CN117884643B - Copper powder, copper powder preparation method and application thereof - Google Patents

Abstract

The invention relates to copper powder, a preparation method and application thereof, and belongs to the technical field of copper powder preparation. The preparation method of copper powder comprises atomizing molten copper liquid into copper liquid drops; atomizing liquid metal into liquid metal droplets, wherein the melting point of the liquid metal is lower than that of copper, and the particle size of the liquid metal droplets is smaller than that of the copper droplets; driving the copper liquid drops and the liquid metal liquid drops to move in opposite directions, so that the liquid metal liquid drops and the copper liquid drops collide with each other, pits are formed on the surfaces of the copper liquid drops when the copper liquid drops are collided, heat is transferred to the liquid metal liquid drops to be solidified into copper powder, and the liquid metal liquid drops are kept in a liquid state; separating the liquid metal from the copper powder. The copper powder prepared by the invention has pits on the surface, so that the copper powder has higher porosity, can contain more working media when being used as a capillary structure layer at the evaporation end of the heat pipe, improves the hottest power which can be born by the heat pipe, and can ensure the heat transfer efficiency.

Description

Copper powder, copper powder preparation method and application thereof

Technical Field

The invention belongs to the technical field of copper powder preparation, in particular to copper powder, a copper powder preparation method and application thereof.

Background technique

Heat pipes are a very common heat-conducting pipe, often used for cooling electronic devices. One end of the heat pipe is the evaporation end, and the other end is the cooling end. A porous capillary structure layer is set on the inner wall of the heat pipe. The inside of the heat pipe is evacuated, and a liquid working medium is set inside. The liquid working medium can be absorbed by the capillary structure layer. During operation, the evaporation end absorbs heat, and the liquid working medium at the evaporation end evaporates into gas and flows to the cooling end. The working medium liquefies at the cooling end and releases heat to achieve heat transfer. After the working medium is liquefied, it returns to the evaporation end along the capillary structure layer under the capillary action of the capillary structure layer to achieve a circulating flow.

Theoretically, when the heat pipe is operating, the height of the working fluid liquid level in the capillary structure layer should just cover the capillary structure layer. However, in reality, when the heat pipe is operating, the working fluid at the evaporation end evaporates into gas, causing the working fluid liquid level in the capillary structure at the evaporation end to drop. When the thermal power continues to rise, the working fluid liquid level continues to drop until the liquid level is zero, forming a local dry-out in the evaporation section, and the heat dissipation efficiency decreases rapidly. Therefore, in order to increase the thermal power that the heat pipe can withstand, the capillary structure layer should be able to accommodate as much working fluid as possible, that is, the capillary structure layer on the inner wall of the evaporation end should have a higher porosity.

The heat transfer performance of the heat pipe is affected by the particle size of the copper powder. The particle size of the copper powder needs to be kept within a certain range to ensure that the heat pipe has better heat transfer performance. Please refer to "The Influence of Copper Powder Particle Size on the Heat Transfer Performance of Sintered Heat Pipes" published by Li Yong, Chen Chunyan, etc., Journal of South China University of Technology (Natural Science Edition), Vol. 40, No. 3, March 2013. The porosity of the capillary structure layer is also related to the particle size of the copper powder. At present, copper powder is generally prepared by atomization. The copper powder particles obtained are similar to spheres and have a relatively regular shape. When the particle size is determined, the porosity is difficult to increase.

Summary of the invention

The technical problem to be solved by the present invention is to provide a copper powder, a copper powder preparation method and its application, which are used to prepare copper powder with pits on the surface, improve the porosity of the copper powder, and use the copper powder to prepare a capillary structure layer at the evaporation end of a heat pipe, increase the work mass that can be accommodated, thereby increasing the maximum thermal power that the heat pipe can withstand.

To solve the above problems, the technical solution adopted by the present invention is: a method for preparing copper powder, comprising:

Atomizing molten copper liquid into copper droplets;

Atomizing liquid metal into liquid metal droplets, wherein the melting point of the liquid metal is lower than the melting point of copper, and the particle size of the liquid metal droplets is smaller than the particle size of the copper droplets;

The copper droplets and the liquid metal droplets are driven to move toward each other, so that the liquid metal droplets and the copper droplets collide with each other, a pit is generated on the surface of the copper droplets when the copper droplets collide, and heat is transferred to the liquid metal droplets to solidify into copper powder, and the liquid metal droplets remain in liquid state;

Separate the liquid metal from the copper powder.

Further, the process of atomizing the molten copper liquid into copper droplets includes: driving the molten copper liquid through a first atomizing plate, the first atomizing plate being provided with a plurality of evenly distributed first atomizing through holes, and the copper liquid forming copper droplets after passing through the first atomizing through holes;

The process of atomizing liquid metal into liquid metal droplets includes: driving the liquid metal through a second atomizing plate, on which a plurality of evenly distributed second atomizing through holes are arranged, the diameter of the second atomizing through holes is smaller than the diameter of the first atomizing through holes, and the liquid metal forms liquid metal droplets after passing through the second atomizing through holes.

Furthermore, the device for atomizing the molten copper liquid into copper droplets comprises a heat preservation furnace, a first liquid outlet is arranged at the bottom of the heat preservation furnace, the first atomizing plate is horizontally arranged below the first liquid outlet, and a first enclosure plate is arranged at the edge of the first atomizing plate, and the first atomizing plate is connected to a first driving mechanism for driving the first atomizing plate to reciprocate and translate;

The device for atomizing liquid metal into liquid metal droplets includes a storage box, a second liquid outlet is arranged at the bottom of the storage box, the second atomizing plate is horizontally arranged below the second liquid outlet, and a second enclosure plate is arranged at the edge of the second atomizing plate, and the second atomizing plate is connected to a second driving mechanism for driving the second atomizing plate to reciprocate.

Furthermore, it also includes a mixing chamber, the top wall of the mixing chamber is provided with a first window and a second window, the first atomizing plate and the second atomizing plate are both slidably matched with the top surface of the mixing chamber, and the first atomizing plate is located above the first window, and the second atomizing plate is located above the second window; a first jet head is provided on the side of the first window away from the second window, and a second jet head is provided on the side of the second window away from the first window, the first jet head and the second jet head are both connected to an inert gas source, and the jet direction of the first jet head is horizontally toward the second jet head, and the jet direction of the second jet head is horizontally toward the first jet head;

The first nozzle and the second nozzle simultaneously spray high-speed flowing inert gas. After the copper droplets enter the mixing chamber through the first window, they move with the inert gas sprayed by the first nozzle. After the liquid metal droplets enter the mixing chamber through the second window, they move with the inert gas sprayed by the second nozzle, so that the liquid metal droplets and the copper droplets move towards each other and collide with each other.

Furthermore, an inclined screening trough is provided at the bottom of the inner cavity of the mixing chamber, and a copper powder collection box is provided at the right end of the screening trough; a reflux pipe is provided on the side wall or bottom wall of the mixing chamber below the screening trough, the reflux pipe is connected to the storage box, and a circulating pump is provided on the reflux pipe.

Further, the device for atomizing the molten copper liquid into copper droplets comprises a heat preservation furnace, a first liquid outlet is arranged at the bottom of the heat preservation furnace, the first atomizing plate is vertically arranged cylindrical, and an upper sealing plate is fixedly arranged at the upper end of the first atomizing plate, and a lower sealing plate is fixedly arranged at the lower end, the upper sealing plate is provided with a connecting port communicating with the first liquid outlet, and the lower sealing plate is connected to a third driving mechanism for driving the lower sealing plate to rotate;

The device for atomizing liquid metal into liquid metal droplets comprises a plurality of storage boxes, the plurality of storage boxes are evenly distributed around the holding furnace, a second liquid outlet is provided at the bottom of each storage box, a vertical atomization chamber is provided below each storage box, the second liquid outlet is communicated with the atomization chamber, a fan blade is provided in the atomization chamber, the fan blade is connected to a fourth driving mechanism for driving the fan blade to rotate, and the side wall of the atomization chamber facing the first atomization plate is the second atomization plate;

The copper liquid in the insulation furnace enters the first atomizing plate, and the third driving mechanism drives the first atomizing plate to rotate. Under the action of centrifugal force, the copper liquid inside passes through the first atomizing through hole on the first atomizing plate to form copper droplets, and moves radially along the first atomizing plate.

After the liquid metal in the storage box enters the atomization chamber, the fourth driving mechanism drives the fan blades to rotate, and the fan blades drive the liquid metal to flow. When the liquid metal reaches the second atomization plate, liquid metal droplets are formed through the second atomization through holes and move toward the first atomization plate. During the movement, the liquid metal droplets collide with the copper droplets.

Furthermore, the atomization chamber and the first atomization plate are both arranged in a mixing chamber, the center of the mixing chamber bottom plate protrudes upward to form a cylindrical installation cavity, and the third driving mechanism is arranged in the installation cavity; a spiral screening groove is arranged at the bottom of the inner cavity of the mixing chamber, and a copper powder collection box is arranged at the right end of the screening groove; a reflux pipe is arranged on the side wall or bottom wall of the mixing chamber below the screening groove, and the reflux pipe is connected to the storage box, and a circulating pump is arranged on the reflux pipe.

Furthermore, the particle size of the liquid metal droplets is 1/4 to 1/3 of the particle size of the copper droplets.

Copper powder is prepared by the above method.

The copper powder prepared by the above method is used as the raw material of the capillary structure layer at the evaporation end of the heat pipe.

The beneficial effects of the present invention are as follows: 1. The present invention uses liquid metal droplets with smaller particle sizes to collide with copper droplets with larger particle sizes, so that pits are generated on the surface of the copper droplets. After the copper droplets are cooled to become copper powder, copper powder with pits on the surface is obtained. Compared with traditional copper powder with the same particle size and relatively regular shape, the copper powder prepared by the present invention has a higher porosity. When it is used as a capillary structure layer at the evaporation end of a heat pipe, it can accommodate more working fluids, increase the maximum thermal power that the heat pipe can withstand, and at the same time ensure the heat transfer efficiency.

2. The liquid metal described in the present invention does not refer to the molten metal formed after conventional metal is melted, but refers to amorphous metal, which is different from conventional metal. Liquid metal droplets are used to collide with copper droplets. Liquid metal, such as metal gallium, has a melting point of only 29.76°C and a boiling point of 2400°C. It has the characteristics of low melting point and high boiling point. When used for the first time, only a small amount of heat is needed to liquefy it. During subsequent use, it can absorb the heat of the copper droplets and remain in liquid state. There is no need for continuous heating and heat preservation, and the energy consumption is low. In addition, liquid metal can withstand large temperature changes and remain stable, will not volatilize or solidify, will not be lost under high temperature conditions, can be reused, reduce costs, and liquid metal can be easily separated from copper powder.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a schematic flow diagram of a method for preparing copper powder according to the present invention;

FIG2 is a schematic diagram of copper powder particles prepared by the present invention;

FIG3 is a schematic diagram of a first embodiment of the present invention;

FIG4 is a schematic top view of the first atomizing plate and the second atomizing plate in Example 1;

FIG5 is a schematic diagram of a second embodiment of the present invention;

Figure numerals: 1—first atomizing plate; 2—second atomizing plate; 3—insulating furnace; 4—first liquid outlet; 5—first enclosure; 6—first driving mechanism; 7—storage box; 8—second liquid outlet; 9—second enclosure; 10—second driving mechanism; 11—mixing chamber; 12—first window; 13—second window; 14—first nozzle; 15—second nozzle; 16—inert gas source; 17—screening trough; 18—copper powder collecting box; 19—reflux pipe; 20—circulating pump; 21—upper sealing plate; 22—lower sealing plate; 23—third driving mechanism; 24—atomizing chamber; 25—fan blades; 26—fourth driving mechanism.

Detailed ways

The present invention is further described below in conjunction with the accompanying drawings and embodiments.

The copper powder preparation method of the present invention, as shown in FIG1, comprises:

Atomizing molten copper liquid into copper droplets;

Atomizing the liquid metal into liquid metal droplets, the melting point of the liquid metal is lower than the melting point of copper, and the particle size of the liquid metal droplets is smaller than the particle size of the copper droplets;

The copper droplets and the liquid metal droplets are driven to move toward each other, so that the liquid metal droplets and the copper droplets collide with each other, a pit is generated on the surface of the copper droplets when the copper droplets collide, and heat is transferred to the liquid metal droplets to solidify into copper powder, and the liquid metal droplets remain in liquid state;

Separate the liquid metal from the copper powder.

The copper raw material is heated to melt, thereby obtaining molten copper liquid. The copper raw material can be pure copper or a copper alloy. The copper raw material can be heated to melt using an existing heating furnace. Atomization refers to dispersing the gathered copper liquid to form small particles of copper liquid droplets.

Conventional metals are crystalline metals, while liquid metals are amorphous metals with low melting points. Liquid metals can be specifically metal cadmium, which has a melting point of only 29.76°C and a boiling point of 2400°C. It has the characteristics of low melting point and high boiling point. When used for the first time, only a small amount of heat is needed to liquefy it. During subsequent use, it can absorb the heat of copper droplets and remain in liquid state. There is no need for continuous heating and heat preservation, and the energy consumption is low. In addition, liquid metal can withstand large temperature changes and remain stable, will not volatilize or solidify, and is easy to separate from copper powder.

If the particle size of the liquid metal droplet is greater than or equal to the particle size of the copper droplet, when the liquid metal droplet collides with the copper droplet, the impact force generated may be relatively large, which may easily cause the copper droplet to disperse into smaller particles and fail to form pits on the surface of the copper droplet. It may also cause the size of the pit to be too large and affect the particle size of the copper droplet. Therefore, the particle size of the liquid metal droplet is smaller than the particle size of the copper droplet. Preferably, the particle size of the liquid metal droplet is 1/4 to 1/3 of the particle size of the copper droplet, so that pits of appropriate size can be formed on the surface of the copper droplet.

The copper droplet and the liquid metal droplet are driven to move toward each other. The movement toward each other refers to the movement in which the movement trajectory of the liquid metal droplet can intersect with the movement trajectory of the copper droplet. Specifically, the movement trajectory of the liquid metal droplet and the movement trajectory of the copper droplet can be on a straight line, but the movement directions of the two are opposite. The movement trajectory of the liquid metal droplet and the movement trajectory of the copper droplet can also form an obtuse angle. For example, the liquid metal droplet moves toward the lower right and the copper droplet moves toward the lower left, and the two can intersect.

By driving the copper droplets and the liquid metal droplets to move toward each other, the copper droplets and the liquid metal droplets collide with each other, thereby generating pits on the surface of the copper droplets. At the same time, the heat of the copper droplets is transferred to the liquid metal droplets, causing the copper droplets to cool rapidly and solidify into copper powder, while the liquid metal remains in liquid state and can be easily separated from the copper powder.

The copper powder prepared by the traditional atomization method is a relatively regular sphere, while the copper powder prepared by the present invention is shown in FIG2 . It can be seen that there are some pits on the surface of the copper powder particles. Compared with the traditional copper powder, the copper powder of the present invention has a higher porosity when the particle size is the same. When it is used as the capillary structure layer of the evaporation end of the heat pipe, it can accommodate more working fluids and ensure the heat transfer efficiency. The particle size of the copper powder of the present invention refers to the distance between any two points on the surface with the largest distance between them. For example, in FIG2 , the particle size is d.

The atomization of the copper liquid and the liquid metal can be carried out by a conventional atomization method, but the atomization method is not easy to control the particle size of the copper droplets or the liquid metal droplets. As a preferred embodiment of the present invention, the process of atomizing the molten copper liquid into copper droplets comprises: driving the molten copper liquid through a first atomization plate 1, the first atomization plate 1 is provided with a plurality of uniformly distributed first atomization through holes, and the copper liquid forms copper droplets after passing through the first atomization through holes;

The process of atomizing liquid metal into liquid metal droplets includes: driving the liquid metal through the second atomizing plate 2, on which a plurality of evenly distributed second atomizing through holes are provided, the diameter of the second atomizing through holes is smaller than the diameter of the first atomizing through holes, and the liquid metal forms liquid metal droplets after passing through the second atomizing through holes.

The first atomizing plate 1 is made of a high temperature resistant plate. After the copper liquid passes through the first atomizing through hole of the first atomizing plate 1, the particle size of the copper droplets formed is adapted to the first atomizing through hole, that is, the particle size of the copper droplets can be controlled by controlling the aperture of the first atomizing through hole, thereby obtaining copper droplets with a particle size that meets the requirements and is uniform. Similarly, liquid metal droplets with a particle size that meets the requirements and is uniform can be obtained.

The present invention specifically provides the following two devices which can realize the atomization of copper liquid and liquid metal and the mutual collision.

Embodiment 1

As shown in Figures 3 and 4, the equipment for atomizing molten copper liquid into copper droplets includes a heat-insulating furnace 3, a first liquid outlet 4 is arranged at the bottom of the heat-insulating furnace 3, a first atomizing plate 1 is horizontally arranged below the first liquid outlet 4, and a first enclosure 5 is arranged at the edge of the first atomizing plate 1, and the first atomizing plate 1 is connected to a first driving mechanism 6 for driving the first atomizing plate 1 to reciprocate.

In the present embodiment, the first atomizing plate 1 is a flat plate in a rectangular shape, and the first enclosure 5 is 4 pieces, which are vertically arranged on the four sides of the first atomizing plate 1, and the first enclosure 5 and the first atomizing plate 1 surround a cavity. The insulation furnace 3 is made of high temperature resistant material, and an insulation layer can be arranged on its outer wall, and an electric heating element can be arranged at the same time to ensure that the copper liquid in the insulation furnace 3 is at a suitable temperature to prevent the copper liquid from cooling down. The copper liquid in the insulation furnace 3 can flow to the first atomizing plate 1 through the first liquid outlet 4, and the first driving mechanism 6 drives the first atomizing plate 1 to move back and forth continuously, so that the copper liquid can be dispersed on the first atomizing plate 1. The copper liquid passes through the first atomizing through hole under the action of gravity and then drips downward.

The device for atomizing liquid metal into liquid metal droplets includes a storage box 7, a second liquid outlet 8 is arranged at the bottom of the storage box 7, a second atomizing plate 2 is horizontally arranged below the second liquid outlet 8, and a second enclosure 9 is arranged at the edge of the second atomizing plate 2, and the second atomizing plate 2 is connected to a second driving mechanism 10 for driving the second atomizing plate 2 to reciprocate.

The storage box 7 is used to store liquid metal. The liquid metal in the storage box 7 flows to the second atomization plate 2 through the second liquid outlet 8. The second driving mechanism 10 drives the second atomization plate 2 to move back and forth continuously, promoting the liquid metal to cover the second atomization plate 2 and pass through the second atomization through hole.

The first driving mechanism 6 and the second driving mechanism 10 can be implemented by hydraulic cylinders, linear motors and other devices.

In addition, a blowing head can be arranged above the first atomizing plate 1 and the second atomizing plate 2 to transport the inert gas to the blowing head, and the blowing head sprays the inert gas downward toward the first atomizing plate 1 and the second atomizing plate 2, which can promote the copper liquid to pass through the first atomizing plate 1 faster, and promote the liquid metal to pass through the second atomizing plate 2 faster. At the same time, the inert gas fills the space above the first atomizing plate 1 and the second atomizing plate 2, preventing the liquid metal and the copper liquid from contacting the oxygen in the air and preventing them from being oxidized.

The present embodiment also includes a mixing chamber 11, the top wall of the mixing chamber 11 is provided with a first window 12 and a second window 13, the first atomizing plate 1 and the second atomizing plate 2 are both slidably matched with the top surface of the mixing chamber 11, and the first atomizing plate 1 is located above the first window 12, and the second atomizing plate 2 is located above the second window 13; a first nozzle 14 is provided on the side of the first window 12 away from the second window 13, and a second nozzle 15 is provided on the side of the second window 13 away from the first window 12, the first nozzle 14 and the second nozzle 15 are both connected to an inert gas source 16, and the jet direction of the first nozzle 14 is horizontally toward the second nozzle 15, and the jet direction of the second nozzle 15 is horizontally toward the first nozzle 14.

The mixing chamber 11 is a rectangular chamber body, made of high temperature resistant material, the first window 12 and the second window 13 are rectangular windows, the first atomizing plate 1 is located above the first window 12, and the second atomizing plate 2 is located above the second window 13, the copper droplets passing through the first atomizing plate 1 can fall downward into the mixing chamber 11 through the first window 12, and the liquid metal droplets passing through the second atomizing plate 2 can fall downward into the mixing chamber 11 through the second window 13. The first atomizing plate 1 and the second atomizing plate 2 are both slidably matched with the top surface of the mixing chamber 11 to ensure the stability of the movement of the first atomizing plate 1 and the second atomizing plate 2. Specifically, guide rails can be set on both sides of the first window 12 and the second window 13, and the guide rails are fixed on the top surface of the mixing chamber 11. The first atomizing plate 1 and the second atomizing plate 2 are slidably matched with the guide rails, and the guide rails can play a role of guiding and limiting, so the stability of the movement of the first atomizing plate 1 and the second atomizing plate 2 can be improved.

The first nozzle 14 and the second nozzle 15 are used to spray high-speed inert gas, and use the inert gas to drive the liquid metal droplets and the copper droplets to move, so as to cause the liquid metal droplets and the copper droplets to move and collide with each other. The inert gas source 16 is used to provide inert gas, and the inert gas can be nitrogen or the like. The inert gas source 16 can be a pressure tank for storing inert gas, and an air pump can be used to increase the flow rate of the inert gas.

The first nozzle 14 and the second nozzle 15 simultaneously spray high-speed flowing inert gas. After the copper droplets enter the mixing chamber 11 through the first window 12, they move with the inert gas sprayed by the first nozzle 14. After the liquid metal droplets enter the mixing chamber 11 through the second window 13, they move with the inert gas sprayed by the second nozzle 15, so that the liquid metal droplets and the copper droplets move toward each other and collide with each other.

Before the liquid metal droplets and the copper droplets enter the mixing chamber 11 , an inert gas may be introduced into the mixing chamber 11 to squeeze out the air in the mixing chamber 11 to prevent the liquid metal droplets and the copper droplets from being oxidized.

In order to facilitate the separation of liquid metal and copper powder, an inclined screening trough 17 is provided at the bottom of the inner cavity of the mixing chamber 11, and a copper powder collecting box 18 is provided at the right end of the screening trough 17; a reflux pipe 19 is provided on the side wall or bottom wall of the mixing chamber 11 below the screening trough 17, and the reflux pipe 19 is connected to the storage box 7, and a circulating pump 20 is provided on the reflux pipe 19.

After the liquid metal droplets collide with the copper droplets, they fall downward at the same time. After the copper droplets cool, they solidify into copper powder, and the liquid metal remains in liquid state. Both fall onto the screening tank 17 at the same time. The screening tank 17 is provided with fine filter holes. The liquid metal can pass through the filter holes to reach the bottom of the screening tank 17 and gather together, while the copper powder rolls down along the screening tank 17 to the copper powder collection box 18. The liquid metal below the screening tank 17 returns to the storage box 7 under the action of the circulation pump 20 to achieve recycling.

In addition, since the density of liquid metal and copper powder is different, for example, when the liquid metal is made of metal gallium, the density is 5.9g/ ^cm3 , and the density of pure copper is 8.960g/ ^cm3 , a sedimentation tank can also be set at the bottom of the mixing chamber 11, and the liquid metal and copper powder fall into the sedimentation tank at the same time. After sedimentation, the copper powder settles to the bottom of the sedimentation tank, and the liquid metal on the upper layer can be reused.

Embodiment 2

As shown in Figure 5, the equipment for atomizing molten copper liquid into copper droplets includes a heat-insulating furnace 3, a first liquid outlet 4 is arranged at the bottom of the heat-insulating furnace 3, a first atomizing plate 1 is vertically arranged cylindrical, and an upper sealing plate 21 is fixedly arranged at the upper end of the first atomizing plate 1, and a lower sealing plate 22 is fixedly arranged at the lower end, a connecting port communicating with the first liquid outlet 4 is arranged on the upper sealing plate 21, and the lower sealing plate 22 is connected to a third driving mechanism 23 for driving the lower sealing plate 22 to rotate.

In the present embodiment, the first atomizing plate 1 is cylindrical, and the upper sealing plate 21 and the lower sealing plate 22 respectively seal the upper and lower ends of the first atomizing plate 1, and the upper sealing plate 21 and the lower sealing plate 22 are fixedly connected to the first atomizing plate 1. The insulation furnace 3 is the same as the first embodiment, and is used to store the melted solution. The copper liquid in the insulation furnace 3 enters the inside of the first atomizing plate 1 through the first liquid outlet 4, and the lower sealing plate 22 and the first atomizing plate 1 are driven to rotate at high speed by the third driving mechanism 23. The copper liquid inside the first atomizing plate 1 generates centrifugal force. Under the action of centrifugal force, the copper liquid passes through the first atomizing through hole and is thrown out radially along the first atomizing plate 1 to achieve the atomization of the copper liquid. The first liquid outlet 4 can be a pipeline, which runs through the upper sealing plate 21, and the clearance between the upper sealing plate 21 and the pipeline is matched, and the upper sealing plate 21 does not affect the rotation of the first atomizing plate 1.

The equipment for atomizing liquid metal into liquid metal droplets includes a plurality of storage boxes 7, which are evenly distributed around the insulation furnace 3. A second liquid outlet 8 is provided at the bottom of each storage box 7. A vertical atomization chamber 24 is provided below each storage box 7. The second liquid outlet 8 is connected to the atomization chamber 24. A fan blade 25 is provided in the atomization chamber 24. The fan blade 25 is connected to a fourth driving mechanism 26 for driving the fan blade 25 to rotate. The side wall of the atomization chamber 24 facing the first atomization plate 1 is the second atomization plate 2.

The copper liquid in the insulation furnace 3 enters the first atomizing plate 1, and the third driving mechanism 23 drives the first atomizing plate 1 to rotate. Under the action of centrifugal force, the internal copper liquid passes through the first atomizing through hole on the first atomizing plate 1 to form copper droplets, and moves radially along the first atomizing plate 1; after the liquid metal in the storage box 7 enters the atomizing chamber 24, the fourth driving mechanism 26 drives the fan blades 25 to rotate, and the fan blades 25 drive the liquid metal to flow. When the liquid metal reaches the second atomizing plate 2, liquid metal droplets are formed through the second atomizing through hole and move toward the first atomizing plate 1. During the movement, the liquid metal droplets collide with the copper droplets.

The storage box 7 is used to store liquid metal, and the second liquid outlet 8 is used to transport the liquid metal in the storage box 7 to the atomizing chamber 24. The atomizing chamber 24 is fixedly installed and can adopt a cylindrical chamber body or a rectangular chamber body. Multiple atomizing chambers 24 are evenly distributed around the first atomizing plate 1. After the liquid metal enters the atomizing chamber 24, the fourth driving mechanism 26 drives the fan blades 25 to rotate at high speed. Under the action of the fan blades 25, the liquid metal forms a vortex and also has a certain centrifugal force. When the liquid metal passes through the second atomizing plate 2, it can be discharged through the second atomizing through hole on the second atomizing plate 2. Since the second atomizing plate 2 is set on the side facing the first atomizing plate 1, the formed liquid metal droplets will move toward the first atomizing plate 1, and can collide with the copper droplets sprayed from the first atomizing plate 1.

The third driving mechanism 23 and the fourth driving mechanism 26 may be motors.

In order to create a stable space, the atomization chamber 24 and the first atomization plate 1 are both arranged in the mixing chamber 11. The center of the bottom plate of the mixing chamber 11 protrudes upward to form a cylindrical installation cavity, and the third driving mechanism 23 is arranged in the installation cavity; a spiral screening groove 17 is arranged at the bottom of the inner cavity of the mixing chamber 11, and a copper powder collection box 18 is arranged at the right end of the screening groove 17; a reflux pipe 19 is arranged on the side wall or bottom wall of the mixing chamber 11 below the screening groove 17, and the reflux pipe 19 is connected to the storage box 7, and a circulating pump 20 is arranged on the reflux pipe 19.

The mixing chamber 11 can adopt a cylindrical chamber body or a rectangular chamber body. The atomizing chamber 24 and the first atomizing plate 1 are arranged inside the mixing chamber 11, and the storage box 7 and the insulation furnace 3 are arranged above the mixing chamber 11. In the process of preparing copper powder, an inert gas can be continuously introduced into the mixing chamber 11 to prevent oxygen from entering the mixing chamber 11 and causing oxidation of liquid metal or copper. The center of the bottom plate of the mixing chamber 11 bulges upward to form a cylindrical installation cavity, and the third drive mechanism 23 is arranged in the installation cavity, so that the third drive mechanism 23 is located outside the mixing chamber 11, which can reduce the influence of high temperature on the third drive mechanism 23. Similarly, the fourth drive mechanism 26 is also installed outside the mixing chamber 11.

After the liquid metal droplets collide with the copper droplets, they fall downward at the same time. After the copper droplets cool, they solidify into copper powder, and the liquid metal remains in liquid state. Both fall onto the screening tank 17 at the same time. The screening tank 17 is provided with fine filter holes. The liquid metal can pass through the filter holes to reach the bottom of the screening tank 17 and gather together, while the copper powder rolls down along the screening tank 17 to the copper powder collection box 18. The liquid metal below the screening tank 17 returns to the storage box 7 under the action of the circulation pump 20 to achieve recycling.

In addition, since the density of liquid metal and copper powder is different, for example, when the liquid metal is made of metal gallium, the density is 5.9g/ ^cm3 , and the density of pure copper is 8.960g/ ^cm3 , a sedimentation tank can also be set at the bottom of the mixing chamber 11, and the liquid metal and copper powder fall into the sedimentation tank at the same time. After sedimentation, the copper powder settles to the bottom of the sedimentation tank, and the liquid metal on the upper layer can be reused.

The copper powder prepared in the present invention is used as the raw material of the capillary structure layer at the evaporation end of the heat pipe, that is, the copper powder prepared in the present invention is used as the raw material, and the capillary structure layer at the evaporation end of the heat pipe is obtained by sintering, which can increase the total amount of working fluid at the evaporation end of the heat pipe and improve the maximum thermal power that the heat pipe can withstand. Of course, the capillary structure layer at other parts of the heat pipe can also be sintered using the copper powder of the present invention.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims (4)

1. A method for producing copper powder, comprising

Atomizing the molten copper liquid into copper droplets;

Atomizing liquid metal into liquid metal droplets, wherein the melting point of the liquid metal is lower than that of copper, the liquid metal adopts metal gallium, the particle size of the liquid metal droplets is smaller than that of the copper droplets, and the particle size of the liquid metal droplets is 1/4 to 1/3 of that of the copper droplets;

Driving the copper liquid drops and the liquid metal liquid drops to move in opposite directions, so that the liquid metal liquid drops and the copper liquid drops collide with each other, pits are formed on the surfaces of the copper liquid drops when the copper liquid drops are collided, heat is transferred to the liquid metal liquid drops to be solidified into copper powder, and the liquid metal liquid drops are kept in a liquid state;

separating the liquid metal from the copper powder;

the process of atomizing molten copper into copper droplets includes: driving molten copper liquid to pass through a first atomization plate (1), wherein a plurality of first atomization through holes which are uniformly distributed are formed in the first atomization plate (1), and copper liquid drops are formed after the copper liquid passes through the first atomization through holes;

the process of atomizing liquid metal into liquid metal droplets includes: driving the liquid metal to pass through a second atomization plate (2), wherein a plurality of second atomization through holes which are uniformly distributed are formed in the second atomization plate (2), the diameter of each second atomization through hole is smaller than that of each first atomization through hole, and liquid metal drops are formed after the liquid metal passes through each second atomization through hole;

The equipment for atomizing molten copper liquid into copper liquid drops comprises a heat preservation furnace (3), wherein a first liquid outlet (4) is formed in the bottom of the heat preservation furnace (3), a first atomization plate (1) is horizontally arranged below the first liquid outlet (4), a first coaming (5) is arranged at the edge of the first atomization plate (1), and the first atomization plate (1) is connected with a first driving mechanism (6) for driving the first atomization plate (1) to reciprocate and translate;

The equipment for atomizing liquid metal into liquid metal liquid drops comprises a storage box (7), wherein a second liquid outlet (8) is formed in the bottom of the storage box (7), a second atomization plate (2) is horizontally arranged below the second liquid outlet (8), a second coaming (9) is arranged at the edge of the second atomization plate (2), and the second atomization plate (2) is connected with a second driving mechanism (10) for driving the second atomization plate (2) to reciprocate and translate;

The mixing device comprises a mixing chamber (11), wherein a first window (12) and a second window (13) are formed in the top wall of the mixing chamber (11), the first atomization plate (1) and the second atomization plate (2) are in sliding fit with the top surface of the mixing chamber (11), the first atomization plate (1) is located above the first window (12), and the second atomization plate (2) is located above the second window (13); a first jet head (14) is arranged on one side, far away from the second window (13), of the first window (12), a second jet head (15) is arranged on one side, far away from the first window (12), of the second window (13), the first jet head (14) and the second jet head (15) are connected with an inert gas source (16), the jet direction of the first jet head (14) horizontally faces the second jet head (15), and the jet direction of the second jet head (15) horizontally faces the first jet head (14);

The first jet head (14) and the second jet head (15) jet inert gas flowing at high speed at the same time, after copper liquid drops enter the mixing chamber (11) through the first window (12), liquid metal liquid drops move along with the inert gas jetted by the first jet head (14) and enter the mixing chamber (11) through the second window (13), and then move along with the inert gas jetted by the second jet head (15), so that the liquid metal liquid drops and the copper liquid drops move towards each other and collide with each other.

2. A copper powder preparation method according to claim 1, wherein an inclined screening groove (17) is formed in the bottom of the inner cavity of the mixing chamber (11), and a copper powder collecting box (18) is arranged at the right end of the screening groove (17); the side wall or the bottom wall of the mixing chamber (11) below the sieving groove (17) is provided with a return pipe (19), the return pipe (19) is connected with the storage box (7), and the return pipe (19) is provided with a circulating pump (20).

3. Copper powder produced by the method of claim 1.

4. Use of copper powder produced by the method of claim 1 as a starting material for a capillary structure layer at the evaporation end of a heat pipe.