A be-al-mg alloy powder and a method for producing the same

Abstract

The application provides a Be-Al-Mg alloy powder and a preparation method thereof, and belongs to the technical field of beryllium alloy materials.The preparation method comprises the following steps: S1, preparing materials; S2, vacuumizing and heating the Be and Al loaded into a smelting crucible to 1060-1140 DEG C, then closing the vacuum, filling argon into the smelting crucible, adding Mg under the conditions of a pressure greater than 5000 Pa and a temperature of 1310-1340 DEG C, and slowly rotating the crucible to obtain a Be-Al-Mg molten solution; and S3, atomizing, rapidly solidifying, cooling to room temperature and grading and screening the Be-Al-Mg molten solution in sequence after the Be-Al-Mg molten solution meets high-speed airflow after passing through an intermediate ladle, a flow guide pipe and an atomizing nozzle in sequence to obtain the Be-Al-Mg alloy powder.The Be-Al-Mg alloy powder is free of segregation and uniform in composition.

Description

Technical Field

[0001] This invention belongs to the field of beryllium alloy materials technology, and particularly relates to a Be-Al-Mg alloy powder and its preparation method. Background Technology

[0002] Be-Al alloys combine the toughness of aluminum with the high strength of beryllium, exhibiting high strength, high dimensional stability, lightweight properties, and good processing ductility. As a key core material in the aerospace field, they have been widely used.

[0003] Currently, the conventional method for preparing high-beryllium aluminum alloys involves mixing beryllium powder, aluminum powder, and magnesium powder. However, this method suffers from uneven mixing and component segregation. Adding magnesium during the traditional vacuum melting process can easily lead to magnesium volatilization, making it impossible to precisely control the alloy composition. Summary of the Invention

[0004] One of the objectives of this invention is to provide a method for preparing Be-Al-Mg alloy powder, which can effectively control the volatilization of magnesium, precisely control the alloy composition, and achieve the absence of segregation and uniform composition of the alloy powder.

[0005] The second objective of this invention is to provide a Be-Al-Mg alloy powder.

[0006] To achieve one of the above objectives, the present invention employs the following technical solution:

[0007] A method for preparing Be-Al-Mg alloy powder, the method being implemented using a vacuum atomization device, comprising the following steps:

[0008] Step S1: Prepare materials according to the following components and their mass percentages;

[0009] Be, 40~70wt%; Al, 20~50wt%; Mg, 4~10wt%;

[0010] Step S2: After loading the prepared Be and Al into the melting crucible, evacuate the vacuum and heat it to 1060-1140℃. Then close the vacuum and fill the melting crucible with argon gas. Add Mg at a pressure greater than 5000Pa and a temperature of 1310℃-1340℃, and keep it at that temperature for 1-3 minutes. Slowly rotate the crucible to obtain a Be-Al-Mg molten solution.

[0011] Step S3: After the Be-Al-Mg molten solution passes through the tundish, the guide tube and the atomizing nozzle in sequence, it is atomized, rapidly solidified, cooled to room temperature and graded and sieved to obtain Be-Al-Mg alloy powder.

[0012] Furthermore, in step S1, the purity of the Be ingot, Al ingot, and Mg block is greater than 99.0 wt%, 99.5 wt%, and 99.5 wt.%, respectively.

[0013] Furthermore, in step S2, the vacuum degree of the vacuum heating is ≤50Pa;

[0014] The pressure is 5050-5080 Pa.

[0015] Furthermore, the melting crucible is an Al2O3 crucible to prevent the solution from reacting with the crucible at high temperatures.

[0016] Furthermore, in step S2, the rotation angle of the slowly rotating crucible is ±30° to ensure that Be, Al and Mg are completely melted and mixed evenly. Maintaining positive pressure in the furnace with argon gas can effectively reduce the volatilization of Mg metal.

[0017] Furthermore, in step S3, the refractory material around the gap of the guide tube includes 85-95 mesh Al2O3 particles and 180-220 mesh Al2O3 powder.

[0018] The mass ratio of 85-95 mesh Al2O3 particles to 180-220 mesh Al2O3 powder is 3:1 to 8:1. Prepared using silica sol as a binder, this process ensures the strength of the refractory material while facilitating the recycling and reuse of the tundish. The tamping process of the refractory material needs to be completed before loading into the furnace, and the calcination of the refractory material in the tundish is completed during the metal melting process. Under the action of the induced draft fan, a negative pressure state will appear inside the melting chamber and the atomizing tower.

[0019] Furthermore, the material of the guide tube is beryllium oxide;

[0020] The diameter of the guide tube is 3-6 mm, which avoids chemical reaction between the melt and the guide tube. At the same time, the diameter of the guide tube can control the flow rate. By controlling the flow rate and argon pressure, the particle size of the powder can be effectively controlled, and the proportion of small powder particles can be increased.

[0021] Furthermore, the atomization pressure is 4–5 MPa; the atomization temperature is 1210°C–1240°C.

[0022] The grading and sieving process in this invention involves sieving Be-Al-Mg alloy powder according to its particle size.

[0023] To achieve the second objective mentioned above, the present invention employs the following technical solution:

[0024] A Be-Al-Mg alloy powder, wherein the Be-Al-Mg alloy powder comprises the following components and their mass percentages:

[0025] Be, 40~70wt%; Al, 20~50wt%; Mg, 4~10wt%.

[0026] Furthermore, the mass percentages of Be, Al, and Mg are 46–64 wt%, 30–40 wt%, and 6–8 wt%, respectively.

[0027] In this invention, the atomized powder after grading and sieving is vacuum-sealed in a polypropylene packaging bag for later use.

[0028] The beneficial effects of this invention are:

[0029] This invention utilizes a slowly rotating melting crucible to ensure complete melting and uniform mixing of Be, Al, and Mg raw materials. The positive pressure maintained within the furnace by argon gas effectively reduces the volatilization of Mg and Al metals and controls the volatilization of magnesium and aluminum elements, ensuring precise control of the alloy composition. This results in alloy powder with no segregation and uniform composition, suitable for preparing beryllium-aluminum alloy series products with lower density and higher strength through hot pressing and hot isostatic pressing. Detailed Implementation

[0030] Example 1:

[0031] 1. Before charging the molten metal, the relevant gas lines should be checked to prevent leaks. The refractory material at the bottom of the tundish should also be prepared. Specifically, the refractory material for the tundish should consist of 85-mesh Al2O3 granules and 180-mesh Al2O3 powder, bound with silica sol in a 3:1 ratio, and tamped into shape. The diameter of the guide tube is 3mm.

[0032] 2. The raw materials are added in the order of Al raw material (46 wt.%) first and then Be raw material (50 wt.%) into a clean melting crucible. Mg blocks (4 wt.%) of a specified weight are added to the secondary feeding system above the melting crucible.

[0033] 3. First, turn on the slide valve pump, then turn on the Roots pump. When the vacuum degree is ≤50Pa, heat the melting crucible and tundish until the internal temperature of the crucible reaches 1060℃. Then, turn off the vacuum and fill with protective gas. After the furnace reaches atmospheric pressure, add an additional 5000Pa of pressure. When the temperature rises to 1310℃, stabilize the heating power and keep the temperature from changing significantly. Add the pre-loaded Mg metal from the secondary charging box on the top of the furnace. After it is fully melted, maintain the power for 1 minute. Slowly rotate the crucible to make the melt mix more evenly.

[0034] 4. The molten liquid is injected into an intermediate ladle located above the atomizing nozzle. The molten liquid flows out through a guide pipe at the bottom of the intermediate ladle and is atomized into fine Be-Al-Mg droplets upon encountering the high-speed gas flow at the atomizing nozzle. The Be-Al-Mg droplets rapidly solidify into Be-Al-Mg alloy powder within the atomization tower. The intermediate ladle is preheated to 1220℃ and maintained at this temperature throughout the atomization process. Under the action of the induced draft fan, a negative pressure state is created inside the melting chamber and the atomization tower. The pressure of the atomizing gas is selected to be 4 MPa.

[0035] 5. Refill the vacuum atomization equipment with the protective gas to atmospheric pressure. Once the vacuum atomization equipment has cooled naturally to room temperature, it can be opened to obtain Be-Al-Mg alloy powder. The vacuum atomization equipment includes a melting system, a vacuum system, an atomization system, a gas supply system, a cooling system, a powder cyclone collection system, and an integrated control system. The melting system includes a melting crucible and an intermediate ladle containing a medium-frequency induction heating device. The atomization system includes an atomizing nozzle, an atomization tower located below the atomizing nozzle, and an induced draft fan.

[0036] 6. The prepared Be-Al-Mg alloy powder is sieved according to particle size, then vacuum sealed for later use.

[0037] The Be-Al-Mg alloy powder in this embodiment has a sphericity of 0.86, a low oxygen content of 2000 ppm, and a uniform internal structure.

[0038] Example 2:

[0039] 1. Before loading the molten metal, the relevant gas lines should be checked to prevent leaks. The refractory material at the bottom of the tundish should also be prepared. Specifically, the refractory material for the tundish should consist of 90-mesh Al2O3 granules and 200-mesh Al2O3 powder, bound with silica sol in a ratio of 8:1, and tamped into shape. A 4mm diameter guide tube should be used.

[0040] 2. Add Al raw material (25 wt.%) first, then Be raw material (70 wt.%) into a clean melting crucible. Add Mg blocks (5 wt.%) of the specified weight into the secondary feeding system above the melting crucible.

[0041] 3. First, turn on the slide valve pump, then turn on the Roots pump. When the vacuum reaches 50 Pa, heat the melting crucible and tundish until the internal temperature of the crucible reaches 1120°C. Then, turn off the vacuum and fill with protective gas. After the furnace reaches atmospheric pressure, add an additional 5000 Pa of pressure. When the temperature rises to 1330°C, stabilize the heating power and keep the temperature from changing significantly. Add the pre-loaded Mg metal from the secondary charging box on the top of the furnace. After it is fully melted, maintain the power for 1 minute and slowly rotate the crucible to make the melt mix more evenly.

[0042] 4. Molten liquid is injected into an tundish located above the atomizing nozzle. The molten liquid flows out through a guide pipe at the bottom of the tundish and is atomized into fine Be-Al-Mg droplets upon encountering the high-speed gas flow at the atomizing nozzle. The Be-Al-Mg droplets rapidly solidify into Be-Al-Mg alloy powder within the atomization tower. The tundish is preheated to 1240℃ and maintained at this temperature throughout the atomization process. Under the action of the induced draft fan, a negative pressure is created inside the melting chamber and atomization tower. The pressure of the atomizing gas is 4 MPa.

[0043] 5. Refill the vacuum atomization equipment with protective gas to atmospheric pressure. Once the vacuum atomization equipment has cooled naturally to room temperature, it can be opened to obtain Be-Al-Mg alloy powder. The vacuum atomization equipment includes a melting system, a vacuum system, an atomization system, a gas supply system, a cooling system, a powder cyclone collection system, and an integrated control system. The melting system includes a melting crucible and an intermediate ladle containing a medium-frequency induction heating device. The atomization system includes an atomizing nozzle, an atomization tower located below the atomizing nozzle, and an induced draft fan.

[0044] 6. The prepared Be-Al-Mg alloy powder is sieved according to particle size, then vacuum sealed for later use.

[0045] The Be-Al-Mg alloy powder in this embodiment has a sphericity of 0.87, an oxygen content of 2100 ppm, and a uniform internal structure.

[0046] Example 3:

[0047] 1. Before loading the molten metal, the relevant gas lines should be checked to prevent leaks. The refractory material at the bottom of the tundish should also be prepared. Specifically, the refractory material for the tundish should consist of 90-mesh Al2O3 granules and 200-mesh Al2O3 powder, bound with silica sol in a ratio of 8:1, and tamped into shape. A 4mm diameter guide tube should be used.

[0048] 2. Add Al raw material (30 wt.%) first, then Be raw material (60 wt.%) into a clean melting crucible. Add Mg blocks (10 wt.%) in a specified proportion by weight through the secondary feeding system above the melting crucible.

[0049] 3. First, turn on the slide valve pump, then turn on the Roots pump. When the vacuum reaches 45Pa, heat the melting crucible and tundish until the internal temperature of the crucible reaches 1140℃. Then, turn off the vacuum and fill with protective gas. After the furnace reaches atmospheric pressure, add an additional 5080Pa of pressure. When the temperature rises to 1340℃, stabilize the heating power and keep the temperature from changing significantly. Add the pre-loaded Mg metal from the secondary charging box on the top of the furnace. After it is fully melted, maintain the power for 2 minutes. Slowly rotate the crucible to make the melt mix more evenly.

[0050] 4. The molten liquid is injected into an intermediate ladle located above the atomizing nozzle. The molten liquid flows out through a guide pipe at the bottom of the intermediate ladle and is atomized into fine Be-Al-Mg droplets upon encountering the high-speed gas flow at the atomizing nozzle. The Be-Al-Mg droplets rapidly solidify into Be-Al-Mg alloy powder within the atomization tower. The intermediate ladle is preheated to 1210℃ and maintained at this temperature throughout the atomization process. Under the action of the induced draft fan, a negative pressure state is created inside the melting chamber and the atomization tower. The pressure of the atomizing gas is 5 MPa.

[0051] 5. Refill the vacuum atomization equipment with the protective gas to atmospheric pressure. Once the vacuum atomization equipment has cooled naturally to room temperature, it can be opened to obtain Be-Al-Mg alloy powder. The vacuum atomization equipment includes a melting system, a vacuum system, an atomization system, a gas supply system, a cooling system, a powder cyclone collection system, and an integrated control system. The melting system includes a melting crucible and an intermediate ladle containing a medium-frequency induction heating device. The atomization system includes an atomizing nozzle, an atomization tower located below the atomizing nozzle, and an induced draft fan.

[0052] 6. The prepared Be-Al-Mg alloy powder is sieved according to particle size, then vacuum sealed for later use.

[0053] The Be-Al-Mg alloy powder in this embodiment has a sphericity of 0.84, an oxygen content of 2000 ppm, and a uniform internal structure.

[0054] Example 4:

[0055] 1. Before loading the molten metal, the relevant gas lines should be checked to prevent leaks. The refractory material at the bottom of the tundish should also be prepared. Specifically, the refractory material for the tundish should consist of 95-mesh Al2O3 granules and 220-mesh Al2O3 powder, bound with silica sol in a ratio of 8:1, and tamped into shape. A 6mm diameter guide tube should be used.

[0056] 2. Add Al raw material (35 wt.%) first, then Be raw material (60 wt.%) into a clean melting crucible. Add Mg blocks (5 wt.%) of the specified weight through the secondary feeding system above the melting crucible.

[0057] 3. First, turn on the slide valve pump, then turn on the Roots pump. When the vacuum reaches 40 Pa, heat the melting crucible and tundish until the internal temperature of the crucible reaches 1060°C. Then, turn off the vacuum and fill with protective gas. After the furnace reaches atmospheric pressure, add an additional pressure of 5060 Pa or more. When the temperature rises to 1330°C, stabilize the heating power and keep the temperature from changing significantly. Add the pre-loaded Mg metal from the secondary charging box on the top of the furnace. After it is fully melted, maintain the power for 3 minutes. Slowly rotate the crucible to make the melt mix more evenly.

[0058] 4. The molten liquid is injected into an intermediate ladle located above the atomizing nozzle. The molten liquid flows out through a guide pipe at the bottom of the intermediate ladle and is atomized into fine Be-Al-Mg droplets upon encountering the high-speed gas flow at the atomizing nozzle. The Be-Al-Mg droplets rapidly solidify into Be-Al-Mg alloy powder within the atomization tower. The intermediate ladle is preheated to 1230℃ and maintained at this temperature throughout the atomization process. Under the action of the induced draft fan, a negative pressure state is created inside the melting chamber and the atomization tower. The pressure of the atomizing gas is 4 MPa.

[0059] 5. Refill the vacuum atomization equipment with protective gas to atmospheric pressure. Once the equipment has cooled naturally to room temperature, it can be opened to obtain Be-Al-Mg alloy powder. The vacuum atomization equipment includes a melting system, a vacuum system, an atomization system, a gas supply system, a cooling system, a powder cyclone collection system, and an integrated control system. The melting system includes a melting crucible and an intermediate ladle containing a medium-frequency induction heating device. The atomization system includes an atomizing nozzle, an atomization tower located below the nozzle, and an induced draft fan.

[0060] 6. The prepared Be-Al-Mg alloy powder is sieved according to particle size, then vacuum sealed for later use.

[0061] The Be-Al-Mg alloy powder in the example has a sphericity of 0.85, an oxygen content of 2200 ppm, and a uniform internal structure.

[0062] Please note that the technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments have been described. However, as long as the combination of these technical features does not contradict each other, it should be considered within the scope of this specification. The above embodiments only illustrate several implementation methods of this application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the invention patent. It should be pointed out that for those skilled in the art, several modifications and improvements can be made without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A method for preparing Be-Al-Mg alloy powder, characterized in that, The preparation method includes the following steps: Step S1: Prepare materials according to the following components and their mass percentages; Be, 40~70wt%; Al, 20~50wt%; Mg, 4~10wt%; Step S2: After loading the prepared Al and Be into the melting crucible, evacuate the vacuum and heat it to 1060~1140℃. Then close the vacuum and fill the melting crucible with argon gas. Add Mg at a pressure of 5050~5080Pa and a temperature of 1310℃~1340℃, and keep it at that temperature for 1~3 minutes. Slowly rotate the crucible to obtain a Be-Al-Mg molten solution. In step S2, the vacuum degree of vacuum heating is ≤50Pa; Step S3: After the Be-Al-Mg molten solution is passed through the tundish, the guide tube and the atomizing nozzle in sequence, it is atomized, rapidly solidified, cooled to room temperature and graded and sieved to obtain Be-Al-Mg alloy powder. The atomization pressure is 4-5 MPa; the atomization temperature is 1210℃-1240℃.

2. The preparation method according to claim 1, characterized in that, In step S1, the purity of Be, Al and Mg is greater than 99.0 wt%, 99.5 wt% and 99.5 wt.%, respectively.

3. The preparation method according to claim 1, characterized in that, The smelting crucible is an Al2O3 crucible.

4. The preparation method according to claim 1, characterized in that, In step S2, the rotation angle of the rotating crucible is ±30°.

5. The preparation method according to claim 1, characterized in that, In step S3, the refractory material around the gap of the guide tube includes 85-95 mesh Al2O3 particles and 180-220 mesh Al2O3 powder. The mass ratio of the 85-95 mesh Al2O3 particles to the 180-220 mesh Al2O3 powder is 3:1 to 8:

1.

6. The preparation method according to claim 1, characterized in that, The material of the flow guide tube is beryllium oxide; The diameter of the guide tube is 3 to 6 mm.