apparent to those skilled in the art. Other embodiments derived from this specification will also be apparent to those skilled in the art. This specification and embodiments are merely exemplary.

[0033] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0034] This invention provides a high-strength, high-damping Mg-Y-Zn-Al-Si magnesium rare earth alloy, comprising the following components by mass percentage: Y 2.0~10.0%, Zn 0.5~5.0%, Al 0.1~2.0%, Si 0.05~1.5%, with the balance being Mg and unavoidable impurities.

[0035] In some alternative embodiments, the high-strength, high-damping Mg-Y-Zn-Al-Si magnesium rare earth alloy comprises the following components by mass percentage: Y 2.0~8.0%, Zn 1.0~3.0%, Al 0.1~0.5%, Si 0.05~0.50%, with the balance being Mg and unavoidable impurities.

[0036] In some alternative embodiments, the Y / Zn mass ratio is 1.5 to 3.5. By controlling the above ratio, the formation of the LPSO-reinforced structural phase and the dispersion of the Al / Si-Y phase can be balanced, while avoiding excessive fixation of Y by Al or coarsening of the Si phase. The content of a single impurity element is preferably not more than 0.03 wt.%, and the total amount of impurities is preferably not more than 0.12 wt.%.

[0037] This invention also discloses a method for preparing the above-mentioned high-strength, high-damping magnesium rare-earth alloy Mg-Y-Zn-Al-Si, comprising the following steps: S1. Batching and Pretreatment: Weigh out pure Mg, Mg-Y master alloy, pure Zn, pure Al, and Mg-Si master alloy according to the target alloy composition. Pure Mg, pure Al, and Zn raw materials with a purity of 99.99 wt.% or higher are preferred. The Y content of the Mg-Y master alloy can be 20–30 wt.%, and the Si content of the Mg-Si master alloy can be 5–10 wt.%. Appropriate compensation should be made based on element loss during batching, and oxide scale and impurities on the surface of the raw materials should be removed. S2. Drying and Preheating: Preheat and dry the raw materials, crucible, stirring tools, and casting mold. The raw materials and crucible are preferably held at 200°C for 30 minutes, and the metal mold is preferably preheated at 250°C for 60 minutes to reduce the impact of moisture and temperature difference on the melting and casting quality. S3. Melting under a protective atmosphere: Pure Mg is melted at 720°C under a CO2 / SF6 mixed gas atmosphere. After melting, preheated Mg-Y master alloy, pure Al, and pure Zn are added. After all the components have melted, Mg-Si master alloy is added. After all the raw material components have completely melted, the temperature is lowered to 720°C. Before casting, the molten liquid is allowed to stand for 15-20 minutes to promote the flotation of inclusions and the homogenization of the melt. S4. Casting and molding: The magnesium alloy melt obtained in step S4 is poured into a preheated mold, cooled and demolded to obtain a cast Mg-Y-Zn-Al-Si magnesium alloy ingot; S5. Solution treatment: The cast magnesium alloy ingot is solution treated at 480-520℃ to promote composition homogenization and controllable phase transformation; water cooling is performed after the solution treatment is completed. S6. Hot Deformation Treatment: The solution-treated ingot is processed into an extrusion billet, held at 420–450 °C for 2 hours, and then hot-extruded at 350–450 °C with an extrusion ratio ≤20 to obtain an extruded high-strength, high-damping magnesium alloy Mg-Y-Zn-Al-Si. Hot deformation is used to break up coarse second phases in the as-cast state, refine grains, and control texture and dislocation structure.

[0038] The microstructure of the alloy of this invention is mainly composed of an α-Mg matrix, and includes multi-scale structural phases such as LPSO phase and Al / Si-Y phase. Y mainly provides the basis for solid solution strengthening and precipitation strengthening, Zn participates in LPSO phase regulation and improves the strength and damping response of Mg-Y based alloys; low content of Al / Si assists in regulating the second phase, grain boundaries and recrystallization behavior. The combination of these three can improve tensile strength and yield strength while enhancing damping capacity through mechanisms such as grain boundary / phase boundary slip, dislocation movement and energy dissipation at the second phase interface.

[0039] Unless otherwise specified, "room temperature" in this invention refers to 20-30℃.

[0040] All raw materials used in this invention were purchased from the market.

[0041] The technical solution of the present invention will be further illustrated by the following embodiments.

[0042] Example 1 A method for preparing a high-strength, high-damping magnesium rare-earth alloy includes the following steps: (1) The raw materials are calculated and batched using industrial pure magnesium ingots, pure zinc, pure aluminum sheets, Mg-Y master alloy and Mg-Si master alloy. The mass percentage of Y in the Mg-Y master alloy is 30% and the mass percentage of Si in the Mg-Si master alloy is 5%. Each raw material is weighed according to the following mass percentages: Y 3.5%, Zn 1.5%, Al 0.1%, Si 0.1%, and the remainder is Mg and unavoidable impurities (total impurity content ≤ 0.12%).

[0043] (2) A CO2 / SF6 mixed gas (volume ratio of the two gases is 99:1) is introduced into the resistance furnace. Magnesium ingots are added to the crucible and heated to 720°C to melt. After all the ingots have melted, preheated Mg-30Y alloy (with a burn-off rate of 10%), pure zinc (without considering the burn-off rate) and pure aluminum (without considering the burn-off rate) are added. After all the ingots have melted, the temperature is raised to 760°C and Mg-5Si intermediate alloy (with a burn-off rate of 5%) is added to melt and obtain a melt. Then, the temperature is lowered to 720°C and the melt is stirred to ensure that the alloy elements in the crucible are evenly distributed. The floating residue is removed and the melt is allowed to stand for 15 minutes before casting in a metal mold preheated to 250°C to obtain a cast alloy.

[0044] (3) The magnesium alloy ingot obtained in step (2) is subjected to solution treatment at 500℃. After the solution treatment is completed, it is quickly cooled to room temperature by water. Then it is kept at 420℃ for 2 h and subjected to forward extrusion at this temperature. The extrusion ratio is 16:1. It is then air-cooled to room temperature to obtain a high-strength, high-damping magnesium alloy.

[0045] Example 2 A method for preparing a high-strength, high-damping magnesium rare-earth alloy includes the following steps: (1) The raw materials are calculated and proportioned using industrial pure magnesium ingots, pure zinc, pure aluminum sheets, Mg-Y master alloy and Mg-Si master alloy. The mass percentage of Y in the Mg-Y master alloy is 30% and the mass percentage of Si in the Mg-Si master alloy is 5%. Each raw material is weighed according to the following mass percentages: Y 5%, Zn 2.0%, Al 0.2%, Si 0.1%, and the remainder is Mg and unavoidable impurities (total impurity content ≤ 0.12 wt.%).

[0046] (2) A CO2 / SF6 mixed gas (volume ratio of the two gases is 99:1) is introduced into the resistance furnace. Magnesium ingots are added to the crucible and heated to 720°C to melt. After all the ingots have melted, preheated Mg-30Y alloy (with a burn-off rate of 10%), pure zinc (without considering the burn-off rate) and pure aluminum (without considering the burn-off rate) are added. After all the ingots have melted, the temperature is raised to 760°C and Mg-5Si intermediate alloy (with a burn-off rate of 5%) is added to melt and obtain a melt. Then, the temperature is lowered to 720°C and the melt is stirred to ensure that the alloy elements in the crucible are evenly distributed. The floating residue is removed and the melt is allowed to stand for 15 minutes before casting in a metal mold preheated to 250°C to obtain a cast alloy.

[0047] (3) The magnesium alloy ingot obtained in step (2) is solution treated at 500℃. After the heat treatment, it is quickly cooled to room temperature by water. Then it is kept at 420℃ for 2 h and subjected to forward extrusion at this temperature. The extrusion ratio is 16:1. It is then air-cooled to room temperature to obtain a high-strength, high-damping magnesium alloy.

[0048] Example 3 A method for preparing a high-strength, high-damping magnesium rare-earth alloy includes the following steps: (1) The raw materials are calculated and batched using industrial pure magnesium ingots, pure zinc, pure aluminum sheets, Mg-Y master alloy and Mg-Si master alloy. The mass percentage of Y in the Mg-Y master alloy is 30% and the mass percentage of Si in the Mg-Si master alloy is 5%. Each raw material is weighed according to the following mass percentages: Y 7%, Zn 2.5%, Al 0.2%, Si 0.2%, and the remainder is Mg and unavoidable impurities (total impurity content ≤ 0.12 wt.%).

[0049] (2) A CO2 / SF6 mixed gas (volume ratio of the two gases is 99:1) is introduced into the resistance furnace. Magnesium ingots are added to the crucible and heated to 720°C to melt. After all the ingots have melted, preheated Mg-30Y alloy (with a burn-off rate of 10%), pure zinc (without considering the burn-off rate) and pure aluminum (without considering the burn-off rate) are added. After all the ingots have melted, the temperature is raised to 760°C and Mg-5Si intermediate alloy (with a burn-off rate of 5%) is added to melt and obtain a melt. Then, the temperature is lowered to 720°C and the melt is stirred to ensure that the alloy elements in the crucible are evenly distributed. The floating residue is removed and the melt is allowed to stand for 15 minutes before casting in a metal mold preheated to 250°C to obtain a cast alloy.

[0050] (3) The magnesium alloy ingot obtained in step (2) is solution treated at 500℃. After the heat treatment, it is quickly cooled to room temperature by water. Then it is kept at 420℃ for 2 h and subjected to forward extrusion at this temperature. The extrusion ratio is 16:1. It is then air-cooled to room temperature to obtain a high-strength, high-damping magnesium alloy.

[0051] Comparative Example 1 The preparation process of a Mg-5Y-2Zn alloy is as follows: (1) The raw materials are calculated and batched using industrial pure magnesium ingots, pure zinc and Mg-Y master alloy. The mass percentage of Y in the Mg-Y master alloy is 30%. Each raw material is weighed according to the following mass percentages: Y 5%, Zn 2%, and the remainder is Mg and unavoidable impurities.

[0052] (2) Place all raw materials into a stainless steel crucible with dimensions of ⌀89mm×280mm, and heat it under a vacuum of 1.85×10 - 2 Heating in a vacuum melting furnace under a protective atmosphere of KPa and argon (Ar) until the alloy raw material is completely melted, and then standing at 730℃ for about 20 minutes, the melting furnace is opened, the crucible is removed with clamps, and slowly rotated in a brine tank to cool, thus obtaining a magnesium alloy ingot.

[0053] (3) The magnesium alloy ingot obtained in step (2) is solution treated at 500°C, and then air-cooled after the heat treatment is completed. Then it is extruded at 420°C with an extrusion ratio of 16:1. After air-cooling to room temperature, a high-strength and high-damping magnesium alloy is obtained.

[0054] Comparative Example 2 The preparation process of a Mg-5Ga-1.2Zn alloy is as follows: (1) Pure magnesium, pure zinc and pure gallium are used as raw materials for batching, wherein the purity of pure magnesium is 99.9%, and the purity of pure zinc and pure gallium is 99.99%. Each raw material is weighed according to the composition of Mg-5Ga-1.2Zn alloy, and the remainder is Mg and unavoidable impurities.

[0055] (2) The raw materials are melted in a low-carbon steel crucible to prepare alloy ingots. The alloy ingots are then kept at 210℃ for 4 h, 300℃ for 24 h and 370℃ for 16 h to homogenize them. The ingots are then processed into slabs with dimensions of 100 mm × 90 mm × 10 mm.

[0056] (3) The slab was preheated at 275 °C for 15 min, and then rolled in a single pass using a twin-roll mill at a rolling speed of 430 mm / s. The rolls were not preheated. The slab was rolled from 10 mm to 2 mm with a reduction rate of 80% and an average strain rate of 9.1 s. -1 Mg-5Ga-1.2Zn alloy plates were obtained.

[0057] Comparative Example 3 The preparation process of a Mg-1.5Gd-1Zn alloy is as follows: (1) The raw materials were calculated and batched using industrial pure magnesium, pure zinc and Mg-30 wt.% Gd master alloy. The purity of pure magnesium and pure zinc were 99.99 wt.% and 99.95 wt.% respectively. The actual composition of the alloy was Mg-1.36Gd-0.88Zn, with the balance being Mg and unavoidable impurities.

[0058] (2) The raw materials were preheated at 200 °C for 2 h. After the pure magnesium melted, Mg-Gd master alloy and pure zinc were added at 780 °C and 760 °C respectively and stirred. After the melt was cooled to 730 °C, argon gas was introduced for refining for 10 min. Then, under the protection of CO2+SF6 mixed gas, the temperature was lowered to 680 °C and poured into a water-cooled mold to obtain a magnesium alloy ingot.

[0059] (3) The ingot is processed into a cylindrical billet of Φ90 mm×150 mm, homogenized at 510 ℃ for 20 h and air-cooled; then it is kept at 420 ℃ for 2 h and subjected to forward extrusion with an extrusion ratio of 25:1. After extrusion, it is air-cooled to room temperature.

[0060] Effect verification The alloys prepared in the above embodiments were subjected to mechanical and damping property tests. The mechanical property test conditions were: tensile rate of 2 mm / min, gauge length of 25 mm and diameter of 5 mm for the tensile bar; the damping test conditions were: constant temperature T = 25℃, frequency f = 1 Hz, and strain ε = 10. ‑3 The performance test results are shown in Table 1.

[0061] Table 1. Test results of room temperature mechanical properties and damping properties of Implementation Cases 1-3 and Comparative Examples 1-3 The test results in Table 1 show that the high-strength, high-damping magnesium alloy prepared in the embodiments of the present invention possesses both excellent mechanical properties and room-temperature damping properties at room temperature, with tensile strength ranging from 268 MPa to 340 MPa, yield strength ranging from 185 MPa to 243 MPa, and room-temperature damping properties (with strain 10) -3 The reciprocal of the quality factor Q -1 The range is 0.017 to 0.028 (expressed as 0.017).

[0062] The microstructure of the sample from Example 3 was observed using metallography and scanning electron microscopy. The results are as follows: Figure 1 As shown in the figure, the alloy contains a multi-scale microstructure with LPSO phase and Al / Si-Y phase synergistic distribution, which gives the alloy high strength and high damping properties.

[0063] The above are merely preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A high-strength, high-damping magnesium rare-earth alloy, characterized in that, It comprises the following components by weight percentage: Y：2.0～10.0%； Zn: 0.5–5.0%; Al：0.1～2.0%； Si: 0.05-1.5%; balance is Mg and unavoidable impurities.

2. The high-strength, high-damping magnesium rare-earth alloy according to claim 1, characterized in that, The high-strength, high-damping magnesium rare-earth alloy comprises the following components by weight percentage: Y：2.0～8.0%； Zn: 1.0~3.0%; Al：0.1～0.5%； Si: 0.05-0.50%; balance is Mg and unavoidable impurities.

3. The high-strength, high-damping magnesium rare-earth alloy according to claim 2, characterized in that, The high-strength, high-damping magnesium rare-earth alloy comprises the following components by weight percentage: Y: 7%; Zn: 2.5%; Al：0.2%； Si: 0.2%; balance is Mg and unavoidable impurities.

4. The high-strength, high-damping magnesium rare-earth alloy according to claim 1, characterized in that, The alloy has a tensile strength of 268 MPa to 340 MPa, a yield strength of 185 MPa to 243 MPa, and a room temperature damping performance of 0.017 to 0.

028.

5. A method for preparing a high-strength, high-damping magnesium rare-earth alloy as described in any one of claims 1 to 4, characterized in that, Includes the following steps: (1) Weigh the raw materials according to the target alloy composition, including pure Mg, Mg-Y master alloy, pure Zn, pure Al and Mg-Si master alloy; (2) Pure Mg is melted under a protective atmosphere, and then preheated Mg-Y master alloy, pure Al, pure Zn and Mg-Si master alloy are added in sequence. After complete melting, magnesium alloy melt is obtained. (3) The magnesium alloy melt is subjected to static treatment and then poured into a preheated mold for cooling to obtain a cast magnesium alloy ingot; (4) The cast magnesium alloy ingot is subjected to solution treatment and then hot deformation treatment to obtain a high-strength, high-damping magnesium rare earth alloy.

6. The method for preparing high-strength, high-damping magnesium rare-earth alloy according to claim 5, characterized in that, In step (1), the Y content in the Mg-Y master alloy is 20-30 wt.%, and the Si content in the Mg-Si master alloy is 5-10 wt.%.

7. The method for preparing high-strength, high-damping magnesium rare-earth alloy according to claim 5, characterized in that, In step (2), the protective atmosphere is a mixture of CO2 and SF6. During the smelting process, pure Mg is first heated to 720°C to melt, and then Mg-Y master alloy, pure Al and pure Zn are added. After all the materials are melted, the temperature is raised to 760°C and Mg-Si master alloy is added. After the addition is completed, the temperature is lowered to 720°C.

8. The method for preparing high-strength, high-damping magnesium rare-earth alloy according to claim 5, characterized in that, In step (3), the settling time is 15 to 20 minutes; the temperature of the preheated mold is 250°C.

9. The method for preparing high-strength, high-damping magnesium rare-earth alloy according to claim 5, characterized in that, In step (4), the solution treatment temperature is 480–520°C; The heat deformation treatment is hot extrusion, which involves first holding the material at 420–450 °C for 2 hours, and then performing hot extrusion at an extrusion temperature of 350–450 °C and an extrusion ratio of ≤20:

1.

10. The application of a high-strength, high-damping magnesium rare earth alloy as described in any one of claims 1 to 4 in the preparation of lightweight load-bearing and vibration-damping structural components for automobiles, aerospace, rail transportation, electronic equipment, and instruments.

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