CN115519128A - Device and method for preparing fixed-size 3D printing powder through centrifugal atomization of hot-melt material - Google Patents

Abstract

The invention provides a device and a method for preparing fixed-size 3D printing powder through centrifugal atomization of a hot-melt material, and relates to the technical field of 3D printing powder. The device comprises a smelting furnace, wherein an atomization bin is arranged at the upper part of the smelting furnace, a roller is arranged in the atomization bin, capillary holes with consistent pore diameters are uniformly distributed on the surface of the side wall of the roller, and the axial directions of all the capillary holes and the diameter of the section of the roller form the same included angle; a liquid distributor extending from one end of the roller to the other end is arranged at the position close to the inner wall of the lower side of the roller, and a plurality of liquid distributing openings are uniformly arranged at intervals on the lower side of the liquid distributor facing the inner wall of the roller. The uniform pore size and shape of the pores ensure equal liquid capacity of each pore, given the material of the drum and the liquid metal. The capillary thus completes the volumetric dispensing of the solution. The constant volume is the basis of the quantification and the sizing of the powder, so that the quantification of the powder is controlled, the consistency of the prepared powder is good, and the yield is high.

Description

Device and method for preparing fixed-size 3D printing powder through centrifugal atomization of hot-melt material

Technical Field

The invention relates to the technical field of 3D printing powder, in particular to a device and a method for preparing fixed-size 3D printing powder through centrifugal atomization of a hot-melt material.

Background

The advanced powder preparation technology is the basis of modern powder metallurgy and product industrialization and is the lead of the development of related emerging industries. In recent years, the annual production and sales of global metal powder are close to 300 ten thousand tons, and the annual production and sales of China are about 140 ten thousand tons, wherein the spherical metal powder accounts for 7 percent of the total powder production, but the yield is as high as 21 percent. From the aspect of the powder growth rate, the growth rate of the traditional powder is not more than 5%, and the average growth rate of the spherical metal powder applied to high-end manufacturing fields such as microelectronic Surface Mount Technology (SMT), additive manufacturing, new energy soft magnetic materials and the like is more than 30%, so that the spherical metal powder shows a high-speed growth tendency. In addition, various high and new technology products are developed in the direction of light weight, miniaturization and multifunctional integration, and the performance requirements of spherical powder materials are gradually improved, so that the spherical powder materials are developed in the direction of high sphericity, narrow granularity, superfine, low oxygen, high stability, consistency and the like.

3D printing is one of mainstream technologies of future material processing, is the core field of spherical powder application, and with the rapid development of metal 3D printing technology, the market of spherical metal powder will keep a high growth situation. The 3D printing powder is typically on the micron scale, on the order of about 30-100 microns. The laser and electron beam slightly differ in the size requirements of the 3D printing powder, the laser 3D printing powder has a particle size of 30-50 μm, and the electron beam printing powder has a slightly larger particle size of 60-80 μm. Although the characteristics of different 3D printing methods and materials are different, the requirements for powder particle size are also different. But the requirements for narrow particle size distribution, high sphericity and good flowability are consistent.

At present, the preparation method of 3D printing metal powder mainly includes an atomization method (mainly including vacuum atomization (VIGA), electrode induction atomization (EIGA), and the like), and a plasma method (plasma rotating electrode atomization (PREP), plasma fuse atomization (WPA), plasma spheroidization technology (PA), and the like). The existing preparation method of 3D printing metal powder is divided into a metal melting granulation method and a metal powder granulation method according to different raw materials, wherein the metal melting granulation method mainly comprises the processes of metal melting, liquid separation and spheroidization. Similarly to the metal powder granulation method (plasma spheronization method), the original powder becomes a base powder after "liquid separation". The particle size distribution is wide, so that the amount of the powder for separating liquid is different, and the particle size distribution of the prepared powder is wide. In recent years, although many studies have been made on the yield of 3D printed metal powder, the focus has been mainly on raw materials, process parameters, nozzle airflow control, tooling, and the like, and the focus has not been always on the quantification of liquid separation of metal solutions, so that the problem of high yield of powder has not been fundamentally changed or improved. Even the highest yield of the plasma atomization wire material technology (PA method) of the highest finished product is stopped between 60 and 70 percent. However, due to the long processing routes of some metal wire/foil materials, the manufacturing cost is high. Particularly, some materials cannot be processed into wires or foils because of the limit of processability, so that the spheroidizing yield of the powder can only be limited to about 30 percent. In fact, the reason why 60-70% yield can be obtained in the plasma atomization wire method (PA method) is the quantitative control of the feeding amount, and the reason why other methods fail to achieve such high yield is also because of this. Therefore, no matter the process of metal melting atomization granulation method "melting-atomization-spheroidizing" or the process of metal powder granulation method (plasma spheroidizing) "powder-melting-spheroidizing", liquid separation is the key step of particle size control. The core of the liquid separation is to realize quantification (constant volume or constant weight). The specific method is quantitative liquid separation in a metal melting granulation method (a spray granulation method and a rotary electrode method), and the specific method is the fixed-length and fixed-speed control of pre-granulation powder/wire/foil in a plasma atomization method.

Similar studies have been made in the relevant fields in terms of quantitative liquid separation. The main methods include a shredding or punching remelting method, a membrane emulsification method, a fixed-length droplet forming method and a pulse small-hole injection method. However, of the above methods, only the pulse small hole spray method of japan has been currently put to industrial use in metal granulation. The preparation of particles of various materials with the particle size ranging from 80 to 600 mu m can be realized, such as Pb-Sn, sn-Ag, bi-Sb alloy particles with low melting point, cu particles with high melting point, si particles and Ge particles, fe-based metal particles, glass particles and the like. However, the equipment has a complex structure, high control difficulty and low efficiency, and the preparation of bulk metal sized particles is yet to be further developed.

Disclosure of Invention

The invention aims to provide a device and a method for preparing sized 3D printing powder by centrifugal atomization of a hot-melt material, and aims to solve the technical and economic problems that the conventional powder preparation method cannot realize quantitative control of powder, so that the powder has wide particle size distribution, low yield, high cost, low productivity and the like. The technical effects that can be produced by the preferred technical scheme in the technical schemes provided by the invention are described in detail in the following.

In order to achieve the purpose, the invention provides the following technical scheme:

the device for preparing the fixed-size 3D printing powder by centrifugally atomizing the hot-melt material comprises a melting furnace, wherein an atomizing bin is arranged at the upper part of the melting furnace, a roller is arranged in the atomizing bin, capillary holes with consistent pore diameters are uniformly distributed on the surface of the side wall surrounding the roller, and the axial directions of all the capillary holes and the diameter of the cross section of the roller are arranged in the same included angle;

and a liquid distributor extending from one end of the roller to the other end is arranged at a position close to the inner wall of the lower side of the roller, and a plurality of liquid distribution ports are uniformly arranged at intervals on the lower side of the liquid distributor facing the inner wall of the roller.

According to a preferred embodiment, the included angle between the axial direction of the capillary holes and the diameter direction of the section of the roller is 30 to 60 degrees along the rotation direction of the roller.

According to a preferred embodiment, the liquid distribution port is an inverted cone-shaped structure which is downwards recessed from the side wall of the liquid distributor, and a liquid spraying port is formed at the lowest end of the liquid distribution port.

According to a preferred embodiment, the distance between the liquid spray opening and the inner wall of the lower side of the drum is 1 to 2mm.

According to a preferred embodiment, a scraping plate is arranged at the lower side of the liquid distributor and close to the liquid distribution port, the upper end of the scraping plate is fixedly connected with the outer wall of the liquid distributor, and the lower end of the scraping plate extends towards the inner wall of the roller and is in contact with the inner wall of the roller.

According to a preferable embodiment, one end of the liquid distributor is communicated with a liquid inlet pipe, the other end of the liquid distributor is arranged in a sealing manner, and a liquid inlet of the liquid inlet pipe extends to the outer side of the smelting furnace.

According to a preferred embodiment, a pulse motor is provided outside the upper part of the furnace, the shaft of the pulse motor is drivingly connected to the drum through the side wall of the furnace, and the central axis of the drum is arranged perpendicular to the side wall of the furnace.

According to a preferred embodiment, a spheroidizing bin, a solidifying bin and a receiving bin which are communicated with the atomizing bin are further formed in the melting furnace, and the spheroidizing bin, the fixing bin and the receiving bin are sequentially arranged below the atomizing bin.

Based on the technical scheme, the device for preparing the fixed-length 3D printing powder by centrifugally atomizing the hot-melt material at least has the following technical effects:

the invention provides a device for preparing fixed-size 3D printing powder by centrifugal atomization of a hot-melt material, which comprises a smelting furnace, wherein an atomization bin is formed at the upper part of the smelting furnace, a roller is arranged in the atomization bin, capillary holes with consistent pore diameters are uniformly distributed on the surface of the side wall surrounding the roller, and the axial directions of all the capillary holes and the diameter of the roller are arranged at the same included angle; a liquid distributor extending from one end of the roller to the other end is arranged at the position close to the inner wall of the lower side of the roller, and a plurality of liquid distributing openings are uniformly arranged at intervals on the liquid distributor towards the lower side of the inner wall of the roller. Therefore, the device can store the immersed liquid in the capillary holes on the roller to realize the constant volume distribution of the metal liquid, the volume of the liquid to be constant volume distribution is determined by the pore size of the capillary holes and the wettability between the liquid metal and the roller material, and therefore, the capillary holes with consistent pore size and shape can ensure that the liquid volume of each capillary hole is equal under the condition that the roller material and the liquid metal are determined by the selection of the roller material and the design of the shape of the capillary holes machined by laser. The capillary thus completes the volumetric dispensing of the solution. The constant volume is the basis of the quantification and the sizing of the powder, so that the quantification of the powder is controlled, the consistency of the prepared powder is good, and the yield is high.

The invention also provides a method for preparing the sized 3D printing powder by the centrifugal atomization of the hot-melt material, which comprises the following steps:

melting: putting metal into a molten pool of a heating furnace to melt to form molten liquid;

solution constant volume distribution: the melted liquid is introduced into the liquid distributor by the liquid inlet pulse of the liquid inlet pipe, so that the liquid enters the liquid distributing port of the liquid distributor, is sprayed out from the liquid spraying port and flows on the inner wall of the lower side of the roller, is stricken off under the action of the strickle, the roller rotates at a low speed under the drive of the pulse motor, and the liquid is hung on the inner wall of the roller along with the directional low-speed rotation of the roller; and under the capillary action, the liquid on the inner wall of the roller is sucked and filled in the capillary holes to finish the constant volume distribution of the liquid.

According to a preferred embodiment, the method further comprises, after the volumetric dispensing step, the steps of:

solution atomization: after the constant volume distribution of the through capillary holes is finished, the pulse motor drives the roller to rotate at a high speed, the metal liquid stored in the through capillary holes in a constant volume mode is instantly thrown out under the action of centrifugal force generated by high-speed rotation, and a constant volume liquid drop group is formed in the outer space of the roller. At this stage, the volumetric atomization process of the droplets is completed.

Sizing the liquid drops: under the action of gravity, the liquid drop group enters the spheroidizing bin, and in the falling process of the spheroidizing bin, the liquid drops complete the spheroidizing process of the liquid drops with constant volume under the action of surface tension. Thus, the process of constant volume and spheroidization is completed.

And (3) solidifying the liquid drops: the liquid drops which finish the constant volume and the spheroidization fall to a cooling solidification bin under the action of gravity. In the solidification bin, the temperature of the liquid drops which have finished the constant volume and spheroidization is reduced to the melting point of the material due to the cooling effect, so that the phase change from liquid state to solid state occurs, and the constant volume, spheroidization and solidification process is finished.

Powder discharging: the solid powder falls to receiving the feed bin under the action of gravity, and is discharged through further cooling to form the sized powder.

Based on the technical scheme, the method for preparing the fixed-size 3D printing powder by centrifugally atomizing the hot-melt material at least has the following technical effects:

the powder prepared by the method has good consistency and high yield, and the capillary pores on the roller can realize constant volume liquid separation and fixed length control, so that the yield of more than 90 percent can be ensured and is far higher than the level that the yield of the existing 3D metal powder is less than 35 percent. And the prepared powder has high sphericization degree.

The method can realize one-step molding of the hot-melt material sized powder, does not need secondary processing from the smelting furnace to the powder particles, and has higher processing efficiency. The metal melting furnace can be transformed once to prepare the sized particles in batches, the energy consumption is low, and the method is applicable to almost all hot-meltable materials and has wide application range.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the prior art descriptions will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic structural diagram of an apparatus for preparing a scaled 3D printing powder by centrifugal atomization of a hot-melt material according to the present invention;

FIG. 2 is a schematic structural diagram of a roller in the apparatus for preparing a scaled 3D printing powder by centrifugal atomization of a hot-melt material according to the present invention;

FIG. 3 is a cross-sectional schematic view of the drum of FIG. 2;

FIG. 4 is a schematic diagram illustrating the arrangement of a roller and a liquid distributor in the apparatus for preparing a scaled 3D printing powder by centrifugal atomization of a hot-melt material according to the present invention;

FIG. 5 is a longitudinal sectional view of a liquid distributor in the device for preparing the sized 3D printing powder by centrifugally atomizing the hot-melt material.

In the figure: 1-a furnace; 11-a roller; 12-capillary pores; 13-liquid distributor; 14-liquid distribution port; 15-liquid spraying port; 16-a liquid inlet pipe; 17-a pulse motor; and 18-scraping the plate.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be described in detail below. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the examples given herein without any inventive step, are within the scope of the present invention.

In the description of the present invention, it is to be noted that, unless otherwise specified, "a plurality" means two or more; the terms "upper", "lower", "left", "right", "inner", "outer", "front", "rear", "head", "tail", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are merely for convenience in describing the present invention and to simplify the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; may be directly connected or indirectly connected through an intermediate. Specific meanings of the above terms in the present invention can be understood as appropriate by those of ordinary skill in the art.

Example 1

As shown in fig. 1 to 4, the present embodiment provides an apparatus for preparing a scaled 3D printing powder by centrifugal atomization of a hot melt material, including a melting furnace 1, an atomization chamber disposed at an upper portion of the melting furnace 1, a drum 11 disposed in the atomization chamber, and capillary holes 12 with consistent pore diameters uniformly distributed around a sidewall surface of the drum 11. And the axial directions of all the capillary holes 12 and the section diameter of the roller 11 are arranged in the same included angle. A liquid distributor 13 extending from one end of the roller 11 to the other end is arranged at a position close to the inner wall of the lower side of the roller 11, and a plurality of liquid distribution ports 14 are uniformly arranged at intervals on the liquid distributor 13 facing the lower side of the inner wall of the roller 11. The side wall surface of the drum is distributed with regular capillary holes with consistent pore diameter and shape by laser processing, preferably, the pore diameter of the capillary hole 12 can be in a micron order to a millimeter order, and the liquid invaded is stored in the capillary action of the capillary hole on the drum. The capacity of the capillary pores for absorbing the solution can be calculated according to a Kelvin law, and according to the Kelvin law, the capillary action force delta P =4 tau cos theta/d = rho gh, wherein tau is surface tension, theta is wetting angle, d is micropore diameter, rho is liquid density, h is liquid height, and V = Pi d tau cos theta/rho g. The volume of the liquid to be quantitatively distributed is determined by the pore size of the capillary pores and the wettability between the liquid metal and the roller material. The liquid capacity of each capillary can thus be determined by the choice of the material of the drum and the laser machined capillary shape design. It can be seen that the volume of the capillary pores capable of adsorbing liquid is a certain value, and the process completes the constant volume distribution of the solution by the capillary. The constant volume is the basis of powder quantification and scaling, so that the powder quantification is controlled, the consistency of the prepared powder is good, and the yield is high.

Preferably, as shown in fig. 3, the angle between the axial direction of the capillary holes 12 and the diameter direction of the section of the drum 11 is 30 to 60 ° in the rotation direction of the drum 11. That is, the axial direction of the capillary holes 12 is not aligned with the diameter direction of the section of the drum, so that the liquid is thrown outward by centrifugal force during rotation.

Preferably, as shown in fig. 4, the liquid distribution port 14 is formed in an inverted cone shape which is downwardly recessed from the side wall of the liquid distributor 13. And a liquid ejecting port 15 is formed at the lowermost end of the liquid distribution port 14. The liquid distribution port 14 is of a large-top and small-bottom structure, and the liquid distribution port is arranged so that the falling amount of the liquid from the tank top to the liquid spraying port in the liquid distribution port is gradually reduced, so that the liquid can be gradually filled into the liquid distribution port at the other end from the liquid distribution port at one end of the liquid distributor, all the liquid distribution ports are full of the liquid, and the liquid can be uniformly sprayed on the inner wall of the roller. Preferably, the distance between the liquid spray opening 15 and the inner wall of the drum 11 is 1 to 2mm. So that the scraping plate positioned at the rear side of the liquid spraying opening scrapes the hot melting material flowing out of the liquid spraying opening on the inner wall of the roller. Preferably, the length of the liquid distributor 13 corresponds to the axial length of the interior of the drum 11, so that the capillary holes in the side wall of the drum can uniformly suck the liquid. Preferably, the pore size of the liquid jet 15 can be selected according to the fluidity of the molten material. Preferably, a scraper 18 is disposed at a position close to the liquid distribution port 14 and below the liquid distributor 13, an upper end of the scraper 18 is fixedly connected to an outer wall of the liquid distributor 13, and a lower end extends toward an inner wall of the drum 11, so that the lower end of the scraper 18 contacts the inner wall of the drum 11. The scraper 18 is used to scrape off the liquid on the inner wall of the drum 11. Further preferably, one end of the liquid distributor 13 is communicated with the liquid inlet pipe 16, and the other end is hermetically arranged, and the liquid distributor 13 may be a tubular structure. The inlet of the inlet pipe 16 extends to the outside of the furnace 1. The liquid inlet pipe 16 and the side wall of the roller 11 can be arranged by adopting a dynamic seal, so that the liquid inlet pipe 16 and the liquid distributor 13 do not rotate along with the rotation of the roller 11.

Further preferably, as shown in fig. 1 or 4, a pulse motor 17 is provided at an upper outer side of the melting furnace 1, a rotation shaft of the pulse motor 17 is drivingly connected to the drum 11 through a side wall of the melting furnace 1, and a central axis of the drum 11 is disposed perpendicular to the side wall of the melting furnace 1. The pulse motor 17 can adjust the rotating speed of the roller, and in the solution constant volume distribution stage, the pulse motor enables the roller to rotate slowly, so that the liquid flowing out of the liquid distribution port flows on the inner wall of the lower side of the roller and is fully hung on the inner wall of the roller along with the rotation of the roller. In the solution atomization stage, the rotary drum is rotated at a high speed through the pulse motor, so that the constant volume liquid in the capillary holes is centrifugally thrown out under the centrifugal action generated by the high-speed rotation of the rotary drum to form atomized constant volume liquid drops.

Further preferably, as shown in fig. 1, a spheroidizing bin, a solidifying bin and a receiving bin which are communicated with the atomizing bin are further formed in the melting furnace 1, and the spheroidizing bin, the fixing bin and the receiving bin are sequentially arranged below the atomizing bin. The solution constant volume distribution and the liquid drop atomization process are carried out in the atomization bin, and the metal liquid drops enter the spheroidizing bin under the action of gravity after leaving the capillary holes of the roller. In the falling process of the spheroidizing bin, because the temperature of the periphery of the liquid drop group is higher, the liquid drop is spheroidized because the surface area of the liquid drop is reduced under the action of gas-liquid surface tension. Thereby completing the transition from constant volume to fixed length of the liquid drop. The liquid drops which finish the fixed-length spheroidizing process continuously fall into a cooling solidification bin. Because the temperature of the solidification bin is rapidly reduced to be lower than the melting point temperature, the phase change from the liquid state to the solid state is completed when the melting point approaches the temperature, and therefore the liquid drops are solidified into solid powder. Finally, the solidified powder is continuously cooled under the protection of inert gas, the surface activity is obviously reduced, the solidified powder is discharged from the material receiving bin, and the obtained metal powder has the characteristics of uniform particle size, narrow distribution, good spheroidization degree and low oxygen content.

Example 2

The embodiment provides a method for preparing sized 3D printing powder by centrifugal atomization of a hot-melt material, which comprises the following steps:

(1) Melting:

the metallic aluminum is put into a melting pool of a heating furnace to be melted to form molten liquid. In the melting process, the metal solution with low purity can be refined in the process, and metal impurities suspended on the surface of the liquid or precipitated at the bottom are removed. For reactive metals, the process can be carried out under vacuum or under argon protection in order to prevent getter reactions.

(2) Solution constant volume distribution:

the melted molten metal aluminum liquid is introduced into a liquid distributor 13 by a liquid inlet pulse of a liquid inlet pipe 16, so that the liquid enters a liquid distribution port 14 of the liquid distributor 13 and is sprayed out from a liquid spray port 15 to flow on the inner wall of the lower side of the roller 11, and is scraped flat under the action of a scraper plate 18, the roller 11 is driven by a pulse motor 17 to rotate at a low speed, and the liquid is carried upwards along with the directional low-speed rotation of the roller 11 to be hung on the inner wall of the roller 11; and under the capillary action, the liquid on the inner wall of the roller 11 is sucked into and fills the capillary holes 12 to complete the constant volume distribution of the liquid.

(3) Solution atomization:

after the constant volume distribution of the through capillary holes is finished, the pulse motor 17 drives the roller 11 to rotate at a high speed, and the metallic aluminum liquid stored in the through capillary holes 12 at a constant volume is instantly thrown out under the action of centrifugal force generated by high rotation, and forms a constant volume liquid drop group in the outer space of the roller 11. At this stage, the volumetric atomization of the droplets is completed.

(4) Sizing the liquid drops:

after the molten metal aluminum drops leave the capillary holes of the roller, the liquid drop groups enter the spheroidizing bin under the action of gravity. In the falling process of the spheroidizing bin, because the temperature of the periphery of the liquid drop group is higher, the liquid drop is spheroidized due to the fact that the surface area of the liquid drop is reduced under the action of gas-liquid surface tension. The spheroidizing process of the liquid drop with constant volume is completed under the action of the surface energy of the atomized liquid drop. Thus, the process of constant volume and spheroidization is completed. For powders with low oxygen requirements, it is optional to introduce a reducing gas, such as H, into the process ₂ 、CO、CH ₄ And the like.

(5) And (3) solidifying the liquid drops:

accomplish the metal aluminium liquid drop of constant volume and balling and descend to solidification storehouse under the action of gravity, accomplish the liquid drop of constant volume and balling in solidification storehouse, because the cooling effect, its temperature reduces to the material melting point, therefore takes place by liquid to solid-state phase transition, because the cooling solidification storehouse temperature reduces to below the melting point temperature rapidly, accomplishes from liquid to solid-state phase transition when the melting point closes on the temperature, realizes the solidification of constant volume and balling liquid drop, forms the scaling powder. Thus finishing the process of constant volume, spheroidization and solidification.

(6) Powder discharging:

the solid powder falls to a material receiving bin under the action of gravity to be discharged. The surface activity of the solidified powder is obviously reduced after further temperature reduction under the protection of inert gas. The material can be discharged at the temperature of less than 100 ℃ according to the active degree of the chemical property of the powder. The metal powder obtained at the moment has the characteristics of uniform granularity, narrow distribution, good spheroidization degree, low oxygen content and the like.

The method can be used for quantitatively distributing metal, nonmetal and organic matters with the melting point below 1800 ℃; and is used for spheroidizing metal, nonmetal and organic matters with the melting point below 1800 ℃; can be used for the quantification and spheroidization of micron and millimeter-sized particles; can be used in vacuum, argon protection and air environment.

The preparation method of the invention utilizes the high-precision characteristic of laser to ensure the high precision and consistency of the aperture and the shape of the roller capillary. The amount of solution stored in the capillary pores is closely related to the internal volume of the pores, the nature of the solution, and the wettability of the solution with the roller. Therefore, the pore diameter of the capillary pores can be accurately designed according to the characteristics, constant volume liquid separation and fixed length control are realized, and the yield can be ensured to be over 90 percent. The yield of the product is far higher than that of the existing 3D metal powder by less than 35 percent. The prepared powder has good consistency and high yield. The degree of sphericization of the powder is high. In addition, the sized particles can be formed by one step of hot-melting sized powder of materials, secondary processing is not needed from a melting furnace to the powder particles, and the processing effect is high. The invention can prepare the sized particles in batches only by once reforming the metal melting furnace, and has low energy consumption. The device can be used for almost all hot-melt materials, and has wide application range. The device has large production batch and can regulate and control the surface area of the roller. The productivity can be adjusted by increasing the diameter, length and rotating speed of the rotary drum.

The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.

Claims (10)

1. The device for preparing the sized 3D printing powder through centrifugal atomization of the hot-melt material is characterized by comprising a smelting furnace (1), wherein an atomization bin is arranged at the upper part of the smelting furnace (1), a roller (11) is arranged in the atomization bin, capillary holes (12) with consistent pore diameters are uniformly distributed on the surface of the side wall surrounding the roller (11), and the axial directions of all the capillary holes (12) and the diameter of the section of the roller (11) form the same included angle;

a liquid distributor (13) extending from one end of the roller (11) to the other end is arranged at a position close to the inner wall of the lower side of the roller (11), and a plurality of liquid distribution ports (14) are uniformly arranged at intervals on the lower side of the inner wall of the roller (11) towards the liquid distributor (13).

2. The device for preparing the sized 3D printing powder through centrifugal atomization of the hot melt material according to claim 1, wherein an included angle between the axial direction of the capillary holes (12) and the diameter direction of the section of the roller (11) along the rotation direction of the roller (11) is 30-60 degrees.

3. The device for preparing the scaled 3D printing powder by centrifugally atomizing the hot melt material as claimed in claim 1, wherein the liquid distribution port (14) is of an inverted cone structure which is downwardly concave from the side wall of the liquid distributor (13), and a liquid spray port (15) is formed at the lowermost end of the liquid distribution port (14).

4. The device for preparing the sized 3D printing powder through centrifugal atomization of the hot melt material according to claim 3, wherein the distance between the liquid spraying port (15) and the inner wall of the lower side of the roller (11) is 1-2 mm.

5. The device for preparing the sized 3D printing powder through centrifugal atomization of the hot melt material according to claim 1, wherein a scraping plate (18) is arranged at a position, close to the liquid distribution port (14), on the lower side of the liquid distributor (13), the upper end of the scraping plate (18) is fixedly connected with the outer wall of the liquid distributor (13), the lower end of the scraping plate extends towards the direction of the inner wall of the lower side of the roller (11), and the lower end of the scraping plate (18) is in contact with the inner wall of the roller (11).

6. The device for preparing the scaled 3D printing powder through centrifugal atomization of the hot melt material according to claim 1, wherein one end of the liquid distributor (13) is communicated with a liquid inlet pipe (16), the other end of the liquid distributor is hermetically arranged, and a liquid inlet of the liquid inlet pipe (16) extends to the outer side of the melting furnace (1).

7. The apparatus for centrifugal atomization of hot melt material for preparing scaled 3D printing powder according to claim 1, wherein a pulse motor (17) is disposed outside an upper portion of the melting furnace (1), a rotating shaft of the pulse motor (17) penetrates through a side wall of the melting furnace (1) to be in driving connection with the drum (11), and a central axis of the drum (11) is perpendicular to the side wall of the melting furnace (1).

8. The device for preparing the sized 3D printing powder through centrifugal atomization of the hot melt material according to claim 1, wherein a spheroidizing bin, a solidifying bin and a receiving bin which are communicated with the atomizing bin are further formed in the smelting furnace (1), and the spheroidizing bin, the solidifying bin and the receiving bin are sequentially arranged below the atomizing bin.

9. A method for preparing sized 3D printing powder by centrifugal atomization of hot melt materials is characterized by comprising the following steps:

melting: putting metal into a molten pool of a heating furnace to melt to form molten liquid;

solution constant volume distribution: introducing molten liquid into a liquid distributor (13) by a liquid inlet pulse of a liquid inlet pipe (16), enabling the liquid to enter a liquid distribution port (14) of the liquid distributor (13), be sprayed out from a liquid spraying port (15) and flow on the inner wall of the lower side of a roller (11), be scraped under the action of a scraping plate (18), enable the roller (11) to rotate at a low speed under the drive of a pulse motor (17), and enable the liquid to be hung on the inner wall of the roller (11) along with the directional low-speed rotation of the roller (11); and under the capillary action, the liquid on the inner wall of the roller (11) is sucked into and fills the capillary holes (12) to complete the constant volume distribution of the liquid.

10. The method of claim 9, further comprising, after the volumetric dispensing step, the steps of:

solution atomization: after the constant volume distribution of the through capillary holes is finished, the pulse motor (17) drives the roller (11) to rotate at a high speed, and under the action of centrifugal force generated by high rotation, the metal liquid stored in the through capillary holes (12) at constant volume is instantly thrown out, and a constant volume liquid drop group is formed in the outer space of the roller (11);

sizing the liquid drops: under the action of gravity, the liquid drop group enters a spheroidizing bin, and under the action of surface energy in the falling process of the spheroidizing bin, the spheroidizing process of the liquid drop with constant volume is completed;

and (3) solidifying the liquid drops: the liquid drops which finish the constant volume and the spheroidization fall to a cooling solidification bin under the action of gravity, the liquid drops which finish the constant volume and the spheroidization in the solidification bin are subjected to phase change from liquid to solid when the temperature is reduced to the melting point of the hot melt material, the solidification process of the liquid drops which finish the constant volume and the spheroidization is realized, and the fixed-size spherical powder is formed;

powder discharging: the solid powder falls to receiving the feed bin under the action of gravity, and is discharged through further cooling to form the fixed-size spherical powder.

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