Multi-element wrought magnesium alloy and preparation method thereof
Through the combination of multi-component alloying and specific elements, the problems of insufficient strength and high cost of magnesium alloys are solved, and the preparation of low-cost and high-strength magnesium alloys are realized, with room temperature tensile strength exceeding 400MPa and elongation after break of more than 7%. Effect.
Patent Information
- Application Number
- CN202411168627.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-23
- Publication Date
- 2024-12-13
AI Technical Summary
The strength of existing magnesium alloys is not high and the rare earth content is generally high, which leads to an increase in alloy cost. It is of great significance to develop low-cost and high-strength magnesium alloys based on controlling the amount of rare earth addition.
Through the multi-component alloying method, the composite addition of light rare earth element Nd and heavy rare earth element Gd is adopted, combined with Zn, Al, Nb, Ca and other elements, solid solution treatment, hot extrusion and time-efficiency treatment are carried out to prepare multi-variable deformation magnesium Alloy, improves its room temperature tensile strength and elongation after break.
On the basis of controlling the amount of rare earth addition, the room temperature tensile strength of magnesium alloy is increased by more than 400MPa, and the elongation after break exceeds 7%, while reducing the cost of the alloy. The reasonable combination of rare earth elements promotes the precipitation of the reinforced phase, which improves the strength of the alloy and Plasticity.
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Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of metal alloy material preparation, and in particular relates to a multi-element deformable magnesium alloy and a preparation method thereof. Background Art
[0002] Magnesium alloys have a lower density, higher specific strength and specific stiffness. They also have excellent casting properties, thermal and electrical conductivity, electromagnetic shielding properties, cutting performance and high damping and vibration resistance. They have unique advantages in the existing engineering structural metal material system and have broad application prospects. Magnesium alloys are increasingly used as structural materials in the aerospace, transportation, chemical, and electronic communications industries.
[0003] The low strength of magnesium alloys is an important factor limiting their widespread application. Adding rare earth elements to magnesium alloys can significantly improve their room temperature and high temperature mechanical properties. Mg-RE alloys are gradually emerging, among which WE43 and WE54 alloys have excellent comprehensive mechanical properties, and their tensile strength reaches 280MPa. In recent years, high Gd rare earth magnesium alloys have attracted more and more attention due to their advantages such as high strength and heat resistance.
[0004] Although the magnesium alloys currently developed have high strength, they generally have high rare earth content, which greatly increases the cost of the alloy. It is of great significance to develop new low-cost and high-strength magnesium alloys by optimizing the alloy composition and content based on controlling the amount of rare earth addition. Summary of the invention
[0005] To solve the above problems, the present invention provides a multi-component deformable magnesium alloy and a preparation method thereof. The present invention improves the mechanical properties of the magnesium alloy by a multi-component alloying method based on controlling the amount of rare earth addition, so that the room temperature tensile strength of the alloy exceeds 400MPa and the elongation after fracture exceeds 7%.
[0006] The present invention is achieved through the following technical solutions: The invention provides a multi-element deformable magnesium alloy, comprising the following components in parts by mass: 1.5 to 2.0 parts of Gd, 1.8 to 2.2 parts of Nd, 0.6 to 0.8 parts of Zn, 2.2 to 2.4 parts of Al, 1.1 to 1.2 parts of Nb, 0.6 to 0.8 parts of Ca, and the balance being Mg.
[0007] Furthermore, a multi-component deformable magnesium alloy includes the following components in parts by mass: 1.8 parts of Gd, 2.2 parts of Nd, 0.7 parts of Zn, 2.4 parts of Al, 1.1 parts of Nb, 0.6 parts of Ca, and the balance is Mg.
[0008] The present invention also provides a method for preparing a multi-component deformable magnesium alloy, comprising weighing raw materials of various components and smelting and casting them into a cast alloy, and subjecting the cast alloy to solid solution treatment, hot extrusion and aging treatment to obtain the multi-component deformable magnesium alloy.
[0009] Further, magnesium, aluminum, zinc, Mg-Gd, Mg-Nd, Mg-Nb, Mg-Ca master alloys are used as raw materials for smelting and casting, and the specific steps are as follows: S1. Melting raw materials magnesium, aluminum and zinc in a medium frequency induction melting furnace under the protection of mixed gas; S2. When the melt temperature reaches 730-740°C, add Mg-Gd, Mg-Nd, Mg-Nb and Mg-Ca intermediate alloys to obtain alloy liquid. After keeping the temperature for 10-12 minutes, form the alloy in a steel mold preheated to 180-200°C to obtain a cast alloy.
[0010] Furthermore, the mixed gas in S1 is CO2 and SF6 in a volume ratio of 99:1.
[0011] Furthermore, the solution treatment is a graded solution treatment, wherein the first step of the solution treatment is at a temperature of 420-430°C and a holding time of 6-8 hours; the second step of the solution treatment is at a temperature of 490-505°C and a holding time of 3-4 hours.
[0012] Furthermore, the hot extrusion process is as follows: preheating the solution treated cast alloy at 380-410°C for 1-2h, hot extruding at 380-410°C, with an extrusion rate of 0.5-1.0mm / s, and air cooling to room temperature after extrusion.
[0013] Furthermore, the aging treatment temperature is 190-210° C., and the treatment time is 12-14 hours.
[0014] The beneficial effects of the present invention are: (1) The multi-component deformable magnesium alloy of the present invention has simple components, the content of rare earth elements Gd and Nd added in the alloy is not high, and the overall price is low. The mechanical properties of the magnesium alloy are improved by a multi-component alloying method. In addition, the present invention adopts a light rare earth element Nd and a heavy rare earth element Gd for composite addition. The maximum solid solubility of Nd and Gd in magnesium is 7.6wt% and 23wt%, respectively. In the present invention, the addition amount of the rare earth element Nd is 1.8-2.2%, which can ensure the formation amount of Nd-containing strengthening phase in the alloy, and the addition amount of the rare earth element Gd is 1.5-2.0%, which can control the alloy cost while ensuring the strengthening effect. The reasonable combination of light and heavy rare earth elements can promote the precipitation and quantity of strengthening phases, which is beneficial to improving the strength of the alloy; (2) The multi-component deformable magnesium alloy of the present invention also adds 0.6-0.8% Zn. The addition of a small amount of Zn element can improve the plasticity of the magnesium alloy. The multi-component deformable magnesium alloy of the present invention also contains 2.2-2.4% Al and 1.1-1.2% Nb. The composite addition of appropriate amounts of Al and Nb forms Al-Nb compounds in the alloy structure, refines the alloy structure, and improves the mechanical properties. On the other hand, it reduces β(Mg 17 Al 12 ) phase, eliminating the β(Mg 17 Al 12 ) phase, which is beneficial to the subsequent hot extrusion treatment; (3) The multi-component deformable magnesium alloy of the present invention also contains 0.6-0.8% Ca. The addition of Ca element can promote the refinement of the structure and form Mg-Ca precipitation phase. The reasonable addition of multiple components can not only achieve the effect of grain refinement, but also form a high melting point strengthening phase in the structure, give full play to the strengthening effect of rare earth elements, and utilize the comprehensive effect of multi-component alloying to improve the strength and plasticity of the alloy. On the basis of controlling the amount of rare earth added, the room temperature tensile strength of the alloy exceeds 400MPa, and the elongation after fracture exceeds 7%; (4) The solution treatment of the multi-component deformable magnesium alloy of the present invention adopts a two-step solution treatment process of first low temperature and then high temperature. 17 Al 12 The melting point of the phase is low, and the Mg-Ca precipitation phase is prone to overburning during the solid solution process. The solid solution treatment is also divided into two stages, low and high, at 420-430℃ and 490-505℃ respectively. Different holding times are optimized so that the precipitation phase can not only be fully dissolved into the matrix, but also prevent the grain length and low melting point phase from being dissolved and overburned, thereby obtaining a good solid solution effect and preparing the organization for subsequent hot extrusion; (5) The multi-component deformable magnesium alloy of the present invention has widely available raw materials, low alloy production cost, and a mature and stable alloy preparation process, which has a basis for mass production. DETAILED DESCRIPTION
[0015] The invention provides a multi-element deformable magnesium alloy, comprising the following components in parts by mass: 1.5 to 2.0 parts of Gd, 1.8 to 2.2 parts of Nd, 0.6 to 0.8 parts of Zn, 2.2 to 2.4 parts of Al, 1.1 to 1.2 parts of Nb, 0.6 to 0.8 parts of Ca, and the balance being Mg.
[0016] Furthermore, a multi-component deformable magnesium alloy includes the following components in parts by mass: 1.8 parts of Gd, 2.2 parts of Nd, 0.7 parts of Zn, 2.4 parts of Al, 1.1 parts of Nb, 0.6 parts of Ca, and the balance is Mg.
[0017] The present invention also provides a method for preparing a multi-element deformable magnesium alloy, which uses magnesium, aluminum, zinc, Mg-Gd, Mg-Nd, Mg-Nb, and Mg-Ca master alloy as raw materials for smelting and casting into a cast alloy, and then subjecting the cast alloy to solid solution treatment, hot extrusion, and aging treatment to obtain a magnesium alloy, and the specific steps are: S1. Under the protection of a mixed gas of CO2 and SF6 with a volume ratio of 99:1, the raw materials of magnesium, aluminum and zinc are melted in a medium frequency induction melting furnace; when the melt temperature reaches 730-740°C, Mg-Gd, Mg-Nd, Mg-Nb and Mg-Ca intermediate alloys are added to obtain alloy liquid, which is kept warm for 10-12 minutes and then formed in a steel mold preheated to 180-200°C to obtain a cast alloy.
[0018] S2, performing solution treatment, wherein the solution treatment is a graded solution treatment, wherein the first step of the solution treatment is at a temperature of 420-430°C and a holding time of 6-8h; and the second step of the solution treatment is at a temperature of 490-505°C and a holding time of 3-4h.
[0019] S3. Perform hot extrusion, preheat the solution treated cast alloy at 380-410°C for 1-2h, and perform hot extrusion at 380-410°C with an extrusion rate of 0.5-1.0mm / s, and air cool to room temperature after extrusion.
[0020] S4, performing aging treatment, wherein the aging treatment temperature is 190-210° C., and the treatment time is 12-14 hours.
[0021] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention is clearly and completely described below.
[0022] Example 1 A multi-component deformable magnesium alloy consists of the following components in percentage by mass: 1.8% Gd, 2.2% Nd, 0.7% Zn, 2.4% Al, 1.1% Nb, 0.6% Ca, and the balance is Mg.
[0023] The preparation method of the multi-element deformable magnesium alloy: (1) Preparation of cast alloy: Under the protection of a mixed gas of CO2 and SF6 with a volume ratio of 99:1, the raw materials magnesium, aluminum and zinc are melted in a medium frequency induction melting furnace, and then the temperature is raised to 730°C, and Mg-Gd, Mg-Nd, Mg-Nb and Mg-Ca intermediate alloys are added to obtain an alloy liquid. The alloy liquid is kept warm for 12 minutes and formed in a steel mold preheated to 180°C to obtain a cast alloy.
[0024] (2) Solution treatment: The first step of solution treatment is at 420°C and the holding time is 8 hours. The second step of solution treatment is at 490°C and the holding time is 4 hours.
[0025] (3) Hot extrusion: The alloy ingot after solution treatment was preheated at 380°C for 2 h, and hot extruded at 380°C with an extrusion rate of 0.5 mm / s. After extrusion, it was air-cooled to room temperature to obtain a deformed magnesium alloy.
[0026] (4) Aging treatment: The treatment temperature is 190°C and the treatment time is 14h.
[0027] Example 2 A multi-element deformable magnesium alloy is composed of the following components in percentage by mass: 1.5% Gd, 2.0% Nd, 0.8% Zn, 2.3% Al, 1.2% Nb, 0.7% Ca, and the balance is Mg.
[0028] The preparation method of the multi-element deformable magnesium alloy: (1) Preparation of cast alloy: Under the protection of a mixed gas of CO2 and SF6 with a volume ratio of 99:1, the raw materials magnesium, aluminum and zinc are melted in a medium frequency induction melting furnace, and then the temperature is raised to 730°C, and Mg-Gd, Mg-Nd, Mg-Nb and Mg-Ca intermediate alloys are added to obtain an alloy liquid. The alloy liquid is kept warm for 12 minutes and formed in a steel mold preheated to 200°C to obtain a cast alloy.
[0029] (2) Solution treatment: The first step of solution treatment is at 420°C and the holding time is 8 hours. The second step of solution treatment is at 495°C and the holding time is 4 hours.
[0030] (3) Hot extrusion: The alloy ingot after solution treatment was preheated at 390°C for 2 h, and hot extruded at 390°C with an extrusion rate of 0.8 mm / s. After extrusion, it was air-cooled to room temperature to obtain a deformed magnesium alloy.
[0031] (4) Aging treatment: The treatment temperature is 200°C and the treatment time is 13h.
[0032] Example 3 A multi-component deformable magnesium alloy consists of the following components in percentage by mass: 2.0% Gd, 1.8% Nd, 0.6% Zn, 2.4% Al, 1.1% Nb, 0.8% Ca, and the balance is Mg.
[0033] The preparation method of the multi-element deformable magnesium alloy: (1) Preparation of cast alloy: Under the protection of a mixed gas of CO2 and SF6 with a volume ratio of 99:1, the raw materials magnesium, aluminum and zinc are melted in a medium frequency induction melting furnace, and then the temperature is raised to 740°C, and Mg-Gd, Mg-Nd, Mg-Nb and Mg-Ca intermediate alloys are added to obtain an alloy liquid. The alloy liquid is kept warm for 10 minutes and formed in a steel mold preheated to 180°C to obtain a cast alloy.
[0034] (2) Solution treatment: The first step of solution treatment: the temperature is 430℃, and the holding time is 6h. The second step of solution treatment: the temperature is 505℃, and the holding time is 3h.
[0035] (3) Hot extrusion: The alloy ingot after solution treatment was preheated at 400°C for 1 h, and hot extruded at 400°C with an extrusion rate of 0.8 mm / s. After extrusion, it was air-cooled to room temperature to obtain a deformed magnesium alloy.
[0036] (4) Aging treatment: The treatment temperature is 210°C and the treatment time is 12h.
[0037] Example 4 A multi-element deformable magnesium alloy is composed of the following components in percentage by mass: 2.0% Gd, 2.2% Nd, 0.6% Zn, 2.2% Al, 1.2% Nb, 0.7% Ca, and the balance is Mg.
[0038] The preparation method of the multi-element deformable magnesium alloy: (1) Preparation of cast alloy: Under the protection of a mixed gas of CO2 and SF6 with a volume ratio of 99:1, the raw materials magnesium, aluminum and zinc are melted in a medium frequency induction melting furnace, and then the temperature is raised to 740°C, and Mg-Gd, Mg-Nd, Mg-Nb and Mg-Ca intermediate alloys are added to obtain an alloy liquid. The alloy liquid is kept warm for 10 minutes and formed in a steel mold preheated to 200°C to obtain a cast alloy.
[0039] (2) Solution treatment: The first step of solution treatment: the temperature is 430℃, and the holding time is 6h. The second step of solution treatment: the temperature is 505℃, and the holding time is 3h.
[0040] (3) Hot extrusion: The alloy ingot after solution treatment was preheated at 410°C for 1 h, and hot extruded at 410°C with an extrusion rate of 1.0 mm / s. After extrusion, it was air-cooled to room temperature to obtain a deformed magnesium alloy.
[0041] (4) Aging treatment: The treatment temperature is 210°C and the treatment time is 12h.
[0042] Comparative Example The difference between this comparative example and Example 1 is that the solid solution treatment of the magnesium alloy in the comparative example adopts the solid solution treatment method commonly used for magnesium alloys, that is, the solid solution treatment temperature is 490° C. and the holding time is 8 hours.
[0043] Test example Tensile tests were carried out on Examples 1 to 4 of the multi-element deformed magnesium alloy and the comparative example. The specific test method is: the alloy is processed into a standard tensile specimen according to the national standard, and a room temperature tensile test is carried out on a Shimadzu AG-I 250kN electronic tensile testing machine. The tensile rate is 1mm / min. The test results are shown in Table 1, and the experimental results are compared with those of the commercial heat-resistant high-strength magnesium alloy WE54 (Mg-5Y-4RE-0.5Zr).
[0044] Table 1 Room temperature tensile mechanical properties of magnesium alloys of the present invention It can be seen from Table 1 that the multi-component deformed magnesium alloy obtained by the present invention has excellent room temperature mechanical properties, and its room temperature tensile strength exceeds 400MPa. Compared with the WE54 alloy, the multi-component deformed magnesium alloy of the present invention has a lower rare earth content and better mechanical properties. On the basis of controlling the rare earth addition amount, the multi-component deformed magnesium alloy of the present invention has a room temperature tensile strength of more than 400MPa and an elongation after fracture of more than 7%.
[0045] It should be noted that although the present invention is described by the above embodiments, the present invention may also have other various embodiments. Without departing from the spirit and scope of the present invention, it is obvious that those skilled in the art may make various corresponding changes and deformations to the present invention, but these changes and deformations should all fall within the scope of protection of the appended claims of the present invention and their equivalents.
Claims
1. A multi-component deformable magnesium alloy, characterized in that: The invention comprises the following components in parts by mass: 1.5 to 2.0 parts of Gd, 1.8 to 2.2 parts of Nd, 0.6 to 0.8 parts of Zn, 2.2 to 2.4 parts of Al, 1.1 to 1.2 parts of Nb, 0.6 to 0.8 parts of Ca, and the balance is Mg.
2. The multi-component deformable magnesium alloy according to claim 1, characterized in that: The composition includes the following components in parts by mass: 1.8 parts of Gd, 2.2 parts of Nd, 0.7 parts of Zn, 2.4 parts of Al, 1.1 parts of Nb, 0.6 parts of Ca, and the balance is Mg.
3. A method for preparing a multi-component deformable magnesium alloy according to any one of claims 1 to 2, characterized in that: The raw materials of various components are weighed and melted and cast into a cast alloy, and the cast alloy is subjected to a solid solution treatment, a hot extrusion and an aging treatment to obtain a multi-component deformable magnesium alloy.
4. The method for preparing a multi-component deformable magnesium alloy according to claim 3, characterized in that: Using magnesium, aluminum, zinc, Mg-Gd, Mg-Nd, Mg-Nb, and Mg-Ca master alloys as raw materials for smelting and casting, the specific steps are as follows: S1. Melting raw materials magnesium, aluminum and zinc in a medium frequency induction melting furnace under the protection of mixed gas; S2. When the melt temperature reaches 730-740°C, add Mg-Gd, Mg-Nd, Mg-Nb and Mg-Ca intermediate alloys to obtain alloy liquid. After keeping the temperature for 10-12 minutes, form the alloy in a steel mold preheated to 180-200°C to obtain a cast alloy.
5. The method for preparing a multi-component deformable magnesium alloy according to claim 4, characterized in that: The mixed gas in S1 is CO2 and SF6 with a volume ratio of 99:
1.
6. The method for preparing a multi-component deformable magnesium alloy according to claim 3, characterized in that: The solution treatment is a graded solution treatment, wherein the first step of the solution treatment is at a temperature of 420-430° C. and a holding time of 6-8 hours; and the second step of the solution treatment is at a temperature of 490-505° C. and a holding time of 3-4 hours.
7. The method for preparing a multi-component deformable magnesium alloy according to claim 3, characterized in that: The hot extrusion process is as follows: preheat the solution treated cast alloy at 380-410°C for 1-2h, and perform hot extrusion at 380-410°C with an extrusion rate of 0.5-1.0mm / s, and air cool to room temperature after extrusion.
8. The method for preparing a multi-component deformable magnesium alloy according to claim 3, characterized in that: The aging treatment temperature is 190-210° C., and the treatment time is 12-14 hours.