Aluminum nitride powder preparation device and preparation process thereof

Abstract

The invention relates to the technical field of aluminum nitride powder preparation, and particularly discloses an aluminum nitride powder preparation device and a preparation process thereof.The aluminum nitride powder preparation device comprises a bottom plate, two mounting frames are fixedly mounted on the top face of the bottom plate, and a rotating frame is rotatably mounted between the two mounting frames through a rotating shaft; mounting shafts are rotationally mounted on the two opposite inner walls in the rotating frame, and the ends, close to each other, of the two mounting shafts are jointly and fixedly connected with a rotating ring which is obliquely arranged. The grinding barrel is driven by the switching assembly to adjust inclination around the axis center of the grinding barrel, so that raw material powder can be sequentially subjected to step-by-step ball milling in the two grinding cavities, the particle size of the raw material powder is rapidly reduced under the action of a large grinding medium, the total ball milling time is shortened, and the cold welding phenomenon is reduced; and the raw material powder is subjected to high-precision ball milling through a small grinding medium, so that the raw material powder is further refined, the influence of cold welding on the ball milling quality is reduced, and the agglomeration phenomenon is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum nitride powder preparation, in particular to an aluminum nitride powder preparation device and a preparation process thereof. Background Art

[0002] Aluminum nitride is an inorganic non-metallic material with unique physical and chemical properties. Due to its high thermal conductivity and good electrical insulation, it is often used to manufacture substrates for high-power electronic devices. Its excellent mechanical strength and wear resistance make aluminum nitride ceramics have important application prospects in aerospace, transportation and other fields. At present, the preparation of aluminum nitride powder is usually carried out by carbonization reduction method or high-energy ball milling method. The high-energy ball milling method refers to reducing the size of powder particles and increasing the specific surface area of ​​the powder by ball milling, thereby improving the activity of the powder. During the ball milling process, raw materials such as alumina or aluminum powder undergo nitridation reaction or carbonization reduction reaction with the assistance of the ball mill to generate aluminum nitride powder.

[0003] However, during the ball milling process of raw materials such as alumina or aluminum powder, the raw powder will experience two opposite forces: fracture and cold welding. These two forces occur simultaneously during the ball milling process and compete with each other, causing the powder particles to increase in size due to cold welding and form agglomeration, resulting in uneven powder particle size, thereby affecting the nitridation reaction or carbonization reduction reaction of the raw powder and reducing product quality. Summary of the invention

[0004] The object of the present invention is to provide an aluminum nitride powder preparation device to solve at least one technical problem existing in the above-mentioned prior art.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: an aluminum nitride powder preparation device, comprising a bottom plate, two mounting frames are fixedly installed on the top surface of the bottom plate, a rotating frame is rotatably installed between the two mounting frames through a rotating shaft, two opposite inner walls inside the rotating frame are rotatably installed with mounting shafts, and ends of the two mounting shafts close to each other are commonly fixedly connected with an inclined rotating ring, a grinding barrel is rotatably installed on the inner wall of the rotating ring, and two mutually connected grinding chambers are provided inside the grinding barrel, a plurality of grinding media are arranged in the two grinding chambers, and the diameters of the grinding media in the two grinding chambers are different, and the inner diameter of the connection between the two grinding chambers is smaller than the diameter of the grinding media;

[0006] Also included is a driving assembly, the driving assembly is used to drive the grinding barrel to rotate along its axis;

[0007] It also includes a switching component, which is used to switch the inclination angle of the grinding barrel so that the height positions of the two grinding chambers therein are exchanged.

[0008] Preferably, the driving assembly includes two fixed frames respectively fixedly mounted on the top surfaces of both sides of the base plate, sliding blocks are installed in the two fixed frames, rotating frames are installed on the two sliding blocks, a motor is fixedly mounted in the rotating frame, fixed shafts are coaxially fixed at the centers of both ends of the grinding barrel, and the main shaft of the motor passes through the end of the rotating frame and is fixedly connected to the fixed shaft through a connecting part.

[0009] Preferably, the connecting portion comprises a connecting shaft fixedly mounted on the end of the motor main shaft, the outer wall of the connecting shaft is slidably connected to a sliding tube via a flat key, and the sliding tube is fixedly connected to the fixed shaft via a universal shaft.

[0010] Preferably, the side wall of the rotating frame is rotatably connected to a fixed sleeve which is sleeved on the outer walls of the sliding tube, the universal shaft and the fixed shaft, and the inner wall of the fixed sleeve is slidably connected to the outer wall of the sliding tube by a flat key, an arc-shaped bar is fixedly installed on one end of the fixed sleeve close to the grinding barrel, a sliding groove is provided in the arc-shaped bar, an electric-controlled slider which can slide in the sliding groove is rotatably installed on the outer wall of the fixed shaft, and a cutting groove for the universal shaft and the fixed shaft to slide in or out is jointly provided on the arc-shaped bar and the side wall of the fixed sleeve.

[0011] Preferably, the switching assembly includes a transverse groove opened on the side wall of the sliding block, and the side wall of the rotating frame is fixed with a rotating shaft that can rotate and slide in the transverse groove. The sliding block is vertically rotatably installed in the fixed frame and can be adjusted vertically up and down.

[0012] Preferably, a fixing plate is fixedly installed on the side wall of the fixed frame, a rotating rod is rotatably installed on the outer wall of the fixed plate, a tension spring is provided between the end of the rotating rod away from the fixed plate and the sliding block, two limit pins that can limit the rotation of the rotating rod are fixedly installed on the side wall of the fixed plate, and a toggle rod that can swing back and forth is also rotatably installed on the side wall of the fixed plate, the toggle rod is set to a V shape, and the ends of the two arms located in the V shape are fixed with toggle pins.

[0013] Preferably, a flow monitor is fixedly installed at the connection between the two grinding chambers, and the flow monitor is connected to the toggle rod via an electrical signal.

[0014] Preferably, the rotating ring and the grinding barrel are jointly provided with an annular cooling cavity, and the cooling cavity in the rotating ring and the cooling cavity in the grinding barrel are sealed and rotatably connected at the joint, and the cooling cavity forms a liquid supply circuit with the external liquid supply component through the cooling channels in the two mounting shafts.

[0015] Preferably, one-way cooling pipes are fixedly mounted on the outer walls of the two grinding chambers in the grinding barrel, and both ends of the one-way cooling pipes are respectively connected to the cooling chambers in one direction.

[0016] A preparation process for aluminum nitride powder using an aluminum nitride powder preparation device comprises the following steps:

[0017] Step 1: When using the device, first put the alumina powder or aluminum powder into the grinding barrel, and adjust the grinding barrel to an inclined state through the switching component, so that the alumina powder enters the grinding chamber on the side with larger grinding media;

[0018] Step 2: Then, the driving assembly drives the grinding barrel to rotate along its axis, and the friction between the larger grinding media and the grinding barrel and the mutual collision between the grinding media are used to ball-mill the powder raw materials in the grinding chamber, so as to quickly reduce the particle size and size of the powder raw materials and reduce the time required for grinding;

[0019] Step 3: After the raw material powder is ball-milled in the grinding chamber with the larger grinding medium for a preset time, the inclination angle of the grinding barrel is adjusted by the switching component to swap the height positions of the two grinding chambers so that the grinding chamber with the smaller grinding medium is at the lower end, and the raw material powder will flow into the grinding chamber with the smaller grinding medium under the action of gravity;

[0020] Step 4: Then, the grinding barrel is driven to rotate along its axis by the driving component, and the raw material powder is ball-milled with a smaller grinding medium, so that the raw material powder is further refined under the action of the smaller grinding medium, and the surface activity of the powder particles is enhanced. After the preset ball milling time is completed, the raw material powder is taken out, and the raw material powder is subsequently nitrided and calcined under appropriate conditions, and finally aluminum nitride powder is obtained;

[0021] Step 5: Replace the raw material powder in the grinding chamber and repeat steps 1 to 4 above.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The present invention drives the grinding barrel to adjust and tilt about its axis center through a switching component, so that the raw material powder can be ball-milled in two grinding chambers in sequence, so that the raw material powder can quickly reduce its particle size under the action of a larger grinding medium, thereby reducing the total ball milling time and reducing the occurrence of cold welding. Subsequently, the raw material powder is ball-milled with high precision through a smaller grinding medium, so that the raw material powder is further refined while reducing the influence of cold welding on the ball milling quality, thereby improving the ball milling quality of alumina powder, so as to achieve the purpose of improving the quality of aluminum nitride powder.

[0024] 2. The present invention drives the grinding barrel to rotate with the fixed axis at the lower position as the center by driving the electric control slider at the upper position, so that the grinding barrel can move in a conical shape, so that the outer wall of the grinding medium at the upper position can be cleaned without affecting the grinding work in the grinding chamber at the lower position. In combination with the switching component to switch the height position of the grinding chambers on both sides, the grinding media on both sides can be cleaned during the ball milling of the raw material powder, and the raw material powder adhering to the outer wall of the grinding medium can enter the grinding chamber at the lower position through the connecting point in the middle to continue grinding, thereby reducing the influence of cold welding on the ball milling quality and improving the utilization rate of the raw materials. After the ball milling is completed, the electric control sliders on both sides are driven to drive the two sides of the grinding barrel to rotate in a conical shape with the midpoint of the axis as the center, so that the outer walls of the grinding media on both sides can be cleaned at the same time, thereby improving the cleaning effect of the grinding medium.

[0025] 3. The present invention cools the grinding chambers on both sides at their connection points, thereby eliminating the heat generated by ball milling and creating a low-temperature environment for the grinding chambers on both sides. This not only reduces the hardness of the powder and increases the brittleness of the material, making it easier for the raw powder to be refined under the influence of ball milling and shortening the time required for ball milling, but also further eliminates the cold welding phenomenon through the low-temperature environment. By ball milling in a low-temperature environment and cleaning the outer wall of the grinding medium, combined with shortening the ball milling time with a large diameter grinding medium, the problem of low quality of aluminum nitride powder caused by poor ball milling quality when preparing aluminum nitride powder by the traditional ball milling method can be solved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the three-dimensional structure of the present invention;

[0027] Figure 2 A cross-sectional view of a schematic diagram of a three-dimensional structure in the present invention;

[0028] Figure 3 It is a side cross-sectional view of the present invention;

[0029] Figure 4 It is a schematic diagram of the three-dimensional structure of the connecting part in the present invention;

[0030] Figure 5 is a three-dimensional structural cross-sectional view of the connecting portion in the present invention;

[0031] Figure 6 For the present invention Figure 3 A partial enlarged view of the middle A;

[0032] Figure 7 This is a state diagram of the electric control slider after sliding in the present invention;

[0033] Figure 8 It is a schematic diagram of the three-dimensional structure of the one-way cooling tube in the present invention.

[0034] In the figure: 1. bottom plate; 2. mounting frame; 3. rotating frame; 4. grinding barrel; 5. fixed shaft; 6. fixed sleeve; 7. arc strip; 8. cutting groove; 9. sliding groove; 10. electric control slider; 11. universal shaft; 12. sliding tube; 13. mounting shaft; 14. rotating ring; 15. cooling chamber; 16. flow monitor; 17. fixed frame; 18. sliding block; 19. rotating frame; 20. motor; 21. fixed plate; 22. rotating rod; 23. tension spring; 24. toggle rod; 25. connecting shaft; 26. one-way cooling tube. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] See also Figures 1 to 8 The present invention provides a technical solution: an aluminum nitride powder preparation device, comprising a bottom plate 1, two mounting frames 2 are fixedly installed on the top surface of the bottom plate 1, a rotating frame 3 is rotatably installed between the two mounting frames 2 through a rotating shaft, two opposite inner walls inside the rotating frame 3 are rotatably installed with mounting shafts 13, one end of the two mounting shafts 13 close to each other is commonly fixedly connected with an inclined rotating ring 14, a grinding barrel 4 is rotatably installed on the inner wall of the rotating ring 14, and two mutually connected grinding chambers are provided inside the grinding barrel 4, a plurality of grinding media are arranged in the two grinding chambers, and the diameters of the grinding media in the two grinding chambers are different, and the inner diameter of the connection between the two grinding chambers is smaller than the diameter of the grinding media;

[0037] It also includes a driving assembly, which is used to drive the grinding barrel 4 to rotate along its axis;

[0038] It also includes a switching component, which is used to switch the inclination angle of the grinding barrel 4 so that the height positions of the two grinding chambers therein are swapped.

[0039] When the device is in use, alumina powder or aluminum powder is first placed in the grinding barrel 4, and the grinding barrel 4 is adjusted to an inclined state by a switching component, so that the alumina powder enters the grinding chamber on the side with a larger grinding medium; then the grinding barrel 4 is driven to rotate along its axis by a driving component, and the larger grinding medium can be used to ball-mill the powder raw material in the grinding chamber by the friction between the small balls made of aluminum nitride and the grinding barrel 4 and the mutual collision between the grinding media, so as to quickly reduce the particle size and size of the powder raw material and reduce the time required for grinding; after the raw material powder has been ball-milled for a preset time in the grinding chamber with a larger grinding medium, By adjusting the inclination angle of the grinding barrel 4 through the switching component, the height positions of the two grinding chambers are exchanged, so that even if the grinding chamber with smaller grinding media is at the lowest end, the raw material powder can enter the grinding chamber with smaller grinding media; then continue to drive the grinding barrel 4 to rotate along its axis through the driving component, and use the smaller grinding media to ball-mill the raw material powder, so that the raw material powder is further refined under the action of the smaller grinding media, and the surface activity of the powder particles is enhanced. After completing the preset ball milling time, it is taken out, and the subsequent nitriding and calcination are completed under suitable conditions to complete the preparation of aluminum nitride powder.

[0040] In this way, the grinding barrel 4 is driven by the switching component to adjust the tilt with its axis center, so that the raw material powder can be graded ball-milled in the two grinding chambers in turn, so that the raw material powder can quickly reduce its particle size under the action of the larger grinding medium, thereby reducing the total ball milling time and reducing the occurrence of cold welding. Subsequently, the raw material powder is subjected to high-precision ball milling with a smaller grinding medium, so that the raw material powder is further refined while reducing the impact of cold welding on the ball milling quality and reducing agglomeration. Moreover, graded ball milling can use ball milling media of different sizes to perform more targeted treatment on particles of different sizes, reduce agglomeration caused by differences in particle size, and thereby obtain a more uniform powder material, thereby improving the ball milling quality of alumina powder, so as to achieve the purpose of improving the quality of aluminum nitride powder.

[0041] Furthermore, the driving assembly includes two fixed frames 17 respectively fixedly mounted on the top surfaces of both sides of the base plate 1, a sliding block 18 is installed in each of the two fixed frames 17, a rotating frame 19 is installed on each of the two sliding blocks 18, a motor 20 is fixedly mounted in the rotating frame 19, and a fixed shaft 5 is coaxially fixed at the center of both ends of the grinding barrel 4, and the main shaft of the motor 20 passes through the end of the rotating frame 19 and is fixedly connected to the fixed shaft 5 through a connecting part.

[0042] According to the above embodiment, a specific embodiment of a driving assembly is provided. Figure 2When the motor 20 drives the fixed shaft 5 to rotate, the fixed shaft 5 drives the grinding barrel 4 to rotate together, thereby achieving the purpose of driving the grinding barrel 4 to rotate along the axis as mentioned above. Since the grinding barrel 4 and the rotating ring 14 are rotatably connected, and the rotating frame 3 can rotate with the mounting shaft 13 as the center, when the inclination angle of the grinding barrel 4 changes, the motor 20 can still drive the fixed shaft 5 to rotate, thereby providing a rotation basis for the subsequent second-stage grinding.

[0043] Furthermore, the connection portion includes a connection shaft 25 fixedly mounted on the end of the main shaft of the motor 20 , the outer wall of the connection shaft 25 is slidably connected to a sliding tube 12 via a flat key, and the sliding tube 12 is fixedly connected to the fixed shaft 5 via a universal shaft 11 .

[0044] According to the above embodiment, a specific embodiment of the connecting part is provided. When the motor 20 drives the connecting shaft 25 to rotate together, the connecting shaft 25 drives the sliding tube 12 and the universal shaft 11 to rotate together through the spline, and drives the fixed shaft 5 to rotate, thereby completing the transmission between the motor 20 and the fixed shaft 5.

[0045] Furthermore, the side wall of the rotating frame 19 is rotatably connected with a fixed sleeve 6 which is sleeved on the outer wall of the sliding tube 12, the universal shaft 11 and the fixed shaft 5, and the inner wall of the fixed sleeve 6 is slidably connected to the outer wall of the sliding tube 12 by a flat key. An arcuate bar 7 is fixedly installed at one end of the fixed sleeve 6 close to the grinding barrel 4, and a sliding groove 9 is provided in the arcuate bar 7. An electric control slider 10 which can slide in the sliding groove 9 is rotatably installed on the outer wall of the fixed shaft 5. The arcuate bar 7 and the side wall of the fixed sleeve 6 are jointly provided with a cutting groove 8 for the universal shaft 11 and the fixed shaft 5 to slide in or out.

[0046] According to the above embodiment, when the electric control slider 10 on one side slides in the sliding groove 9, the Figure 3 At this time, the axis of the grinding barrel 4 rotates counterclockwise with the lower left corner as the center. Figure 7 As shown, at this time, the grinding barrel 4 can be driven to rotate in a conical shape with the left fixed shaft 5 as the center by driving the left motor 20. Even if the end of the grinding barrel 4 on the right side makes a circular motion with its axis as the center, since the mounting shaft 13 rotates and is rotatably connected to the rotating frame 3, and the rotating frame 3 can rotate with the connecting shaft 25 between the mounting frame 2 as the center, the mounting shaft 13 can still provide support for the grinding barrel 4 when the grinding barrel 4 rotates in a conical shape, and the grinding barrel 4 also switches from self-rotation to self-rotation and revolves at the same time. At this time, the grinding media in the grinding chamber on the right side of the grinding barrel 4 will shake in the grinding chamber under the drive of the grinding barrel 4, and the powder adhered to the outer wall of the grinding media will be shaken off by vibration under the collision between them, so as to avoid the outer walls of the grinding media adhered to the raw material powder from being adsorbed to each other under the action of cold welding to form large-particle powder, thereby reducing the grinding quality. When the electric control sliders 10 on the left and right sides slide along the sliding grooves 9 in which they are located at the same time, the fixed shafts 5 on both sides can be deflected at the same time. For details, please refer to Figure 7 At this time, the driving motor 20 can drive the left and right sides of the grinding barrel 4 to rotate in a cone shape with the midpoint of its axis as the center, so that the grinding media in the grinding chambers on both sides can vibrate off the powder raw materials on their outer walls under the action of vibration, that is, the outer walls of the grinding media on both sides are cleaned at the same time, further eliminating the influence of cold welding on the ball milling quality, and also further reducing the agglomeration of powder materials.

[0047] In this way, by driving the electric control slider 10 at the upper position to drive the grinding barrel 4 to rotate with the fixed axis 5 at the lower position as the center, the grinding barrel 4 can be made to move in a conical shape, so that the outer wall of the grinding medium at the upper position can be cleaned without affecting the grinding work in the grinding chamber at the lower position. By coordinating the switching component to switch the height position of the grinding chambers on both sides, the grinding media on both sides can be cleaned during the ball milling of the raw material powder, and the raw material powder adhering to the outer wall of the grinding medium can be allowed to enter the grinding chamber at the lower position through the connecting point in the middle to continue grinding, thereby reducing the influence of cold welding on the ball milling quality and improving the utilization rate of the raw materials. After the ball milling is completed, by driving the electric control sliders 10 on both sides to drive the grinding barrel 4 to rotate in a conical shape with the midpoint of the axis as the center, the outer walls of the grinding media on both sides can be cleaned at the same time, thereby improving the cleaning effect of the grinding media.

[0048] It is worth mentioning that during the rotation of the grinding barrel 4, the electric control slider 10 switches back and forth between sliding on one side and sliding on both sides, which can continuously clean the outer wall of the grinding medium during the grinding process, thereby minimizing the cold welding phenomenon caused by the adhesion of the raw material powder, further improving the ball milling quality, and thus improving the final quality of the aluminum nitride powder.

[0049] Furthermore, the switching assembly includes a transverse groove opened on the side wall of the sliding block 18, and a rotating shaft that can rotate and slide in the transverse groove is fixed to the side wall of the rotating frame 19. The sliding block 18 is vertically rotatably installed in the fixed frame 17 and can be adjusted vertically up and down.

[0050] According to the above embodiment, when the sliding block 18 slides along the fixed frame 17, the distance between the sliding block 18 and the grinding barrel 4 is shortened. Figure 3 At this time, the rotating frame 19 slides along the side wall of the sliding block 18, which can ensure that the axis of the grinding barrel 4 does not deflect when the sliding block 18 slides. When the left sliding block 18 slides upward, the right sliding block 18 is driven to slide downward at the same time, even if the left grinding chamber rises to a high position and the right grinding chamber is lowered to a low position at the same time, the height position switching of the grinding chambers on both sides is completed.

[0051] Furthermore, a fixed plate 21 is fixedly installed on the side wall of the fixed frame 17, and a rotating rod 22 is rotatably installed on the outer wall of the fixed plate 21. A tension spring 23 is provided between the end of the rotating rod 22 away from the fixed plate 21 and the sliding block 18. Two limit pins that can limit the rotation of the rotating rod 22 are fixedly installed on the side wall of the fixed plate 21. A toggle rod 24 that can swing back and forth is also rotatably installed on the side wall of the fixed plate 21. The toggle rod 24 is set to a V shape, and the ends of the two arms located in the V shape are fixed with toggle pins.

[0052] According to the above embodiment, the toggle lever 24 is a V-shaped connecting rod composed of two connecting rods, and a toggle pin is provided at both ends. When the external driving structure drives the toggle lever 24 to swing back and forth, the toggle pin on one of the arms of the toggle lever 24 will toggle the rotating lever 22 to swing, and when the rotating lever 22 swings, the tension spring 23 can pull the sliding block 18 to slide along the fixed frame 17, so that the swing of the toggle levers 24 on both sides can drive the sliding blocks 18 on both sides to switch their upper and lower positions, thereby switching the tilt direction of the grinding barrel 4, and thus achieving the purpose of switching the grinding chamber;

[0053] It is worth noting that the rotation angle of the toggle rod 24 when the rotating rod 22 is rotated by the toggle pin cannot make the rotating rod 22 pass the state of being in the same straight line with the connection point of the tension spring 23 and the sliding block 18, that is, after the toggle rod 24 is reset and rotated, the rotating rod 22 loses the support of the toggle pin, and under the action of the weight in the grinding chamber below, the sliding block 18 will move down and reset, and pull the tension spring 23 to reset the rotating rod 22. However, in this process, when the sliding block 18 moves up under the action of the tension spring 23, the grinding barrel 4 will pass the horizontal state, which will cause the grinding chamber originally in the low position to temporarily switch to the high position, and the raw material powder therein will move to The raw material powder flows in another grinding chamber. During the process of the sliding block 18 moving downward and resetting under the gravity of the corresponding grinding chamber and the pulling force of the tension spring 23, if the flow of the raw material powder makes the gravity in the other grinding chamber greater than the gravity in the grinding chamber, that is, the gravity in the other grinding chamber is sufficient to overcome the pulling force of the side tension spring 23, the grinding barrel 4 will be tilted and switched, and will no longer be reset. This means that the grinding degree of the raw material powder in the first grinding chamber (that is, the grinding chamber with a large-diameter grinding medium) has reached the standard. After the initial grinding, the particle size and fluidity of the raw material powder meet the subsequent secondary grinding, so the grinding chamber is switched at this time.

[0054] On the contrary, when the amount of powder flowing into the original high grinding chamber is insufficient, that is, when the gravity in the other grinding chamber is sufficient to overcome the tension of the side tension spring 23, the grinding barrel 4 will be reset, and the powder material in the other grinding chamber will flow back to the grinding chamber below to continue grinding.

[0055] In this way, the switching between the grinding chambers can be automatically controlled by utilizing the changes in the raw material powder during the grinding process, so as to achieve the effect of real-time switching according to the degree of grinding, and further improve the effect of raw material powder preparation.

[0056] It is worth mentioning that since the sliding block 18 is limited only by the tension spring 23 and the rotating rod 22, when the grinding barrel 4 makes a conical motion with its lower fixed axis 5 as the center, that is, when the outer wall of the grinding medium at a high position is cleaned, the sliding block 18 at a high position continuously swings up and down under the action of the centrifugal force of the rotation of the grinding barrel 4, which can provide the contraction and stretching of the tension spring 23 to eliminate the vibration generated when the grinding barrel 4 rotates, thereby avoiding dislocation or other influences caused by vibration after long-term use of the device.

[0057] Furthermore, a flow monitor 16 is fixedly installed at the connection between the two grinding chambers, and the flow monitor 16 is connected to the toggle rod 24 through an electrical signal.

[0058] According to the above embodiment, by using the flow monitor 16 at the connection between the two grinding chambers, the sensitivity of the device to the powder grinding effect can be increased. After the grinding effect of the grinding medium on one side reaches the standard, the toggle lever 24 can be driven to switch the height positions of the two grinding chambers, and the powder can be ground in two stages using the grinding medium on the other side. In combination with the cleaning of the outer wall of the grinding medium, it can be ensured that the agglomeration effect of the cold welding on the powder is far lower than the crushing effect of the ball milling, thereby improving the quality of the ball milling.

[0059] In this embodiment, compared with the above embodiment, the initial swing amplitude of the toggle lever 24 is the same. When the flow monitor 16 detects that the grinding effect of the powder meets the standard, it will control the toggle amplitude of the toggle lever 24 to increase, and then complete the switching of the above-mentioned grinding chamber by toggling, rather than by the gravity of the grinding chamber, which can further improve the sensitivity of the device.

[0060] Furthermore, an annular cooling chamber 15 is provided in the rotating ring 14 and the grinding barrel 4, and the cooling chamber 15 in the rotating ring 14 is sealed and rotatably connected with the cooling chamber 15 in the grinding barrel 4 at the joint, and the cooling chamber 15 forms a liquid supply circuit with the external liquid supply component through the cooling channels in the two mounting shafts 13 respectively.

[0061] According to the above-mentioned embodiment, liquid nitrogen is introduced into the cooling circuit composed of the cooling channel and the cooling cavity 15 in the mounting shaft 13 through an external liquid supply component, so that a cooling effect can be provided from the center position of the grinding barrel 4 to the grinding cavities on both sides, so that the raw material powder can be ground in a low temperature environment, while reducing the hardness of the raw material and increasing its brittleness, and further eliminating the cold welding phenomenon through the low temperature environment.

[0062] In this way, by cooling the grinding chambers on both sides at the connection point, a low-temperature environment is created for the grinding chambers on both sides while eliminating the heat generated by ball milling. This can not only reduce the hardness of the powder and increase the brittleness of the material, making it easier for the raw powder to be refined under the influence of ball milling and shortening the time required for ball milling, but also further eliminate the cold welding phenomenon through the low-temperature environment. By ball milling in a low-temperature environment and cleaning the outer wall of the grinding medium, combined with shortening the ball milling time with large-diameter grinding media, the pain point of low quality of aluminum nitride powder caused by poor ball milling quality when preparing aluminum nitride powder by traditional ball milling can be solved.

[0063] Furthermore, one-way cooling pipes 26 are fixedly mounted on the outer walls of the two grinding chambers in the grinding barrel 4 , and both ends of the one-way cooling pipes 26 are respectively connected to the cooling chamber 15 in one direction.

[0064] According to the above embodiment, when the external liquid supply component introduces liquid nitrogen into the cooling circuit composed of the cooling channel in the mounting shaft 13 and the cooling chamber 15, the liquid nitrogen enters the one-way cooling tube 26, circles around the outer walls of the grinding chamber on both sides, and then returns to the cooling chamber 15 and circulates through the external liquid supply component, further improving the cooling effect of the grinding chamber, thereby eliminating the influence of cold welding on the ball milling quality.

[0065] A preparation process for aluminum nitride powder using an aluminum nitride powder preparation device comprises the following steps:

[0066] Step 1: When the device is used, firstly put the aluminum oxide powder or aluminum powder into the grinding barrel 4, and adjust the grinding barrel 4 to an inclined state by switching the assembly, so that the aluminum oxide powder enters the grinding chamber on the side with the larger grinding medium;

[0067] Step 2: Then, the driving assembly drives the grinding barrel 4 to rotate along its axis, and the friction between the larger grinding medium and the grinding barrel 4 and the mutual collision between the grinding media are used to ball-mill the powder raw materials in the grinding chamber, so as to quickly reduce the particle size and size of the powder raw materials and reduce the time required for grinding;

[0068] Step 3: After the raw material powder is ball-milled for a preset time in the grinding chamber with the larger grinding medium, the inclination angle of the grinding barrel 4 is adjusted by the switching component to exchange the height positions of the two grinding chambers, so that the raw material powder can enter the grinding chamber with the smaller grinding medium even if the grinding chamber with the smaller grinding medium is at the lowest end;

[0069] Step 4: Then, the grinding barrel 4 is driven to rotate along its axis by the driving component, and the raw material powder is ball-milled with a smaller grinding medium, so that the raw material powder is further refined under the action of the smaller grinding medium, and the surface activity of the powder particles is enhanced. After the preset ball milling time is completed, the raw material powder is taken out, and the subsequent nitridation and calcination of the raw material powder are completed under appropriate conditions;

[0070] Step 5: Replace the raw material powder in the grinding chamber and repeat steps 1 to 4 above.

[0071] The standard parts used in this embodiment can be purchased directly from the market, and the non-standard structural components recorded in the specification and the drawings can also be directly processed according to the existing technical common sense. At the same time, the connection method of each component adopts the mature conventional means in the prior art, and the machinery, parts and equipment all adopt the conventional models in the prior art, so no specific description will be given here.

[0072] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An aluminum nitride powder preparation device, comprising a bottom plate (1), characterized in that: Two mounting frames (2) are fixedly mounted on the top surface of the bottom plate (1); a rotating frame (3) is rotatably mounted between the two mounting frames (2) via a rotating shaft; mounting shafts (13) are rotatably mounted on two opposite inner walls inside the rotating frame (3); ends of the two mounting shafts (13) close to each other are commonly fixedly connected to an inclined rotating ring (14); a grinding barrel (4) is rotatably mounted on the inner wall of the rotating ring (14); two mutually connected grinding chambers are provided inside the grinding barrel (4); a plurality of grinding media are arranged in the two grinding chambers; the diameters of the grinding media in the two grinding chambers are different; and the inner diameter of the connection between the two grinding chambers is smaller than the diameter of the grinding media; It also includes a driving assembly, which is used to drive the grinding barrel (4) to rotate along its axis; It also comprises a switching component, which is used to switch the inclination angle of the grinding barrel (4) so ​​as to exchange the height positions of the two grinding chambers therein.

2. The aluminum nitride powder preparation device according to claim 1, characterized in that: The driving assembly comprises two fixed frames (17) respectively fixedly mounted on the top surfaces of both sides of the bottom plate (1), a sliding block (18) being mounted in each of the two fixed frames (17), a rotating frame (19) being mounted on each of the two sliding blocks (18), a motor (20) being fixedly mounted in the rotating frame (19), fixed shafts (5) being coaxially fixed at the centers of both ends of the grinding barrel (4), and the main shaft of the motor (20) passing through the end of the rotating frame (19) being fixedly connected to the fixed shaft (5) through a connecting portion.

3. The aluminum nitride powder preparation device according to claim 2, characterized in that: The connecting portion comprises a connecting shaft (25) fixedly mounted on the end of the main shaft of the motor (20); the outer wall of the connecting shaft (25) is slidably connected to a sliding tube (12) via a flat key; the sliding tube (12) is fixedly connected to the fixed shaft (5) via a universal shaft (11).

4. The aluminum nitride powder preparation device according to claim 3, characterized in that: The side wall of the rotating frame (19) is rotatably connected with a fixed sleeve (6) sleeved on the outer wall of the sliding tube (12), the universal shaft (11) and the fixed shaft (5), and the inner wall of the fixed sleeve (6) is slidably connected with the outer wall of the sliding tube (12) via a flat key. An arc strip (7) is fixedly installed at one end of the fixed sleeve (6) close to the grinding barrel (4), and a sliding groove (9) is provided in the arc strip (7). An electric control slider (10) capable of sliding in the sliding groove (9) is rotatably installed on the outer wall of the fixed shaft (5). The arc strip (7) and the side wall of the fixed sleeve (6) are jointly provided with a cutting groove (8) capable of allowing the universal shaft (11) and the fixed shaft (5) to slide in or out.

5. The aluminum nitride powder preparation device according to claim 2, characterized in that: The switching assembly comprises a transverse groove formed in the side wall of the sliding block (18); a rotating shaft capable of rotating and sliding in the transverse groove is fixed to the side wall of the rotating frame (19); the sliding block (18) is vertically rotatably mounted in the fixed frame (17) and can be adjusted vertically up and down.

6. The aluminum nitride powder preparation device according to claim 5, characterized in that: A fixing plate (21) is fixedly mounted on the side wall of the fixing frame (17); a rotating rod (22) is rotatably mounted on the outer wall of the fixing plate (21); a tension spring (23) is provided between the end of the rotating rod (22) away from the fixing plate (21) and the sliding block (18); two limit pins capable of limiting the rotation of the rotating rod (22) are fixedly mounted on the side wall of the fixing plate (21); a toggle rod (24) capable of reciprocating swing is also rotatably mounted on the side wall of the fixing plate (21); the toggle rod (24) is set in a V shape, and the ends of the two arms located in the V shape are both fixed with toggle pins.

7. The aluminum nitride powder preparation device according to claim 4, characterized in that: A flow monitor (16) is fixedly installed at the connection between the two grinding chambers, and the flow monitor (16) is connected to the toggle rod (24) via an electrical signal.

8. The aluminum nitride powder preparation device according to claim 7, characterized in that: The rotating ring (14) and the grinding barrel (4) are both provided with an annular cooling chamber (15), and the cooling chamber (15) in the rotating ring (14) and the cooling chamber (15) in the grinding barrel (4) are sealed and rotatably connected at the joint, and the cooling chamber (15) forms a liquid supply circuit with an external liquid supply component through cooling channels in the two mounting shafts (13).

9. The aluminum nitride powder preparation device according to claim 8, characterized in that: One-way cooling pipes (26) are fixedly mounted on the outer walls of the two grinding chambers in the grinding barrel (4), and both ends of the one-way cooling pipes (26) are respectively connected to the cooling chamber (15) in one direction.

10. A process for preparing aluminum nitride powder using the aluminum nitride powder preparation device according to claim 1, characterized in that: The preparation process comprises the following steps: Step 1: firstly put the aluminum oxide powder or aluminum powder into the grinding barrel (4), and adjust the grinding barrel (4) to an inclined state by means of a switching component, so that the aluminum oxide powder enters the grinding chamber on the side with a larger grinding medium; Step 2: Then, the driving assembly drives the grinding barrel (4) to rotate along its axis, and utilizes the friction between the larger grinding medium and the grinding barrel (4) and the mutual collision between the grinding mediums to ball-mill the powder raw materials in the grinding chamber, thereby quickly reducing the particle size and size of the powder raw materials and reducing the time required for grinding; Step 3: After the raw material powder is ball-milled in the grinding chamber with the larger grinding medium for a preset time, the inclination angle of the grinding barrel (4) is adjusted by the switching component to exchange the height positions of the two grinding chambers so that the grinding chamber with the smaller grinding medium is at the lower end, and the raw material powder flows into the grinding chamber with the smaller grinding medium under the action of gravity; Step 4: Then, the grinding barrel (4) is driven to rotate along its axis by the driving component, and the raw material powder is ball-milled by using a smaller grinding medium, so that the raw material powder is further refined under the action of the smaller grinding medium, and the surface activity of the powder particles is enhanced. After the preset ball milling time is completed, the raw material powder is taken out, and the raw material powder is subsequently nitrided and calcined under appropriate conditions, and finally aluminum nitride powder is obtained; Step 5: Replace the raw material powder in the grinding chamber and repeat steps 1 to 4 above.

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