CN114101690B - Device based on gas-solid coupling atomization preparation metal powder - Google Patents
Device based on gas-solid coupling atomization preparation metal powder Download PDFInfo
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/06—Making metallic powder or suspensions thereof using physical processes starting from liquid material
- B22F9/08—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying
- B22F9/082—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying atomising using a fluid
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B33—ADDITIVE MANUFACTURING TECHNOLOGY
- B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
- B33Y40/00—Auxiliary operations or equipment, e.g. for material handling
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/06—Making metallic powder or suspensions thereof using physical processes starting from liquid material
- B22F9/08—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying
- B22F9/082—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying atomising using a fluid
- B22F2009/0824—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying atomising using a fluid with a specific atomising fluid
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/06—Making metallic powder or suspensions thereof using physical processes starting from liquid material
- B22F9/08—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying
- B22F9/082—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying atomising using a fluid
- B22F2009/0848—Melting process before atomisation
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/06—Making metallic powder or suspensions thereof using physical processes starting from liquid material
- B22F9/08—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying
- B22F9/082—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying atomising using a fluid
- B22F2009/0888—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying atomising using a fluid casting construction of the melt process, apparatus, intermediate reservoir, e.g. tundish, devices for temperature control
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/25—Process efficiency
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Abstract
The invention relates to a device for preparing metal powder based on gas-solid coupling atomization, and belongs to the technical field of metal powder preparation. The feeding mechanism in the device is arranged on a melting chamber, the melting heating equipment is arranged in the melting chamber, and the melting chamber is arranged at the upper part of an atomizing tower and used for conveying metal bars to the melting chamber and heating and melting the metal bars; two ends of the atomizing nozzle are correspondingly positioned in the melting chamber and the atomizing tower one by one, the powder feeder and the gas storage tank are respectively connected with the atomizing nozzle, and the impact crushing effect on the metal liquid drops is enhanced by adopting a gas-solid coupling atomizing medium; the spheroidization time-delay induction coil assembly is arranged inside the atomizing tower, so that the spheroidization time of the metal liquid drops is prolonged; the powder collector is arranged at the lower part of the atomizing tower and is used for collecting the powder atomized and condensed by the atomizing tower. The device disclosed by the invention is simple in structure and easy to operate, can be used for preparing high-performance metal powder with good sphericity, good fluidity, small particle size and narrow particle size distribution, and has a good application prospect.
Description
Technical Field
The invention relates to a device for preparing metal powder based on gas-solid coupling atomization, and belongs to the technical field of metal powder preparation.
Background
The metal powder is one of the most important raw materials in the 3D printing technology, and the performance of the metal powder directly influences the forming performance and the mechanical property of 3D printing parts. The powder for 3D printing is required to have the characteristics of high purity, low oxygen content, good sphericity, small particle size, uniform distribution and the like. From the current metal powder preparation process, the metal reduction and hydride dehydrogenation processes can cause the powder to have high oxygen content and irregular shape; the oxygen content and the fine powder yield of the powder prepared by the plasma spheroidization method are difficult to control, and the equipment cost is higher; the powder prepared by the plasma atomization process has high quality, but the raw materials need good plasticity to be processed into wires and are limited by foreign patents; the powder prepared by the plasma rotating electrode method has larger granularity, and the technology at the present stage is monopolized abroad. Therefore, how to prepare high-performance metal powder with good sphericity, good fluidity, small particle size and narrow distribution becomes an urgent problem to be solved in the metal powder manufacturing industry.
Disclosure of Invention
Aiming at the technical problems in the prior art, the invention provides a device for preparing metal powder based on gas-solid coupling atomization, on one hand, a gas-solid two phase is adopted to replace a single gas phase as an atomization medium, so that the impact crushing effect on metal liquid drops is enhanced, and finer metal liquid drops are obtained; on the other hand, a spheroidizing time-delay induction coil component is added in an atomizing area, so that the spheroidizing time of the metal liquid drops is prolonged, and the powder has good sphericity.
The purpose of the invention is realized by the following technical scheme.
A device for preparing metal powder based on gas-solid coupling atomization comprises a powder feeder, a gas storage tank, a feeding mechanism, melting and heating equipment, a melting chamber, an atomizing nozzle, a spheroidization delay induction coil assembly, an atomizing tower, a support frame and a powder collector;
the atomizing tower is arranged on the supporting frame, the melting chamber is arranged at the upper part of the atomizing tower, the melt inlet end of the atomizing nozzle is positioned in the melting chamber, and the atomizing outlet end of the atomizing nozzle is positioned in the atomizing tower; the feeding mechanism is arranged on the melting chamber and is used for conveying the metal bar to be melted into the melting chamber; the melting and heating equipment is arranged inside the melting chamber and is used for heating the metal bar to melt the metal bar; solid particles serving as an atomizing medium are loaded into a powder feeder, gas (preferably nitrogen or inert gas) serving as the atomizing medium is stored in a gas storage tank, and the powder feeder and the gas storage tank are respectively connected with an atomizing nozzle; the spheroidization delay induction coil assembly is arranged in the atomizing tower and is positioned at the lower part of the atomizing outlet end of the atomizing nozzle, and a conical atomizing area formed by spraying of the atomizing nozzle is positioned in the spheroidization delay induction coil assembly; the powder collector is arranged at the lower part of the atomizing tower and is used for collecting the powder atomized and condensed by the atomizing tower.
The principle of the device for preparing metal powder is as follows: the metal bar is arranged in the feeding mechanism, the feeding mechanism enables the metal bar to move downwards and progressively, the metal bar is delivered into the melting chamber and melted by the melting heating equipment, and the metal bar moves in a rotating manner, so that molten metal liquid drops are separated from the molten semi-solid metal bar in the rotating manner; the molten metal flow melted by the melting and heating equipment enters an atomizing nozzle and is then impacted and crushed by solid particles conveyed into the atomizing nozzle by a powder feeder and a gas coupling medium conveyed into the atomizing nozzle by a gas storage tank to form fine irregular metal droplets; fine irregular metal droplets sprayed out of the atomizing nozzle enter an induction coil of the spheroidizing delay induction coil assembly, the lower part of the atomizing nozzle is ensured to still keep higher temperature, the metal droplets are fully spheroidized for sufficient time, and finally, the metal droplets are condensed in an atomizing tower and enter a powder collector; and separating the mixed powder of the prepared metal powder and solid particles serving as an atomizing medium in a powder collector according to the physicochemical properties of the metal powder and the solid particles, and sieving the separated metal powder to obtain the metal powder with good sphericity, small size and narrow particle size distribution.
Furthermore, the melting and heating equipment adopts an induction heater which is an inductance coil, and the prefabricated metal bar is heated and melted by utilizing the electromagnetic induction principle. The structure of the induction heating coil in the induction heater plays an important role in the heating effect, the geometric structure of the induction heating coil is designed to be conical, the included angle between a conical generatrix and the central axis of the conical generatrix is preferably 28-35 degrees, the number of turns of the coil in the induction heating coil is preferably 4-6 turns, and the inner diameter of the small end of the induction heating coil is preferably 1.0-3.0 mm larger than the diameter of the metal bar.
Further, the selection of the induction heater requires consideration of the power supply power and the current frequency; in the process of melting the metal bar by induction heating, the size, specific heat capacity and feeding speed of the metal bar are considered, the current frequency of the induction heater is also depended on, and the power supply can be calculated by the formula (1):
p＝(0.3～0.4)CρπD 2 v(T 2 -T 1 ) (1)
in the formula (1), p is power, C is specific heat capacity of the metal bar, ρ is density of the metal bar, D is diameter of the metal bar, v is feeding speed of the metal bar, T 2 Temperature after heating of the metal bar, T 1 Is the temperature of the metal plate before heating.
In addition, during induction heating, the current frequency affects the heating rate and temperature distribution of the metal bar. The heating efficiency is ensured and the uniformity of the heating temperature distribution is considered in the induction heating process. Under certain physical property parameters of the heating material, the current penetration depth can be calculated by a current penetration formula:
in the current penetration formula, δ is the current penetration depth, ρ E Is resistivity, μ r For relative permeability, f is the current frequency. According to the practical production, when the ratio of the diameter (D) of the metal bar to the current penetration depth (delta) is 3-6, the induction heating efficiency is optimal, namely:
based on the above formula, the optimum current frequency (f) can be derived b ) The relationship with the diameter (D) of the metal bar is shown in formula (2):
further, the powder feeder comprises a powder tank, a stirring bin, a powder guide pipe, a gas accelerating pipe and a stirring wheel;
the upper part of the powder tank is provided with an air inlet, and the lower part of the powder tank is provided with a powder outlet;
the lower part of the stirring bin is provided with a powder outlet and a stirring gas inlet, the upper part of the stirring bin is provided with an accelerating gas inlet and a powder inlet, and the inside of the stirring bin is provided with a cavity for stirring powder;
the powder tank is arranged at the upper part of the stirring bin, a powder outlet of the powder tank is communicated with a powder inlet of the stirring bin through a powder guide pipe, and an air inlet of the powder tank is connected with the gas storage tank through a conveying pipeline; a powder outlet of the stirring bin is connected with the atomizing nozzle through a conveying pipeline, a stirring gas inlet and an accelerating gas inlet of the stirring bin are both connected with the gas storage tank through the conveying pipeline, two ends of the gas accelerating tube are respectively connected with the accelerating gas inlet and the powder outlet in a one-to-one correspondence manner, one end of the gas guide tube is connected with the stirring gas inlet, and the other end of the gas guide tube is positioned below the stirring wheel; the stirring wheel is installed inside the stirring bin and is used for stirring the powder in the cavity, one end of the powder guide pipe is located in the cavity, and the gas accelerating pipe is communicated with the cavity. The solid particles filled in the powder tank flow into the stirring bin under the action of gas, the stirring wheel is driven to rotate under the action of the gas, so that the solid particles output from the powder guide pipe are stirred and input into the gas accelerating pipe, and the gas obtains higher speed in the gas accelerating pipe so as to convey the solid particles into the atomizing nozzle.
On one hand, gas-solid coupling atomization utilizes interaction of ultrahigh-speed and ultrahigh-pressure gas generated when high-pressure gas passes through an atomizing nozzle and molten metal droplets to break and atomize the high-speed and ultrahigh-pressure gas into smaller droplets, and on the other hand, introduction of solid particles increases impact force on a melt, so that the molten metal droplets are sufficiently broken and atomized to form ultrafine molten metal droplets, and the yield of fine powder is improved. Calculate the Weber number (We) according to equation (3):
in the formula (3), ρ FL Is the density of the flow field, V is the relative velocity of the flow field and the droplets, D di To the initial diameter of the droplet, σ is the surface tension of the droplet. The Weber number is used to represent the ratio of the inertial force required to break up the droplets to the maintained surface tension, when the Weber number is greater than the critical Weber number, the droplets break up, and the diameters of all droplet fragments are less than the maximum stable critical Weber number (We) c ) The calculation formula is shown in formula 4:
We c ＝12(1+1.077On 1.6 ) (4)
in the formula (4), on is an Olympic lattice number and is used for expressing the influence of the viscosity effect On the liquid drop breakage, and the calculation formula is shown as the formula (5):
in the formula (5), mu d Is the dynamic viscosity of the droplets, p d Is the drop density. The time (T) for complete break-up of the droplets was calculated from the initial weber number as follows:
T＝6(We-12) -0.25 ，12≤We≤18
T＝2.45(We-12) 0.25 ，18≤We≤45
T＝14.1(We-12) 0.25 ，45≤We≤351
T＝0.766(We-12) 0.25 ，351≤We≤2670
calculating the velocity (V) of the finally broken droplets from the correlation of the time to complete break and the velocity d )，
∈＝ρ FL /ρ d
In the formula, C d Is the mean coefficient of resistance (compressible flow)Body C d =2.5, incompressible fluid C d ＝1.7)，ρ d Is the drop density. By combining the above formulas, the maximum stable diameter of the droplet can be calculated by the critical weber number, and the calculation formula is shown as formula (6):
in the formula (6), d is the maximum stable diameter of the droplet. According to the formula (6), the density of the flow field can be effectively improved by introducing the solid particles, so that the atomized and crushed metal droplets have smaller maximum stable diameters, and the metal powder formed by condensation has smaller particle sizes.
Further, in order to facilitate separation from the prepared metal powder at a later stage, the solid particles used as the atomizing medium are selected from magnetic or water-soluble solid particles.
Furthermore, the larger particle size of the solid particles can provide larger impulse, so that the metal liquid drops are more easily dispersed, the fragmentation effect is increased, and the solid particles are conveniently separated from the prepared metal powder in the later period, but the dispersibility of the solid particles in the atomization area is also considered, and under the condition of certain air pressure, the dispersion of the solid particles in the atomization area is reduced due to the excessively large particle size, so that the particle size of the solid particles is 100-1000 microns, the gas pressure output from the gas storage tank to the powder feeder is 0.5-5 MPa, and the gas pressure output from the gas storage tank to the atomization nozzle is 0.5-5 MPa.
Further, the purpose of providing the spheroidizing delay induction coil assembly in the atomizing tower is to improve the sphericity of the metal powder. After the metal bar is melted by the melting chamber and atomized by the gas-solid coupling atomization medium, the metal liquid drop can show an irregular shape, the surface tension of the metal liquid drop and the solidification process show a competitive relationship, and if the solidification time is short, the metal liquid drop cannot be spheroidized in time under the action of the surface tension, so that the sphericity of the metal powder is poor. The temperature field distribution in the atomization process is solved through CFD fluid dynamics simulation, a spheroidizing delay induction coil assembly is installed in an area with large temperature gradient change below a nozzle, the temperature in an atomization tower is improved, the temperature gradient between metal liquid drops and the environment is reduced, heat exchange between the metal liquid drops and the environment is reduced, the solidification speed of the metal liquid drops is reduced, and the spheroidizing time is prolonged, so that the sphericity of metal powder prepared by a gas-solid coupling atomization technology is improved.
Further, the influence of an induction coil structure in the spheroidizing delay induction coil assembly on the delay spheroidizing effect is large, the geometric structure of the induction coil is designed to be conical, the difference between the included angle between a conical bus and the central axis of the conical bus and the corresponding included angle of the conical atomization area is 0-5 degrees, the number of turns of a coil in the induction coil is preferably 4-6 turns, and the diameter of the small end of the induction coil is preferably 2.0-6.0 mm larger than that of the small end of the induction coil at the position corresponding to the conical atomization area.
Has the advantages that:
(1) In the device, the powder feeder and the gas storage tank are respectively connected with the nozzle of the atomizing disk, and the two phases of solid particles and gas are adopted to replace the traditional single gas phase as an atomizing medium, so that the crushing effect on the metal bar melt is improved, and therefore, finer metal droplets are obtained, and the yield of fine powder is increased.
(2) In the device, the induction heater is selected to heat and melt the metal bar, and the structural parameters, the power supply power and the current frequency of the induction heating coil in the induction heating heat are optimized, so that the heating efficiency can be ensured, the uniformity of the heating temperature distribution can be ensured, the metal bar can be quickly and fully melted, the resource waste caused by insufficient melting of the metal bar is avoided, and the energy consumption is saved.
(3) According to the device, the powder feeder is conveyed into the atomizing nozzle under the action of gas, and the gas can be used as protective atmosphere to reduce the oxygen content of solid particles, so that the final influence on the performance of 3D printing parts is avoided.
(4) In the device, the spheroidizing time-delay induction coil component is additionally arranged in the atomizing tower, so that the spheroidizing time of molten drops is effectively prolonged, and the sphericity of powder is improved. Through optimizing the structural parameters and the installation position of the induction coil in the spheroidizing time-delay induction coil assembly, the sphericity of the powder can be effectively improved, and the energy is saved.
In conclusion, the device disclosed by the invention is simple in structure and easy to operate, can be used for preparing high-performance metal powder with good sphericity, good fluidity, small particle size and narrow particle size distribution, and has a good application prospect.
Drawings
Fig. 1 is a schematic view of the structure of an induction heating coil used in the embodiment.
Fig. 2 is a schematic structural view of a powder feeder used in the embodiment.
Fig. 3 is a schematic structural diagram of an induction coil of the spheroidized delay induction coil assembly used in the embodiment.
FIG. 4 is a schematic structural diagram of a device for preparing metal powder based on gas-solid coupling atomization adopted in the embodiment.
Fig. 5 is an SEM (scanning electron microscope) image of Ti811 ultra-fine powder prepared in example 1.
Fig. 6 is a graph showing the results of particle size characterization of Ti811 micropowder prepared in example 1.
Fig. 7 is an SEM image of Ti811 micropowder prepared in example 2.
Fig. 8 is a graph showing the results of particle size characterization of Ti811 micropowder prepared in example 2.
In the figure, 1-gas inlet, 2-powder tank, 3-stirring wheel, 4-powder outlet, 5-stirring bin, 6-stirring gas inlet, 7-powder guide pipe, 8-gas guide pipe, 9-gas accelerating pipe, 10-powder feeder, 11-argon steel cylinder, 12-powder collector, 13-support frame, 14-solidified powder, 15-atomizing tower, 16-spheroidized metal liquid drop, 17-induction coil, 18-atomizing nozzle, 19-induction heating coil, 20-metal bar, 21-melting chamber and 22-feeding mechanism.
Detailed Description
The present invention is further illustrated in the following figures and detailed description, wherein the processes are conventional unless otherwise specified, and the starting materials are commercially available from published sources unless otherwise specified. In addition, in the description of the present invention, it is to be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.
In the following embodiments, the apparatus for preparing metal powder based on gas-solid coupling atomization comprises a powder feeder 10, a gas storage tank, a feeding mechanism 22, a melting and heating device, a melting chamber 21, an atomizing nozzle 18, a spheroidizing delay induction coil assembly, an atomizing tower 15, a support frame 13 and a powder collector 12, as shown in fig. 4;
as shown in fig. 2, the powder feeder 10 includes a powder tank 2, a stirring bin 5, a powder duct 7, a gas duct 8, a gas accelerating tube 9, and a stirring wheel 3; the upper part of the powder tank 2 is provided with an air inlet 1, and the lower part is provided with a powder outlet; a powder outlet 4 and a stirring gas inlet 6 are processed at the lower part of the stirring bin 5, an accelerating gas inlet and a powder inlet are processed at the upper part of the stirring bin, and a cavity for stirring powder is processed inside the stirring bin;
the gas storage tank comprises two argon gas steel cylinders 11;
the melting heating equipment adopts an induction heater, is an induction coil and comprises an induction heating power supply, an induction heating coil 19 and a heat dissipation assembly; the geometric structure of the induction heating coil 19 is designed to be conical, the included angle between a conical bus and the central axis of the conical bus is 28.8 degrees, the number of turns of a coil in the induction heating coil 19 is 4 turns, the axial central distance between two adjacent turns of the coil is 6.75mm, the coil is made of red copper, the diameter of the coil is 6mm, the inner diameter of the small end of the induction heating coil 19 is 26mm, and the inner diameter of the small end of the induction heating coil is 1.0 mm-3.0 mm larger than the diameter of the metal bar 20, as shown in fig. 1;
as shown in fig. 3, the geometric structure of the induction coil 17 in the spheroidizing delay induction coil assembly is designed to be conical, the included angle between a conical bus and the central axis of the conical bus is 30 degrees and is 2 degrees larger than the corresponding included angle of a conical atomization area, the number of turns of the coil in the induction coil 17 is 4 turns, the axial center distance between two adjacent turns of the coil is 20mm, the coil is made of red copper, the diameter of the coil is 15mm, the inner diameter of the small end of the induction coil 17 is 100mm, and the inner diameter of the small end of the induction coil 17 is 2.0 mm-6.0 mm larger than the diameter of the corresponding position of the conical atomization area;
the atomizing tower 15 is arranged on the supporting frame 13, the melting chamber 21 is arranged at the upper part of the atomizing tower 15, the melt inlet end of the atomizing nozzle 18 is positioned in the melting chamber 21, and the atomizing outlet end of the atomizing nozzle 18 is positioned in the atomizing tower 15; a feeding mechanism 22 is installed on the melting chamber 21, and the metal bar 20 to be melted is fed into the melting chamber 21 by the feeding mechanism 22; the induction heating power supply, the induction heating coil 19 and the heat dissipation assembly are all arranged in the melting chamber 21, the induction heating power supply is connected with the induction heating coil 19, and the heat dissipation assembly is used for cooling the induction heating coil 19; the powder tank 2 is arranged at the upper part of the stirring bin 5, solid particles serving as an atomizing medium are filled into the powder tank 2, a powder outlet of the powder tank 2 is communicated with a powder inlet of the stirring bin 5 through a powder guide pipe 7, an air inlet 1 of the powder tank 2, a stirring gas inlet 6 of the stirring bin 5 and an accelerating gas inlet are respectively connected with the same argon steel cylinder 11 through conveying pipelines, the other argon steel cylinder 12 is connected with an atomizing nozzle 18 through a conveying pipeline, a powder outlet 4 of the stirring bin 5 is connected with the atomizing nozzle 18 through a conveying pipeline, two ends of a gas accelerating pipe 9 are respectively connected with the accelerating gas inlet and the powder outlet 4 in a one-to-one correspondence manner, one end of the gas guide pipe 8 is connected with the stirring gas inlet 6, the other end of the gas guide pipe 8 is positioned below the stirring wheel 3, the stirring wheel 3 is arranged in the stirring bin 5 and used for stirring the powder in the cavity, one end of the powder guide pipe 7 is positioned in the cavity, and the gas accelerating pipe 9 is communicated with the cavity; the spheroidization delay induction coil assembly is arranged inside the atomizing tower 15, and an induction coil 17 in the spheroidization delay induction coil assembly is positioned at the lower part of the atomizing outlet end of the atomizing nozzle 18, so that a conical atomizing area formed by spraying of the atomizing nozzle 18 is positioned inside the induction coil 17; the powder collector 12 is installed at the lower part of the atomizing tower 15 and is used for collecting the powder atomized and condensed by the atomizing tower 15.
The principle of the device for preparing the metal powder is as follows: the prefabricated metal bar 20 is installed in a feeding mechanism 22, the feeding mechanism 22 not only enables the metal bar 20 to move downwards and progressively, and the metal bar 20 is delivered into an induction heating coil 19 in a melting chamber 21 to be subjected to induction heating melting, but also enables the molten metal liquid drops to be separated from the molten semi-solid metal bar 20 under the rotary motion; the molten metal stream melted by the melting and heating apparatus enters the atomizing nozzle 18; the solid particles in the powder tank 2 flow into the stirring bin 5 under the action of gas, the stirring wheel 3 is driven to rotate under the action of the gas, so that the solid particles output from the powder guide pipe 7 are stirred and input into the gas accelerating pipe 9, the gas obtains higher speed in the gas accelerating pipe 9 to convey the solid particles to the atomizing nozzle 18, meanwhile, an argon gas steel cylinder 11 directly conveys argon gas into the atomizing nozzle 18, and molten metal entering the atomizing nozzle 18 is impacted and crushed by the solid particles and the gas coupling medium to form fine irregular metal droplets; tiny irregular metal droplets sprayed by the atomizing nozzle 18 enter an induction coil 17 in the spheroidizing delay induction coil assembly, the existence of the induction coil 17 can ensure that the lower part of the atomizing nozzle 18 still keeps higher temperature, the metal droplets are fully spheroidized for sufficient time, and finally the metal droplets are condensed in the atomizing tower 15 and enter the powder collector 12; the mixed powder of the prepared metal powder and the solid particles serving as the atomizing medium in the powder collector 12 is separated according to the physicochemical properties of the metal powder and the solid particles, and the separated metal powder is screened to obtain the metal powder with good sphericity, small size and narrow particle size distribution.
Example 1
The device for preparing the metal powder based on gas-solid coupling atomization comprises the following concrete steps of:
(1) The Ti811 metal bar 20 with the prefabricated dimension phi 25 multiplied by 800mm is arranged on the feeding mechanism 22; the feeding speed is 0.1cm/s, the power of the power supply required by calculation is 3.1kW and the current frequency is 15.7kHz, and an induction heating power supply capable of providing power of 30kW and the current frequency of 20 kHz-30 kHz is adopted in consideration of the condition of low heat exchange efficiency; circulating cooling water is introduced into a heat dissipation assembly of the induction heater;
selecting alumina ceramic particles with the particle size of 400-800 mu m as solid particles of an atomizing medium; the argon pressure output by the argon steel cylinder 11 which introduces argon into the powder feeder 10 is 0.8MPa, and the argon pressure output by the argon steel cylinder 11 which directly introduces argon into the atomizing nozzle 18 is 0.5MPa;
(2) Introducing argon into the powder feeder 10 and the atomizing nozzle 18 respectively by two argon steel cylinders 11, starting the induction heater and the spheroidizing time-delay induction coil assembly, starting the feeding mechanism 22 to work after the atomizing tower 15 is in an argon atmosphere, and delivering the prefabricated Ti811 metal bar 20 into the induction heating coil 19 for induction heating and melting; the molten metal drops are dropped into an atomizing nozzle 18 and are impacted by gas-solid coupling atomizing media (argon and alumina ceramic particles), the metal drops are crushed into small drops in irregular shapes, then the small metal drops in irregular shapes are sprayed out of the atomizing nozzle 18 and enter an induction coil 17 in a spheroidization delay induction coil assembly, the position still keeps high temperature under the action of the induction coil 17, the small and irregular metal drops gradually expand into a spherical shape under the action of surface tension, and the metal drops are all positioned in the range of the induction coil 17; the spheroidized metal droplets 16 begin to solidify in the atomizing tower 15 under the action of gravity to form solidified powder 14 and enter the powder collector 12; and (3) pickling the powder collected in the powder collector 12 with 10% hydrochloric acid, dissolving alumina particles, filtering, washing with water, and drying to obtain Ti811 ultrafine powder.
Fig. 5 is an SEM image of the prepared Ti811 ultrafine powder, from which it can be seen that the powder sphericity is good. As is apparent from the particle size characterization of the prepared Ti811 micropowder, the yield of the Ti811 micropowder having a particle size of less than 53 μm was 62.21%, and the particle size of 50% of the Ti811 micropowder was less than 48.665 μm, as shown in FIG. 6.
Example 2
The device for preparing the metal powder based on gas-solid coupling atomization comprises the following concrete steps of:
(1) The prefabricated Ti811 metal bar 20 with the dimension phi 25 multiplied by 800mm is arranged on a feeding mechanism 22; the feeding speed is 0.1cm/s, the power of the power supply required by calculation is 3.1kW and the current frequency is 15.7kHz, and an induction heating power supply capable of providing power of 30kW and the current frequency of 20 kHz-30 kHz is adopted in consideration of the condition of low heat exchange efficiency; circulating cooling water is introduced into a heat dissipation assembly of the induction heater;
NaCl particles with the particle size of 800-1000 mu m are selected as solid particles of the atomizing medium; the argon gas pressure output by the argon gas steel cylinder 11 which is introduced with argon gas into the powder feeder 10 is 1.0MPa, and the argon gas pressure output by the argon gas steel cylinder 11 which is directly introduced with argon gas into the atomizing nozzle 18 is 0.8MPa;
(2) Introducing argon into the powder feeder 10 and the atomizing nozzle 18 respectively by two argon steel cylinders 11, starting the induction heater and the spheroidizing time-delay induction coil assembly, starting the feeding mechanism 22 to work after the atomizing tower 15 is in an argon atmosphere, and delivering the prefabricated Ti811 metal bar 20 into the induction heating coil 19 for induction heating and melting; the molten metal drops are dropped into an atomizing nozzle 18 and are impacted by gas-solid coupling atomizing media (argon and NaCl particles), the metal drops are crushed into irregular tiny drops, then the irregular tiny drops are sprayed out from the atomizing nozzle 18 and enter an induction coil 17 in a spheroidization delay induction coil assembly, at the moment, the position still keeps high temperature under the action of the induction coil 17, the tiny irregular drops gradually expand into a sphere under the action of surface tension, and at the moment, the metal drops are all in the range of the induction coil 17; the spheroidized metal droplets 16 begin to solidify in the atomizing tower 15 under the action of gravity to form solidified powder 14 and enter the powder collector 12; and pouring the powder collected in the powder collector 12 into warm water of 60 ℃, dissolving NaCl particles, filtering, washing with water, and drying to obtain Ti811 ultrafine powder.
Fig. 7 is an SEM image of the prepared Ti811 ultrafine powder, from which it can be seen that the powder sphericity is good. As is apparent from the particle size characterization of the prepared Ti811 micropowder, the yield of the Ti811 micropowder having a particle size of less than 53 μm was 43.23%, and the particle size of 50% of the Ti811 micropowder was less than 63.822 μm, as shown in FIG. 8.
In summary, the above description is only a preferred embodiment of the present invention, and is not intended to limit the scope of the present invention. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (4)
1. The utility model provides a device based on gas-solid coupling atomizing preparation metal powder which characterized in that: the device comprises a powder feeder, a gas storage tank, a feeding mechanism, melting and heating equipment, a melting chamber, an atomizing nozzle, a spheroidization delay induction coil assembly, an atomizing tower, a support frame and a powder collector;
the atomizing tower is arranged on the support frame, the melting chamber is arranged at the upper part of the atomizing tower, the melt inlet end of the atomizing nozzle is positioned in the melting chamber, and the atomizing outlet end of the atomizing nozzle is positioned in the atomizing tower; the feeding mechanism is arranged on the melting chamber and is used for conveying the metal bar to be melted into the melting chamber; the melting and heating device is arranged inside the melting chamber and is used for heating the metal bar to melt the metal bar; solid particles serving as an atomizing medium are filled into a powder feeder, gas serving as the atomizing medium is stored in a gas storage tank, and the powder feeder and the gas storage tank are respectively connected with an atomizing nozzle; the spheroidization delay induction coil assembly is arranged in the atomizing tower and is positioned at the lower part of the atomizing outlet end of the atomizing nozzle, and a conical atomizing area formed by spraying of the atomizing nozzle is positioned in the spheroidization delay induction coil assembly; the powder collector is arranged at the lower part of the atomizing tower and is used for collecting the powder atomized and condensed by the atomizing tower;
the melting heating equipment adopts an induction heater, the geometric structure of an induction heating coil in the induction heater is designed to be conical, the included angle between a conical bus and the central axis of the conical bus is 28-35 degrees, the number of turns of the coil in the induction heating coil is 4-6 turns, the inner diameter of the small end of the induction heating coil is 1.0-3.0 mm larger than the diameter of the metal bar, the power supply power of the induction heater is calculated by adopting a formula (1), and the optimal current frequency is calculated by adopting a formula (2):
p＝(0.3～0.4)CρπD 2 v(T 2 -T 1 ) (1)
wherein the content of the first and second substances,
wherein p is power, C is specific heat capacity of the metal bar, and rho is metalThe density of the bar, D the diameter of the metal bar, v the feed speed of the metal bar, T 2 Temperature after heating of the metal bar, T 1 The temperature of the metal bar before heating, delta the current penetration depth, rho E Is resistivity, μ r Is relative magnetic permeability;
the particle diameter of solid particles as an atomizing medium is 100-1000 μm, the gas pressure output from the gas storage tank to the powder feeder is 0.5-5 MPa, and the gas pressure output from the gas storage tank to the atomizing nozzle is 0.5-5 MPa;
the geometric structure of the induction coil in the spheroidizing delay induction coil assembly is designed to be conical, the difference value between the included angle between a conical bus and the central axis of the conical bus and the corresponding included angle of the conical atomization area is 0-5 degrees, the number of turns of the coil in the induction coil is 4-6 turns, and the inner diameter of the small end of the induction coil is 2.0-6.0 mm larger than the diameter of the corresponding position of the conical atomization area.
2. The device for preparing metal powder based on gas-solid coupling atomization of claim 1, which is characterized in that: the powder feeder comprises a powder tank, a stirring bin, a powder guide pipe, a gas accelerating pipe and a stirring wheel;
the upper part of the powder tank is provided with an air inlet, and the lower part of the powder tank is provided with a powder outlet;
the lower part of the stirring bin is provided with a powder outlet and a stirring gas inlet, the upper part of the stirring bin is provided with an accelerating gas inlet and a powder inlet, and the inside of the stirring bin is provided with a cavity for stirring powder;
the powder tank is arranged at the upper part of the stirring bin, a powder outlet of the powder tank is communicated with a powder inlet of the stirring bin through a powder guide pipe, and a gas inlet of the powder tank is connected with the gas storage tank through a conveying pipeline; a powder outlet of the stirring bin is connected with the atomizing nozzle through a conveying pipeline, a stirring gas inlet and an accelerating gas inlet of the stirring bin are both connected with the gas storage tank through the conveying pipeline, two ends of the gas accelerating tube are respectively connected with the accelerating gas inlet and the powder outlet in a one-to-one correspondence manner, one end of the gas guide tube is connected with the stirring gas inlet, and the other end of the gas guide tube is positioned below the stirring wheel; the stirring wheel is installed inside the stirring bin and is used for stirring the powder in the cavity, one end of the powder guide pipe is located in the cavity, and the gas accelerating pipe is communicated with the cavity.
3. The device for preparing metal powder based on gas-solid coupling atomization of claim 1, which is characterized in that: the solid particles used as the atomizing medium are magnetic or water-soluble solid particles.
4. The device for preparing metal powder based on gas-solid coupling atomization according to claim 1, characterized in that: and solving the temperature field distribution in the atomization process through CFD fluid dynamics simulation, and selecting a spheroidizing time-delay induction coil assembly to be installed in a region with large temperature gradient change below the nozzle.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4202686A (en) * | 1976-12-27 | 1980-05-13 | Mitsubishi Kinzoku Kabushiki Kaisha | Process for manufacturing fine powder of metal |
| CN1369339A (en) * | 2001-02-13 | 2002-09-18 | 中南大学 | Solid atomizing process for molten metal and alloy |
| CN1911570A (en) * | 2006-08-18 | 2007-02-14 | 陕西科技大学 | Device for preparing metal ultrafine powder and its method |
| CN102250584A (en) * | 2011-06-11 | 2011-11-23 | 山东理工大学 | Equipment for preparing atomized quick-setting magnetic abrasive |
| CN102389979A (en) * | 2011-10-13 | 2012-03-28 | 西北工业大学 | Method and system for preparing particle-reinforced metal-based composite material through injection molding |
| CN110253029A (en) * | 2019-06-21 | 2019-09-20 | 燕山大学 | A kind of granule enhancement type pre-alloyed powder and the preparation method and application thereof |
| CN111014699A (en) * | 2019-11-28 | 2020-04-17 | 安徽中体新材料科技有限公司 | 3D prints and makes equipment with alloy powder |
-
2021
- 2021-11-17 CN CN202111374727.2A patent/CN114101690B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4202686A (en) * | 1976-12-27 | 1980-05-13 | Mitsubishi Kinzoku Kabushiki Kaisha | Process for manufacturing fine powder of metal |
| CN1369339A (en) * | 2001-02-13 | 2002-09-18 | 中南大学 | Solid atomizing process for molten metal and alloy |
| CN1911570A (en) * | 2006-08-18 | 2007-02-14 | 陕西科技大学 | Device for preparing metal ultrafine powder and its method |
| CN102250584A (en) * | 2011-06-11 | 2011-11-23 | 山东理工大学 | Equipment for preparing atomized quick-setting magnetic abrasive |
| CN102389979A (en) * | 2011-10-13 | 2012-03-28 | 西北工业大学 | Method and system for preparing particle-reinforced metal-based composite material through injection molding |
| CN110253029A (en) * | 2019-06-21 | 2019-09-20 | 燕山大学 | A kind of granule enhancement type pre-alloyed powder and the preparation method and application thereof |
| CN111014699A (en) * | 2019-11-28 | 2020-04-17 | 安徽中体新材料科技有限公司 | 3D prints and makes equipment with alloy powder |
Non-Patent Citations (1)
| Title |
|---|
| Criterion of gas and solid dual-phase flow atomization crash in molten metal;Gang CHEN等;《Transactions of Nonferrous Metals Society of China》;20140131;第24卷(第1期);第208-216页 * |
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