Silicon nitride conductive ceramic material and preparation method thereof

Abstract

The invention belongs to the technical field of conductive ceramics, and discloses a silicon nitride conductive ceramic material and a preparation method thereof.The method comprises the steps that a yttrium oxide, aluminum oxide and magnesium oxide ternary composite system is arranged, rare earth elements are doped, and a sintering aid is formed; a resistance adjusting agent is composed of a titanium nitride-titanium dioxide core-shell structure and silicon carbide fibers, and the silicon carbide fibers are directionally distributed and arranged in a magnetic field, so that efficient composition of the silicon nitride conductive ceramic material is achieved, and the effects of high bending resistance, high conductivity and low sintering temperature are achieved; forming the slurry; performing spark plasma sintering; conducting network directional regulation and control; the preparation method comprises the steps of raw material mixing and ball milling, post-treatment and performance optimization, a convenient preparation process can be formed, too many tedious steps are not needed, a ball mill used in raw material mixing and ball milling is further provided with a pre-grinding device for pre-grinding the materials, the subsequent ball milling quality is enhanced, and the situation that the materials are not completely ground is avoided.

Description

Technical Field

[0001] The invention relates to the technical field of conductive ceramics, in particular to a silicon nitride conductive ceramic material and a preparation method thereof. Background Art

[0002] Silicon nitride has excellent physical and mechanical properties and is widely used in the field of structural ceramics. In recent years, in order to further explore the material properties and expand its application scenarios, functional research on silicon nitride ceramics has been widely carried out, and research on conductive silicon nitride ceramics is one of the important directions.

[0003] Due to the inherent high hardness and great brittleness of silicon nitride ceramics, the processing efficiency of silicon nitride ceramics is low, and it is difficult to be processed into complex shaped special-shaped parts, which limits its wide application. The current methods for improving the processing performance of silicon nitride ceramics mainly focus on making silicon nitride conductive ceramics and then processing them into special-shaped parts by electrospark machining.

[0004] For example, the existing application number is CN202211590307.2, which is a high-performance silicon nitride conductive ceramic and its preparation method and application. 3 N 4 -MgO-Re 2 O 3 - Paraffin wax mixed slurry spray drying to make Si 3 N 4 Granulate balls; then use CCl 4 The binder composed of paraffin wax is sprayed on Si 3 N 4 The surface of the granulated ball is uniformly coated with a paraffin layer. 3 N 4 Granulate balls; then add M x N y B 2 Nano powder, obtained coated M x N y B 2 Conductive layer / paraffin Si 3 N 4 Granulated balls; keeping them at 450-550°C to obtain coated M x N y B 2 Conductive layer Si 3 N 4 Granulated balls; in an argon atmosphere of 1 atm, the temperature is raised to 1550-1750° C., and the axial pressure is 10-50 MPa during the heat preservation process. High-performance silicon nitride conductive ceramics are obtained through spark plasma sintering.

[0005] In the above-mentioned prior art, although the prepared silicon nitride conductive ceramics have high strength, high toughness and high conductivity, the preparation process is relatively complicated. At the same time, the prepared silicon nitride conductive ceramics are still not in the best state. Secondly, in the preparation process of silicon nitride conductive ceramics, it is generally necessary to use a ball mill to achieve ball milling of the raw materials. However, the current ball mills are inefficient in grinding the materials by heavy impact with steel balls, which makes the ball milling time longer and has a certain impact on the subsequent preparation efficiency. Summary of the invention

[0006] The object of the present invention is to provide a silicon nitride conductive ceramic material and a preparation method thereof to solve the problems raised in the above background technology.

[0007] In order to achieve the above object, the present invention adopts the following technical scheme: a silicon nitride conductive ceramic material and a preparation method thereof, comprising the following steps:

[0008] S1. Raw material mixing and ball milling: Add silicon nitride powder, sintering aid and resistance adjusting agent into a ball mill in proportion, use anhydrous ethanol as solvent, rotate at a speed of 200-300 r / min, and ball mill for 10-12 hours to obtain a uniformly mixed slurry;

[0009] S2. Slurry molding: The slurry is made into a green blank by dry pressing or injection molding, and then dried at 70-80℃ for 8-10h;

[0010] S3, spark plasma sintering: placing the green blank into a sintering furnace, heating it to 1600-1800°C at 200°C / min and keeping it at that temperature for 10-20min to obtain silicon nitride conductive ceramics;

[0011] S4. Directional control of the conductive network: During the sintering process of the green embryo, a 0.5-1T axial magnetic field is applied to align the conductive fibers inside the resistor along the direction of the magnetic field to form a longitudinal conductive path;

[0012] S5. Post-processing and performance optimization: The silicon nitride conductive ceramic obtained after sintering is immersed in the graphene and epoxy resin composite liquid to fill the micropores on its surface. Finally, it is finalized through steps such as edge grinding, grinding, ultrasonic cleaning, drying, and laser cutting.

[0013] Preferably, the ball mill used in the step S1 includes a bracket, bearings are installed on both sides of the upper end of the bracket, a ball mill is docked between the bearings on both sides, the left side of the ball mill is connected to the feed pipe, the outside of the feed pipe is docked with a storage box, a feed auger is installed inside the feed pipe, and one side of the feed auger is connected to the inside of the ball mill, a steel ball is placed inside the ball mill, a discharging auger is installed inside the right side of the ball mill, and a discharging pipe is provided on the right side of the ball mill, a large gear is installed outside the right side of the ball mill, and a small gear is meshed on the front side of the large gear, the right side of the middle part of the small gear is connected to the motor, and the motor is installed on the right side of the front end of the bracket, a pre-grinding device is provided on the left side of the ball mill, and the pre-grinding device is connected to one side of the feed auger.

[0014] Preferably, the pre-grinding device includes a connecting shaft, which is connected to one side of the feed auger, a rotating drum is installed on the outside of one side of the connecting shaft, a rotational displacement component is installed inside the rotating drum, and the rotational displacement component is connected to one end of the connecting shaft, the rotational displacement component is connected to a partition plate on the side away from the connecting shaft, and the partition plate is installed inside the ball mill, grinding plates are installed on both sides of the outer end of the rotational displacement component, the right side of the rotating drum is connected to the auxiliary component, a locking rod is fixed to the middle part of the right side of the partition, and the right side of the locking rod is connected to the external bolt of the discharge pipe.

[0015] Preferably, the rotational displacement assembly includes a first bevel gear, which is installed inside the rotating drum, and a support rod is fixed to one side of the middle part of the first bevel gear, and the end of the support rod away from the first bevel gear is locked and connected to the middle part of the partition, the upper end of the first bevel gear is meshed and connected with the second bevel gear, and the second bevel gear is rotatably connected to the outside of the connecting shaft, and a pin is inserted into the upper end of the second bevel gear, and the pin is inserted into the docking groove, and the docking groove is opened inside the connecting ring, and the connecting ring is installed inside the rotating drum.

[0016] Preferably, the auxiliary component includes a protective shell, which is relatively arranged on the outside of one end of the rotating drum, and a driving structure is installed inside the protective shell, and one side of the driving structure is connected to the rotating drum, and the driving structure is connected to the linkage structure on the side away from the rotating drum, one end of the linkage structure is connected to a brush bar, and the other end of the linkage structure is connected to a rolling wheel, and the linkage structure is connected to the right side of the protective shell.

[0017] Preferably, the protective shell includes a shell, a fixed shaft is fixedly inserted on one side of the shell, a docking tube is docked in the middle of the right side of the shell, and a positioning tube is slidably installed inside the docking tube, and the right side of the positioning tube is fixed to the partition.

[0018] Preferably, the driving structure includes a connecting sleeve, which is connected to the middle part of the left side of the shell, and the left side of the connecting sleeve is locked with the rotating drum, the connecting sleeve is inserted into the middle part of the main gear, the outside of the main gear is meshed with a secondary gear, and the middle part of the secondary gear is connected to the fixed shaft, the outside of the secondary gear is meshed with a gear ring, and the outside of the gear ring is embedded in the limiting groove, the limiting groove is opened inside the limiting ring, and the limiting ring is installed inside the shell.

[0019] Preferably, the linkage structure includes a swivel, which is rotatably installed on the right side of the shell, a docking shaft is plugged into one side of the swivel, and the docking shaft is connected to the outside of the gear ring, fixed plates are fixed on the upper and lower sides of one end of the swivel, and the outer end of the fixed plate is plugged into the plug-in rod, the plug-in rod is fixed to the vertical plate at one end away from the fixed plate, and the side of the vertical plate away from the plug-in rod is connected to the third bevel gear, the third bevel gear is meshed with the outside of the fourth bevel gear, and the fourth bevel gear is locked with the middle part of one side of the partition.

[0020] A silicon nitride conductive ceramic material: Calculated by mass percentage, the raw materials of silicon nitride ceramic are: 5%-8% sintering aid, 5%-10% resistance adjusting agent and 82%-90% silicon nitride powder.

[0021] Preferably, the sintering aid is composed of a ternary composite of yttrium oxide, aluminum oxide and magnesium oxide, and the mass ratio of yttrium oxide, aluminum oxide and magnesium oxide is 5:2:3, and the sintering aid is doped with 0.5% rare earth elements;

[0022] The resistance adjusting agent includes a titanium nitride-titanium dioxide core-shell structure and silicon carbide fibers, and the silicon carbide fibers are distributed and arranged in a magnetic field-oriented manner.

[0023] Compared with the prior art, the beneficial effects of this application are:

[0024] The present application forms a sintering aid by setting up a ternary composite system of yttrium oxide, aluminum oxide and magnesium oxide and doping it with rare earth elements, and forms a resistor by setting up a titanium nitride-titanium dioxide core-shell structure and silicon carbide fibers, and the silicon carbide fibers are arranged in a magnetic field-oriented distribution, so as to achieve an efficient composition of silicon nitride conductive ceramic materials, high bending resistance, high conductivity and low sintering temperature effects. At the same time, through raw material mixing and ball milling; slurry molding; spark plasma sintering; conductive network directional control; post-processing and performance optimization steps, a convenient preparation process can be formed without too many cumbersome steps, and the ball mill used in raw material mixing and ball milling is also provided with a pre-grinding device to pre-grind the material, enhance the quality of subsequent ball milling, and avoid the occurrence of incomplete grinding of the material.

[0025] The arrangement of the connecting shaft, the rotating drum, the rotary displacement assembly, the partition and the grinding plate, that is, when the ball mill realizes the rotation of the feed auger connected to the left side, the rotation of the connecting shaft can be realized synchronously, and the rotating connecting shaft can not only realize the rotation of the externally connected rotating drum, but also drive the rotary displacement assembly to make the rotating drum reciprocate left and right. Therefore, the grinding plates arranged at the upper and lower ends of the rotating drum can not only perform rotational pre-grinding on the incoming materials, but also reciprocate left and right for grinding, thereby improving the grinding range and quality, and reducing the occurrence of insufficient material grinding problems during subsequent ball milling.

[0026] The setting of the rotational displacement component, that is, when the connecting shaft rotates, the second bevel gear rotated and connected at the upper right end can be realized to revolve, and because the second bevel gear is meshed with the first bevel gear in a fixed state, the second bevel gear can also rotate during its revolution. In this way, the pin shaft vertically arranged at the upper end of the second bevel gear will be transmitted and coordinated with the docking groove opened inside the connecting ring to realize the left and right reciprocating movement of the connecting ring. Therefore, the rotating drum docked to the outside of the connecting ring will synchronously realize the linkage of the left and right reciprocating movement during the rotation.

[0027] The setting of the auxiliary component, that is, when the drum is in a state of rotation and left-right reciprocating movement, the rotation and left-right reciprocating movement of the connecting sleeve connected in the middle of the right side can be realized. When the connecting sleeve is in a rotating state, it can drive the main gear connected on the right side, so that the main gear cooperates with the auxiliary gears meshed and connected up and down to realize the rotation of the gear ring, and the rotating gear can realize the rotation of the swivel through the connection effect of the docking shaft, and the rotating swivel can realize the rotation of the third bevel gear along the outside of the fourth bevel gear through the docking effect of the fixed plate and the plug-in rod, and rotate on its own through the meshing effect, so as to dock on both sides. The brush bar and the grinding wheel on the outside of the third bevel gear will sweep away and strengthen the grinding of the materials that are not fully pre-ground and attached to the outside of the partition, so that the materials can be fully pre-ground, ensuring that the materials can smoothly pass through the partition and enter the right side of the ball mill for ball milling. When the connecting sleeve is in the left and right reciprocating movement, the movement of the external connected shell can be realized, and the upper and lower side fixed plates of the rotating ring and the corresponding plug-in rods are connected. When the rotating drum rotates and reciprocates left and right with the rotary displacement component, the brush bar and the grinding wheel can be linked to realize the rotation and revolution, thereby greatly enhancing the structural functionality. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the preparation process of the silicon nitride conductive ceramic material of the present invention;

[0029] Figure 2 It is a schematic diagram of the structure of the ball mill of the present invention;

[0030] Figure 3 It is a schematic diagram of the internal structure of the ball mill of the present invention;

[0031] Figure 4 This is a schematic diagram of the internal structure of the pre-grinding device of the present invention;

[0032] Figure 5 It is a schematic diagram of the three-dimensional structure of the rotation displacement assembly of the present invention;

[0033] Figure 6 This is a schematic diagram of the internal structure of the auxiliary component of the present invention;

[0034] Figure 7 This is a schematic diagram of the internal structure of the protective shell of the present invention;

[0035] Figure 8 It is a schematic diagram of the front view of the combined structure of the driving structure and the linkage structure of the present invention;

[0036] Fig. 9 This is a schematic diagram of the three-dimensional split structure of the driving structure of the present invention;

[0037] Fig.10 It is a schematic diagram of the three-dimensional split structure of the linkage structure of the present invention.

[0038] In the figure: bracket 1, bearing 2, ball mill 3, feed pipe 4, storage box 5, feed auger 6, steel ball 7, discharge auger 8, discharge pipe 9, large gear 10, small gear 11, motor 12, pre-grinding device 13, connecting shaft 131, rotating drum 132, rotation displacement component 133, first bevel gear 1331, support rod 1332, second bevel gear 1333, pin 1334, docking groove 1335, connecting ring 1336, partition 134, grinding plate 135, auxiliary component 136, protective shell 1361, shell 136 11. Fixed shaft 13612, docking tube 13613, positioning tube 13614, driving structure 1362, connecting sleeve 13621, main gear 13622, sub gear 13623, gear ring 13624, limiting groove 13625, limiting ring 13626, linkage structure 1363, swivel 13631, docking shaft 13632, fixed plate 13633, plug-in rod 13634, vertical plate 13635, third bevel gear 13636, fourth bevel gear 13637, brush strip 1364, rolling wheel 1365, locking rod 137. DETAILED DESCRIPTION

[0039] In order to further explain the technical solution of the present invention, it is described in detail below through specific embodiments.

[0040] See also Figure 1 The present invention provides a silicon nitride conductive ceramic material and a preparation method thereof, comprising the following steps:

[0041] S1. Raw material mixing and ball milling: Add silicon nitride powder, sintering aid and resistance adjusting agent into a ball mill in proportion, use anhydrous ethanol as solvent, rotate at a speed of 200-300 r / min, and ball mill for 10-12 hours to obtain a uniformly mixed slurry;

[0042] S2. Slurry molding: The slurry is made into a green blank by dry pressing or injection molding, and then dried at 70-80℃ for 8-10h;

[0043] S3, spark plasma sintering: placing the green blank into a sintering furnace, heating it to 1600-1800°C at 200°C / min and keeping it at that temperature for 10-20min to obtain silicon nitride conductive ceramics;

[0044] S4. Directional control of the conductive network: During the sintering process of the green embryo, a 0.5-1T axial magnetic field is applied to align the conductive fibers inside the resistor along the direction of the magnetic field to form a longitudinal conductive path;

[0045] S5. Post-processing and performance optimization: The silicon nitride conductive ceramic obtained after sintering is immersed in the graphene and epoxy resin composite liquid to fill the micropores on its surface. Finally, it is finalized through steps such as edge grinding, grinding, ultrasonic cleaning, drying, and laser cutting.

[0046] On the other hand, the present application also provides a silicon nitride conductive ceramic material: in terms of mass percentage, the raw materials of silicon nitride ceramics are: sintering aid 5%-8%, resistance adjusting agent 5%-10% and silicon nitride powder 82%-90%.

[0047] The sintering aid is composed of a ternary composite of yttrium oxide, aluminum oxide and magnesium oxide, and the mass ratio of yttrium oxide, aluminum oxide and magnesium oxide is 5:2:3. In addition, 0.5% rare earth elements are doped inside the sintering aid. The ternary composite system of yttrium oxide, aluminum oxide and magnesium oxide doped with rare earth elements can optimize the liquid phase sintering behavior, that is, promote grain rearrangement and density, balance the liquid phase amount and high temperature stability, and the addition of rare earth elements can inhibit the abnormal growth of silicon nitride grains and enhance the self-toughening effect.

[0048] Among them, the resistor includes titanium nitride-titanium dioxide core-shell structure and silicon carbide fiber, and the silicon carbide fiber is arranged in a magnetic field-oriented distribution. The titanium nitride-titanium dioxide core-shell structure accounts for 3%-6%, while the silicon carbide fiber accounts for 2%-4%. By introducing the titanium nitride-titanium dioxide core-shell structure and the silicon carbide fiber arranged in a magnetic field as a composite resistor, multiple synergistic optimizations are achieved. The titanium nitride-titanium dioxide core-shell structure (3%-6%) suppresses the interface reaction while increasing the density of the conductive network through the high conductivity of the core and the interface passivation effect of the shell, while the silicon carbide fiber (2%-4%) forms an oriented conductive channel after being oriented by the magnetic field, significantly reducing the resistance anisotropy. The two work together to construct a three-dimensional gradient conductive network, so that the material has both high conductivity (>10^3 S / m) and bending strength (1200~1350 MPa).

[0049] See also Figure 2-3 The ball mill used in step S1 of this embodiment includes a bracket 1, bearings 2 are installed inside the left and right sides of the upper end of the bracket 1, and a ball mill 3 is connected between the bearings 2 on both sides to ensure that the ball mill 3 can rotate stably and smoothly. The left side of the ball mill 3 is connected and connected with the feed pipe 4, and the ball mill 3 is locked and connected with the left side of the upper end of the bracket 1. A storage box 5 is connected to the outside of the feed pipe 4, and a feed auger 6 is installed inside the feed pipe 4, and the right side of the feed auger 6 is connected to the left side of the ball mill 3. A plurality of steel balls 7 are placed inside the ball mill 3, a discharge auger 8 is installed inside the right side of the ball mill 3, and a discharge pipe 9 is connected and docked to the right side of the ball mill 3, a large gear 10 is installed outside the right side of the ball mill 3, and a small gear 11 is meshed and connected to the front side of the large gear 10, the right side of the middle part of the small gear 11 is connected to the motor 12, and the motor 12 is installed on the right side of the front end of the bracket 1, a pre-grinding device 13 is provided on the left side of the ball mill 3, and the pre-grinding device 13 is connected to the right side of the feed auger 6.

[0050] Specifically, when silicon nitride powder, sintering aid and resistance adjusting agent are to be prepared by ball milling, the silicon nitride powder, sintering aid and resistance adjusting agent can be put into the storage box 5 in proportion. At this time, the motor 12 arranged on the right side of the front end of the bracket 1 can be driven to make the motor 12 realize the rotation of the small gear 11 connected to the output end. As the small gear 11 rotates, the large gear 10 arranged on the right side of the outer end of the ball mill 3 can realize the rotation of the ball mill 3 through the meshing transmission effect, and the ball mill 3 can realize the smooth rotation process through the bearings 2 arranged on the left and right sides of the upper end of the bracket 1. When the silicon nitride powder in the storage box 5 When the sintering aid and the resistance adjusting agent enter the feed pipe 4, they can be transmitted to the ball mill 3 by the spiral rotation of the feed auger 6 rotating inside the feed pipe 4. At the same time, during the rotation of the ball mill 3, the steel ball 7 arranged inside the ball mill 3 will be lifted to a certain height and then fall down to perform heavy impact and grinding activities on the material, so that the material is ball-milled into a suitable slurry. The slurry that has completed ball milling will enter the discharge pipe 9 and be quickly discharged through the spiral transmission activity of the discharge auger 8 arranged inside the discharge pipe 9, thereby conveniently completing the rapid preparation of the slurry required for the preparation of silicon nitride conductive ceramic materials.

[0051] See also Figure 4 The pre-grinding device 13 in the embodiment includes a connecting shaft 131, which is connected to the right side of the feed auger 6 and can rotate synchronously with the feed auger 6. A rotating drum 132 is sleeved on the right side of the connecting shaft 131. A rotating displacement component 133 is installed inside the rotating drum 132, and the rotating displacement component 133 is connected to the right end of the connecting shaft 131. The side of the rotating displacement component 133 away from the connecting shaft 131 is connected to a partition 134, and the partition 134 is installed inside the ball mill 3, and the outer side of the partition 134 is not connected to the inside of the ball mill 3. Fixed connection, at the same time, the partition 134 is arranged in the shape of a porous sieve plate as a whole, grinding plates 135 are installed on the upper and lower sides of the rotation displacement component 133, and a plurality of balls are embedded in the external grinding end of the grinding plate 135, the right side of the rotating drum 132 is connected to the auxiliary component 136, and a locking rod 137 is fixed to the middle part of the right side of the partition 134, and the right side of the locking rod 137 is connected to the external bolt of the discharge pipe 9, and the locking rod 137 is laterally inserted into the feed auger 6, thereby assisting in locking the partition 134, so that subsequent pre-grinding activities can be carried out stably.

[0052] See also Figure 5The rotation displacement assembly 133 in this embodiment includes a first bevel gear 1331, which is built into the drum 132, and a support rod 1332 is fixedly disposed laterally in the middle of the first bevel gear 1331, and one end of the support rod 1332 away from the first bevel gear 1331 is locked and connected to the middle of the left side of the partition 134, so that the first bevel gear 1331 can be fixed by fixing the support rod 1332, and the upper end of the first bevel gear 1331 is meshedly connected with the second bevel gear 1333, and the second bevel gear 1333 It is rotatably connected to the upper right end of the connecting shaft 131, so that when the connecting shaft 131 rotates, the second bevel gear 1333 can be rotated, and the meshing connection between the second bevel gear 1333 and the first bevel gear 1331 can also assist in realizing the self-rotation effect of the second bevel gear 1333. A pin shaft 1334 is vertically inserted into the upper end of the second bevel gear 1333, and the pin shaft 1334 is inserted into the docking groove 1335. The docking groove 1335 is opened in the connecting ring 1336, and the connecting ring 1336 is installed in the rotating drum 132.

[0053] Specifically, when the ball mill 3 rotates and realizes the rotation of the feed auger connected to the left side, the rotating feed auger can be driven by the connecting shaft 131 connected to the right side synchronously. When the connecting shaft 131 rotates, not only the rotation of the external sleeved drum 132 can be driven, but also the grinding plates 135 arranged at the upper and lower ends of the drum 132 can be rotated in a circle to pre-rotate and grind the materials entering the ball mill 3. At the same time, the rotating connecting shaft 131 can also realize the revolution of the second bevel gear 1333 connected to the upper end on the right side. When the second bevel gear 1333 performs the revolution, because its second bevel gear 1333 is meshed and connected with the first bevel gear 1331 in a fixed installation state inside the drum 132, the second bevel gear 1333 can be linked to realize the self-rotation of the second bevel gear 1333, and along with the second bevel gear 1 333 rotates, and the pin shaft 1334 vertically inserted in the upper end of the second bevel gear 1333 will rotate accordingly to drive the connecting ring 1336 connected to the pin shaft 1334 through the docking groove 1335 to reciprocate left and right. When the connecting ring 1336 reciprocates, the rotating drum 132 connected to the outside of the connecting ring 1336 can synchronously reciprocate left and right. Therefore, the rotating drum 132 driven to rotate by the connecting shaft 131 can not only realize the rotation activity, but also can reciprocate left and right. Furthermore, the grinding plates 135 arranged at the upper and lower ends of the rotating drum 132 can carry out the rotation grinding and reciprocating left and right grinding processes at the same time, so as to further enhance the pre-grinding effect of the material, ensure the quality of subsequent material ball milling, and avoid the problems of insufficient material ball milling and long ball milling time.

[0054] See also Figure 6-10The auxiliary component 136 in this embodiment includes a protective shell 1361, which is arranged at the right outer end of the rotating drum 132. A driving structure 1362 is installed inside the protective shell 1361, and the left side of the driving structure 1362 is connected to the rotating drum 132, and the side of the driving structure 1362 away from the rotating drum 132 is connected to the linkage structure 1363, one end of the linkage structure 1363 is connected to the brush strip 1364, and the other end of the linkage structure 1363 is connected to the rolling wheel 1365, and the linkage structure 1363 is connected to the right side of the protective shell 1361.

[0055] The brush strip 1364 is overall arranged in a cross brush structure, and a spiral grinding strip is integrally provided on the outside of the grinding wheel 1365 to assist in enhancing the pre-grinding effect.

[0056] Among them, the protective shell 1361 includes a shell body 13611, and a fixed shaft 13612 is fixedly inserted at the upper and lower ends of the left side of the shell body 13611. A docking tube 13613 is docked in the middle of the right side of the shell body 13611, and a positioning tube 13614 is slidably installed inside the docking tube 13613. In this way, the docking tube 13613 and the positioning tube 13614 can form a telescopic structure to cooperate with the transmission activity of the rotation displacement component 133, and the right side of the positioning tube 13614 is fixed to the partition 134.

[0057] Among them, the driving structure 1362 includes a connecting sleeve 13621, which is connected to the middle part of the left side of the shell 13611, and the left side of the connecting sleeve 13621 is locked and connected with the rotating drum 132, so that the connecting sleeve 13621 can rotate and displace synchronously with the rotating drum 132, the right side of the connecting sleeve 13621 is inserted into the middle part of the main gear 13622, and the main gear 13622 is built into the middle part of the shell 13611, the upper and lower ends of the main gear 13622 are meshed and connected with the sub-gear 13623, and the middle parts of the sub-gears 13623 on both sides are connected to the fixed shafts 13612 on both sides, the outside of the sub-gears 13623 on both sides is meshed and connected with the gear ring 13624, and the outside of the gear ring 13624 is embedded in the limiting groove 13625, the limiting groove 13625 is opened in the limiting ring 13626, and the limiting ring 13626 is installed in the shell 13611.

[0058] The linkage structure 1363 includes a swivel 13631, which is rotatably mounted on the right side of the housing 13611, and the inner side of the swivel 13631 is rotatably connected to the outer side of the left side of the docking tube 13613, and docking shafts 13632 are laterally inserted at the upper and lower ends of the left side of the swivel 13631, and the docking shafts 13632 on both sides are respectively connected to the upper and lower ends of the right side of the gear ring 13624, so that when the gear ring 13624 rotates, the rotation of the swivel 13631 can be synchronously realized through the docking effect of the docking shafts 13632 on both sides, and the swivel 13631 can be driven by the rotation. A fixing plate 13633 is fixed to the upper and lower sections of the right side of the ring 13631, and a connecting rod 13634 is horizontally inserted into the fixing plate 13633 corresponding to the side away from the rotating ring 13631, and the connecting rod 13634 is fixed to the vertical plate 13635 at one end away from the fixing plate 13633, and the vertical plate 13635 is connected to the third bevel gear 13636 at the side away from the connecting rod 13634, and the third bevel gear 13636 is meshedly connected with the fourth bevel gear 13637 on the outside, and the fourth bevel gear 13637 is locked with the middle part of one side of the partition 134.

[0059] Among them, the third bevel gear 13636 is symmetrically arranged along the fourth bevel gear 13637, and the third bevel gears 13636 on both sides are respectively connected to the brush bar 1364 and the rolling wheel 1365.

[0060] Specifically, when the rotating drum 132 rotates and reciprocates left and right, the synchronous rotation and reciprocating movement of the connecting sleeve 13621 connected to the middle part of the right side can be realized, and when the connecting sleeve 13621 is in a rotating activity, it can drive the rotation of the main gear 13622 connected to the right side, and thereby mesh with the sub-gear 13623 connected to the upper and lower ends of the transmission, so that the sub-gears 13623 on both sides can realize the meshing rotation of the externally connected gear ring 13624. When the gear ring 13624 is in a rotating state, the rotating ring 13631 connected to the right side of the gear ring 13624 through the connecting shafts 13632 on both sides can rotate synchronously with the gear ring 13624, and as the rotating ring 13631 rotates, the fixed plate 13633 fixed to the upper and lower ends of the right side of the rotating ring 13631 will be combined with the plug-in rod 13634 plugged in the inside, so that the vertical shafts 13632 and the vertical shafts 13632 on both sides can rotate synchronously with ... The third bevel gear 13636 connected to the plate 13635 correspondingly makes the third bevel gears 13636 on both sides revolve and rotate along the outside of the fourth bevel gear 13637 fixedly installed, thereby, the brush strips 1364 and the rolling wheel 1365 respectively connected to the outer ends of the third bevel gears 13636 on both sides can not only revolve and rotate, but also rotate and rotate, so that the material that has been partially pre-ground but has not passed through the partition 134 can be swept away and the material is further ground by the reciprocating brushing of the brush strips 1364 and the auxiliary rotation grinding of the rolling wheel 1365, so that the pre-treated material can pass through the partition 134 and enter the right side of the ball mill 3 to cooperate with the steel ball 7 provided on the right side of the ball mill 3 to carry out ball milling, so that the material pre-grinding effect and the anti-blocking cooperation of the partition 134 can be strengthened;

[0061] Secondly, when the rotating drum 132 reciprocates left and right, the reciprocating pulling of the connecting sleeve 13621 can also be realized. When the connecting sleeve 13621 reciprocates, the movement of the externally connected shell 13611 can be realized synchronously, and the shell 13611 can be stably reciprocated left and right through the right-side telescopic combination of the docking tube 13613 and the positioning tube 13614. Through the coordination of the telescopic state, the transmission process of the rotation displacement component 133 can be avoided from being blocked. At the same time, because the plug-in rod 13634 is laterally plugged into the outside of the fixed plate 13633, the shell 13611 can drive the swivel 13631 to reciprocate left and right, while it can still ensure the stable realization of the revolution and rotation activities of the third bevel gears 13636 on both sides, so that the pre-grinding activities can be realized efficiently and stably.

[0062] The above description is only a preferred example of the present invention and is not intended to limit the present invention. Although the present invention is described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. 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

1. A method for preparing a silicon nitride conductive ceramic material, characterized in that: The steps include: S1. Raw material mixing and ball milling: silicon nitride powder, sintering aid and resistance adjusting agent are added into a ball mill in proportion, anhydrous ethanol is used as solvent, the speed is 200-300r / min, and the ball milling is performed for 10-12h to obtain a uniformly mixed slurry; the sintering aid is composed of a ternary composite of yttrium oxide, aluminum oxide and magnesium oxide, and the mass ratio of yttrium oxide, aluminum oxide and magnesium oxide is 5:2:3, and the sintering aid is doped with 0.5% rare earth elements; the resistance adjusting agent includes a titanium nitride-titanium dioxide core-shell structure and silicon carbide fibers, and the silicon carbide fibers are arranged in a magnetic field-oriented distribution; S2. Slurry molding: The slurry is made into a green blank by dry pressing or injection molding, and then dried at 70-80℃ for 8-10h; S3, spark plasma sintering: placing the green blank into a sintering furnace, heating it to 1600-1800°C at 200°C / min and keeping it at that temperature for 10-20min to obtain silicon nitride conductive ceramics; S4. Directional control of the conductive network: During the sintering process of the green embryo, a 0.5-1T axial magnetic field is applied to align the conductive fibers inside the resistor along the direction of the magnetic field to form a longitudinal conductive path; S5. Post-processing and performance optimization: The silicon nitride conductive ceramic obtained after sintering is immersed in the graphene and epoxy resin composite liquid to fill the micropores on its surface. Finally, it is finalized through steps such as edge grinding, grinding, ultrasonic cleaning, drying, and laser cutting.

2. The method for preparing a silicon nitride conductive ceramic material according to claim 1, characterized in that: The ball mill used in step S1 comprises a support (1), bearings (2) are installed on both sides of the upper end of the support (1), a ball mill (3) is connected between the bearings (2) on both sides, the left side of the ball mill (3) is connected to a feed pipe (4), the outside of the feed pipe (4) is connected to a storage box (5), a feed auger (6) is installed inside the feed pipe (4), and one side of the feed auger (6) is connected to the inside of the ball mill (3), a steel ball (7) is placed inside the ball mill (3), and the ball mill A discharge auger (8) is installed inside the right side of the cylinder (3), and a discharge pipe (9) is provided on the right side of the ball mill cylinder (3). A large gear (10) is installed outside the right side of the ball mill cylinder (3), and a small gear (11) is meshed with the front side of the large gear (10). The right side of the middle of the small gear (11) is connected to a motor (12), and the motor (12) is installed on the right side of the front end of the bracket (1). A pre-grinding device (13) is provided on the left side of the inside of the ball mill cylinder (3), and the pre-grinding device (13) is connected to one side of the feed auger (6).

3. The method for preparing a silicon nitride conductive ceramic material according to claim 2, characterized in that: The pre-grinding device (13) comprises a connecting shaft (131), the connecting shaft (131) being connected to one side of a feed auger (6), a rotating drum (132) being installed on the outside of one side of the connecting shaft (131), a rotating displacement assembly (133) being installed inside the rotating drum (132), and the rotating displacement assembly (133) being connected to one end of the connecting shaft (131), the rotating displacement assembly (133) being connected to a partition (134) on a side away from the connecting shaft (131), and the partition (134) being installed inside the ball mill (3), grinding plates (135) being installed on both sides of the outer end of the rotating displacement assembly (133), the right side of the rotating drum (132) being connected to an auxiliary assembly (136), a locking rod (137) being fixedly provided in the middle of the right side of the partition (134), and the right side of the locking rod (137) being connected to an outer bolt of a discharge pipe (9).

4. The method for preparing a silicon nitride conductive ceramic material according to claim 3, characterized in that: The rotation displacement assembly (133) comprises a first bevel gear (1331), the first bevel gear (1331) is mounted inside the rotating drum (132), and a support rod (1332) is fixedly provided on one side of the middle part of the first bevel gear (1331), and one end of the support rod (1332) away from the first bevel gear (1331) is locked and connected to the middle part of the partition (134), the upper end of the first bevel gear (1331) is meshingly connected with the second bevel gear (1333), and the second bevel gear (1333) is rotationally connected to the outside of the connecting shaft (131), and the upper end of the second bevel gear (1333) is plugged with a pin shaft (1334), and the pin shaft (1334) is inserted into the inside of the docking groove (1335), and the docking groove (1335) is arranged inside the connecting ring (1336), and the connecting ring (1336) is mounted inside the rotating drum (132).

5. The method for preparing a silicon nitride conductive ceramic material according to claim 3, characterized in that: The auxiliary component (136) comprises a protective shell (1361), the protective shell (1361) being arranged on the outside of one end of the rotating drum (132), a driving structure (1362) being installed inside the protective shell (1361), and one side of the driving structure (1362) is connected to the rotating drum (132), and the side of the driving structure (1362) away from the rotating drum (132) is connected to a linkage structure (1363), one end of the linkage structure (1363) is connected to a brush strip (1364), and the other end of the linkage structure (1363) is connected to a rolling wheel (1365), and the linkage structure (1363) is connected to the right side of the protective shell (1361).

6. The method for preparing a silicon nitride conductive ceramic material according to claim 5, characterized in that: The protective shell (1361) comprises a shell (13611), a fixed shaft (13612) is fixedly inserted into one side of the shell (13611), a butt joint tube (13613) is butt jointed in the middle of the right side of the shell (13611), and a positioning tube (13614) is slidably installed inside the butt joint tube (13613), and the right side of the positioning tube (13614) is fixed to the partition (134).

7. The method for preparing a silicon nitride conductive ceramic material according to claim 6, characterized in that: The driving structure (1362) comprises a connecting sleeve (13621), wherein the connecting sleeve (13621) is connected to the middle part of the left side of the housing (13611), and the left side of the connecting sleeve (13621) is locked and connected to the rotating drum (132), the connecting sleeve (13621) is inserted into the middle part of the main gear (13622), the main gear (13622) is meshedly connected to the outside of the secondary gear (13623), and the middle part of the secondary gear (13623) is connected to the fixed shaft (13612), the secondary gear (13623) is meshedly connected to the outside of the secondary gear (13624), and the outside of the secondary gear (13624) is embedded in the inside of the limiting groove (13625), the limiting groove (13625) is arranged inside the limiting ring (13626), and the limiting ring (13626) is installed inside the housing (13611).

8. The method for preparing a silicon nitride conductive ceramic material according to claim 7, characterized in that: The linkage structure (1363) comprises a rotating ring (13631), the rotating ring (13631) is rotatably mounted on the right side of the housing (13611), a docking shaft (13632) is plugged into one side of the rotating ring (13631), and the docking shaft (13632) is connected to the outside of the gear ring (13624), and a fixing plate (13633) is fixedly provided on the upper and lower sides of one end of the rotating ring (13631), and the outer end of the fixing plate (13633) is connected to the plug-in rod (13624). The plug-in rod (13634) is plugged with the fixing plate (13633), one end of the plug-in rod (13634) away from the fixing plate (13633) is fixed to the vertical plate (13635), the side of the vertical plate (13635) away from the plug-in rod (13634) is connected to the third bevel gear (13636), the third bevel gear (13636) is meshedly connected with the fourth bevel gear (13637) on the outside, and the fourth bevel gear (13637) is locked with the middle part of one side of the partition plate (134).

9. A silicon nitride conductive ceramic material, according to the method for preparing a silicon nitride conductive ceramic material according to any one of claims 1 to 8, characterized in that: Calculated by mass percentage, the raw materials of silicon nitride ceramics are: sintering aid 5%-8%, resistance adjuster 5%-10% and silicon nitride powder 82%-90%.

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