Method for preparing micron-sized beryllium powder based on gas atomization method

Abstract

The invention provides a micron-sized beryllium powder preparation method based on a gas atomization method, and particularly relates to the technical field of metal powder material preparation. The preparation method provided by the invention comprises the following steps: (1) melting raw materials, namely putting a high-purity beryllium ingot with the purity of more than or equal to 99.9% into a vacuum induction melting furnace, vacuumizing until the pressure is less than or equal to 1 * 10 <-3 > Pa, filling inert gas, heating to 1300-1400 DEG C, and keeping the temperature for 10-30 minutes until the superheat degree of beryllium liquid reaches 50-100 DEG C; (2) gas atomization treatment: spraying beryllium liquid through a supersonic nozzle, crushing liquid beryllium into fine liquid drops by using atomized gas, and solidifying the fine liquid drops into powder; (3) multiple layers of cyclone separators connected in series are arranged, parameters are adjusted step by step, and powder with different particle sizes is sequentially collected in a graded mode; and the powder with the target particle size is sealed and packaged after vacuum drying. According to the method, secondary screening can be effectively avoided, continuous production can be achieved, and the obtained micron-sized beryllium powder is controllable in particle size, high in sphericity degree and low in oxygen content.

Description

Technical Field

[0001] The present invention belongs to the technical field of preparation of metal powder materials, and particularly relates to a method for preparing micron-sized beryllium powder based on gas atomization method. Background Art

[0002] Beryllium powder plays an irreplaceable role in many key fields. In nuclear reactors, beryllium powder is a key material for neutron reflector layers. It can effectively reflect neutrons, reduce neutron leakage, improve the efficiency and safety of nuclear reactors, and ensure the stable progress of nuclear reactions. In the aerospace field, beryllium powder is an ideal choice for manufacturing aerospace materials due to its low density, high specific strength, and good thermal stability. It can be used to manufacture structural components such as aircraft wings and fuselages, as well as the outer shells and key components of spacecraft, helping to reduce the weight of aircraft and improve their performance and reliability. In electronic devices, beryllium powder also has important applications. Due to its good electrical conductivity and thermal conductivity, beryllium powder can be used to manufacture high-performance electronic components such as heat sinks for integrated circuits and electrodes for electron tubes, effectively improving the heat dissipation performance and working stability of electronic devices. In addition, beryllium powder can be used to manufacture the windows of X-ray tubes. Because of its strong X-ray penetration ability, it can meet the requirements for high-quality X-ray imaging in the medical and scientific research fields. At the same time, beryllium can also be used to manufacture various alloys, such as beryllium bronze with high elasticity and copper-beryllium-nickel alloy for manufacturing non-sparking tools, and has extensive applications in industries such as machinery manufacturing and chemical engineering.

[0003] However, to apply beryllium powder in the above fields, strict requirements are imposed on the purity, particle size, particle size distribution, and particle shape of beryllium powder. First of all, the purity of beryllium powder plays a decisive role in its application effects in various fields. In nuclear reactors, high-purity beryllium powder can ensure the high efficiency and stability of neutron reflection. The presence of impurities may absorb neutrons, reduce the efficiency of the reactor, and even affect its safety. In aerospace materials, high-purity beryllium powder helps to improve the strength and thermal stability of the materials. Impurities may cause defects in the materials, affecting the performance and reliability of aircraft. In the field of electronic devices, beryllium powder with high purity can ensure good electrical conductivity and thermal conductivity, improving the working stability of electronic components. Generally speaking, the purity of beryllium powder for nuclear reactors needs to reach more than 99.9%, the purity requirement of beryllium powder for aerospace materials is above 99%, and the purity of beryllium powder for electronic devices also needs to be close to 99%. Secondly, a suitable particle size distribution is crucial for the performance of beryllium powder. A uniform particle size distribution enables beryllium powder to exhibit better consistency and stability in applications. In nuclear reactors, beryllium powder with a suitable particle size can reflect neutrons more effectively, improving the utilization rate of neutrons. In aerospace materials, a suitable particle size helps to improve the formability and mechanical properties of the materials. In electronic devices, a uniform particle size can ensure the dispersion of beryllium powder in electronic components, improving its electrical conductivity and thermal conductivity. Different applications have different requirements for particle size. The particle size of beryllium powder for nuclear reactors is generally between dozens of micrometers and hundreds of micrometers. The particle size of beryllium powder for aerospace materials may be slightly larger, while the particle size of beryllium powder for electronic devices is relatively smaller, usually between a few micrometers and dozens of micrometers. Finally, sphericity has a significant impact on the fluidity and filling property of beryllium powder. Spherical beryllium powder has good fluidity and can be more smoothly transported and filled into molds during the processing, improving production efficiency. At the same time, spherical beryllium powder has better filling property and can form a more compact packing structure in the materials, thereby improving the density and performance of the materials. In practical applications, good fluidity and filling property make it easier for beryllium powder to form into complex-shaped parts, ensuring the quality and precision of the products. For example, when manufacturing precision parts in the aerospace field, spherical beryllium powder can better meet the process requirements, improving the reliability and performance of the products.

[0004] The preparation methods of beryllium powder include traditional mechanical pulverization method, conventional atomization method, and gas atomization technology. Currently, gas atomization technology is usually used to prepare micron-sized beryllium powder. Gas atomization technology uses high-speed gas flow to break liquid beryllium into fine droplets and solidify them into powder, which has advantages such as relatively high production efficiency and has certain development in the field of beryllium powder preparation. However, the beryllium powder prepared by this technology has a relatively wide particle size distribution, and beryllium powders with different particle sizes have differences in performance and application. In order to meet the strict requirements for the particle size of beryllium powder in various fields, secondary screening has to be carried out, which not only increases the production cost and production cycle, but may also introduce new impurities during the screening process, affecting the purity and quality of beryllium powder. Summary of the Invention

[0005] The object of the present invention is to overcome the deficiencies of the prior art. The present invention aims to provide a method for preparing micron-sized beryllium powder based on the gas atomization method, so as to solve the technical problem of secondary screening caused by the wide particle size distribution in the preparation of micron-sized beryllium powder by the existing gas atomization method.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A method for preparing micron-sized beryllium powder based on the gas atomization method, comprising the following steps:

[0008] (1) Melting of raw materials: Place a high-purity beryllium ingot with a purity ≥ 99.9% in a vacuum induction melting furnace, evacuate to ≤ 1×10 -3 Pa and then fill with an inert gas, and then heat to 1300 - 1400 °C and keep warm for 10 - 30 minutes to make the superheat of the beryllium liquid reach 50 - 100 °C;

[0009] (2) Gas atomization treatment: Spray the beryllium liquid through a supersonic nozzle, and use the atomization gas to break the liquid beryllium into fine droplets and solidify them into powder;

[0010] (3) Set up a multi-layer series-connected cyclone separator, adjust the parameters step by step, and collect powders with different particle sizes in sequence; the powder with the target particle size is vacuum dried and then sealed and packaged.

[0011] Further, the atomization gas is high-pressure argon with a pressure of 6 - 15 MPa and a flow rate of 5 - 15 m 3 / min.

[0012] Further, the supersonic nozzle is a Laval nozzle with a throat diameter of 0.5 - 2.0 mm, and the ratio of the beryllium liquid flow diameter to the throat diameter is controlled at 1:1.2 - 1.5.

[0013] Further, during the gas atomization treatment, the ratio of the atomization gas flow rate to the beryllium liquid flow mass flow rate is 3 - 10:1, and the pressure of the gas atomization chamber is maintained ≤ 0.1 MPa.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] By adjusting the gas atomization parameters and combining with a multi-layer series-connected cyclone separator, the present invention can obtain micron-sized beryllium powder with a narrow particle size distribution at one time, avoid secondary screening, can realize continuous production, and the obtained micron-sized beryllium powder has controllable particle size, high sphericity and low oxygen content. Specific embodiments

[0016] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0017] In the examples and comparative examples, unless otherwise specified, the experimental methods used are all conventional methods, and the materials, reagents, etc. used, unless otherwise specified, can all be obtained from commercial channels.

[0018] The present invention will be further described below in combination with multiple embodiments.

[0019] Example 1

[0020] The steps for preparing micron-sized beryllium powder in this example are as follows:

[0021] (1) Melting of raw materials: Place a high-purity beryllium ingot with a purity of ≥99.9% in a vacuum induction melting furnace, evacuate to ≤1×10 -3 Pa and then fill with an inert gas, and then heat to 1350 °C and keep warm for 10 - 30 minutes to make the superheat of the beryllium liquid reach 50 °C;

[0022] (2) Gas atomization treatment: Spray the beryllium liquid through a Laval supersonic nozzle with a throat diameter of 0.8 mm, and use high-pressure argon gas with a pressure of 10 MPa and a flow rate of 5 m 3 / min to break the liquid beryllium into fine droplets and solidify them into powder. Among them, the ratio of the beryllium liquid flow diameter to the nozzle throat diameter is controlled at 1:1.2, and the ratio of the gas flow rate to the mass flow rate of the metal liquid flow is 5:1. During the gas atomization process, the pressure in the gas atomization chamber is maintained at ≤0.1 MPa;

[0023] (3) Set up a multi-layer series of cyclone separators, adjust the parameters step by step, and collect powders with different particle sizes in sequence; the powder with the target particle size is vacuum dried and then sealed and packaged.

[0024] The beryllium powder obtained in this example has D50 = 12.3 μm, Span value = 1.1, sphericity > 90%, and oxygen content of 320 ppm.

[0025] Example 2

[0026] The steps for preparing micron-sized beryllium powder in this example are as follows:

[0027] (1) Melting of raw materials: Place a high-purity beryllium ingot with a purity of ≥99.9% in a vacuum induction melting furnace, evacuate to ≤1×10 -3 Pa and then fill with an inert gas, and then heat to 1350 °C and keep warm for 10 - 30 minutes to make the superheat of the beryllium liquid reach 50 °C;

[0028] (2) Gas atomization treatment: Spraying beryllium liquid through a Laval supersonic nozzle with a nozzle throat diameter of 1.0 mm. Using high-pressure argon gas with a pressure of 8 MPa and a flow rate of 8 m 3 / min to break the liquid beryllium into fine droplets and solidify them into powder. Among them, the ratio of the beryllium liquid flow diameter to the nozzle throat diameter is controlled at 1:1.4, the ratio of the gas flow rate to the mass flow rate of the metal liquid flow is 3:1, and the pressure in the gas atomization chamber is maintained ≤ 0.1 MPa during the gas atomization process;

[0029] (3) Set up a multi-layer series of cyclone separators, adjust the parameters step by step, and collect powders with different particle sizes in stages; The powder with the target particle size is sealed and packaged after vacuum drying.

[0030] The beryllium powder obtained in this example has D50 = 38.7 μm, Span value = 0.8, sphericity > 90%, and oxygen content of 311 ppm.

[0031] Finally, it should also be noted that the term "including", "comprising" or any other variant is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications to these embodiments once they know the basic creative concept. Therefore, the appended claims are intended to be construed as including the preferred embodiments and all changes and modifications falling within the scope of the present invention.

[0032] The above-described embodiments only represent the specific implementation manners of the present application, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the protection scope of the present application. It should be pointed out that for those of ordinary skill in the art, without departing from the concept of the technical solution of the present application, several deformations and improvements can still be made, and these all belong to the protection scope of the present application.

Claims

1. A method for preparing micron-sized beryllium powder based on the gas atomization method, characterized in that, Including the following steps: (1) Melting of raw materials: Place a high-purity beryllium ingot with a purity of ≥99.9% in a vacuum induction melting furnace, evacuate to ≤1×10 - 3 Pa, then fill with an inert gas, and then heat to 1300 - 1400 °C and hold for 10 - 30 minutes to make the superheat of the beryllium liquid reach 50 - 100 °C; (2) Gas atomization treatment: Spraying beryllium liquid through a supersonic nozzle, and using atomizing gas to break the liquid beryllium into fine droplets and solidify them into powder; (3) Setting up a multi-layer series of cyclone separators, adjusting parameters step by step, and sequentially collecting powders with different particle sizes; The powder with the target particle size is vacuum dried and then sealed and packaged.

2. The method for preparing micron-sized beryllium powder according to claim 1, wherein The atomizing gas is high-pressure argon gas with a pressure of 6 to 15 MPa and a flow rate of 5 to 15 m 3 / min.

3. The method for preparing micron-sized beryllium powder according to claim 1, wherein The supersonic nozzle is a Laval nozzle, with a throat diameter of 0.5 - 2.0 mm, and the ratio of the beryllium liquid flow diameter to the throat diameter is controlled at 1:1.2 - 1.

5.

4. The method for preparing micron-sized beryllium powder according to claim 1, wherein During the gas atomization treatment process, the ratio of the atomizing gas flow rate to the beryllium liquid flow mass flow rate is 3 - 10:1, and the pressure in the gas atomization chamber is maintained ≤ 0.1 MPa.