Apparatus and method for preparing black alumina ceramic substrate with high mechanical and breakdown strength

Abstract

The application discloses a high-mechanical and high-breakdown-strength black alumina ceramic substrate preparation device and method, relates to the technical field of ceramic substrate preparation, and comprises an outer cylinder and a support for mounting the outer cylinder. A driving element for driving the rotation of the outer cylinder is mounted on the support. The inner part of the outer cylinder is provided with grinding balls of different sizes. A plurality of separation seats are arranged in a ring shape on the inner wall of the outer cylinder around the axis of the outer cylinder. A reset groove for accommodating a separation arc plate is formed in each separation seat. The application has adjustable grinding ball distribution control, significantly improves the uniformity and grinding efficiency of black alumina ceramic slurry, solves the core problems of low efficiency, high pollution and poor uniformity in traditional ball milling, and makes the color of the substrate uniform after sintering. Different sizes of grinding balls can be discharged according to the requirements of nodular cast iron, the nodular cast iron effect is improved, the composition uniformity of the black alumina ceramic substrate is improved, and problems such as agglomeration and pollution can be effectively avoided, so that the substrate can meet the requirements of high mechanical strength and high insulation at the same time.

Description

Technical Field

[0001] This invention relates to the field of ceramic substrate preparation technology, and particularly to an apparatus and method for preparing black alumina ceramic substrates with high mechanical strength and breakdown strength. Background Technology

[0002] In the preparation of black alumina ceramic substrates with high mechanical properties and high breakdown strength, ball milling is a key step that affects powder uniformity, sintering activity and final performance.

[0003] Black colorants (such as CoFe2O4, Cr2O3, etc.) vary in density (e.g., Al2O3 has a density of 3.95 g / cm³). 3 CoFe₂O₄ density 5.3 g / cm³ 3 It is easy to settle, leading to local enrichment. When grinding balls of different sizes are used together during the ball milling process, the particle size after ball milling will be uneven, resulting in low efficiency, high pollution and poor uniformity in ball milling, and uneven color of the substrate after sintering. Summary of the Invention

[0004] The purpose of this invention is to provide an apparatus and method for preparing black alumina ceramic substrates with high mechanical strength and breakdown strength. It features adjustable grinding ball distribution control, which significantly improves the uniformity and grinding efficiency of black alumina ceramic slurry. It solves the core problems of low efficiency, high pollution and poor uniformity in traditional ball milling, and has the advantage of uniform substrate color after sintering.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a device for preparing a black alumina ceramic substrate with high mechanical strength and breakdown strength, comprising an outer cylinder and a bracket for mounting the outer cylinder, wherein a driving component for rotating the outer cylinder is mounted on the bracket, and grinding balls of different sizes are arranged inside the outer cylinder, and a number of partition seats are arranged in a ring around its axis on the inner wall of the outer cylinder, and each partition seat is provided with a return groove for accommodating a partition arc plate.

[0006] When the outer cylinder is stationary, grinding balls are respectively arranged between the partition seats, and the partition arc plate can rotate around the axis of the outer cylinder in the return groove to adjust the opening distance between two adjacent partition seats.

[0007] Furthermore, the outer cylinder is axially connected to the support at both ends, and a feed inlet is provided on the outer surface of the outer cylinder, with a sealing door provided on the feed inlet.

[0008] Furthermore, one end of the partition arc plate is connected to a linkage ring, and an external gear is provided on the linkage ring. One end of the outer cylinder is provided with a drive assembly, which is connected to the external gear.

[0009] Further, the partition seat is provided with an extension plate, the extension plate is provided with a linkage gear connected with an axis, and the surface of the partition arc plate is provided with an arc-shaped tooth groove meshing with the linkage gear.

[0010] Further, one end of the partition arc plate is a U-shaped end, and the U-shaped end is connected with the reset groove through a spring.

[0011] Further, one end of the outer cylinder body is provided with a center plate through a bearing, the center plate is provided with an extendable shaft rod, and the shaft rod is provided with two arc-shaped teeth.

[0012] Further, the two arc-shaped teeth are movably meshed with the linkage gear, and the bracket is provided with a driver capable of driving the center plate to rotate.

[0013] The application also provides a preparation method of black alumina ceramic substrate with high mechanical strength and breakdown strength, comprising the following steps:

[0014] S1: mixing alpha-alumina powder with purity ≥ 99.5%, black colorant, sintering aid and dispersant, wherein the black colorant is at least one of spinel CoFe2O4 or MnFe2O4, the addition amount is 2-5wt%, the sintering aid is MgO-SiO2-CaO system, and the addition amount is 0.5-2wt%;

[0015] S2: ball milling the mixed powder with organic solvent, binder and plasticizer to prepare uniform slurry, and the ball milling time is ≥ 12 hours;

[0016] S3: preparing a green body by using flow casting or dry pressing, the thickness of the green body prepared by flow casting is 0.1-1mm, and the pressure of the green body prepared by dry pressing is 100-200MPa;

[0017] S4: heating at a rate of 1-2℃ / min to 600℃, and keeping the temperature for 2 hours to remove organic matter;

[0018] S5: pre-sintering at 1200-1400℃ for 2 hours, and then sintering at 1500-1650℃ in hydrogen or vacuum environment for 1-3 hours;

[0019] S6: heat isostatic pressing the sintered body under the condition of 1600℃, 100-200MPa Ar atmosphere and keeping the temperature for 1 hour.

[0020] Further, the black colorant is Cr2O3 and MnO2 compounded and doped at a mass ratio of 1:1, and the total addition amount is 3-6wt%, and the mass ratio of MgO, SiO2 and CaO in the sintering aid is 1:1:0.5.

[0021] Further, in the sintering process, the grain size is controlled to be less than 5 μm, the porosity of the final ceramic substrate is less than 0.5%, and after static pressure treatment, the substrate surface needs to be polished, and the substrate surface roughness is controlled to be less than 0.1 μm by using diamond grinding fluid.

[0022] Technical effects and advantages of the present application:

[0023] 1、The separation arc plate can rotate around the outer cylinder axis in the reset groove, and is used for adjusting the opening spacing between two adjacent separation seats, and the adjustable grinding ball distribution control can significantly improve the uniformity and grinding efficiency of black alumina ceramic slurry, the grinding balls are partitioned according to size through the separation seat, the problem of uneven grinding efficiency caused by mixing of large and small grinding balls in traditional ball milling is avoided, the opening size between adjacent separation seats can be adjusted by rotating the separation arc plate, the movement range of the grinding ball is flexibly controlled, a pressure sensor and a temperature probe are embedded in the inner wall of the outer cylinder, and the slurry viscosity and temperature are fed back in real time, and the rotation speed and cooling rate of the driving member are automatically adjusted, the device solves the core problems of low efficiency, high pollution and poor uniformity in traditional ball milling through dynamic partition grinding and intelligent control, the color of the sintered substrate is uniform, and reliable equipment support is provided for industrial production of high-performance ceramic substrates.

[0024] 2、The driving assembly can drive the separation arc plate to rotate in the reset groove, so as to adjust the opening spacing between two adjacent separation seats, the separation arc plate can be controlled to rotate out of the spacing according to needs, different sizes of grinding balls can be discharged according to the needs of the nodular cast iron, the effect of the nodular cast iron is improved, the composition uniformity of the black alumina ceramic substrate is improved, and problems such as agglomeration and pollution can be effectively avoided, so that the substrate can meet the requirements of high mechanical strength and high insulation at the same time.

[0025] 3、The arc-shaped teeth groove is arranged on each separation arc plate, when the separation arc plate moves to the discharging position, the opening is realized by driving the arc-shaped teeth, when the separation arc plate rotates to be separated from the discharging position, the separation arc plate is automatically reset, the opening between two adjacent separation seats is closed, the material and the grinding ball can be uniformly contacted in the closed state of the outer cylinder, the problem of difficult discharge of the material is solved while the ball separation ball milling is realized, and the grinding efficiency is improved. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a schematic diagram of the overall structure of the present application;

[0027] Figure 2 It is a half sectional view of the outer cylinder structure of the present application;

[0028] Figure 3 It is a half sectional view of the outer cylinder structure of the present application;

[0029] Figure 4 It is a split structure schematic diagram of the separation seat and the separation arc plate of the present application;

[0030] Figure 5 Fig. 2 is a schematic diagram of the overall structure of the second embodiment of the present application;

[0031] Figure 6 Fig. 3 is a schematic diagram of the internal structure of the outer cylinder of the second embodiment of the present application;

[0032] Figure 7 Fig. 4 is an enlarged view of A of the second embodiment of the present application; Figure 6

[0033] Figure 8 Fig. 5 is a plan view of the interface between the partition seat and the partition arc plate of the second embodiment of the present application.

[0034] In the drawings:

[0035] 1, outer cylinder; 11, support; 12, driving member; 13, grinding ball; 14, feed inlet; 141, closing door; 2, partition seat; 21, partition arc plate; 211, arc-shaped tooth groove; 22, reset groove; 23, linkage ring; 231, external gear; 24, driving assembly; 25, extension plate; 251, linkage gear; 3, center plate; 31, shaft; 32, arc-shaped tooth. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0037] Embodiment 1: Refer to Figure 1 - Figure 4 ​For the first embodiment of the present application, a device for preparing black alumina ceramic substrate with high mechanical strength and breakdown strength is provided, which comprises an outer cylinder 1 and a support 11 for mounting the outer cylinder 1, a driving member 12 mounted on the support 11 for driving the rotation of the outer cylinder 1, a plurality of grinding balls 13 of different sizes arranged in the inner part of the outer cylinder 1, a plurality of partition seats 2 arranged in a ring around the axis of the outer cylinder 1 on the inner wall of the outer cylinder 1, a reset groove 22 for accommodating a partition arc plate 21 formed in each partition seat 2, the grinding balls 13 being arranged between the partition seats 2 in the stationary state of the outer cylinder 1, and the partition arc plate 21 being rotatable in the reset groove 22 around the axis of the outer cylinder 1 for adjusting the opening distance between two adjacent partition seats 2. The adjustable grinding balls 13 distribution control significantly improves the uniformity and grinding efficiency of the black alumina ceramic slurry. The grinding balls 13 are partitioned by the partition seats 2 according to size, avoiding the problem of uneven grinding efficiency caused by the mixing of grinding balls 13 of different sizes in traditional ball milling. The partition arc plate 21 can be rotated to adjust the opening size between adjacent partition seats 2, and the movement range of the grinding balls 13 can be flexibly controlled. A pressure sensor and a temperature probe are embedded in the inner wall of the outer cylinder 1 to provide real-time feedback on the viscosity and temperature of the slurry, and the speed of the driving member 12 and the cooling rate are automatically adjusted. This device solves the core problems of low efficiency, high pollution, and poor uniformity in traditional ball milling through dynamic partition grinding and intelligent control, and provides reliable equipment support for the industrial production of high-performance ceramic substrates.

[0038] The outer cylinder 1 is axially connected to the support 11, and a feeding port 14 is formed on the outer surface of the outer cylinder 1. A closing door 141 is arranged on the feeding port 14 and can be opened and closed to realize the feeding and discharging of materials.

[0039] One end of the partition arc plate 21 is connected to a linkage ring 23, and an external gear 231 is arranged on the linkage ring 23. A driving assembly 24 is arranged at one end of the outer cylinder 1, and the driving assembly 24 is in butt joint with the external gear 231. The driving assembly 24 comprises a motor and a gear combination, and can drive the partition arc plate 21 to rotate in the reset groove 22, thereby adjusting the opening distance between two adjacent partition seats 2. The partition arc plate 21 can be rotated out of the distance as needed to control the discharge of grinding balls 13 of different sizes, improve the nodularity effect, and make the composition of the black alumina ceramic substrate uniform. This can effectively avoid problems such as agglomeration and pollution, and ensure that the substrate meets the requirements of high mechanical strength and high insulation at the same time.

[0040] Specifically, when small size grinding ball 13 is needed for nodulizing, the motor drives the outer gear 231 and the linkage ring 23 to rotate through the gear, rotates the separation arc plate 21 out of the reset groove 22, closes a part of the opening between the two adjacent separation seats 2, and only allows small size grinding ball 13 to pass through the opening between the two adjacent separation seats 2, so that the small size grinding ball 13 falls from the opening to finely nodulize the material in the outer cylinder 1. When large size grinding ball 13 is needed for nodulizing, the separation arc plate 21 is rotated into the reset groove 22, the opening between the two adjacent separation seats 2 is opened, and the opening can meet the falling of large size grinding ball 13, so that the nodulizing is realized by different sizes.

[0041] Embodiment two: refer to Figure 5 - Figure 8 For the second embodiment of the application, which is different from the first embodiment, it is found in the implementation process of embodiment one that when the separation arc plate 21 closes a part of the opening between the two adjacent separation seats 2, the material is easy to enter between the separation seats 2, resulting in poor discharge of the material.

[0042] In order to solve the above problems, the embodiment is provided with an arc-shaped tooth groove 211 on each separation arc plate 21, which is driven by the arc-shaped teeth 32 to open when the separation arc plate 21 moves to the discharging position, and the separation arc plate 21 is automatically reset when it rotates away from the discharging position, so as to close the opening between the two adjacent separation seats 2 and make the outer cylinder 1 in a closed state, so that the material and the grinding ball 13 can be uniformly contacted, the problem of poor discharge of the material is solved while the ball grinding is realized, and the grinding efficiency is improved.

[0043] The extension plate 25 is arranged on the partition seat 2, the linkage gear 251 is arranged on the extension plate 25 through the shaft, the arc-shaped tooth groove 211 is arranged on the surface of the partition arc plate 21 and meshes with the linkage gear 251, one end of the partition arc plate 21 is a U-shaped end, the U-shaped end is butted to the reset groove 22 through the spring, the outer cylinder body 1 is provided with the center plate 3 through the bearing at one end, the shaft rod 31 capable of stretching and retracting is arranged on the center plate 3, the two arc-shaped teeth 32 are arranged on the shaft rod 31 and movably mesh with the linkage gear 251, the driver capable of driving the center plate 3 to rotate is arranged on the support 11, the partition arc plate 21 can automatically pop out through the spring, in the initial state, the partition arc plate 21 is extended to completely close the opening between two adjacent partition seats 2, so that the material is prevented from entering between the partition seats 2 and the grinding dead angle is avoided, and through the arrangement of the two arc-shaped teeth 32, the retraction degree of the partition arc plate 21 can be adjusted according to the length of the arc-shaped tooth 32 at the discharging position, the size of the falling grinding ball 13 can be adjusted according to the need of the ball mill, it should be noted that the arc-shaped tooth 32 can be provided with multiple sections according to the need, different lengths of the arc-shaped tooth 32 are arranged, so that the size of the opening between the adjacent partition seats 2 is adjusted, when the ball mill is completed and the material is discharged, the center plate 3 is driven to rotate through the driver, then the arc-shaped tooth 32 is rotated to the lower side of the outer cylinder body 1, when the partition arc plate 21 is rotated to the lower side of the outer cylinder body 1, the linkage gear 251 meshes with the arc-shaped tooth 32, then the partition arc plate 21 is driven to retract into the reset groove 22 at the lower side of the outer cylinder body 1, at this time, the grinding ball 13 in the outer cylinder body 1 falls into the opening between the partition seats 2, the pre-storage of the grinding ball 13 is completed, when the arc-shaped tooth 32 needs to be adjusted, the shaft rod 31 is moved through the cylinder drive, so that the arc-shaped tooth 32 with different lengths is aligned with the linkage gear 251.

[0044] Embodiment three: the third embodiment of the present application provides a preparation method of black alumina ceramic substrate with high mechanical strength and breakdown strength, comprising the following steps:

[0045] S1: mixing α-alumina powder with purity ≥ 99.5%, black colorant, sintering aid and dispersant, wherein the black colorant is at least one of spinel CoFe2O4 or MnFe2O4, the addition amount is 2-5wt%, the sintering aid is MgO-SiO2-CaO system, and the addition amount is 0.5-2wt%;

[0046] S2: ball milling the mixed powder with organic solvent, binder and plasticizer to prepare uniform slurry, the ball milling time is ≥ 12 hours;

[0047] S3: preparing green body by tape casting or dry pressing, the thickness of the green body prepared by tape casting is 0.1-1mm, and the dry pressing pressure is 100-200MPa;

[0048] S4: removing organic matter by increasing the temperature to 600℃ at 1-2℃ / min and keeping for 2 hours;

[0049] S5: first pre-sintering at 1200-1400℃ for 2 hours, and then sintering at 1500-1650℃ in hydrogen or vacuum environment for 1-3 hours;

[0050] S6: hot isostatic pressing treatment of the sintered body under the conditions of 1600℃, 100-200MPa Ar atmosphere, and heat preservation for 1 hour.

[0051] The black colorant is Cr2O3 and MnO2 compounded and doped at a mass ratio of 1:1, and the total addition amount is 3-6wt%, and the mass ratio of MgO, SiO2 and CaO in the sintering aid is 1:1:0.5.

[0052] During the sintering process, the grain size is controlled to be less than 5μm, the porosity of the final ceramic substrate is less than 0.5%, and after the static pressure treatment, the substrate surface needs to be polished, and the diamond grinding liquid is used to control the substrate surface roughness to be less than 0.1μm.

[0053] Finally, it should be noted that: the above only for the preferred embodiments of the present application, and not for limiting the present application, although the foregoing embodiments of the present application are described in detail, for those skilled in the art, it still can be modified, or part of the technical features of the equivalent replacement, within the spirit and principles of the present application, any modification, equivalent replacement, improvement, etc., should be included in the protection scope of the present application.

Claims

1. A device for preparing a black alumina ceramic substrate with high mechanical strength and breakdown strength, comprising an outer cylinder (1) and a bracket (11) for mounting the outer cylinder (1), wherein a driving component (12) for driving the outer cylinder (1) to rotate is mounted on the bracket (11), characterized in that, The outer cylinder (1) is provided with grinding balls (13) of different sizes inside. Several partition seats (2) are arranged in a ring around its axis on the inner wall of the outer cylinder (1). Each partition seat (2) is provided with a return groove (22) to accommodate the partition arc plate (21). In the static state of the outer cylinder (1), grinding balls (13) are respectively arranged between the partition seats (2), and the partition arc plate (21) can rotate around the axis of the outer cylinder (1) in the return groove (22) to adjust the opening distance between two adjacent partition seats (2); One end of the partition arc plate (21) is connected to a linkage ring (23), and an external gear (231) is provided on the linkage ring (23). One end of the outer cylinder (1) is provided with a drive assembly (24), and the drive assembly (24) is connected to the external gear (231). The partition seat (2) is provided with an extension plate (25), and a linkage gear (251) is shaft-connected to the extension plate (25). The surface of the partition arc plate (21) is provided with an arc-shaped tooth groove (211) that meshes with the linkage gear (251). One end of the dividing arc plate (21) is a U-shaped end, which is connected to the return groove (22) by a spring. One end of the outer cylinder (1) is equipped with a center plate (3) through a bearing. The center plate (3) is provided with a telescopic shaft (31). Two arc-shaped teeth (32) are installed on the shaft (31). The two arc-shaped teeth (32) are in active engagement with the linkage gear (251). The bracket (11) is provided with a driver that can drive the center plate (3) to rotate.

2. The apparatus for preparing a black alumina ceramic substrate with high mechanical strength and breakdown strength according to claim 1, characterized in that, The outer cylinder (1) is axially connected to the support (11) at both ends. The outer surface of the outer cylinder (1) is provided with a feed inlet (14) and a closed door (141) is provided on the feed inlet (14).

3. A method for preparing a black alumina ceramic substrate with high mechanical strength and breakdown strength, wherein the method is applied to the apparatus for preparing a black alumina ceramic substrate with high mechanical strength and breakdown strength as described in claim 1, characterized in that: Includes the following steps: S1: Mix α-alumina powder with a purity ≥99.5%, a black colorant, a sintering aid, and a dispersant, wherein the black colorant is at least one of spinel-type CoFe2O4 or MnFe2O4, with an addition amount of 2-5wt%, and the sintering aid is a MgO-SiO2-CaO system, with an addition amount of 0.5-2wt%; S2: The mixed powder is ball-milled with organic solvent, binder and plasticizer to form a uniform slurry, with a ball-milling time of ≥12 hours; S3: Green blanks are prepared by casting or dry pressing. The thickness of the casting green blank is 0.1-1mm, and the dry pressing pressure is 100-200MPa. S4: Heat to 600℃ at 1-2℃ / min and hold for 2 hours to remove organic matter; S5: First, pre-fire at 1200-1400℃ for 2 hours, then sinter at 1500-1650℃ in a hydrogen or vacuum environment for 1-3 hours; S6: Perform hot isostatic pressing on the sintered body under the conditions of 1600℃, 100-200MPa Ar atmosphere, and hold for 1 hour.

4. The method for preparing a black alumina ceramic substrate with high mechanical and breakdown strength according to claim 3, characterized in that, The black colorant is a composite doping of Cr2O3 and MnO2 in a 1:1 mass ratio, with a total addition amount of 3-6 wt%. The sintering aid has a mass ratio of MgO, SiO2, and CaO of 1:1:0.

5.

5. The method for preparing a black alumina ceramic substrate with high mechanical strength and breakdown strength according to claim 4, characterized in that, During the sintering process, the grain size is controlled to be <5μm, and the porosity of the final ceramic substrate is <0.5%. After static pressing, the substrate surface needs to be polished. Diamond polishing fluid is used to control the surface roughness of the substrate to Ra <0.1μm.

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