Preparation method for beryllium-aluminum alloy with high beryllium content

Abstract

Provided is a preparation method for a beryllium-aluminum alloy with high beryllium content. Under the action of the synergistic combination of ammonium fluoroberyllate and a refining agent, harmful impurities such as hydrogen and oxide inclusions are removed from a molten alloy. The synergistic combination of ammonium fluoroberyllate and the refining agent reduces the amount of the refining agent, realizes large gas evolution amount, and involves a simple refining process. By adding other metallic elements such as cobalt, nickel, and germanium in the preparation process of a beryllium-aluminum alloy and in combination with a specific casting process, the prepared beryllium-aluminum alloy with high beryllium content has excellent comprehensive performance.

Description

A method for preparing beryllium aluminum alloy with high beryllium content Technical Field

[0001] The invention belongs to the field of alloys, and in particular relates to a method for preparing a beryllium aluminum alloy with a high beryllium content. Background Art

[0002] High-beryllium-content beryllium aluminum alloys refer to those with a beryllium content of 60% or more. Their high beryllium content offers excellent properties. High-beryllium-content beryllium aluminum alloys, also known as Lockalloy, were first developed by Nuclear Metal Corporation in the United States. They contain approximately 62% beryllium. They possess excellent mechanical properties and are used in high-end manufacturing industries, such as aerospace and fighter aircraft. The main methods for manufacturing high-beryllium-content beryllium aluminum alloys include powder metallurgy and precision casting. Powder metallurgy yields high-quality alloys, but the process is complex. The core technology is currently largely controlled by foreign companies, and improper processing can make it difficult to produce high-quality high-beryllium-content beryllium aluminum alloys. Precision casting, however, is a simple process with low manufacturing costs and is widely used by domestic manufacturers. To produce high-quality high-beryllium-content beryllium aluminum alloys using precision casting, various alloying elements are often added and the processing is optimized to improve the various properties of the beryllium aluminum alloy, particularly to overcome the reduced toughness associated with high beryllium content.

[0003] Prior art reports have reported improving the properties of cast beryllium aluminum alloys by adding elements such as Ag, Mg, Ni, Co, and Ge. However, during the casting process, the melting points of beryllium and aluminum differ significantly: beryllium melts at 1287°C, while aluminum melts at 661°C. This leads to low mutual solubility and the absence of intermetallic compounds. The wide solidification temperature range of beryllium aluminum alloys can result in structural defects such as shrinkage cavities and porosity. Furthermore, aluminum tends to accumulate at the interface of the beryllium aluminum alloy, causing aluminum segregation and degrading various properties.

[0004] The casting process of beryllium aluminum alloys is carried out at high temperatures, which easily produces solid impurity particles and slag on the melt surface. This leads to structural defects such as inclusions and pores, resulting in a decrease in strength. Refining agents and deslagging agents are generally required for treatment. However, existing refining agent systems are not yet sufficient to meet the manufacturing requirements of beryllium aluminum alloys with high beryllium content.

[0005] The inventor's previous patent CN202311786007.6 disclosed a method for preparing a beryllium aluminum alloy. This method uses ammonium fluoroberyllate and a compounded refining agent to produce a beryllium aluminum alloy with excellent overall performance. However, as the beryllium content increases, further improvements to the preparation process are needed. To overcome the significant difference in the capacities of beryllium and aluminum, which results in very low solid solubility, the beryllium phase and the aluminum phase are essentially two separate pure phases. This patent uses a beryllium-tin-zinc mixed melt instead of a beryllium melt to mitigate the drawback of the significant difference in melting points. However, the inventors discovered that when the beryllium content increases to above 50%, the casting process in this patent becomes difficult to match, and it is impossible to produce a high-beryllium-content beryllium aluminum alloy with excellent performance. This may be because the small amount of Zn and Sn added is not suitable for the components of high-beryllium-content beryllium aluminum alloys. Therefore, further research is needed on the manufacturing process of high-beryllium-content beryllium aluminum alloys.

[0006] Summary of the Invention

[0007] To address the lack of an effective method for manufacturing high-beryllium-content beryllium aluminum alloys in the prior art, the present invention improves various properties of high-beryllium-content beryllium aluminum alloys, particularly their poor toughness, by adding a refining agent and ammonium fluoroberyllate in a synergistic compound and optimizing the casting process. The present invention achieves the above-mentioned objectives through the following technical solutions:

[0008] A method for preparing a beryllium aluminum alloy with a high beryllium content comprises the following steps:

[0009] (S1) mixing 10-15 parts by mass of aluminum, 1.1-1.7 parts by mass of cobalt, and 2-3 parts by mass of nickel, and vacuum melting at 1450-1550° C. to obtain an aluminum-cobalt-nickel mixed melt;

[0010] (S2) 5-8 parts by mass of aluminum and 0.4-0.7 parts by mass of ammonium fluoroberyllate are uniformly mixed, and vacuum smelted at 660-720° C. to obtain an aluminum melt containing ammonium fluoroberyllate.

[0011] (S3) uniformly mixing 70-75 parts by mass of beryllium, 15-20 parts by mass of aluminum, and 3-5 parts by mass of germanium, and vacuum melting at 1450-1550° C. to form a melt, adding the aluminum-cobalt-nickel mixed melt of step (S1), and heat-treating at 1450-1550° C. for 1-2 hours, adding the aluminum melt containing ammonium fluoroberyllate of step (S2), continuing to melt, removing surface scum, adding 0.5-0.8 parts by mass of a refining agent, and heat-refining to obtain a mixed melt;

[0012] (S4) pouring the mixed melt obtained in step (S3) into a mold, first cooling it slowly, and then cooling it rapidly to obtain a beryllium aluminum alloy blank;

[0013] (S5) Degassing and hot isostatic pressing the beryllium aluminum alloy blank obtained in step (S4) to obtain a beryllium aluminum alloy with a high beryllium content.

[0014] The inventors unexpectedly discovered that preparing an alloy by mixing aluminum, cobalt, and nickel in the form of a mixed melt produces a product with better performance than directly mixing the raw materials and then smelting them.

[0015] In the present invention, the metallic aluminum raw material is added in three parts, one part is made into an aluminum-cobalt-nickel mixed melt, one part is made into an aluminum melt containing ammonium fluoroberyllate, and the remaining part is mixed with beryllium and germanium to make a beryllium-aluminum-germanium mixed melt.

[0016] Ammonium fluoroberyllate decomposes into beryllium fluoride and ammonium fluoride at 900°C. Ammonium fluoride does not dissolve in the melt and will not introduce new impurities. It achieves the purpose of removing impurities and exhausting gases through floating. The inventor unexpectedly found that the various strength performance indicators of the obtained beryllium aluminum alloy are improved to a certain extent when ammonium fluoroberyllate is combined with a refining agent. The refining agent of the present invention does not add conventional refining agents such as hexachloroethane, and does not introduce carbon elements, thereby reducing the structural defect problems caused by the introduction of carbon elements. Fluorides can react with impurities in the aluminum liquid to form fluorides or fluoride oxides, accelerating the separation of impurities and the alloy liquid; the presence of fluorides can also increase the surface tension between the refining agent and the alloy liquid, making the refining agent and the alloy liquid easy to separate, accelerating the refining agent to adsorb hydrogen and oxide inclusions in the alloy liquid, reducing beryllium metal loss, and reducing manufacturing costs. In the present invention, if ammonium fluoroberyllate is directly added to the mixed melt, due to the high temperature, it is easy to release gas instantly on the melt surface, affecting the strength and failing to fully exert its synergistic effect with the refining agent. Therefore, during the preparation of the beryllium aluminum alloy of the present invention, ammonium fluoroberyllate is mixed with a portion of aluminum. Since the melting point of aluminum is approximately 660°C, ammonium fluoroberyllate does not decompose during the melting process, and an aluminum melt containing ammonium fluoroberyllate is obtained after melting. The ammonium fluoroberyllate of the present invention is used in combination with a specific refining agent, which reduces the amount of refining agent used, generates a large amount of gas, and simplifies the refining process.

[0017] Furthermore, in the above preparation method, beryllium accounts for 60-65 wt%, preferably 62-63 wt%, of the total mass of the metal raw materials.

[0018] Furthermore, the purity of the metal raw materials used in the present invention is ≥99.9%, preferably ≥99.99%. The use of high-purity metal raw materials reduces the impurity content in the product, which helps to improve the quality of the alloy.

[0019] Furthermore, vacuum melting is carried out in a vacuum induction furnace with a vacuum degree of 1×10 -3 to 1×10 -2 Pa.

[0020] Furthermore, in step (S3), the refining agent is a mixture of sodium fluoroborate, borax, and beryllium salt, and the beryllium salt is selected from at least one of sodium beryllium salt and potassium beryllium salt.

[0021] Furthermore, the refining agent is a mixture of sodium fluoroborate, borax, and beryllium salt in a mass ratio of 32-45:11-17:13-20.

[0022] Furthermore, the refining agent is obtained by a preparation method comprising the following steps: mixing sodium fluoroborate, borax, and beryllium salt, followed by high-temperature dehydration. Furthermore, the mixing is performed by ball milling, and the process conditions for ball milling are well known in the art. For example, in one embodiment of the present invention, the ball-to-material ratio is 20-40:1, the rotation speed is 400-600 rpm, and the ball milling time is 2-4 hours. The high-temperature dehydration is performed under a protective atmosphere at 300-350°C for 4-10 hours, and the resulting refining agent has a water content of ≤10 ppm.

[0023] Furthermore, in step (S3), the refining agent can be added by evenly spreading it on the melt surface and then pressing it into the melt. Alternatively, the refining agent can be sprayed into the melt using a jet. Using a jet is preferred, as this results in a more even distribution of the refining agent and a better refining effect. The heat-insulating refining temperature is maintained at 1100-1200°C for 1-2 hours.

[0024] Furthermore, in step (S4), the mold is made of ceramic, and slow cooling is performed using magnetic field cooling at a controlled cooling rate of 1-5°C / s to a temperature of 1000-1050°C. Rapid cooling is then performed using strong air cooling at a cooling rate of 140-180°C / s. The present invention utilizes a method of first slow cooling and then rapid cooling to enhance the solution treatment of the alloy and strengthen the interaction between the beryllium phase and other metal phases.

[0025] Furthermore, in step (S5), the degassing temperature is 500-600°C, and the vacuum degree is ≤5×10 -3 Pa, degassing time 3-5h; the temperature of the hot isostatic pressing treatment is 600-700℃, the pressure is 120-150MPa, and the treatment time is 3-5h.

[0026] Furthermore, steps (S1) to (S4) are all carried out under a protective atmosphere, and the protective atmosphere is argon and / or nitrogen.

[0027] Compared with the prior art, the present invention has achieved the following technical advancements:

[0028] 1. The present invention removes harmful impurities in the molten alloy liquid, such as hydrogen and oxide inclusions, through the synergistic compounding effect of ammonium fluoroberyllate and refining agent through a series of physical and chemical reactions. The two work together to reduce the amount of refining agent used, increase the gas emission, and simplify the refining process.

[0029] 2. The present invention adds other metal elements such as cobalt, nickel and germanium to the beryllium aluminum alloy preparation process and combines it with a specific casting process to make the high beryllium content beryllium aluminum alloy prepared by the present invention have excellent comprehensive properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG1 is a photograph of the beryllium aluminum alloy ingot with high beryllium content obtained in Example 1. DETAILED DESCRIPTION

[0031] The present invention is further explained and illustrated with reference to specific embodiments below.

[0032] In the embodiments of the present invention, parts are by mass unless otherwise specified; % are by mass unless otherwise specified.

[0033] The purity of the materials used in the embodiments of the present invention is ≥99.9%.

[0034] Preparation Example Preparation of Refining Agent

[0035] Sodium fluoroborate, borax and beryllium salt are evenly mixed by ball milling. The process conditions of ball milling are ball-to-material ratio of 30:1, rotation speed of 400 rpm, ball milling time of 4 hours, heat treatment at 300°C for 6 hours under high nitrogen atmosphere, so that the water content of the refining agent is ≤10ppm.

[0036] Example 1

[0037] (S1) 15 parts by mass of aluminum, 1.1 parts by mass of cobalt, and 3 parts by mass of nickel were mixed uniformly and vacuum melted at 1500°C (vacuum degree ≤ 1×10 -3 Pa), to obtain an aluminum-cobalt-nickel mixed melt;

[0038] (S2) 5 parts by mass of aluminum and 0.4 parts by mass of ammonium fluoroberyllate were uniformly mixed and vacuum-melted at 710° C. to obtain an aluminum melt containing ammonium fluoroberyllate.

[0039] (S3) 70 parts by mass of beryllium, 15 parts by mass of aluminum, and 3 parts by mass of germanium are uniformly mixed, vacuum-smelted at 1500° C. to form a melt, the aluminum-cobalt-nickel mixed melt of step (S1) is added, and the mixture is heat-treated at 1500° C. for 2 hours, and the aluminum melt containing ammonium fluoroberyllate of step (S2) is added, and the smelting is continued, and surface scum is removed, and 0.8 parts by mass of a refining agent is sprayed into the melt using a sprayer, wherein the refining agent is a mixture of sodium fluoroborate, borax, and potassium beryllium in a mass ratio of 32:17:13, and the mixture is heat-treated and refined for 2 hours to obtain a mixed melt;

[0040] (S4) pouring the mixed melt obtained in step (S3) into a ceramic mold, first slowly cooling the mixture in a magnetic field at a cooling rate of 1-2°C / s to 1050°C, then rapidly cooling the mixture in a strong wind at a cooling rate of about 180°C / s to room temperature to obtain an alloy blank;

[0041] (S5) The alloy blank obtained in step (S4) is placed in a low-carbon steel jacket and degassed in a vacuum muffle furnace at a temperature of 500° C. and a vacuum degree of ≤5×10 -3 Pa, degassing time 5h, sealing after degassing treatment is completed; the low carbon steel jacket is placed in a hot isostatic pressing equipment, hot isostatic pressing treatment is carried out at 600℃ and pressure 150MPa for 5h, and the low carbon steel jacket is removed after natural cooling to obtain the product beryllium aluminum alloy with high beryllium content.

[0042] Example 2

[0043] (S1) 10 parts by mass of aluminum, 1.7 parts by mass of cobalt, and 2 parts by mass of nickel were mixed uniformly and vacuum melted at 1500°C (vacuum degree ≤ 1×10 -3 Pa), to obtain an aluminum-cobalt-nickel mixed melt;

[0044] (S2) 8 parts by mass of aluminum and 0.7 parts by mass of ammonium fluoroberyllate are uniformly mixed and vacuum-smelted at 700° C. to obtain an aluminum melt containing ammonium fluoroberyllate.

[0045] (S3) 70 parts by mass of beryllium, 15 parts by mass of aluminum, and 5 parts by mass of germanium are uniformly mixed, vacuum-smelted at 1500° C. to form a melt, the aluminum-cobalt-nickel mixed melt of step (S1) is added, and the mixture is heat-treated at 1500° C. for 2 hours, and the aluminum melt containing ammonium fluoroberyllate of step (S2) is added, and the smelting is continued, and surface scum is removed. 0.5 parts by mass of a refining agent is sprayed into the melt using a sprayer, wherein the refining agent is a mixture of sodium fluoroborate, borax, and potassium beryllium in a mass ratio of 45:11:20, and the mixture is heat-treated and refined for 2 hours to obtain a mixed melt;

[0046] (S4) pouring the mixed melt obtained in step (S3) into a ceramic mold, first slowly cooling the mixed melt in a magnetic field at a cooling rate of 1-2°C / s to 1000°C, then rapidly cooling the mixed melt in a strong wind at a cooling rate of about 180°C / s to room temperature to obtain an alloy blank;

[0047] (S5) The alloy blank obtained in step (S4) is placed in a low-carbon steel jacket and degassed in a vacuum muffle furnace at a temperature of 500° C. and a vacuum degree of ≤5×10 -3 Pa, degassing time 5h, sealing after degassing treatment is completed; the low carbon steel jacket is placed in a hot isostatic pressing equipment, hot isostatic pressing treatment is carried out at 600℃ and pressure 150MPa for 5h, and the low carbon steel jacket is removed after natural cooling to obtain the product beryllium aluminum alloy with high beryllium content.

[0048] Example 3

[0049] (S1) 13 parts by mass of aluminum, 1.5 parts by mass of cobalt, and 2.7 parts by mass of nickel were mixed uniformly and vacuum melted at 1500°C (vacuum degree ≤ 1×10 -3 Pa), to obtain an aluminum-cobalt-nickel mixed melt;

[0050] (S2) 7 parts by mass of aluminum and 0.6 parts by mass of ammonium fluoroberyllate were mixed uniformly, and vacuum-melted at 710° C. to obtain an aluminum melt containing ammonium fluoroberyllate.

[0051] (S3) 73 parts by mass of beryllium, 16 parts by mass of aluminum, and 4 parts by mass of germanium are uniformly mixed, vacuum-smelted at 1500° C. to form a melt, the aluminum-cobalt-nickel mixed melt of step (S1) is added, and the mixture is heat-treated at 1500° C. for 2 hours, and the aluminum melt containing ammonium fluoroberyllate of step (S2) is added, and the smelting is continued, and surface scum is removed, and 0.6 parts by mass of a refining agent is sprayed into the melt using a jet, wherein the refining agent is a mixture of sodium fluoroborate, borax, and potassium beryllium in a mass ratio of 40:15:15, and the mixture is heat-treated and refined for 2 hours to obtain a mixed melt;

[0052] (S4) pouring the mixed melt obtained in step (S3) into a ceramic mold, first slowly cooling the mixed melt in a magnetic field at a cooling rate of 1-2°C / s to 1000°C, then rapidly cooling the mixed melt in a strong wind at a cooling rate of about 180°C / s to room temperature to obtain an alloy blank;

[0053] (S5) The alloy blank obtained in step (S4) is placed in a low-carbon steel jacket and degassed in a vacuum muffle furnace at a temperature of 500° C. and a vacuum degree of ≤5×10 -3 Pa, degassing time 5h, sealing after degassing treatment is completed; the low carbon steel jacket is placed in a hot isostatic pressing equipment, hot isostatic pressing treatment is carried out at 600℃ and pressure 150MPa for 5h, and the low carbon steel jacket is removed after natural cooling to obtain the product beryllium aluminum alloy with high beryllium content.

[0054] Comparative Example 1

[0055] Other conditions are the same as those in Example 3, except that in step (S4), the cooling method is natural cooling to room temperature.

[0056] Comparative Example 2

[0057] (S1) 20 parts by mass of aluminum, 1.5 parts by mass of cobalt, and 2.7 parts by mass of nickel were mixed uniformly and vacuum melted at 1500°C (vacuum degree ≤ 1×10 -3 Pa), to obtain an aluminum-cobalt-nickel mixed melt;

[0058] (S2) 73 parts by mass of beryllium, 16 parts by mass of aluminum, and 4 parts by mass of germanium are uniformly mixed, and vacuum-smelted at 1500° C. to form a melt, and the aluminum-cobalt-nickel mixed melt of step (S1) is added, and the mixture is kept at 1500° C. for 2 hours, and the surface scum is removed. 1.2 parts by mass of a refining agent is sprayed into the melt using a sprayer, and the refining agent is a mixture of sodium fluoroborate, borax, and potassium beryllium in a mass ratio of 40:15:15. The mixture is kept and refined for 2 hours to obtain a mixed melt;

[0059] (S3) pouring the mixed melt obtained in step (S2) into a ceramic mold, first slowly cooling the mixed melt in a magnetic field at a cooling rate of 1-2°C / s to 1000°C, then rapidly cooling the mixed melt in a strong wind at a cooling rate of about 180°C / s to room temperature to obtain an alloy blank;

[0060] (S4) The alloy blank obtained in step (S3) is placed in a low carbon steel jacket and degassed in a vacuum muffle furnace at a temperature of 500° C. and a vacuum degree of ≤5×10 -3 Pa, degassing time 5h, sealing after degassing treatment is completed; the low carbon steel jacket is placed in a hot isostatic pressing equipment, hot isostatic pressing treatment is carried out at 600℃ and pressure 150MPa for 5h, and the low carbon steel jacket is removed after natural cooling to obtain the product beryllium aluminum alloy with high beryllium content.

[0061] That is, compared with Example 3, no ammonium fluoroberyllate was added in Comparative Example 2, and the amount of the scouring agent used was 1.2 parts by mass, which was the sum of the amounts of ammonium fluoroberyllate and the scouring agent used in Example 3.

[0062] Comparative Example 3

[0063] (S1) 7 parts by mass of aluminum and 0.6 parts by mass of ammonium fluoroberyllate were uniformly mixed and vacuum-melted at 710° C. to obtain an aluminum melt containing ammonium fluoroberyllate.

[0064] (S2) 73 parts by mass of beryllium, 29 parts by mass of aluminum, 4 parts by mass of germanium, 1.5 parts by mass of cobalt, and 2.7 parts by mass of nickel are uniformly mixed, vacuum-smelted at 1500° C. to form a melt, and heat-treated at 1500° C. for 2 hours. The aluminum melt containing ammonium fluoroberyllate from step (S1) is added, and the smelting is continued. Surface scum is removed, and 0.6 parts by mass of a refining agent is sprayed into the melt using a sprayer. The refining agent is a mixture of sodium fluoroborate, borax, and potassium beryllium in a mass ratio of 40:15:15. The mixture is heat-treated and refined for 2 hours to obtain a mixed melt.

[0065] (S3) pouring the mixed melt obtained in step (S2) into a ceramic mold, first slowly cooling the mixed melt in a magnetic field at a cooling rate of 1-2°C / s to 1000°C, then rapidly cooling the mixed melt in a strong wind at a cooling rate of about 180°C / s to room temperature to obtain an alloy blank;

[0066] (S4) The alloy blank obtained in step (S3) is placed in a low carbon steel jacket and degassed in a vacuum muffle furnace at a temperature of 500° C. and a vacuum degree of ≤5×10 -3 Pa, degassing time 5h, sealing after degassing treatment is completed; the low carbon steel jacket is placed in a hot isostatic pressing equipment, hot isostatic pressing treatment is carried out at 600℃ and pressure 150MPa for 5h, and the low carbon steel jacket is removed after natural cooling to obtain the product beryllium aluminum alloy with high beryllium content.

[0067] That is, compared with Example 3, Comparative Example 3 eliminates the step (S1) of preparing the aluminum-cobalt-nickel mixed melt, and directly feeds nickel and cobalt together for smelting in step (S2).

[0068] Application Examples

[0069] The properties of the high beryllium content beryllium alloys obtained in the above examples and comparative examples were tested, and the results are shown in Table 1 below:

[0070] Table 1 Performance test of high beryllium content beryllium aluminum alloy

[0071] It can be seen that the high-beryllium-content beryllium aluminum alloy produced by the preparation method of the present invention has very excellent comprehensive mechanical properties. By increasing the beryllium content to above 60%, adding germanium, cobalt, and nickel, using ammonium fluoroberyllate and a specific refining agent, and first preparing an aluminum-cobalt-nickel mixed melt, a high-beryllium-content beryllium aluminum alloy product with excellent mechanical properties is obtained. The preparation method of the high-beryllium-content beryllium aluminum alloy proposed by the present invention is simple and has low equipment requirements, which can meet the needs of large-scale production of high-quality high-beryllium-content beryllium aluminum alloys.

Claims

1. A preparation method of a beryllium-aluminum alloy with a high beryllium content, characterized in that, It includes the following steps: (S1) Mix 10 - 15 parts by mass of aluminum, 1.1 - 1.7 parts by mass of cobalt, and 2 - 3 parts by mass of nickel evenly, and melt them under vacuum at 1450 - 1550 °C to obtain an aluminum-cobalt-nickel mixed melt; (S2) Mix 5 - 8 parts by mass of aluminum and 0.4 - 0.7 parts by mass of ammonium fluoberyllate evenly, and melt them under vacuum at 660 - 720 °C to obtain an aluminum melt containing ammonium fluoberyllate, (S3) Mix 70 - 75 parts by mass of beryllium, 15 - 20 parts by mass of aluminum, and 3 - 5 parts by mass of germanium evenly, melt them into a melt under vacuum at 1450 - 1550 °C, add the aluminum-cobalt-nickel mixed melt in step (S1), keep it warm at 1450 - 1550 °C for 1 - 2 h, add the aluminum melt containing ammonium fluoberyllate in step (S2), continue melting, remove the surface scum, add 0.5 - 0.8 parts by mass of a refining agent, keep it warm and refine to obtain a mixed melt; (S4) Pour the mixed melt obtained in step (S3) into a mold, cool it slowly first and then quickly to obtain a beryllium-aluminum alloy blank; (S5) Perform degassing treatment and hot isostatic pressing on the beryllium-aluminum alloy blank obtained in step (S4) to obtain a beryllium-aluminum alloy with a high beryllium content.

2. The preparation method of the beryllium-aluminum alloy with a high beryllium content according to claim 1, characterized in that, Beryllium accounts for 60 - 65 wt% of the total mass of the metal raw materials, preferably 62 - 63 wt%.

3. The preparation method of the beryllium-aluminum alloy with a high beryllium content according to claim 1, wherein The purity of the metal raw materials used in the present invention is ≥99.9%.

4. The preparation method of the beryllium-aluminum alloy with a high beryllium content according to claim 1, characterized in that, The vacuum melting is carried out in a vacuum induction furnace with a vacuum degree of 1×10 -3 to 1×10 -2 Pa.

5. The preparation method of the beryllium-aluminum alloy with a high beryllium content according to claim 1, characterized in that, In step (S3), the refining agent is a mixture of sodium fluoroborate, borax, and beryllate, and the beryllate is selected from at least one of sodium beryllate and potassium beryllate.

6. The preparation method of the beryllium-aluminum alloy with a high beryllium content according to claim 5, wherein, The refining agent is a mixture of sodium fluoroborate, borax, and beryllate in a mass ratio of 32 - 45:11 - 17:13 - 20.

7. The preparation method of the beryllium-aluminum alloy with a high beryllium content according to claim 5, characterized in that, The refining agent is obtained by a preparation method including the following steps: mix sodium fluoroborate, borax, and beryllate, and perform high-temperature dehydration.

8. The preparation method of the beryllium-aluminum alloy with a high beryllium content according to claim 1, characterized in that, In step (S3), the refining agent can be evenly spread on the surface of the melt and pressed into the melt; or a spraying machine can be used to spray the refining agent into the melt.

9. The preparation method of the beryllium-aluminum alloy with a high beryllium content according to claim 1, characterized in that, In step (S4), the material of the mold is ceramic. Slow cooling is carried out by magnetic field cooling, and the cooling rate is controlled at 1 - 5 °C / s. Slow cooling is carried out to 1000 - 1050 °C, and then rapid cooling is carried out. Rapid cooling is carried out by strong wind cooling, and the cooling rate is 140 - 180 °C / s.

10. The preparation method of the beryllium-aluminum alloy with a high beryllium content according to claim 1, characterized in that, In step (S5), the temperature of the degassing treatment is 500 - 600 °C, the vacuum degree ≤ 5×10 -3 Pa, and the degassing time is 3 - 5 h; the temperature of the hot isostatic pressing treatment is 600 - 700 °C, the pressure is 120 - 150 MPa, and the treatment time is 3 - 5 h.

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