Preparation method of high-purity large-size aluminum oxide ceramic ring material

Abstract

The invention discloses a preparation method of a high-purity large-size aluminum oxide ceramic ring material, which comprises the following steps: filling aluminum oxide finished product powder into an annular forming mold, carrying out cold isostatic pressing to obtain a ring column green body, machining the ring column green body into a plurality of aluminum oxide ceramic ring green bodies, and stacking m layers of coaxial aluminum oxide ceramic ring green bodies on a setter plate, the bottom-layer aluminum oxide ceramic circular ring green body and the load bearing plate as well as any two adjacent aluminum oxide ceramic circular ring green bodies are separated through n rectangular gaskets which are uniformly distributed in the circumferential direction, and then sintering is performed to obtain the large-size aluminum oxide ceramic ring material which is high in purity, compact and complete in appearance. According to the method, the n rectangular gaskets are accurately and uniformly distributed in the circumferential direction, and it is ensured that sufficient flame paths which are uniformly distributed in the circumferential direction can be formed, so that the heating uniformity of the aluminum oxide ceramic circular ring green body is improved, and the phenomenon that the aluminum oxide ceramic circular ring green body deforms or cracks in the sintering process is effectively avoided.

Description

Technical Field

[0001] The invention relates to the technical field of large-size ceramic ring material preparation, and in particular to a method for preparing high-purity large-size alumina ceramic ring material. Background Art

[0002] Most of the components in semiconductor equipment are ceramic components, which are usually made of high-purity, ultra-fine inorganic materials. Alumina ceramic products are used in the vast majority of semiconductor ceramic components because of their good high temperature resistance, corrosion resistance, plasma erosion resistance and other properties.

[0003] At present, alumina sheets widely used in the semiconductor industry are usually prepared using high-purity alumina materials with a purity greater than 99.5%, and the products are precision ceramic parts. At this stage, the gap in the preparation of ceramic devices for domestic semiconductor equipment has been supplemented to a certain extent, and some sheet products can be produced in-house. However, some products still have some problems; especially large-sized annular alumina ceramics, due to uneven heating during sintering, it is easy to cause appearance defects such as shape distortion, ellipticalization, cracking after shrinkage, and poor density of ceramic products, which directly affects the promotion and application of large-sized annular alumina ceramic products. Therefore, it is urgent to develop a preparation method for large-sized annular alumina ceramics to improve the uniformity of heating during sintering and avoid the aforementioned related defects. Summary of the invention

[0004] In view of the deficiencies in the prior art, the present invention discloses a method for preparing a high-purity large-size alumina ceramic ring material, thereby solving or at least alleviating one or more of the above-mentioned problems and other problems in the prior art.

[0005] The present invention discloses a method for preparing a high-purity large-size alumina ceramic ring material, comprising the following steps:

[0006] S1, using finished alumina powder as raw material;

[0007] S2, filling the finished aluminum oxide powder into the annular forming mold for primary filling, and vibrating and compacting the finished aluminum oxide powder in the annular forming mold; then filling the annular forming mold with the finished aluminum oxide powder for secondary filling, and vibrating and compacting the finished aluminum oxide powder in the annular forming mold again;

[0008] S3, sealing the annular forming mold after the secondary filler is vibrated and compacted;

[0009] S4, transferring the sealed annular forming mold to a cold isostatic press for cold isostatic pressing to obtain a ring column green body;

[0010] S5, machining the ring column green body into a plurality of alumina ceramic circular ring green bodies; machining the remaining ring column green body edge material into a plurality of rectangular gaskets;

[0011] S6, lay n rectangular gaskets evenly distributed in the circumferential direction on the support plate, the n rectangular gaskets form a circular ring, and place a single piece of alumina ceramic circular ring green body on the n rectangular gaskets; lay n rectangular gaskets evenly distributed in the circumferential direction on the layer of alumina ceramic circular ring green body, and then place another piece of alumina ceramic circular ring green body on the layer of n rectangular gaskets; and overlap and place m layers of alumina ceramic circular ring green bodies with the same axial center line in this way;

[0012] S7, transferring the m layers of overlapping alumina ceramic ring green bodies and the support plates to a high-temperature sintering furnace for sintering, and obtaining large-sized alumina ceramic ring materials after cooling.

[0013] Preferably, in step S6, the center line of the rectangular gasket along its length direction is consistent with the radial direction of the alumina ceramic ring green body, and the rectangular gasket is arranged in the central area between the outer diameter and the inner diameter of the alumina ceramic ring green body; the ratio of the sum of the areas of n rectangular gaskets to the area of ​​the alumina ceramic ring green body is defined as the contact area ratio, and the contact area ratio is 50-80%.

[0014] Preferably, in step S7, the sintering process in the high temperature sintering furnace comprises the following steps:

[0015] S701, heating from room temperature to T1 130-175℃, time 11h, insulation time 4h;

[0016] S702, heating from T1 to T2 is 225-275℃, takes 11h, and the holding time is 4h;

[0017] S703, heating from T2 to T3 is 300-400℃, takes 11h, and the holding time is 8h;

[0018] S704, heating from T3 to T4 is 600-800℃, takes 15h, and the holding time is 4h;

[0019] S705, heating from T4 to T5 is 1000-1100℃, takes 20h, and keeps warm for 2h;

[0020] S706, heating from T5 to T6 is 1200-1300℃, takes 5h, and keeps warm for 4h;

[0021] S707, heating from T6 to T7 is 1400-1450℃, takes 6h, and keeps warm for 2h;

[0022] S708, heating from T7 to 1500℃, taking 3h, keeping warm for 2h;

[0023] S709, heating from 1500℃ to 1600℃, taking 3h, keeping warm for 4h;

[0024] S710, cooling from 1600℃ to 800℃ for 20h;

[0025] S711, cooling from 800℃ to 100℃, time is 41h;

[0026] S712, cool in the furnace from 100°C to room temperature.

[0027] Preferably, in step S6, the n rectangular gaskets are evenly arranged using a circumferential evenly distributed device;

[0028] The circumferentially uniformly distributed device includes a bearing ring, n limiting mechanisms, fan-shaped isolation plates of various specifications and sizes, and at least one supporting ring; the bearing ring is movably matched on the supporting ring coaxially with the center line, the n limiting mechanisms are all slidably matched on the bearing ring, and the n limiting mechanisms are circumferentially uniformly distributed on the bearing ring, and the limiting mechanisms are used to locate the position of the rectangular gasket on the alumina ceramic circular ring green body or the support plate;

[0029] The sector-shaped isolation plate is used to evenly arrange n limiting mechanisms circumferentially on the carrying ring;

[0030] The limiting mechanism includes a strip slider and two limiting rods connected to one end of the strip slider, the two limiting rods are arranged in parallel, and the length direction of the two limiting rods is parallel to the length direction of the strip slider; the strip slider slides along the circumferential direction of the load-bearing ring, and the length direction of the strip slider is consistent with the radial direction of the load-bearing ring; the two limiting rods are located in the inner ring area of ​​the load-bearing ring.

[0031] Preferably, the limiting mechanism also includes width limiting strips of various sizes, with a certain number of width limiting strips of each size, and a D-shaped through hole is provided on one side of the width limiting strip along its length direction; the cross-section of the limiting rod is D-shaped, and the width limiting strip can be mounted on the limiting rod of the limiting mechanism through its D-shaped through hole.

[0032] Preferably, the central angles of the sector-shaped isolation plates of different specifications and sizes are different;

[0033] The fan-shaped isolation plate is printed or written with numbers, and the numbers on the fan-shaped isolation plate correspond to the number of the limiting mechanisms arranged on the carrying ring.

[0034] Preferably, a pressure ring is provided on the carrying ring, and the pressure ring is connected to the carrying ring through a plurality of U-shaped pieces;

[0035] The outer edge of the carrying ring is provided with an upwardly protruding annular enclosure, and a side of the annular enclosure away from the carrying ring 1 is provided with an inwardly folded limiting ring, and an annular sliding groove between the limiting ring and the pressure ring;

[0036] The load-bearing ring, the annular enclosure, the limiting ring and the pressing ring together form an annular limiting groove, and the annular sliding groove is connected to the annular limiting groove;

[0037] One end of the strip sliding block away from the limiting rod is slidably fitted in the annular limiting groove; one end of the strip sliding block away from the limiting rod is provided with a locking bolt, and the screw rod of the locking bolt is slidably fitted in the annular sliding groove.

[0038] Preferably, the inner ring of the support ring is also provided with a plurality of center locators evenly distributed in the circumferential direction, the center locator comprising a telescopic plate and a baffle, the two ends of the telescopic plate are respectively connected to the baffle and the inner ring of the support ring, the length direction of the telescopic plate is consistent with the radial direction of the support ring, and the baffle is used to position and limit the alumina ceramic ring green body.

[0039] Preferably, in step S6, the process of arranging the rectangular gaskets and stacking the alumina ceramic ring green bodies comprises the following steps:

[0040] S601, determining the number n of rectangular gaskets according to the contact area ratio;

[0041] S602, draw an inner diameter line and an outer diameter line of the same size as the alumina ceramic circular ring green body on the setter plate; then draw a circular outer contour line A of the bearing ring and a circular outer contour line B of the support ring on the setter plate; make the inner diameter line, the outer diameter line, the circular outer contour line A and the circular outer contour line B coaxial with the axial center line;

[0042] S603, placing the support ring at a position corresponding to the circular outer contour line A on the setter plate, arranging n limiting mechanisms at designated positions on the support ring in a circumferentially uniform manner, with two limiting rods of the limiting mechanisms covering the inner diameter line and the outer diameter line, and placing a rectangular gasket in the middle of the area surrounded by the inner diameter line, the outer diameter line and every two limiting rods;

[0043] S604, take out the support ring and the n limiting mechanisms arranged on the support ring, place the support ring on the support plate, and make the circular outer contour of the support ring coincide with the circular outer contour line B of the support plate; then place the alumina ceramic ring green body placed on the bottom layer on the n rectangular gaskets on the support plate, and the inner diameter and outer diameter of the alumina ceramic ring green body coincide with the inner diameter line and outer diameter line on the support plate respectively;

[0044] S605, matching the taken-out carrying ring and the n limiting mechanisms arranged on the carrying ring to the supporting ring, wherein two limiting rods of each limiting mechanism are located above the alumina ceramic ring green body on the lower layer;

[0045] S606, placing rectangular gaskets in the middle of the inner diameter and outer diameter of the lower layer of the alumina ceramic annular green body and the area surrounded by the two limiting rods of each limiting mechanism, so as to complete the circumferential uniform arrangement of n rectangular gaskets on the lower layer of the alumina ceramic annular green body;

[0046] S607, take out the carrying ring and the n limiting mechanisms arranged on the carrying ring, place another supporting ring on the lower supporting ring; place another alumina ceramic ring green body on the n rectangular gaskets of the lower alumina ceramic ring green body;

[0047] S608, repeating steps S605, S606 and S607 until the number of stacked alumina ceramic ring green bodies reaches m layers and is coaxial with the center line;

[0048] S609, taking out all the support rings on the setter plate, and then completing the stacking and placing of m layers of alumina ceramic ring green bodies on the setter plate.

[0049] Preferably, in step S603, the arrangement process of n limiting mechanisms includes the following steps:

[0050] S6031. Determine the number n of the limiting mechanisms according to the number of rectangular gaskets;

[0051] S6032, slidingly fitting all n limiting mechanisms on the carrying ring, and selecting corresponding sector-shaped isolation plates according to the number of limiting mechanisms;

[0052] S6033, using one of the limiting mechanisms as the limiting mechanism at the first position, and locking the limiting mechanism on the carrying ring;

[0053] S6034. Place the selected fan-shaped isolation plate on the inner diameter line and the outer diameter line of the supporting plate, with a limit rod of the limit mechanism at the first position as the starting point; move the fan-shaped isolation plate to another limit rod of the limit mechanism at the n-1th position, so that a radial edge of the fan-shaped isolation plate contacts with another limit rod of the limit mechanism at the n-1th position; move the strip slider of the limit mechanism at the nth position, so that a limit rod of the limit mechanism at the nth position contacts with another radial edge of the fan-shaped isolation plate, and lock the limit mechanism at the nth position; in this way, the fan-shaped isolation plate is gradually moved and the limit mechanism is positioned, so that n limit mechanisms can be evenly distributed circumferentially on the supporting ring.

[0054] The present invention has the following beneficial effects:

[0055] The technical solution provides a method for preparing high-purity large-size alumina ceramic ring materials, wherein finished alumina powder is filled in an annular forming mold and a ring column green body is obtained by cold isostatic pressing, the ring column green body is machined into multiple alumina ceramic circular ring green bodies, and m layers of coaxial alumina ceramic circular ring green bodies are stacked on a firing plate, n circumferentially arranged rectangular gaskets are arranged between the bottom layer of alumina ceramic circular ring green bodies and the firing plate, and n circumferentially arranged rectangular gaskets are also arranged between any two adjacent alumina ceramic circular ring green bodies, and the rectangular gaskets are arranged in the center area between the outer diameter and the inner diameter of the alumina ceramic circular ring green bodies; then the firing plate and the m layers of alumina ceramic circular ring green bodies are sintered to obtain a high-purity, dense and well-shaped large-size alumina ceramic ring material. N rectangular gaskets are precisely and evenly distributed circumferentially in the central area between the outer diameter and the inner diameter of the alumina ceramic ring green body, ensuring that a sufficient number of fire channels with good circumferential uniform distribution can be formed, thereby improving the heating uniformity of the alumina ceramic ring green body and effectively avoiding deformation or cracking of the alumina ceramic ring green body during the sintering process. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] In order to more clearly illustrate the specific embodiments of the present disclosure, the following briefly introduces the drawings required for use in the specific embodiments. In all the drawings, each element or part is not necessarily drawn according to the actual scale.

[0057] Figure 1 This is an appearance diagram of a large-sized alumina ceramic ring material prepared in Examples 1-6 of the present invention;

[0058] Figure 2 This is an appearance diagram of a large-sized alumina ceramic ring material prepared in Comparative Examples 1-5 of the present invention;

[0059] Figure 3 A schematic diagram of a circumferentially uniformly distributed device arranging rectangular gaskets in one embodiment;

[0060] Figure 4 It is a schematic diagram of the structure of a circumferentially uniformly distributed device when arranging a multi-layer alumina ceramic ring green body in one embodiment;

[0061] Figure 5 This is a schematic diagram of the structure of the cooperation between a carrying ring and a plurality of supporting rings in one embodiment;

[0062] Figure 6 It is a schematic diagram of the structure of the cooperation between the carrying ring and multiple limiting mechanisms in one embodiment;

[0063] Figure 7 This is a schematic diagram of the structure of the C-shaped ring and the closed ring in one embodiment;

[0064] Figure 8 is a structural schematic diagram of a center locator in one embodiment;

[0065] Fig. 9 Schematic diagram of the structure of a limiting mechanism in one embodiment.

[0066] Reference numerals:

[0067] 1-Carrying ring;

[0068] 101-first annular protrusion, 102-second annular protrusion, 103-pressing ring, 104-U-shaped piece, 105-annular enclosure, 106-limiting ring, 107-annular sliding groove, 108-annular limiting groove, 109-C-shaped ring, 110-closing ring, 111-support ear;

[0069] 2-Limiting mechanism;

[0070] 201-strip slider, 202-limiting rod, 203-first groove, 204-second groove; 205-width limiting strip, 206-locking bolt;

[0071] 3-Support ring;

[0072] 301-first annular step, 302-second annular step, 303-annular groove, 304-telescopic plate, 305-baffle, 306-first plate body, 307-second plate body, 308-sliding cavity, 309-strip groove, 310-bolt;

[0073] 4- fan-shaped isolation plate;

[0074] 5-alumina ceramic ring green body;

[0075] 6-Rectangular spacer;

[0076] 7-Fire support plate. DETAILED DESCRIPTION

[0077] The following embodiments of the technical solution of the present disclosure are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present disclosure, and are therefore only used as examples, and cannot be used to limit the protection scope of the present disclosure.

[0078] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.

[0079] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0080] In addition, the terms "first", "second", etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0081] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0082] In the present application, unless otherwise clearly specified and limited, a first feature being “above” or “below” a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being “above”, “above”, and “above” a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being “below”, “below”, and “below” a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0083] Embodiments 1-6 of the present invention and comparative examples 1-4 provide a method for preparing a high-purity large-size alumina ceramic ring material. The specific parameters of the preparation process of the large-size alumina ceramic plate are shown in Table 1.

[0084] A method for preparing a high-purity large-size alumina ceramic ring material comprises:

[0085] S1. Use finished alumina powder as raw material, the purity of which is not less than 99.7%;

[0086] S2, filling the finished aluminum oxide powder into the annular forming mold for primary filling, and vibrating and compacting the finished aluminum oxide powder in the annular forming mold; then filling the annular forming mold with the finished aluminum oxide powder for secondary filling, and vibrating and compacting the finished aluminum oxide powder in the annular forming mold again;

[0087] S3, sealing the annular forming mold after the secondary filler is vibrated and compacted;

[0088] S4, transferring the sealed annular forming mold to a cold isostatic press for cold isostatic pressing to obtain a ring column green body; the cold isostatic pressing pressure is 130 MPa, and the holding time is 300 s;

[0089] S5, machining the ring column green body into a plurality of alumina ceramic circular ring green bodies; machining the remaining ring column green body edge material into a plurality of rectangular gaskets;

[0090] S6. Lay n rectangular gaskets evenly distributed in the circumferential direction on the support plate, and the n rectangular gaskets form a circular ring. Place a single alumina ceramic circular ring green body on the n rectangular gaskets; lay n rectangular gaskets evenly distributed in the circumferential direction on the layer of alumina ceramic circular ring green body, and then place another alumina ceramic circular ring green body on this layer of n rectangular gaskets; and overlap m layers of alumina ceramic circular ring green bodies with the same axial center line; the range of m is 1-3; the circular ring surrounded by the n rectangular gaskets of each layer is coaxial with the alumina ceramic circular ring green body, the center line of the rectangular gasket along its length direction is consistent with the radial direction of the alumina ceramic circular ring green body, and the rectangular gasket is arranged in the central area between the outer diameter and the inner diameter of the alumina ceramic circular ring green body; the ratio of the sum of the areas of the n rectangular gaskets to the area of ​​the alumina ceramic circular ring green body is defined as the contact area ratio, and the contact area ratio is 50-80%;

[0091] S7, transferring the m layers of overlapping alumina ceramic ring green bodies and the support plates to a high-temperature sintering furnace for sintering, and obtaining large-sized alumina ceramic ring materials after cooling; wherein the sintering process of the high-temperature sintering furnace comprises the following steps:

[0092] S701, heating from room temperature to T1 130-175℃, time 11h, insulation time 4h;

[0093] S702, heating from T1 to T2 is 225-275℃, takes 11h, and the holding time is 4h;

[0094] S703, heating from T2 to T3 is 300-400℃, takes 11h, and the holding time is 8h;

[0095] S704, heating from T3 to T4 is 600-800℃, takes 15h, and the holding time is 4h;

[0096] S705, heating from T4 to T5 is 1000-1100℃, takes 20h, and keeps warm for 2h;

[0097] S706, heating from T5 to T6 is 1200-1300℃, takes 5h, and keeps warm for 4h;

[0098] S707, heating from T6 to T7 is 1400-1450℃, takes 6h, and keeps warm for 2h;

[0099] S708, heating from T7 to 1500℃, taking 3h, keeping warm for 2h;

[0100] S709, heating from 1500℃ to 1600℃, taking 3h, keeping warm for 4h;

[0101] S710, cooling from 1600℃ to 800℃ for 20h;

[0102] S711, cooling from 800℃ to 100℃, time is 41h;

[0103] S712, cool in the furnace from 100°C to room temperature.

[0104] Among them, in different tests and production practices, the length of the rectangular gasket is 40-60mm, the width is 20-40mm, and the thickness is 3-4mm, and the specifications and dimensions of the rectangular gasket are all within this range. The outer diameter of the alumina ceramic ring green body is 300-600mm, the inner diameter is 200-340mm, and the thickness is 20-45mm, and the specifications and dimensions of the alumina ceramic ring green body are all within this range. The number of layers m of the alumina ceramic ring green bodies stacked together can be 1-3. The contact area ratio can range from 50-80%, and the preferred contact area ratio range is 50-70%.

[0105] In step S6, the process of arranging the rectangular gaskets and stacking the alumina ceramic ring green bodies includes the following steps:

[0106] S601, determining the number n of rectangular gaskets according to the contact area ratio;

[0107] S602, draw an inner diameter line and an outer diameter line of the same size as the alumina ceramic circular ring green body on the setter plate; then draw a circular outer contour line A of the bearing ring and a circular outer contour line B of the support ring on the setter plate; make the inner diameter line, the outer diameter line, the circular outer contour line A and the circular outer contour line B coaxial with the axial center line;

[0108] S603, placing the support ring at a position corresponding to the circular outer contour line A on the setter plate, arranging n limiting mechanisms at designated positions on the support ring in a circumferentially uniform manner, with two limiting rods of the limiting mechanisms covering the inner diameter line and the outer diameter line, and placing a rectangular gasket in the middle of the area surrounded by the inner diameter line, the outer diameter line and every two limiting rods;

[0109] S604, take out the support ring and the n limiting mechanisms arranged on the support ring, place the support ring on the support plate, and make the circular outer contour of the support ring coincide with the circular outer contour line B of the support plate; then place the alumina ceramic ring green body placed on the bottom layer on the n rectangular gaskets on the support plate, and the inner diameter and outer diameter of the alumina ceramic ring green body coincide with the inner diameter line and outer diameter line on the support plate respectively;

[0110] S605, matching the taken-out carrying ring and the n limiting mechanisms arranged on the carrying ring to the supporting ring, wherein two limiting rods of each limiting mechanism are located above the alumina ceramic ring green body on the lower layer;

[0111] S606, placing rectangular gaskets in the middle of the inner diameter and outer diameter of the lower layer of the alumina ceramic annular green body and the area surrounded by the two limiting rods of each limiting mechanism, so as to complete the circumferential uniform arrangement of n rectangular gaskets on the lower layer of the alumina ceramic annular green body;

[0112] S607, take out the carrying ring and the n limiting mechanisms arranged on the carrying ring, place another supporting ring on the lower supporting ring; place another alumina ceramic ring green body on the n rectangular gaskets of the lower alumina ceramic ring green body;

[0113] S608, repeating steps S605, S606 and S607 until the number of stacked alumina ceramic ring green bodies reaches m layers; and two adjacent layers of alumina ceramic ring green bodies are separated by n circumferentially evenly distributed rectangular gaskets, and the m layers of alumina ceramic ring green bodies are coaxially aligned with the center line;

[0114] S609, taking out all the support rings on the setter plate, and then completing the stacking and placing of m layers of alumina ceramic ring green bodies on the setter plate.

[0115] In the above step 603, the arrangement process of n limiting mechanisms includes the following steps:

[0116] S6031. Determine the number n of the limiting mechanisms according to the number of rectangular gaskets;

[0117] S6032, slidingly fitting all n limiting mechanisms on the carrying ring, and selecting corresponding sector-shaped isolation plates according to the number of limiting mechanisms;

[0118] S6033, using one of the limiting mechanisms as the limiting mechanism at the first position, and locking the limiting mechanism on the carrying ring;

[0119] S6034. Place the selected fan-shaped isolation plate on the inner diameter line and the outer diameter line of the supporting plate, with a limit rod of the limit mechanism at the first position as the starting point; move the fan-shaped isolation plate to another limit rod of the limit mechanism at the n-1th position, so that a radial edge of the fan-shaped isolation plate contacts with another limit rod of the limit mechanism at the n-1th position; move the strip slider of the limit mechanism at the nth position, so that a limit rod of the limit mechanism at the nth position contacts with another radial edge of the fan-shaped isolation plate, and lock the limit mechanism at the nth position; in this way, the fan-shaped isolation plate is gradually moved and the limit mechanism is positioned, so that n limit mechanisms can be evenly distributed circumferentially on the supporting ring.

[0120] In step S6034, the specific operation process is as follows:

[0121] Place the selected fan-shaped isolation plate on the inner diameter line and the outer diameter line of the supporting plate, with a limit rod of the limit mechanism at the first position as the starting point; make a radial edge of the fan-shaped isolation plate contact with another limit rod of the limit mechanism at the first position; move the bar slider of the limit mechanism at the second position so that a limit rod of the limit mechanism at the second position contacts with another radial edge of the fan-shaped isolation plate, and lock the limit mechanism at the second position; move the fan-shaped isolation plate to the other limit rod of the limit mechanism at the second position so that a radial edge of the fan-shaped isolation plate contacts with another limit rod of the limit mechanism at the second position; move the bar slider of the limit mechanism at the third position so that a limit rod of the limit mechanism at the third position contacts with another radial edge of the fan-shaped isolation plate, and lock the limit mechanism at the third position. Repeat this process to move the fan-shaped isolation plate to the other limit rod of the limit mechanism at the n-1th position, so that one radial edge of the fan-shaped isolation plate contacts the other limit rod of the limit mechanism at the n-1th position; move the strip slider of the limit mechanism at the nth position, so that one limit rod of the limit mechanism at the nth position contacts the other radial edge of the fan-shaped isolation plate, and lock the limit mechanism at the nth position, thereby completing the precise circumferential distribution of n limit mechanisms on the load-bearing ring.

[0122] Alumina ceramic ring green body (Φ 外 450mm*Φ 内342mm*25mm) as an example, a rectangular gasket with a length, width and thickness of 50mm*25mm*4mm is selected. When the contact area ratio is 50%, it is deduced that n is (π*225*225-π*171*171)*0.5 / (50*25)=26.86, and after rounding, n is 27 pieces. 27 rectangular gaskets are laid on the support plate or the alumina ceramic ring green body in a circumferentially uniform manner; at this time, the contact area ratio is 50*25*27 / (π*225*225-π*171*171)=50.26%, and there is a difference of 0.26%; when the difference is less than 1.5%, it can be ignored, that is, the difference should be controlled within 1.5% to ensure the accuracy of calculating the number of rectangular gaskets. Therefore, when calculating the number n of rectangular gaskets, it is necessary to consider the contact area ratio and the rounded n value comprehensively, and ultimately ensure that the contact area ratio is in the range of 50-80%.

[0123] Table 1 (alumina ceramic ring green body is Φ 外 450mm*Φ 内 342mm*25mm, m=3)

[0124]

[0125] Performance Testing

[0126] Test standard:

[0127] (1) The density of the porcelain body shall be in accordance with GB / T5593-2015.

[0128] Test results: The performance test results are shown in Table 2.

[0129] Table 2

[0130]

[0131] Figure 1 (a) Figure 1 (b) Figure 1 (c) Figure 1 (d) Figure 1 (e) and Figure 1 (f) Appearance pictures of large-sized alumina ceramic ring materials prepared in Examples 1-6 respectively. Figure 2 (a) Figure 2 (b) Figure 2 (c) Figure 2 (d) and Figure 2 (e) Appearance pictures of large-sized alumina ceramic ring materials prepared in Comparative Examples 1-5 respectively.

[0132] like Figure 1 (a) Figure 1 (b) and Figure 1As shown in (c), by comparing Examples 1-3, it can be seen that by adopting the sintering process of step S7, the large-sized alumina ceramic ring materials prepared in Examples 1-3 have a good shape and a ceramic body density of 3.91-3.95 g / cm 3 , so that the large-sized alumina ceramic ring material after sintering has excellent density; at the same time, the large-sized alumina ceramic ring material prepared in Examples 1-3 has a high purity. After testing, the purity of the large-sized alumina ceramic ring material prepared in Examples 1-3 is ≥99.7%. Through the sintering process of this technical solution, the moisture and binder in the alumina ceramic ring green body can be well discharged from the green body, effectively preventing the deformation or cracking caused by it; at the same time, the pores in the green body are effectively eliminated, and the density of the large-sized alumina ceramic ring material is improved, which is consistent with the test results in Table 2.

[0133] like Figure 1 (a) Figure 1 (d) Figure 1 (e) and Figure 1 As shown in (f), by comparing and analyzing Example 1 and Examples 4-6, it can be seen that when the contact area ratio is between 50-80%, large-sized alumina ceramic ring materials with good appearance and excellent density can be prepared, as shown in Table 2. A good fire channel is formed between the adjacent rectangular gaskets of each layer. When the contact area ratio is between 50-80%, it not only ensures that the upper rectangular gasket can be effectively supported, but also ensures that there are sufficient and circumferentially evenly distributed fire channels to improve the heating uniformity of the alumina ceramic ring green body. Specifically, a number of fire channels are precisely and evenly distributed circumferentially between the bottom layer of the alumina ceramic ring green body and the supporting plate, and a number of fire channels between the upper and lower adjacent alumina ceramic ring green bodies are also precisely and evenly distributed circumferentially; this arrangement ensures the uniform diffusion of the external temperature to the middle part of the alumina ceramic ring green body through the fire channels, and ensures the absolute uniformity of heating of each layer of the alumina ceramic ring green body, thereby effectively avoiding deformation or cracking of the alumina ceramic ring green body during the sintering process, and finally obtaining a large-sized alumina ceramic ring material with intact appearance and shape.

[0134] like Figure 1 (a) and Figure 2 As shown in (a), by comparing and analyzing Example 1 and Comparative Example 1, it can be seen that when the temperature of steps 701 to 703 during the sintering process is low, the alumina ceramic ring green body cannot effectively remove the moisture and binder inside it. Due to the presence of some moisture and binder in the green body during the subsequent sintering process, the green body is deformed during the subsequent sintering process, and the density of the large-sized alumina ceramic ring material after sintering is low, which is consistent with the test results in Table 2. Figure 1 (a) and Figure 2As shown in (b), by comparing and analyzing Example 1 and Comparative Example 2, it can be seen that when the temperature in steps 701 to 703 during the sintering process is high, the alumina ceramic ring green body will shrink faster. At the same time, the density of the alumina ceramic ring green body does not change much at this stage, which leads to the phenomenon of increased internal pressure and cracking of the alumina ceramic ring green body during the sintering stage. The density of the large-sized alumina ceramic ring material after firing is relatively low, which is consistent with the test results in Table 2.

[0135] like Figure 1 (a) and Figure 2 As shown in (c), from the comparative analysis of Example 1 and Comparative Example 3, it can be seen that when the contact area is relatively low, the number of rectangular gaskets is small. Although the fire channel left between adjacent rectangular gaskets is large, the number of rectangular gaskets cannot effectively support the upper layer of the alumina ceramic ring green body, resulting in the deformation of the alumina ceramic ring green body during the sintering shrinkage process. Figure 1 (a) and Figure 2 As shown in (d), by comparing and analyzing Example 1 and Comparative Example 4, it can be seen that when the contact area is relatively large, the number of rectangular gaskets is relatively large. Although the number of rectangular gaskets can effectively support the upper layer of the alumina ceramic ring green body, the fire channel retained between adjacent rectangular gaskets is relatively small, which will cause the alumina ceramic ring green body to be deformed due to uneven heating inside and outside during the sintering process.

[0136] like Figure 1 and Figure 2 (e) Figure 2 (e) is a large-sized alumina ceramic ring material prepared using corundum sand as a cushion layer according to the prior art. From the comparative analysis of Examples 1-6 and Comparative Example 5, it can be seen that the large-sized alumina ceramic ring material prepared in Comparative Example 5 exhibited severe distortion after sintering. This is because the use of corundum sand as a cushion layer caused uneven heating of the alumina ceramic ring green body during sintering. It is worth noting that the large-sized alumina ceramic ring material prepared in Examples 1-6 has excellent density and good appearance, which is far superior to the large-sized alumina ceramic ring material prepared in Comparative Example 5 according to the prior art.

[0137] The arrangement process of the aforementioned rectangular gaskets is carried out by using a circumferential uniform distribution device.

[0138] like Figure 3-9 As shown, the circumferentially uniformly distributed device includes a bearing ring 1, n limiting mechanisms 2 and at least one supporting ring 3; the bearing ring 1 is movably fitted on the supporting ring 3 coaxially with the center line, the n limiting mechanisms 2 are all slidably fitted on the bearing ring 1, and the n limiting mechanisms 2 are circumferentially uniformly distributed on the bearing ring 1, and the limiting mechanisms 2 are used to locate the rectangular gasket 6 on the alumina ceramic circular ring green body 5 or the supporting plate 7.

[0139] Among them, the limiting mechanism 2 includes a strip slider 201 and two limiting rods 202 connected to one end of the strip slider 201, the two limiting rods 202 are arranged in parallel, and the length direction of the two limiting rods 202 is parallel to the length direction of the strip slider 201; the strip slider 201 slides along the circumferential direction of the carrying ring 1, that is, the strip slider 201 can slide along the circumferential direction of the carrying ring 1, and the length direction of the strip slider 201 is consistent with the radial direction of the carrying ring 1; the two limiting rods 202 are located in the inner ring area of ​​the carrying ring 1.

[0140] When it is necessary to arrange the rectangular gasket 6 on the support plate 7, first draw the inner diameter line and outer diameter line of the same size as the alumina ceramic circular ring green body 5 on the support plate 7; then draw the circular outer contour line A of the bearing ring 1 and the circular outer contour line B of the support ring 3 on the support plate 7; make the inner diameter line, outer diameter line, circular outer contour line A and circular outer contour line B drawn on the support plate 7 coaxial with the center line. Place the bearing ring 1 at the corresponding position of the circular outer contour line A on the support plate 7, arrange n limiting mechanisms 2 in a circumferentially uniform manner to the specified position, and the two limiting rods 202 of the limiting mechanism 2 cover the inner diameter line and the outer diameter line, and place the rectangular gasket 6 in the middle of the area surrounded by the two limiting rods 202, the inner diameter line and the outer diameter line. Then take out the carrying ring 1 and the n limiting mechanisms 2 arranged on the carrying ring 1, and place the supporting ring 3 on the supporting plate 7 so that the circular outer contour of the supporting ring 3 coincides with the circular outer contour line B of the supporting plate 7; then place the alumina ceramic ring green body 5 placed on the bottom layer on the n rectangular gaskets 6 on the supporting plate 7, and the inner diameter and outer diameter of the alumina ceramic ring green body 5 coincide with the inner diameter line and outer diameter line on the supporting plate 7 respectively. Then, the taken-out carrying ring 1 and the n limiting mechanisms 2 arranged on the carrying ring 1 are matched on the supporting ring 3, and the carrying ring 1 and the supporting ring 3 are coaxially aligned with the center line; at this time, the two limiting rods 202 of each limiting mechanism 2 are just located above the lower layer of alumina ceramic circular ring blank 5; a rectangular gasket 6 is placed in the middle of the area surrounded by the inner diameter and outer diameter of the lower layer of alumina ceramic circular ring blank 5 and the two limiting rods 202 of each limiting mechanism 2, so that the circumferential uniform arrangement of the n rectangular gaskets 9 of the second layer can be completed; then, the carrying ring 1 and the n limiting mechanisms 2 arranged on the carrying ring 1 are taken out, and the supporting ring 3 of the second layer is matched on the supporting ring of the first layer, and the supporting ring 3 of the second layer is coaxially aligned with the supporting ring of the first layer; then, the alumina ceramic circular ring blank 5 placed on the second layer is placed on the n rectangular gaskets 6 of the second layer, and the alumina ceramic circular ring blank 5 of the second layer is coaxially aligned with the alumina ceramic circular ring blank of the bottom layer. By repeatedly stacking and arranging in this way, m layers of alumina ceramic ring green bodies 5 can be stacked and placed.

[0141] Since the positions of the n limiting mechanisms 2 on the carrier ring 1 have been arranged and locked when the n rectangular gaskets 6 of the bottom layer are arranged, there is no need to adjust the n limiting mechanisms 2 when the carrier ring 1 and the n limiting mechanisms 2 arranged on the carrier ring 1 are subsequently used, and they can be used directly. Moreover, when considering the position arrangement of the n rectangular gaskets 6 of the upper layer and the n rectangular gaskets 6 of the lower layer, the rectangular gaskets 6 at the same position of the upper and lower adjacent layers can be overlapped or misaligned.

[0142] The limiting mechanism 2 also includes width limiting strips 205 of various sizes, and each size has a certain number of width limiting strips 205. One side of the width limiting strip 205 is provided with a D-shaped through hole along its length direction. The cross section of the limiting rod 202 is D-shaped, and the width limiting strip 205 can be sleeved on the limiting rod 202 of the limiting mechanism 2 through its D-shaped through hole. The two limiting rods 202 can accommodate a rectangular gasket 6 of the maximum width size at the width of the strip slider 201; when the width of the rectangular gasket 6 is not the maximum size, it needs to be adjusted through the width limiting strip 205. Fig. 9 As shown, when the width limiting strip 205 is mounted on the limiting rod 202, the two width limiting strips 205 are arranged relative to each other; by selecting the width limiting strip 205 of the appropriate size, the distance between the two width limiting strips 205 can be made consistent with the width of the processed rectangular gasket. The two limiting rods 202 or the two width limiting strips 205 are in a clearance fit state with the width direction of the rectangular gasket 6, and the rectangular gasket can be easily placed between the two limiting rods 202 or the two width limiting strips 205. The entire arrangement process of the rectangular gasket 6 improves accuracy, and it is also convenient to check whether there is a leakage phenomenon.

[0143] The circumferentially uniformly distributed device also includes sector-shaped partition plates 4 of various sizes and specifications. The sector-shaped partition plates 4 of various sizes and specifications have different central angles, and the sector-shaped partition plates 4 of various sizes and specifications correspond to the number of the limiting mechanisms 2. The sector-shaped partition plates 4 of various sizes and specifications are used to arrange different numbers of limiting mechanisms 2 on the carrying ring 1. In order to conveniently distinguish the sector-shaped partition plates 4 of various sizes and specifications, numbers can be printed or written on the sector-shaped partition plates 4, and the numbers on the sector-shaped partition plates 4 correspond to the number of the limiting mechanisms 2. For example, if the number on the sector-shaped partition plate 4 is 32, the sector-shaped partition plate 4 corresponding to the number 32 is used to evenly arrange 32 limiting mechanisms 2 circumferentially on the carrying ring 1.

[0144] When arranging n limiting mechanisms 5, first determine the number of limiting mechanisms 2 according to the number of rectangular gaskets 6, then slide all n limiting mechanisms 2 on the supporting ring 1, and select corresponding fan-shaped isolation plates 4 according to the number of limiting mechanisms 2. Use one of the limiting mechanisms 2 as the limiting mechanism at the first position, and lock the limiting mechanism at the first position by a weight or a locking mechanism. Then select the fan-shaped isolation plate 4 and place it on the inner diameter line and outer diameter line of the supporting plate 7, so that one radial edge of the fan-shaped isolation plate 4 contacts with one limiting rod of the limiting mechanism 2 at the first position; then move the bar slider of the limiting mechanism at the adjacent position (the limiting mechanism at the second position) so that one limiting rod of the limiting mechanism at the second position contacts with another radial edge of the fan-shaped isolation plate 4, so as to complete the positioning of the limiting mechanism at the second position and lock the limiting mechanism at the second position. Then move the sector isolation plate 4 to another limiting rod of the limiting mechanism at the second position, so that one radial edge of the sector isolation plate 4 contacts another limiting rod of the limiting mechanism at the second position; then move the bar-shaped slider of the limiting mechanism at the third position, so that one limiting rod of the limiting mechanism at the third position contacts another radial edge of the sector isolation plate 4, thus completing the positioning of the limiting mechanism at the third position and locking the limiting mechanism at the third position. Repeating this process, n limiting mechanisms 2 can be evenly arranged in the circumferential direction on the carrying ring 1.

[0145] Specifically, the bearing ring 1 is provided with a first annular protrusion 101 and a second annular protrusion 102 coaxially disposed on the center line, the first annular protrusion 101 is close to the inner ring of the bearing ring 1, and the second annular protrusion 102 is close to the outer edge of the bearing ring 1. The strip slider 201 is provided with a first groove 203 and a second groove 204 corresponding to the first annular protrusion 101 and the second annular protrusion 102, and the first groove 203 and the second groove 204 of the strip slider 201 are slidably fitted on the first annular protrusion 101 and the second annular protrusion 102, respectively.

[0146] Furthermore, a pressure ring 103 is provided on the load-bearing ring 1, and the pressure ring 103 is connected to the load-bearing ring 1 through a plurality of U-shaped pieces 104, and the plurality of U-shaped pieces 104 are evenly distributed in the circumferential direction on the load-bearing ring 1. An upwardly protruding annular enclosure 105 is provided on the outer edge of the load-bearing ring 1, and an inwardly folded limiting ring 106 is provided on the side of the annular enclosure 105 away from the load-bearing ring 1, and an annular slide 107 is provided between the limiting ring 106 and the pressure ring 103. The load-bearing ring 1, the annular enclosure 105, the limiting ring 106 and the pressure ring 103 are surrounded by an annular limiting groove 108, and the annular slide 107 is connected to the annular limiting groove 108. The end of the strip slider 201 away from the limiting rod is slidably fitted in the annular limiting groove 108. A locking bolt 206 is provided at one end of the strip slider 201 away from the limiting rod. The screw of the locking bolt 206 is slidably fitted in the annular groove 107 . The strip slider 201 can be positioned at a specified position on the carrying ring 1 by rotating the locking bolt 206 .

[0147] Further, the load-bearing ring 1 comprises a closed ring 110 and a C-shaped ring 109 with a notch, the closed ring 110 is adapted to the notch of the C-shaped ring 109, and the closed ring 110 and the C-shaped ring 109 cooperate to form a complete load-bearing ring 1; both sides of the closed ring 110 are provided with lugs 111, and the lugs 111 of the closed ring 110 are connected to the bottom of the notch of the C-shaped ring 109 by bolts. n limiting mechanisms 2 are installed on the load-bearing ring 1 through the notch of the C-shaped ring 109.

[0148] Furthermore, the inner side of the support ring 3 is provided with a first annular step 301 that matches the bearing ring 1, and the top of the support ring 3 is provided with a second annular step 302, and the annular vertical surface of the second annular step 302 is a conical surface; the outer edge of the bottom of the support ring 3 is provided with an annular groove 303 that matches the second annular step 302. The design of the second annular step 302 and the annular groove 303 of the support ring 3 facilitates the stacking and arrangement of multiple support rings 3 and the coaxial center line; the design of the first annular step 301 of the support ring 3 facilitates the support of the bearing ring 1 and the coaxial center line arrangement. In addition, the inner ring of the support ring 3 is also provided with a plurality of circumferentially uniformly distributed center locators, which include a telescopic plate 304 and a baffle 305. The two ends of the telescopic plate 304 are respectively connected to the baffle 305 and the inner ring of the support ring 3. The length direction of the telescopic plate 304 is consistent with the radial direction of the support ring 3, and the baffle 305 is used to position and limit the alumina ceramic ring green body 5. The telescopic plate 304 includes a first plate body 306 and a second plate body 307. The first plate body 306 is provided with a sliding cavity 308 along its length direction. The first plate body 306 is provided with a strip groove 309 connected to the sliding cavity 308. The length direction of the strip groove 309 is consistent with the length direction of the first plate body 306. A bolt 310 is provided at one end of the second plate body 307. The bolt end of the second plate body 307 is movably fitted in the sliding cavity 308, and the screw rod of the bolt 310 is slidably fitted in the strip groove 309. The first plate body 306 and the second plate body 307 can be telescoped in the length direction. After the first plate body 306 and the second plate body 307 are telescoped to the desired position, they can be locked by the bolt 310. When in use, the first plate 306 and the second plate 307 are telescopically adjusted to the desired position according to the size of the alumina ceramic ring green body 5, and the first plate 306 and the second plate 307 are locked by the bolt 310; then the alumina ceramic ring green body is placed in the area surrounded by the baffle 305 on the multiple telescopic plates 304, and the alumina ceramic ring green body 5 can be positioned or limited, so that the alumina ceramic ring green body 5 can be accurately placed on the supporting plate 7, or multiple alumina ceramic ring green bodies 5 can be coaxially arranged.

[0149] The above embodiments are only used to illustrate the technical solutions of the present disclosure, rather than to limit them. Although the present disclosure has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present disclosure, and they should all be included in the scope of the claims and specification of the present disclosure.

Claims

1. A method for preparing high-purity large-size alumina ceramic ring material, characterized in that: The steps include: S1, using finished alumina powder as raw material; S2, filling the finished aluminum oxide powder into the annular forming mold for primary filling, and vibrating and compacting the finished aluminum oxide powder in the annular forming mold; then filling the annular forming mold with the finished aluminum oxide powder for secondary filling, and vibrating and compacting the finished aluminum oxide powder in the annular forming mold again; S3, sealing the annular forming mold after the secondary filler is vibrated and compacted; S4, transferring the sealed annular forming mold to a cold isostatic press for cold isostatic pressing to obtain a ring column green body; S5, machining the ring column green body into a plurality of alumina ceramic circular ring green bodies; machining the remaining ring column green body edge material into a plurality of rectangular gaskets; S6, lay n rectangular gaskets evenly distributed in the circumferential direction on the support plate, the n rectangular gaskets form a circular ring, and place a single piece of alumina ceramic circular ring green body on the n rectangular gaskets; lay n rectangular gaskets evenly distributed in the circumferential direction on the layer of alumina ceramic circular ring green body, and then place another piece of alumina ceramic circular ring green body on the layer of n rectangular gaskets; and overlap and place m layers of alumina ceramic circular ring green bodies with the same axial center line in this way; S7, transferring the m layers of overlapping alumina ceramic ring green bodies and the support plates to a high-temperature sintering furnace for sintering, and obtaining large-sized alumina ceramic ring materials after cooling.

2. The method for preparing a high-purity large-size alumina ceramic ring material according to claim 1, characterized in that: In step S6, the center line of the rectangular gasket along its length direction is consistent with the radial direction of the alumina ceramic ring green body, and the rectangular gasket is arranged in the central area between the outer diameter and the inner diameter of the alumina ceramic ring green body; the ratio of the sum of the areas of n rectangular gaskets to the area of ​​the alumina ceramic ring green body is defined as the contact area ratio, and the contact area ratio is 50-80%.

3. The method for preparing a high-purity large-size alumina ceramic ring material according to claim 1, characterized in that: In step S7, the sintering process in the high temperature sintering furnace includes the following steps: S701, heating from room temperature to T1 130-175℃, time 11h, insulation time 4h; S702, heating from T1 to T2 is 225-275℃, takes 11h, and the holding time is 4h; S703, heating from T2 to T3 is 300-400℃, takes 11h, and the holding time is 8h; S704, heating from T3 to T4 is 600-800℃, takes 15h, and the holding time is 4h; S705, heating from T4 to T5 is 1000-1100℃, takes 20h, and keeps warm for 2h; S706, heating from T5 to T6 is 1200-1300℃, takes 5h, and keeps warm for 4h; S707, heating from T6 to T7 is 1400-1450℃, takes 6h, and keeps warm for 2h; S708, heating from T7 to 1500℃, taking 3h, keeping warm for 2h; S709, heating from 1500℃ to 1600℃, taking 3h, keeping warm for 4h; S710, cooling from 1600℃ to 800℃ for 20h; S711, cooling from 800℃ to 100℃, time is 41h; S712, cool in the furnace from 100°C to room temperature.

4. The method for preparing a high-purity large-size alumina ceramic ring material according to any one of claims 1 to 3, characterized in that: In the step S6, n rectangular gaskets are evenly arranged using a circumferential evenly distributed device; The circumferentially uniformly distributed device includes a bearing ring, n limiting mechanisms, fan-shaped isolation plates of various specifications and sizes, and at least one supporting ring; the bearing ring is movably matched on the supporting ring coaxially with the center line, the n limiting mechanisms are all slidably matched on the bearing ring, and the n limiting mechanisms are circumferentially uniformly distributed on the bearing ring, and the limiting mechanisms are used to locate the position of the rectangular gasket on the alumina ceramic circular ring green body or the support plate; The sector-shaped isolation plate is used to evenly arrange n limiting mechanisms circumferentially on the carrying ring; The limiting mechanism includes a strip slider and two limiting rods connected to one end of the strip slider, the two limiting rods are arranged in parallel, and the length direction of the two limiting rods is parallel to the length direction of the strip slider; the strip slider slides along the circumferential direction of the load-bearing ring, and the length direction of the strip slider is consistent with the radial direction of the load-bearing ring; the two limiting rods are located in the inner ring area of ​​the load-bearing ring.

5. The method for preparing a high-purity large-size alumina ceramic ring material according to claim 4, characterized in that: The limiting mechanism also includes width limiting strips of various sizes, with a certain number of width limiting strips of each size. A D-shaped through hole is provided on one side of the width limiting strip along its length direction; the cross-section of the limiting rod is D-shaped, and the width limiting strip can be mounted on the limiting rod of the limiting mechanism through its D-shaped through hole.

6. The method for preparing a high-purity large-size alumina ceramic ring material according to claim 4, characterized in that: The central angles of the sector-shaped isolation plates of different specifications and sizes are different; The fan-shaped isolation plate is printed or written with numbers, and the numbers on the fan-shaped isolation plate correspond to the number of the limiting mechanisms arranged on the carrying ring.

7. The method for preparing a high-purity large-size alumina ceramic ring material according to claim 4, characterized in that: The carrying ring is provided with a pressure ring, and the pressure ring is connected to the carrying ring through a plurality of U-shaped pieces; The outer edge of the carrying ring is provided with an upwardly protruding annular enclosure, and a side of the annular enclosure away from the carrying ring 1 is provided with an inwardly folded limiting ring, and an annular sliding groove between the limiting ring and the pressure ring; The load-bearing ring, the annular enclosure, the limiting ring and the pressing ring together form an annular limiting groove, and the annular sliding groove is connected to the annular limiting groove; One end of the strip sliding block away from the limiting rod is slidably fitted in the annular limiting groove; one end of the strip sliding block away from the limiting rod is provided with a locking bolt, and the screw rod of the locking bolt is slidably fitted in the annular sliding groove.

8. The method for preparing a high-purity large-size alumina ceramic ring material according to claim 4, characterized in that: The inner ring of the support ring is also provided with a plurality of center locators evenly distributed in the circumferential direction, the center locator comprises a telescopic plate and a baffle, the two ends of the telescopic plate are respectively connected to the baffle and the inner ring of the support ring, the length direction of the telescopic plate is consistent with the radial direction of the support ring, and the baffle is used to position and limit the alumina ceramic ring green body.

9. The method for preparing a high-purity large-size alumina ceramic ring material according to claim 4, characterized in that: In step S6, the process of arranging the rectangular gaskets and stacking the alumina ceramic ring green bodies includes the following steps: S601, determining the number n of rectangular gaskets according to the contact area ratio; S602, draw an inner diameter line and an outer diameter line of the same size as the alumina ceramic circular ring green body on the setter plate; then draw a circular outer contour line A of the bearing ring and a circular outer contour line B of the support ring on the setter plate; make the inner diameter line, the outer diameter line, the circular outer contour line A and the circular outer contour line B coaxial with the axial center line; S603, placing the support ring at a position corresponding to the circular outer contour line A on the setter plate, arranging n limiting mechanisms at designated positions on the support ring in a circumferentially uniform manner, with two limiting rods of the limiting mechanisms covering the inner diameter line and the outer diameter line, and placing a rectangular gasket in the middle of the area surrounded by the inner diameter line, the outer diameter line and every two limiting rods; S604, take out the support ring and the n limiting mechanisms arranged on the support ring, place the support ring on the support plate, and make the circular outer contour of the support ring coincide with the circular outer contour line B of the support plate; then place the alumina ceramic ring green body placed on the bottom layer on the n rectangular gaskets on the support plate, and the inner diameter and outer diameter of the alumina ceramic ring green body coincide with the inner diameter line and outer diameter line on the support plate respectively; S605, matching the taken-out carrying ring and the n limiting mechanisms arranged on the carrying ring to the supporting ring, wherein two limiting rods of each limiting mechanism are located above the alumina ceramic ring green body on the lower layer; S606, placing rectangular gaskets in the middle of the inner diameter and outer diameter of the lower layer of the alumina ceramic annular green body and the area surrounded by the two limiting rods of each limiting mechanism, so as to complete the circumferential uniform arrangement of n rectangular gaskets on the lower layer of the alumina ceramic annular green body; S607, take out the carrying ring and the n limiting mechanisms arranged on the carrying ring, place another supporting ring on the lower supporting ring; place another alumina ceramic ring green body on the n rectangular gaskets of the lower alumina ceramic ring green body; S608, repeating steps S605, S606 and S607 until the number of stacked alumina ceramic ring green bodies reaches m layers and is coaxial with the center line; S609, taking out all the support rings on the setter plate, and then completing the stacking and placing of m layers of alumina ceramic ring green bodies on the setter plate.

10. The method for preparing a high-purity large-size alumina ceramic ring material according to claim 9, characterized in that: In step S603, the arrangement process of n limiting mechanisms includes the following steps: S6031. Determine the number n of the limiting mechanisms according to the number of rectangular gaskets; S6032, slidingly fitting all n limiting mechanisms on the carrying ring, and selecting corresponding sector-shaped isolation plates according to the number of limiting mechanisms; S6033, using one of the limiting mechanisms as the limiting mechanism at the first position, and locking the limiting mechanism on the carrying ring; S6034. Place the selected fan-shaped isolation plate on the inner diameter line and the outer diameter line of the supporting plate, with a limit rod of the limit mechanism at the first position as the starting point; move the fan-shaped isolation plate to another limit rod of the limit mechanism at the n-1th position, so that a radial edge of the fan-shaped isolation plate contacts with another limit rod of the limit mechanism at the n-1th position; move the strip slider of the limit mechanism at the nth position, so that a limit rod of the limit mechanism at the nth position contacts with another radial edge of the fan-shaped isolation plate, and lock the limit mechanism at the nth position; in this way, the fan-shaped isolation plate is gradually moved and the limit mechanism is positioned, so that n limit mechanisms can be evenly distributed circumferentially on the supporting ring.

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