Beryllium-aluminum alloy powder and preparation method thereof

Abstract

The invention discloses beryllium-aluminum alloy powder and a preparation method thereof, and relates to the technical field of beryllium-aluminum alloys. Comprising the following steps: bar preparation: processing a beryllium raw material to prepare a beryllium bar; powder is prepared, specifically, a liquid film is melted out of the end face of the beryllium bar through an electric arc, the liquid film is broken into liquid drops through centrifugal force, and the liquid drops are rapidly solidified into spherical beryllium powder; powder screening, wherein after beryllium powder is cooled, screening and grading are conducted on the powder according to the particle size; the beryllium powder is placed in a thermal evaporation deposition chamber, a metal aluminum wire serves as an evaporation source, an aluminum film layer is deposited on the surface of the beryllium powder, and beryllium aluminum alloy powder with the surface coated with an aluminum layer can be prepared; according to the beryllium-aluminum alloy powder and the preparation method thereof, the anisotropy of the beryllium-aluminum alloy powder can be remarkably reduced or eliminated, and the alloy powder is spherical and has good fluidity and high filling density.

Description

Technical Field

[0001] The invention relates to the technical field of beryllium aluminum alloy, in particular to a beryllium aluminum alloy powder and a preparation method thereof. Background Art

[0002] Beryllium has a low density and an elastic modulus six times that of any other metal. It is light, has high rigidity, and has good thermal properties. It has excellent properties such as high melting point, high specific heat, high thermal conductivity, and suitable thermal expansion coefficient. The application scope of beryllium is mainly concentrated in the nuclear industry, weapon systems, and aerospace industry. It is a strategic key material. There are two main methods for preparing metal beryllium powder: airflow impact method and inert gas atomization method. The beryllium powder prepared by the airflow impact method has significant anisotropy, and the powder produced by the inert gas atomization method is spherical particles, which can significantly reduce or eliminate the anisotropy of beryllium powder. At the same time, the spherical powder has good fluidity and high filling density.

[0003] Beryllium aluminum alloy combines the rigidity of beryllium and the toughness of aluminum, and has the characteristics of light weight, good thermal stability, high specific strength, high specific stiffness and high toughness. With its characteristics, beryllium aluminum alloy powder is widely used in the fields of aviation and aerospace, computer manufacturing, automobile manufacturing, etc. At present, beryllium aluminum alloy powder is mainly prepared by inert gas atomization method and plasma rotating electrode method. The existing technology uses metal beryllium, aluminum and rare earth elements as raw materials, and prepares a non-dendritic alloy with fine and uniform structure through vacuum induction melting, pre-alloying, magnetic levitation melting, remelting and rapid cooling, as well as reasonable adjustment of reaction conditions, and then prepares the beryllium aluminum alloy into powder with significant anisotropy. Summary of the invention

[0004] The purpose of the present invention is to provide a method for preparing beryllium aluminum alloy powder to obtain spherical beryllium aluminum alloy powder, which can significantly reduce or eliminate the anisotropy of the beryllium aluminum alloy powder and has good fluidity and high filling density.

[0005] Another object of the present invention is to provide a beryllium aluminum alloy powder, wherein the surface of the beryllium aluminum alloy is coated with an aluminum film layer to avoid aluminum evaporation in the beryllium aluminum alloy powder prepared by a conventional method.

[0006] In order to solve the above technical problems, the present invention provides a method for preparing beryllium aluminum alloy powder, comprising the following steps:

[0007] S1, rod preparation: processing beryllium raw materials to prepare beryllium rods;

[0008] S2, preparing powder: placing the beryllium rod in a vacuum of 1×10 -3 -5×10 -3In an inert gas environment of 1.57 Pa, an electric arc is used to melt the end surface of the beryllium rod to form a liquid film, and the liquid film is broken into droplets by centrifugal force. The droplets are quickly solidified into spherical beryllium powder.

[0009] S3, powder screening: after cooling the beryllium powder obtained in S2, the powder particle size is screened and graded for subsequent preparation of beryllium aluminum alloy powder;

[0010] S4, depositing an aluminum film: placing the beryllium powder in a thermal evaporation deposition chamber, using a metal aluminum wire as an evaporation source, and depositing an aluminum film layer on the surface of the beryllium powder to obtain a beryllium aluminum alloy powder with an aluminum layer coated on the surface;

[0011] In the deposition process of S4, the beryllium powder in the thermal evaporation deposition chamber is continuously stirred so that the beryllium powder rotates in a suspended state in the thermal evaporation deposition chamber, so that the aluminum thin film layer is evenly deposited on the surface of the beryllium powder.

[0012] Optionally, in S1, the beryllium raw material includes beryllium, nickel, a refining agent and silicon;

[0013] Among them, the mass ratio of beryllium, nickel, refining agent and silicon is 65-75:2-3:1-2:0.05-1.

[0014] Optionally, in S1, the beryllium raw material is placed in a crucible in a vacuum container for smelting to obtain the beryllium rod.

[0015] Optionally, in S1, the smelting process is: adding beryllium, nickel and silicon into a vacuum melting furnace, heating to 1450-1550°C, vacuum melting to obtain a melt, adding a refining agent, and refining at a heat preservation condition to obtain a mixed melt; then pouring the mixed melt into a mold, first slowly cooling it, and then rapidly cooling it to obtain a beryllium rod.

[0016] The vacuum melting refers to the melting at a vacuum degree of less than 1×10 -2 Pa is used for smelting.

[0017] Optionally, the heat preservation refining is to use heat preservation treatment for 1-2 hours to remove surface scum;

[0018] The slow cooling is carried out by using magnetic field cooling, controlling the cooling rate to be 1-5°C / s, and slowly cooling to 1000-1050°C.

[0019] The rapid cooling is carried out by strong wind cooling, and the cooling rate is 140-180°C / s.

[0020] Optionally, in S2, the inert gas is argon; the arc length of the arc is 35-60 mm; the rotation speed of the beryllium rod is 10000-20000 rpm; the feeding speed of the beryllium rod is 30-80 mm / min; and the working current of the arc is 1800-2600 A.

[0021] Optionally, during the deposition process of S4, the deposition is carried out in a thermal evaporation deposition chamber, and the vacuum degree of the thermal evaporation deposition chamber is 1×10 -3 -5×10 -3 Pa, deposition temperature is 800-950°C;

[0022] The thickness of the aluminum film layer of the beryllium aluminum alloy powder is adjusted by controlling the deposition temperature and the deposition time.

[0023] Optionally, during the deposition process of S4, a circulating gas flow of inert gas argon is set in the thermal evaporation deposition chamber, and the flow direction of the circulating gas flow is from the bottom center of the thermal evaporation deposition chamber toward the top of the thermal evaporation deposition chamber, and then downward along the side wall of the thermal evaporation deposition chamber, so that the beryllium powder is suspended in the thermal evaporation deposition chamber.

[0024] The present invention provides a beryllium aluminum alloy powder, which includes beryllium aluminum alloy powder prepared by the above-mentioned beryllium aluminum alloy powder preparation method. The beryllium aluminum alloy powder is spherical, with a particle size of 10-200 μm, wherein beryllium is spherical and located at the center of the powder, and aluminum is coated on the surface of the beryllium powder in the form of a thin film, and the thickness of the aluminum film layer is 0.5-20 μm.

[0025] The invention provides a method for preparing beryllium aluminum alloy powder, which comprises the following steps: firstly processing beryllium raw material to prepare beryllium rods; then arc melting the beryllium rods and atomizing them under the action of centrifugal force to prepare spherical beryllium powder; then screening and grading the powder particle size to obtain beryllium powder with appropriate particle size; and finally thermal evaporation deposition to form an aluminum film on the surface of the beryllium powder to obtain spherical beryllium aluminum alloy powder. The prepared beryllium aluminum alloy powder can significantly reduce or eliminate the anisotropy of the spherical powder, and the spherical powder has good fluidity and high filling density.

[0026] Compared with the prior art, the beneficial effects of the present invention may include:

[0027] 1. The evaporation deposition method in the prior art is only applicable to the surface of bulk materials for deposition. Compared with the prior art, in the present invention, the beryllium powder is suspended and flowed during the deposition process by means of a stirring device and a circulating inert gas flow, thereby achieving uniform deposition on the surface.

[0028] 2. The method provided by the present invention can deposit an aluminum film layer on the surface of beryllium powder to obtain beryllium aluminum alloy powder with spherical interior and aluminum film layer coated on the exterior. The prepared beryllium aluminum alloy powder has good sphericity, can significantly reduce or eliminate the anisotropy of the spherical powder, and has good fluidity and high filling density.

[0029] 3. The method provided by the present invention can avoid the evaporation of aluminum in the beryllium aluminum alloy powder produced by the traditional preparation method, thereby reducing the loss of aluminum. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the prior art and the drawings required for use in the embodiments are briefly introduced below. It is obvious that the drawings described below are only individual embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 A schematic flow chart of a method for preparing beryllium aluminum alloy powder provided by the present invention;

[0032] Figure 2 This is a scanning electron microscope (SEM) morphology image of a beryllium aluminum alloy powder provided by the present invention. DETAILED DESCRIPTION

[0033] 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 will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] like Figure 1-Figure 2 As shown, the method for preparing a beryllium aluminum alloy powder provided by the present invention may specifically include the following steps:

[0035] S1, rod preparation: processing beryllium raw materials to prepare beryllium rods;

[0036] S2, preparing powder: placing the beryllium rod in a vacuum of 1×10 -3 -5×10 -3 In an inert gas environment of 1.57 Pa, an electric arc is used to melt the end surface of the beryllium rod to form a liquid film, and the liquid film is broken into droplets by centrifugal force. The droplets are quickly solidified into spherical beryllium powder.

[0037] S3, powder screening: after cooling the beryllium powder obtained in S2, the powder particle size is screened and graded for subsequent preparation of beryllium aluminum alloy powder;

[0038] S4, depositing an aluminum film: placing the beryllium powder in a thermal evaporation deposition chamber, using a metal aluminum wire as an evaporation source, and depositing an aluminum film layer on the surface of the beryllium powder to obtain a beryllium aluminum alloy powder with an aluminum layer coated on the surface;

[0039] In the deposition process of S4, the beryllium powder in the thermal evaporation deposition chamber is continuously stirred so that the beryllium powder rotates in a suspended state in the thermal evaporation deposition chamber, so that the aluminum thin film layer is evenly deposited on the surface of the beryllium powder.

[0040] Specifically, in S1, the beryllium raw material includes beryllium, nickel, a refining agent and silicon; wherein the mass ratio of beryllium, nickel, a refining agent and silicon is 65-75:2-3:1-2:0.05-1.

[0041] In S1, a beryllium raw material is placed in a crucible in a vacuum container for smelting to obtain a beryllium rod.

[0042] Specifically, the specific steps of preparing the rod material may be: adding beryllium, nickel and silicon into a vacuum melting furnace, and evacuating the furnace until the vacuum degree of the melting furnace is less than 1×10 -2 Pa, heat to 1450-1550℃, vacuum melt to form a melt, use a jet machine to spray the refining agent into the melt, keep the temperature and refine for 1-2h, remove the surface scum to obtain a mixed melt; pour the obtained mixed melt into a mold, first slowly cool it in a magnetic field at a cooling rate of 1-5℃ / s, cool it to 1000-1050℃, then quickly cool it with strong wind at a cooling rate of 140-180℃ / s, cool it to room temperature to obtain beryllium rods.

[0043] The refining agent is lithium bis(oxalatoborate), which can achieve repeated degassing and improve the refining effect. It should be noted that in the smelting process of this embodiment, other processes known to those skilled in the art can also be used to produce beryllium rods, which are not limited here.

[0044] In S2, the inert gas is argon; the arc length of the arc is 35-60 mm; the rotation speed of the beryllium rod is 10000-20000 rpm; the feeding speed of the beryllium rod is 30-80 mm / min, and the working current of the arc is 1800-2600A.

[0045] At the beginning of preparation, the beryllium rod can be completely placed in the vacuum chamber of the device, and the beryllium rod is rotated and fed at the same time. When the arc length reaches the preparation requirement, the arc is turned on. One end of the beryllium rod can be connected to the feeding system, and the other end can be connected to the positive electrode of the plasma gun through the arc.

[0046] In the process of preparing powder, due to different metal properties and melting points, the viscosity of the molten metal is also different. The energy density of the melting arc determines the thickness of the liquid film layer on the melting end of the beryllium rod, which in turn affects the powder particle size and the smooth progress of the atomization process. If the arc energy density is too low, it will extend the time for the raw material rod to be melted, resulting in a large amount of heat being transferred to the motor shaft and bearings, causing the motor to not work properly. If the arc energy density is too high, the liquid film layer on the melting end of the raw material rod is too thick, which not only makes the powder coarser, but also easily produces flash and increases the vibration of the beryllium rod, making the atomization process impossible. The working current determines the arc energy density. Parameters such as the rotation speed of the raw material rod, the working current, the length of the arc distance, and the feed speed of the raw material rod can be adjusted and selected by technicians in this field as needed, so that the particle size of the prepared beryllium powder is uniform.

[0047] In S4, the deposition process is carried out in a vacuum chamber, and the vacuum degree of the vacuum chamber is 1×10 -3 -5×10 -3 Pa, the deposition temperature is 800-950℃.

[0048] When evacuating the vacuum, in order to prevent the beryllium powder from being extracted by the vacuum, a filter needs to be added to the vacuum extraction hole, and the mesh size of the filter is smaller than the particle size of the beryllium powder.

[0049] During the deposition process of S4, a circulating gas flow of inert gas argon is set in the thermal evaporation deposition chamber, and the flow direction of the circulating gas flow is from the bottom center of the thermal evaporation deposition chamber toward the top of the thermal evaporation deposition chamber, and then downward along the side wall of the thermal evaporation deposition chamber, so that the beryllium powder is suspended in the thermal evaporation deposition chamber.

[0050] By controlling the deposition temperature and deposition time, the thickness of the aluminum film layer of the prepared beryllium aluminum alloy powder can be adjusted. Optionally, the thickness of the aluminum film layer is 0.5 μm-20 μm.

[0051] The invention provides a beryllium aluminum alloy powder, which is spherical and has a particle size of 10-200 μm, wherein beryllium is spherical and located at the center of the powder, and aluminum is coated on the surface of the powder in a thin film, and the thickness of the aluminum film layer is 0.5 μm-20 μm.

[0052] Embodiment 1:

[0053] The following steps are used to prepare beryllium aluminum alloy powder with high sphericity:

[0054] Preparation of rods: The raw materials are beryllium, nickel, refining agent and silicon, and the mass ratio of beryllium, nickel, refining agent and silicon is 75:2:2:1. Add beryllium, nickel and silicon into a vacuum melting furnace and evacuate the furnace until the vacuum degree is less than 1×10 -2Pa, heating to 1550℃ to obtain a melt, spraying the refining agent into the melt with a jet machine, keeping the temperature for 1h, removing the surface scum, and obtaining a mixed melt. The mixed melt is poured into a mold, first slowly cooled in a magnetic field at a cooling rate of 1℃ / s, cooled to 1050℃, and then quickly cooled by strong wind at a cooling rate of 180℃ / s, cooled to room temperature, and obtained beryllium rods.

[0055] Preparation of powder: Place the beryllium rod into an arc melting rotary atomizer and evacuate to a vacuum degree of 1×10 -3 Pa, and then inert gas argon is introduced into the device to ensure that the oxygen content in the atomization chamber is less than 3ppm. The arc melting rotary atomization device is turned on under the protection of inert gas, and the arc melting power is controlled by adjusting the working current to control the melting speed of the beryllium rod. The working current output is 2200A, the arc length is 45mm, and the speed of the rotating raw beryllium rod is 15000rpm. The front end of the beryllium rod is melted into a liquid film by the arc, and the liquid film is broken into fine droplets by rotary centrifugation. After the droplets are thrown out, they are cooled and solidified in an inert gas environment to form spherical beryllium powder. The feeding speed of the beryllium rod is 50mm / min.

[0056] The beryllium powder prepared by this step is spherical and has a particle size of 30-180 μm.

[0057] Powder screening: After the prepared beryllium powder is fully cooled, it is screened and graded according to the particle size requirements for the powder (for example: 30-80μm).

[0058] Deposition of aluminum film: After beryllium powder is cleaned with anhydrous alcohol, it is placed in a thermal evaporation deposition chamber. The crucible is made of boron nitride material, and high-purity aluminum wire (99.99at.%) is placed in the crucible as the evaporation raw material. The baffle is placed directly above the evaporation source, the deposition chamber is closed, and the vacuum system is turned on until the vacuum degree reaches 1×10 -3 Pa. Turn on the AC power supply, slowly increase the heating voltage to the evaporation temperature of 800℃, open the baffle and start the formal evaporation of aluminum film. During the coating process, the beryllium powder is continuously stirred by the stirring device in the thermal evaporation deposition chamber, and the argon gas flow is circulated to make the beryllium powder in the thermal evaporation deposition chamber in a suspended and flowing state.

[0059] When the thickness of the aluminum film reaches 0.5-5μm, slowly reduce the heating voltage to zero, turn off the AC power supply, turn off the stirring device and circulating airflow, open the deposition chamber, and take out the beryllium powder after the aluminum film has been evaporated.

[0060] The particle morphology of the beryllium aluminum alloy powder prepared in this embodiment is as follows: Figure 2 As shown, the average particle size is 65.6 μm, the sphericity is 0.93, and the fluidity is 54.9 s / 50 g.

[0061] Embodiment 2:

[0062] The following steps are used to prepare beryllium aluminum alloy powder with high sphericity:

[0063] Preparation of rods: The raw materials are beryllium, nickel, refining agent and silicon. The mass ratio of beryllium, nickel, refining agent and silicon is 65:3:1:0.05. Add beryllium, nickel and silicon into a vacuum melting furnace and evacuate the furnace until the vacuum degree is less than 1×10 -2 Pa, heated to 1450℃, obtained melt, sprayed refining agent into the melt with a jet machine, kept refining for 2h, removed surface scum, obtained mixed melt. Poured the mixed melt into a mold, first slowly cooled in a magnetic field at a cooling rate of 5℃ / s, cooled to 1000℃, then quickly cooled in a strong wind at a cooling rate of 140℃ / s, cooled to room temperature, obtained beryllium rod.

[0064] Preparation of powder: Place the beryllium rod into an arc melting rotary atomizer and evacuate to a vacuum of 5×10 -3 Pa, and then inert gas argon is introduced into the device to ensure that the oxygen content in the atomization chamber is less than 3ppm. The arc melting rotary atomization device is turned on under the protection of inert gas, and the arc melting power is controlled by adjusting the working current to control the melting speed of the beryllium rod. The working current output is 2600A, the arc length is 60mm, and the speed of the rotating raw material beryllium rod is 20000rpm. The front end of the beryllium rod is melted into a liquid film by the arc, and the liquid film is broken into fine droplets by rotating centrifugation. After the droplets are thrown out, they are cooled and solidified in an inert gas environment to form spherical beryllium powder. The feeding speed of the beryllium rod is 80mm / min.

[0065] The beryllium powder prepared by this step is spherical and has a particle size of 10-150 μm. The particle size of the prepared beryllium powder can be controlled by controlling the specific process parameters of this step.

[0066] Powder screening: After the prepared beryllium powder is fully cooled, it is screened and graded according to the particle size requirements of the powder (for example: 10 to 100 μm).

[0067] Deposition of aluminum film: After beryllium powder is cleaned with anhydrous alcohol, it is placed in a thermal evaporation deposition chamber. The crucible is made of boron nitride material, and high-purity aluminum wire (99.99at.%) is placed in the crucible as the evaporation raw material. The baffle is placed directly above the evaporation source, the deposition chamber is closed, and the vacuum system is turned on until the vacuum degree reaches 5×10 -3 Pa. Turn on the AC power supply, slowly increase the heating voltage to the evaporation temperature of 950℃, open the baffle and start the formal evaporation of aluminum film. During the coating process, the beryllium powder is continuously stirred by the stirring device in the thermal evaporation deposition chamber, and the argon gas flow is circulated to make the beryllium powder in the thermal evaporation deposition chamber in a suspended and flowing state.

[0068] When the thickness of the aluminum film reaches 5-10 μm, slowly reduce the heating voltage to zero, turn off the AC power supply, turn off the stirring device and circulating airflow, open the deposition chamber, and take out the beryllium powder after the aluminum film has been evaporated.

[0069] The beryllium aluminum alloy powder particles prepared in this Example 2 have an average particle size of 58.8 μm, a sphericity of 0.92, and a fluidity of 56.2 s / 50 g.

[0070] Embodiment 3:

[0071] The following steps are used to prepare beryllium aluminum alloy powder with high sphericity:

[0072] Rod preparation: The raw material composition is: beryllium, nickel, refining agent and silicon, and the mass ratio of beryllium, nickel, refining agent and silicon is: 70:2.5:1.5:0.5. Add beryllium, nickel and silicon into a vacuum melting furnace and evacuate the furnace until the vacuum degree is less than 1×10 -2 Pa, heated to 1500℃, obtained melt, sprayed refining agent into the melt with a jet machine, kept refining temperature for 1.5h, removed surface scum, obtained mixed melt. Poured the mixed melt into a mold, first slowly cooled in a magnetic field at a cooling rate of 3℃ / s, cooled to 1020℃, then quickly cooled in a strong wind at a cooling rate of 150℃ / s, cooled to room temperature, obtained beryllium rod.

[0073] Preparation of powder: Place the beryllium rod into an arc melting rotary atomizer and evacuate to a vacuum degree of 3×10 -3 Pa, and then inert gas argon is introduced into the device to ensure that the oxygen content in the atomization chamber is less than 3ppm. The arc melting rotary atomization device is turned on under the protection of inert gas, and the arc melting power is controlled by adjusting the working current to control the melting speed of the beryllium rod. The working current output is 1800A, the arc length is 35mm, and the speed of rotating the raw beryllium rod is 10000rpm. The front end of the beryllium rod is melted into a liquid film by the arc, and the liquid film is broken into fine droplets by rotating centrifugation. After the droplets are thrown out, they are cooled and solidified in an inert gas environment to form spherical beryllium powder. The feeding speed of the beryllium rod is 30mm / min.

[0074] The beryllium powder prepared by this step is spherical and has a particle size of 35-200 μm. The particle size of the prepared beryllium powder can be controlled by controlling the specific process parameters of this step.

[0075] Powder screening: After the prepared beryllium powder is fully cooled, it is screened and graded according to the particle size requirements of the powder (for example: 50 to 150 μm).

[0076] Deposition of aluminum film: After beryllium powder is cleaned with anhydrous alcohol, it is placed in a thermal evaporation deposition chamber. The crucible is made of boron nitride material, and high-purity aluminum wire (99.99at.%) is placed in the crucible as the evaporation raw material. The baffle is placed directly above the evaporation source, the deposition chamber is closed, and the vacuum system is turned on until the vacuum degree reaches 3×10 -3 Pa. Turn on the AC power supply, slowly increase the heating voltage to the evaporation temperature of 900°C, open the baffle and start the formal evaporation of aluminum film. During the coating process, the beryllium powder is continuously stirred by the stirring device in the thermal evaporation deposition chamber, and the argon gas flow is circulated to make the beryllium powder in the thermal evaporation deposition chamber in a suspended and flowing state.

[0077] When the thickness of the aluminum film reaches 10-20 μm, slowly reduce the heating voltage to zero, turn off the AC power supply, turn off the stirring device and circulating airflow, open the deposition chamber, and take out the beryllium powder after the aluminum film has been evaporated.

[0078] The beryllium aluminum alloy powder particles prepared in this Example 3 had an average particle size of 113.2 μm, a sphericity of 0.93, and a fluidity of 55.1 s / 50 g.

[0079] The invention provides a method for preparing beryllium aluminum alloy powder, which includes first processing beryllium raw material to prepare beryllium rods; then melting the beryllium rods by plasma arc, and atomizing under the action of centrifugal force to prepare spherical beryllium powder; then screening and grading the powder particle size to obtain beryllium powder of appropriate size; finally thermal evaporation deposition to form an aluminum film on the surface of the beryllium powder, and finally obtaining spherical particles of beryllium aluminum alloy powder. The obtained beryllium aluminum alloy powder has a spherical shape, which can significantly reduce or eliminate the anisotropy of the spherical powder, and the spherical particles have good fluidity and high filling density.

[0080] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A method for preparing beryllium aluminum alloy powder, characterized in that: The following steps are involved: S1, rod preparation: processing beryllium raw materials to prepare beryllium rods; S2, preparing powder: placing the beryllium rod in a vacuum at a degree of 1×10 -3 -5×10 -3 In an inert gas environment of 1.57 Pa, an electric arc is used to melt the end surface of the beryllium rod to form a liquid film, and the liquid film is broken into droplets by centrifugal force. The droplets are quickly solidified into spherical beryllium powder. S3, powder screening: after cooling the beryllium powder obtained in S2, the powder particle size is screened and graded for subsequent preparation of beryllium aluminum alloy powder; S4, depositing an aluminum film: placing the beryllium powder in a thermal evaporation deposition chamber, using a metal aluminum wire as an evaporation source, and depositing an aluminum film layer on the surface of the beryllium powder to obtain a beryllium aluminum alloy powder with an aluminum layer coated on the surface; In the deposition process of S4, the beryllium powder in the thermal evaporation deposition chamber is continuously stirred so that the beryllium powder rotates in a suspended state in the thermal evaporation deposition chamber, so that the aluminum thin film layer is evenly deposited on the surface of the beryllium powder.

2. The method for preparing beryllium aluminum alloy powder according to claim 1, characterized in that: In S1, the beryllium raw material includes beryllium, nickel, a refining agent and silicon; Among them, the mass ratio of beryllium, nickel, refining agent and silicon is 65-75:2-3:1-2:0.05-1.

3. The method for preparing beryllium aluminum alloy powder according to claim 1, characterized in that: In S1, the beryllium raw material is placed in a crucible in a vacuum container for smelting to obtain the beryllium rod.

4. The method for preparing beryllium aluminum alloy powder according to claim 3, characterized in that: In S1, the smelting process is as follows: beryllium, nickel and silicon are added into a vacuum melting furnace and heated to 1450-1550°C, vacuum melted to obtain a melt, a refining agent is added, and the mixture is refined by heat preservation to obtain a mixed melt; the mixed melt is then poured into a mold, first slowly cooled, and then quickly cooled to obtain a beryllium rod. The vacuum melting refers to the melting at a vacuum degree of less than 1×10 -2 Pa is used for smelting.

5. The method for preparing beryllium aluminum alloy powder according to claim 4, characterized in that: The heat preservation refining is to use heat preservation treatment for 1-2 hours to remove surface scum; The slow cooling is carried out by using magnetic field cooling, controlling the cooling rate to be 1-5°C / s, and slowly cooling to 1000-1050°C. The rapid cooling is carried out by strong wind cooling, and the cooling rate is 140-180°C / s.

6. The method for preparing beryllium aluminum alloy powder according to claim 1, characterized in that: In S2, the inert gas is argon; the arc length of the arc is 35-60 mm; the rotation speed of the beryllium rod is 10000-20000 rpm; the feeding speed of the beryllium rod is 30-80 mm / min; and the working current of the arc is 1800-2600A.

7. The method for preparing beryllium aluminum alloy powder according to claim 1, characterized in that: During the deposition process of S4, the deposition is carried out in a thermal evaporation deposition chamber, and the vacuum degree of the thermal evaporation deposition chamber is 1×10 -3 -5×10 -3 Pa, deposition temperature is 800-950°C; The thickness of the aluminum film layer of the beryllium aluminum alloy powder is adjusted by controlling the deposition temperature and the deposition time.

8. The method for preparing beryllium aluminum alloy powder according to claim 1, characterized in that: During the deposition process of S4, a circulating gas flow of inert gas argon is set in the thermal evaporation deposition chamber, and the flow direction of the circulating gas flow is from the bottom center of the thermal evaporation deposition chamber toward the top of the thermal evaporation deposition chamber, and then downward along the side wall of the thermal evaporation deposition chamber, so that the beryllium powder is suspended in the thermal evaporation deposition chamber.

9. A beryllium aluminum alloy powder, characterized in that: The beryllium aluminum alloy powder includes the beryllium aluminum alloy powder prepared by the preparation method of the beryllium aluminum alloy powder according to any one of claims 1 to 8.

10. The beryllium aluminum alloy powder according to claim 9, characterized in that: The beryllium aluminum alloy powder is spherical and has a particle size of 10-200 μm, wherein the beryllium is spherical and located at the center of the powder, and the aluminum is coated on the surface of the powder in the form of a film, and the thickness of the aluminum film layer is 0.5-20 μm.

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