A method and apparatus for forming a metal powder and a manufacturing apparatus
By forming atomized medium vortices with opposite and identical rotation directions on the inner and outer periphery of the liquid metal jet, and combining this with heating and cooling zone control, the problem of poor particle size uniformity in the prior art has been solved, and metal powders with smaller particle size and higher flowability have been prepared.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- ZHEJIANG QUANDING MAGNETOELECTRIC MATERIAL CO LTD
- Filing Date
- 2023-12-25
- Publication Date
- 2026-08-04
AI Technical Summary
In existing atomization methods, the particle size uniformity of metal powder is low, and increasing the spray speed of the atomizing medium will increase costs.
The inner and outer peripheries of the annular metal liquid jet are respectively formed with first and second atomizing medium vortices rotating in opposite directions, and third and fourth atomizing medium vortices rotating in the same direction are respectively formed with the inner and outer peripheries of the annular metal liquid jet. The solidification process of the metal droplets is controlled by heating and cooling intervals, and the atomization efficiency is improved by turbulence and multi-point injection.
This improves the particle size uniformity and minimum particle size of metal powder, reduces the formation of satellite particles, and yields metal powder with smaller particle size and higher flowability.
Smart Images
Figure CN117733162B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to an atomization method and apparatus for forming metal powder, as well as a preparation apparatus, belonging to the field of metal powder preparation technology. Background Technology
[0002] Currently, in the field of metal powder preparation technology, a commonly used method is to use an atomizing medium to disperse, atomize, and then cool and solidify a jet of molten metal into metal powder. Metal powders obtained using this method have good sphericity and excellent physical properties.
[0003] However, existing atomization processes employ a direct injection of the atomizing medium into the metal jet. This method of atomizing metal droplets is relatively simple, resulting in insufficient contact between the molten metal and the atomizing medium. Consequently, the molten metal is not adequately dispersed and broken up, leading to a wide particle size distribution in the final metal powder, i.e., low particle size uniformity. While increasing the injection velocity of the atomizing medium can improve this, it results in insufficient utilization of the atomizing medium and increases costs. Summary of the Invention
[0004] The technical problem to be solved by the present invention is to provide an atomization method, apparatus and preparation device for forming metal powder, which can obtain metal powder with better particle size uniformity.
[0005] The present invention is achieved through the following technical solution.
[0006] A method for forming metal powder by atomization, comprising the following steps: S1: Liquid metal is ejected from the flow guiding mechanism and forms a ring-shaped liquid metal jet band; S2: A first atomizing medium vortex and a second atomizing medium vortex are formed in the inner and outer peripheries of the metal liquid jet zone and come into contact with the metal liquid jet zone.
[0007] The first atomizing medium vortex and the second atomizing medium vortex rotate in opposite directions.
[0008] As a further improvement of the present invention, the steps also include: S3: A third atomizing medium vortex and a fourth atomizing medium vortex are formed in the inner and outer peripheries of the metal liquid jet zone and come into contact with the metal liquid jet zone. Among them, the third atomizing medium vortex and the fourth atomizing medium vortex rotate in the same direction; The first and third atomizing medium vortices are positioned upstream and downstream in the flow direction of the liquid metal jet, while the second and fourth atomizing medium vortices are positioned upstream and downstream in the injection direction of the liquid metal.
[0009] As a further improvement of the present invention, the atomizing medium of the first atomizing medium vortex and / or the second atomizing medium vortex is heated, and the atomizing medium of the third atomizing medium vortex and / or the fourth atomizing medium vortex is cooled, so that the atomizing space in which the metal liquid jet is located forms a heating zone corresponding to the first atomizing medium vortex and the second atomizing medium vortex, and a cooling zone corresponding to the third atomizing medium vortex and the fourth atomizing medium vortex.
[0010] As a further improvement of the present invention, in S2: the atomizing medium is ejected from a plurality of first injection points located on the periphery of the metal liquid jet band and forms a first atomizing medium vortex, and the atomizing medium is ejected from a plurality of second injection points located on the inner periphery of the metal liquid jet band and forms a second atomizing medium vortex. In S3: the atomizing medium is ejected from multiple third injection points located on the periphery of the metal liquid jet zone and forms a third atomizing medium vortex; the atomizing medium is ejected from multiple fourth injection points located on the inner periphery of the metal liquid jet zone and forms a fourth atomizing medium vortex.
[0011] As a further improvement of the present invention, the spraying directions of the first spraying point, the second spraying point, the third spraying point, and the fourth spraying point are all orthogonally decomposed into a first spraying direction along the liquid metal spraying direction and a second spraying direction that forms a vortex.
[0012] As a further improvement of the present invention, the atomizing medium used to form the first atomizing medium vortex, the second atomizing medium vortex, the third atomizing medium vortex, and the fourth atomizing medium vortex is the same medium.
[0013] As a further improvement of the present invention, the atomizing medium is set to nitrogen or argon.
[0014] An apparatus for implementing the above-described atomization method includes: A melting chamber is used to melt metallic materials into liquid metal. Atomization chamber, used to atomize and cool liquid metal to form metal powder; The flow guiding mechanism includes multiple flow guiding holes or flow guiding channels arranged in a ring for injecting liquid metal from the melting chamber into the atomization chamber and forming a liquid metal jet band; A first vortex mechanism is used to form and contact a first atomizing medium vortex within and in the inner periphery of the liquid metal jet. The second vortex mechanism is used to form and contact a second atomizing medium vortex around and in contact with the metal liquid jet zone.
[0015] As a further improvement to the present invention, it also includes: The third vortex mechanism is used to form and contact a third atomizing medium vortex within and in the inner periphery of the liquid metal jet. The fourth vortex mechanism is used to form and contact a fourth atomizing medium vortex on the periphery of and with the metal liquid jet.
[0016] The beneficial effects of this invention are: The inner periphery of the liquid metal jet is in contact with the first atomizing medium vortex, while the outer periphery is in contact with the second atomizing medium vortex. The first and second atomizing medium vortices can fully impact and disperse the liquid metal, thereby improving the efficiency of contact and atomization with the atomizing medium. Since the first and second atomizing medium vortices form turbulence, the liquid metal can be further dispersed in the turbulence. This not only allows for repeated dispersion of larger-diameter liquid metal droplets but also increases the frequency of collisions between the droplets, resulting in smaller-diameter liquid metal droplets. These droplets gradually cool to form metal powder, resulting in a final metal powder with higher particle size uniformity and smaller particle size. Attached Figure Description
[0017] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings to aid in understanding the objectives and advantages of the present invention, wherein: Figure 1 This is a schematic diagram of a liquid metal jet zone under the action of four types of eddies. Figure 2 This is a schematic diagram showing the effect of a first atomizing medium vortex and a second atomizing medium vortex on a metal liquid jet. Figure 3 This is a schematic diagram showing the effect of the third and fourth atomizing medium eddies on the metal liquid jet. Figure 4 A schematic diagram of an apparatus for preparing metal powder. Detailed Implementation
[0018] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.
[0019] The directional terms such as up, down, left, right, front, back, front, back, top, and bottom mentioned or possibly used in this specification are defined relative to the construction shown in the accompanying drawings. The terms "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively. These are relative concepts and may therefore vary depending on their location and usage. Therefore, these or other directional terms should not be interpreted as restrictive.
[0020] Implementation Case 1: Reference Figure 1-3 A method for atomizing metal powder, comprising the steps of: S1: Liquid metal is ejected from the guide mechanism 3 and forms a ring-shaped liquid metal jet.
[0021] Liquid metal is obtained by melting metallic materials through a melting device. The metallic materials can be pure metals, such as aluminum, iron, and copper, or alloys, such as iron alloys and aluminum alloys.
[0022] The metal liquid jet can be in the form of a curtain-like, continuously flowing liquid in an overall ring shape, or it can be composed of multiple liquid jets distributed in a ring shape with extremely small gaps between them. The specific shape of the metal liquid jet is defined by the flow guiding mechanism 3.
[0023] S2: A first atomizing medium vortex and a second atomizing medium vortex are formed in the inner and outer peripheries of the metal liquid jet band and come into contact with the metal liquid jet band, wherein the rotation directions of the first atomizing medium vortex and the second atomizing medium vortex are opposite.
[0024] The liquid metal jet comes into contact with the first and second atomizing medium vortices, dispersing into metal droplets, which gradually cool and solidify to form the final metal powder. The media used to form the first and second atomizing medium vortices are atomizing media. These atomizing media need to be inactive in the metal powder preparation process to avoid negatively impacting the quality and performance of the metal powder. Furthermore, they should be easily evaporated or removed after preparation to avoid affecting the final product. The media in the first and second atomizing medium vortices can be the same or different media, but both must be gaseous media.
[0025] In the atomization method of this embodiment, the metal liquid jet band presents an annular ribbon-like flowing liquid in its overall shape. Compared with a columnar jet, the metal liquid jet band has a larger inner "surface" and outer "surface" that can contact the atomizing medium. The inner circumference of the metal liquid jet band contacts the first atomizing medium vortex, and the outer circumference contacts the second atomizing medium vortex. The first and second atomizing medium vortices can fully impact and disperse the liquid metal, thereby improving the efficiency of contact and atomization with the atomizing medium. Since the first and second atomizing medium vortices rotate in opposite directions, turbulence is formed under the action of these two vortices. The metal liquid can be further dispersed in the turbulence, which can not only repeatedly disperse larger metal droplets, but also increase the frequency of collisions between metal droplets, making them form smaller metal droplets. These metal droplets gradually cool to form metal powder, so that the final metal powder not only has higher particle size uniformity, but also can achieve a smaller particle size.
[0026] The atomization method in this implementation case also includes the following steps: S3: A third atomizing medium vortex and a fourth atomizing medium vortex are formed on the inner and outer peripheries of the liquid metal jet, respectively, and they come into contact with the liquid metal jet. The third and fourth atomizing medium vortices rotate in the same direction. The first and third atomizing medium vortices are upstream and downstream in the flow direction of the liquid metal jet, and the second and fourth atomizing medium vortices are upstream and downstream in the injection direction of the liquid metal.
[0027] After the liquid metal jet comes into contact with the first and second atomizing medium vortices, it forms small and more uniform metal droplets. These droplets then come into contact with the third and fourth atomizing medium vortices. Since the third and fourth atomizing medium vortices rotate in the same direction, they form larger vortices than the turbulence created by the first and second atomizing medium vortices. Therefore, the frequency of collisions between the metal droplets can be relatively reduced, while the frequency of contact with the atomizing medium can be increased, which can accelerate the rate at which the metal droplets cool and solidify into metal powder.
[0028] In this embodiment, heating the first atomizing medium vortex and / or the second atomizing medium vortex, and cooling the third atomizing medium vortex and / or the fourth atomizing medium vortex, causes the atomization space where the liquid metal jet is located to form a heating zone corresponding to the first atomizing medium vortex and the second atomizing medium vortex, and a cooling zone corresponding to the third atomizing medium vortex and the fourth atomizing medium vortex.
[0029] In existing technologies, during the atomization process of a metal jet by an atomizing medium, a large number of small satellite particles are formed on the surface of large metal particles. This affects the flowability of the metal powder and is detrimental to its application. In this embodiment, however, as the liquid metal jet flows through the heating zone, the metal droplets do not cool and solidify into solid particles but remain in a liquid state. Furthermore, the turbulence formed by the eddies of the first and second atomizing media on the liquid metal jet results in higher particle size uniformity and smaller particle size of the metal droplets. Consequently, when the jet gradually cools and solidifies in the cooling zone, large satellite particles do not form, resulting in a metal powder with higher particle size uniformity and smaller particle size.
[0030] In addition, under normal circumstances, it is sufficient to heat one of the first atomizing medium vortex and the second atomizing medium vortex, and to cool one of the third atomizing medium vortex and the fourth atomizing medium vortex.
[0031] In this embodiment, in S2: the atomizing medium is ejected from multiple first injection points a1 located on the periphery of the metal liquid jet band and forms a first atomizing medium vortex; the atomizing medium is ejected from multiple second injection points b1 located on the inner periphery of the metal liquid jet band and forms a second atomizing medium vortex.
[0032] In S3: the atomizing medium is ejected from multiple third injection points c1 located on the periphery of the metal liquid jet zone and forms a third atomizing medium vortex; the atomizing medium is ejected from multiple fourth injection points d1 located on the inner periphery of the metal liquid jet zone and forms a fourth atomizing medium vortex.
[0033] The first spray point a1 and the third spray point c1 spray from the inside out, while the second spray point b1 and the fourth spray point d1 spray from the outside in.
[0034] Multiple rows can be set, with multiple first injection points a1 in each row. Each row is arranged at intervals along the injection direction of the liquid metal, and the multiple first injection points a1 in each row are arranged in a ring. The first injection points a1 in adjacent rows can be staggered to make the injected medium more uniform. The arrangement of the second injection point b1, the third injection point c1, and the fourth injection point is set in the same way.
[0035] In this embodiment, the spray directions of the first spray point a1, the second spray point b1, the third spray point c1, and the fourth spray point d1 are all orthogonally decomposed into a first spray direction r1 along the liquid metal spray direction r and a second spray direction r2 forming a vortex. That is to say, the first atomizing medium vortex, the second atomizing medium vortex, the third atomizing medium vortex, and the fourth atomizing medium vortex are all advanced along the liquid metal spray direction, thereby accelerating the overall atomization efficiency of the liquid metal jet.
[0036] In this implementation example, the atomizing medium used to form the first atomizing medium vortex, the second atomizing medium vortex, the third atomizing medium vortex, and the fourth atomizing medium vortex is the same medium. The type of atomizing medium has no significant impact on the result. Choosing the same medium is mainly for ease of implementation and lower cost.
[0037] In this embodiment, the atomizing medium is set as nitrogen or argon. As inert gases, nitrogen or argon is not prone to chemical reactions with other substances. Therefore, undesirable chemical reaction products can be avoided during the atomization process. In addition, inert gases usually have high stability and purity, which can ensure the quality and stability of the atomizing medium and help achieve the desired atomization effect.
[0038] The atomization method used in this implementation case yields a final metal powder with a particle size distribution (μm) of 21-22 μm on D10, 25-26 μm on D50, and 43-33 μm on D90, conforming to GB / T 1480-2012; and a flowability of 42-45 s / 50 g, conforming to GB / T 1482-2010.
[0039] Implementation Case 2: Reference Figure 4 and combined Figure 1-3 An apparatus for preparing metal powder, used to perform an atomization method as shown in Example 1.
[0040] The preparation apparatus of this embodiment includes a melting chamber 1, an atomization chamber 2, a flow guiding mechanism 3, a first vortex mechanism a, a second vortex mechanism b, a third vortex mechanism c, and a fourth vortex mechanism d.
[0041] The melting chamber 1 is used to melt metal materials into liquid metal, and the atomization chamber 2 is used to atomize the liquid metal and cool it to form metal powder.
[0042] The flow guiding mechanism 3 includes multiple flow guiding holes or flow guiding channels arranged in a ring, so that liquid metal is injected from the melting chamber 1 into the atomization chamber 2 and forms a liquid metal jet band.
[0043] The first vortex mechanism a is located in the inner periphery of the metal liquid jet zone and has multiple first injection points a1. The atomized medium ejected from the first injection points a1 forms a first atomized medium vortex that contacts it.
[0044] The second vortex mechanism b is located on the periphery of the metal liquid jet zone and has multiple second injection points b1. The atomized medium ejected from the second injection points b1 forms a second atomized medium vortex that contacts it.
[0045] The third vortex mechanism c is located within the inner periphery of the metal liquid jet zone and has multiple third injection points c1. The atomized medium ejected from the third injection points c1 forms a third atomized medium vortex that contacts it.
[0046] The fourth vortex mechanism d is located on the periphery of the metal liquid jet zone and has multiple fourth injection points d1. The atomized medium ejected from the fourth injection points d1 forms a fourth atomized medium vortex with the contact of the atomized medium.
[0047] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.
Claims
1. A method for forming metal powder by atomization, characterized in that the steps include... include: S1: Liquid metal is ejected from the flow guiding mechanism and forms a ring-shaped liquid metal jet band; S2: A first atomizing medium vortex and a second atomizing medium vortex are formed in the inner and outer peripheries of the metal liquid jet band and come into contact with the metal liquid jet band, wherein the rotation directions of the first atomizing medium vortex and the second atomizing medium vortex are opposite. S3: A third atomizing medium vortex and a fourth atomizing medium vortex are formed in the inner and outer peripheries of the metal liquid jet band and come into contact with the metal liquid jet band, wherein the rotation directions of the third atomizing medium vortex and the fourth atomizing medium vortex are the same. The first and third atomizing medium vortices are positioned upstream and downstream in the flow direction of the liquid metal jet, while the second and fourth atomizing medium vortices are positioned upstream and downstream in the injection direction of the liquid metal. The atomizing medium of the first atomizing medium vortex and / or the second atomizing medium vortex is heated, and the atomizing medium of the third atomizing medium vortex and / or the fourth atomizing medium vortex is cooled, so that the atomizing space in which the metal liquid jet is located forms a heating zone corresponding to the first atomizing medium vortex and the second atomizing medium vortex, and a cooling zone corresponding to the third atomizing medium vortex and the fourth atomizing medium vortex.
2. The atomization method according to claim 1, characterized in that, In S2: the atomizing medium is ejected from multiple first injection points located on the periphery of the metal liquid jet band and forms a first atomizing medium vortex; the atomizing medium is ejected from multiple second injection points located on the inner periphery of the metal liquid jet band and forms a second atomizing medium vortex. In S3: the atomizing medium is ejected from multiple third injection points located on the periphery of the metal liquid jet zone and forms a third atomizing medium vortex; the atomizing medium is ejected from multiple fourth injection points located on the inner periphery of the metal liquid jet zone and forms a fourth atomizing medium vortex.
3. The atomization method according to claim 2, characterized in that, The spray directions of the first, second, third, and fourth spray points are orthogonally decomposed into a first spray direction along the direction of liquid metal spraying and a second spray direction that forms a vortex.
4. The atomization method according to claim 1, characterized in that, The atomizing medium used to form the first atomizing medium vortex, the second atomizing medium vortex, the third atomizing medium vortex, and the fourth atomizing medium vortex is the same medium.
5. The atomization method according to claim 4, characterized in that, The atomizing medium is set to nitrogen or argon.
6. An apparatus for implementing the atomization method according to any one of claims 1-5, characterized in that, include: A melting chamber is used to melt metallic materials into liquid metal. Atomization chamber, used to atomize and cool liquid metal to form metal powder; The flow guiding mechanism includes multiple flow guiding holes or flow guiding channels arranged in a ring for injecting liquid metal from the melting chamber into the atomization chamber and forming a liquid metal jet band; A first vortex mechanism is used to form and contact a first atomizing medium vortex within and in the inner periphery of the liquid metal jet. The second vortex mechanism is used to form and contact a second atomizing medium vortex around and in contact with the metal liquid jet zone.
7. The apparatus according to claim 6, characterized in that, Also includes: The third vortex mechanism is used to form and contact a third atomizing medium vortex within and in the inner periphery of the liquid metal jet. The fourth vortex mechanism is used to form and contact a fourth atomizing medium vortex on the periphery of and with the metal liquid jet.