Preparation technology of ceramic special-shaped parts

Abstract

The present invention belongs to the technical field of preparation of ceramic products, and specifically relates to a preparation process for ceramic special-shaped parts. The preparation process for ceramic special-shaped parts includes the following steps: dividing a ceramic green block into a plurality of partitions, the special-shaped parts of each partition are arranged in an axisymmetric manner, processing the special-shaped parts, processing calibration columns on different partitions, recording the coordinate positions of the calibration columns, firing at high temperature, measuring the coordinate positions of the calibration columns, and calculating the firing shrinkage rates of the calibration columns in different partitions according to the coordinate positions of the calibration columns before and after firing; calculating the relative positions of different positioning columns according to the firing shrinkage rates; taking the same batch of ceramic green blocks, processing different positioning columns according to the relative positions of different positioning columns, and processing the special-shaped parts, and firing at high temperature to obtain ceramic special-shaped parts. The preparation process for ceramic special-shaped parts provided by the present invention is simple to operate, short in working hours, high in efficiency, high in yield, and saves raw materials.

Description

Technical Field

[0001] The invention belongs to the technical field of preparation of ceramic products, and in particular relates to a preparation process of ceramic special-shaped parts. Background Art

[0002] The materials of ceramic special-shaped parts include alumina, zirconium oxide, silicon carbide, silicon nitride, etc. They have high wear resistance, mechanical strength, chemical corrosion resistance, etc. Therefore, they are widely used in many fields, especially in the fields of mechanical industry ceramic parts, smart wear ceramic parts, chemical industry, sanitary ceramic parts, flow valve body control ceramic parts, electronic fixture component ceramic parts, semiconductor ceramic parts, etc. Most of these ceramic special-shaped parts are axisymmetric.

[0003] During the high-temperature firing process of special-shaped ceramic parts, the special-shaped ceramic parts are subjected to inconsistent heat and stress in all directions due to the special-shaped shapes of the products, which leads to the special-shaped ceramic parts shrinking in all directions and inconsistent shrinkage in all parts during the high-temperature firing process. Due to the different positions, the special-shaped ceramic parts shrink inconsistently, which leads to the relative positions of the holes, special-shaped columns, and special-shaped parts being offset, resulting in the unqualified dimensions of the special-shaped ceramic parts, becoming waste products, and wasting raw materials and man-hours. The uses of special-shaped ceramic parts are mostly based on the fitting and installation of the positioning columns on the special-shaped ceramic parts with the positioning holes in the application equipment. Therefore, there are strict requirements on the size and accuracy of the positioning columns and special-shaped parts on the special-shaped ceramic parts. Once the position is offset, it cannot be assembled and becomes waste. Therefore, the current processing method for this type of special-shaped ceramic parts is mainly: after the regular whole ceramic part with processing allowance is fired, holes are opened and special-shaped or positioning columns are processed at the corresponding positions of the ceramic plate blank according to the drawings.

[0004] However, the hardness of ceramic parts after firing is very high. For example, alumina ceramics have a hardness of up to 16GPa after firing. They are brittle materials. The processing and feed amount of the products after firing are very small and demanding. Therefore, the current processing methods lead to low efficiency of fine processing and long processing time. It is very easy to have edge collapse and cracking during processing, resulting in low processing yield. For example, the hardness of silicon carbide ceramics after firing is as high as 23GPa, which is more difficult to process, takes longer to process, and has lower processing efficiency.

[0005] Therefore, the current method for preparing ceramic special-shaped parts is very slow and has a very high scrap rate, which has become a technical bottleneck in this field and is difficult to break through. Summary of the invention

[0006] The technical problem to be solved by the present invention is to overcome the above-mentioned defects in the prior art and provide a preparation process for ceramic special-shaped parts, which has simple operation, short processing time, high efficiency, high yield rate and saves raw materials.

[0007] The preparation process of the ceramic special-shaped part of the present invention comprises the following steps:

[0008] (1) Preparing calibration parts and calculating firing shrinkage: According to the drawings, the ceramic green body is divided into a plurality of partitions, and the irregularly shaped parts of each partition are arranged in an axisymmetric manner. The irregularly shaped parts are processed, and calibration columns are processed on different partitions respectively. The coordinate positions of the calibration columns are recorded. The number of calibration columns is ≥ the number of partitions. After high-temperature firing, the coordinate positions of the calibration columns are measured to obtain calibration parts. According to the coordinate positions of the calibration columns before and after firing, the firing shrinkage rates of the calibration columns in different partitions are calculated respectively.

[0009] (2) Calculate the relative positions of different positioning columns according to the firing shrinkage rates of different partitions;

[0010] (3) Processing ceramic special-shaped parts: Take the same batch of ceramic green blocks as in step (1), process all the positioning columns according to the relative positions of different positioning columns, and process the special-shaped parts, and finally sinter at high temperature to obtain ceramic special-shaped parts.

[0011] The step (1) of dividing the ceramic green block into a plurality of partitions is performed by calibrating the center position of the ceramic green block as the origin. The center position, according to three-dimensional space, has the X-axis direction and the Y-axis direction in the horizontal direction and the Z-axis direction in the vertical direction. Therefore, the position of the origin is marked as O: (X:Y:Z=0:0:0).

[0012] The ceramic green body block is divided into a plurality of partitions, the number of which is denoted by S, S≥1, and marked as zone 1, zone 2, zone 3...zone S; the number of calibration columns is denoted by N, N≥S, ensuring that each partition has at least one calibration column, and if each partition has multiple calibration columns, the average value of the calibration columns in the partition is calculated.

[0013] The coordinate positions of the calibration posts recorded in step (1) are marked as J1: (X1: Y1: Z1), J2: (X2: Y2: Z2), J3: (X3: Y3: Z3) ... J N :(X N : Y N :Z N ), N is the number of calibration columns.

[0014] The coordinate positions of the calibration columns measured after high temperature sintering in step (1) are marked as j1: (x1: y1: z1), j2: (x2: y2: z2), j3: (x3: y3: z3) ... j N :(x N :y N :z N ), N is the number of calibration columns.

[0015] In step (1), the firing shrinkage rates of the calibration columns in different partitions are calculated based on the coordinate positions of the calibration columns before and after firing, and the calculation method is:

[0016] Calibration column in zone 1: X-axis firing shrinkage A1: A1=(X1-x1)×100% / X1;

[0017] Y-axis firing shrinkage B1: B1= (Y1-y1) × 100% / Y1;

[0018] Z-axis firing shrinkage C1: C1= (Z1-z1) × 100% / z1;

[0019] Calibration column in zone 2: X-axis firing shrinkage A2: A2=(X2-x2)×100% / X2;

[0020] Y-axis firing shrinkage B2: B2=(Y2-y2)×100% / Y2;

[0021] Z-axis firing shrinkage C2: C2= (Z2-z2) × 100% / z2;

[0022] …

[0023] S area calibration column: X-axis firing shrinkage A s : A s =(X s -x s )×100% / X s ;

[0024] Y-axis firing shrinkage B s :B s =(Y s -y s )×100% / Y s ;

[0025] Z-axis firing shrinkage C s :C s =(Z s -z s )×100% / z s .

[0026] Step (2) The firing shrinkage rates of the X-axis, Y-axis and Z-axis are calculated according to step (1). According to the partition positions of the positioning columns marked on the drawings of the finished ceramic product after firing, the relative coordinates of the upper surface center positions of the positioning columns in different partitions of the ceramic blank are calculated respectively. Different positioning columns are marked as D1, D2, D3...D n , the coordinate positions are marked as (DX1:DY1:DZ1), (DX2:DY2:DZ2), (DX3:DY3:DZ3)...(DX n :DY n:DZ n ), n is the number of positioning columns marked on the finished product drawing after the ceramic is fired.

[0027] Therefore, the relative positions of the different positioning columns calculated in step (2) are:

[0028] DX1=x1 / (100%-A t );

[0029] DY1=y1 / (100%-B t );

[0030] DZ1=z1 / (100%-C t );

[0031] …

[0032] DX n =x n / (100%-A t );

[0033] DY n =y n / (100%-B t );

[0034] DZ n =z n / (100%-C t );

[0035] Among them, t is the partition to which each positioning column belongs, A t , B t , C t They are the firing shrinkage rates of the X-axis, Y-axis, and Z-axis of the t-zone respectively.

[0036] The irregularly shaped parts in step (1) include holes of different shapes and / or ear-shaped protrusions. The holes of different shapes include circular holes, regular polygonal holes, irregular polygonal holes, and irregular ring-shaped holes.

[0037] The ceramic green body block in step (1) is a ceramic green body block formed by dry pressing or isostatic pressing.

[0038] The sintering temperature in step (1) is 1500-1700°C.

[0039] The processing of the special-shaped parts in step (1) includes processing the outer contour, holes, and special-shaped parts, using a precision engraving machine or CNC equipment.

[0040] The processing technology for processing the special-shaped parts and the calibration column in step (1) is as follows: use a Φ20-25mm vertical milling cutter, set the spindle speed to 6000-8000r / min, the feed rate to 1200-1500mm / min, the cutting rate to 200-400mm / min, the cutting direction to down milling, the cutting depth to 1mm / layer, the XY stepping amount to 1-2mm, the tool diameter to 35-45%, the maximum rough cutting stepping amount of the Z layer to 1-2mm, the entry method to oblique insertion, the safety height to 100mm, the reference height to 10mm, the cutting position to 3mm, and the cutting depth to 0.5-1mm.

[0041] In step (1), the calibration posts are processed separately in different partitions, and each partition has at least one calibration post.

[0042] In step (2), the relative positions of the irregularly shaped parts are calculated according to the firing shrinkage rates of the calibration columns in different partitions.

[0043] Before processing the irregularly shaped part in step (3), a calibration mark is first made on the relative position of the irregularly shaped part.

[0044] The processing technology of the different positioning posts and the special-shaped parts in step (3) is the same as the processing technology of the special-shaped parts and the calibration posts in step (1), and the high-temperature sintering temperature in step (3) is the same as that in step (1).

[0045] The special-shaped parts of the ceramic plate of the present invention include holes and / or ear-shaped protrusions of different shapes, and a plurality of ceramic positioning columns are provided on the ceramic plate. After the ceramic green block formed by dry pressing or isostatic pressing is processed into a special shape by a precision engraving machine or a CNC CNC device, the ceramic green block is divided into a plurality of partitions according to the drawing, and the special-shaped parts of each partition are arranged in an axisymmetric manner. The special-shaped parts are processed, and calibration columns are processed on different partitions to obtain calibration parts. After the processed calibration parts are fired at a high temperature (1500-1700°C), the firing shrinkage rates of different partitions are calculated respectively. Then, according to the firing shrinkage rates, the relative positions of different positioning columns are calculated respectively, and the special-shaped and positioning columns are processed on the special-shaped ceramic plate in sequence on a precision engraving machine or a CNC CNC device, and finally fired at a high temperature (1500-1700°C). The special-shaped ceramic parts prepared by the method have a simple processing method, save time, and overcome the position deviation of the positioning columns caused by the inconsistent firing shrinkage caused by the ceramic plate with holes and / or ear-shaped protrusions. It overcomes the problems of large processing allowance, long processing time, easy edge collapse, cracking, etc. caused by the commonly used method of processing special shapes and positioning columns after high-temperature firing of ceramic plates. It can be used to process ceramic parts with holes and / or ear-shaped protrusions of different sizes and multiple positioning columns.

[0046] Compared with the prior art, the present invention has the following beneficial effects:

[0047] (1) The preparation process of the ceramic special-shaped parts of the present invention can be used to process ceramic plates with holes, special-shaped columns, special-shaped parts, etc. The processing is simple, time-saving, high in processing efficiency and high in yield rate.

[0048] (2) The preparation process of ceramic special-shaped parts of the present invention overcomes the following problems existing in the prior art: since the ceramic plate has holes, special-shaped columns, special shapes, etc., after the blank is processed into a special shape, it shrinks in all directions during the high-temperature firing process and the shrinkage of each part during firing is inconsistent. Due to the different positions, the shrinkage of each part of the special-shaped ceramic part is inconsistent, which causes the relative positions of its holes, special-shaped columns and special-shaped parts to shift, resulting in the special-shaped ceramic part product size not meeting the requirements, becoming waste, wasting raw materials and wasting work time.

[0049] (3) The preparation process of special-shaped ceramic parts of the present invention overcomes the following problems existing in the prior art: after a regular whole ceramic part with processing allowance is fired, holes are opened at corresponding positions of the ceramic plate blank according to the drawings to process special-shaped or positioning columns. This method results in a large processing allowance, and due to the high hardness of the ceramic after firing, the processing efficiency is low, the processing time is long, and the processing yield is low. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is a schematic diagram of a ceramic special-shaped part prepared in Example 1, wherein a is a top view and b is a side view.

[0051] Figure 2 This is a calibration sample diagram of the preparation process of ceramic special-shaped parts in Example 1.

[0052] Figure 3 This is a schematic diagram of a ceramic special-shaped part prepared in Example 2, wherein c is a top view and d is a side view.

[0053] Figure 4 This is a calibration sample diagram of the preparation process of ceramic special-shaped parts in Example 2.

[0054] Figure 5 Schematic diagram of the ceramic special-shaped part prepared in Example 3, wherein e is a top view and f is a side view.

[0055] Figure 6 This is a calibration sample diagram of the preparation process of ceramic special-shaped parts in Example 3. DETAILED DESCRIPTION

[0056] The present invention will be further described below in conjunction with specific embodiments.

[0057] Example 1

[0058] The prepared ceramic special-shaped part is an alumina circular ceramic disk, and the preparation method comprises the following steps:

[0059] On the alumina circular ceramic disk (Φ300mm, H10mm), 8 Φ5mm evenly spaced through holes are opened at the Φ200mm and Φ100mm positions respectively. There are 5 positioning posts (Φ10mm, H15mm) on the ceramic disk. The center of the bottom circle is calibrated as the center origin. The corresponding center coordinates of the upper surface of the positioning posts are: D1 (-144:15:25), D2 (70:-142:25), D3 (-20:-65:25), D4 (80:30:25), D5 (0:0:25), as shown in Figure 1. Figure 1 As shown in Figures a and b.

[0060] According to the drawing, the special-shaped partitions of the ceramic plate are divided into three zones from the outside to the inside: Zone 1, Zone 2, and Zone 3. Figure 2 shown.

[0061] like Figure 2 As shown, two circles of through holes are first punched on the ceramic disk, and then calibration columns are processed in each partition, namely: Zone 1 J 1.1 (X 1.1 : Y 1.1 :Z 1.1 ), J 1.2 (X 1.2 : Y 1.2 :Z 1.2 ) Two calibration columns; Zone 2 J 2.1 (X 2.1 : Y 2.1 :Z 2.1 ), J 2.2 (X 2.2 : Y 2.2 :Z 2.2 ) Two calibration columns; Zone 3 J 3.1 (X 3.1 : Y 3.1 :Z 3.1 )Calibration column. Since the ceramic green body has low strength and is easy to crack, a low speed and large feed processing method is adopted.

[0062] Processing parameters: Use Φ25mm vertical milling cutter to set the spindle speed to 6000r / min, feed rate to 1500mm / min, cutting rate: 300mm / min, cutting direction: down milling, cutting amount 1mm / layer, XY stepping amount: 1mm, tool diameter 45%, Z layer maximum rough cutting stepping amount: 2mm, entry method: oblique insertion, safety height: 100mm, reference height: 10mm, cutting position: 3mm, cutting depth: 1mm.

[0063] The ceramic calibration piece is fired at 1600℃.

[0064] Measure the positions of the calibration columns respectively: Zone 1 j 1.1 , j 1.2 Calibration column: j 1.1 :(x 1.1 :y 1.1 :z 1.1 ),j 1.2 :(x 1.2 :y 1.2 :z 1.2 ); Zone 2 2.1 , j 2.2 Calibration column: j 2.1 :(x 2.1 :y 2.1 :z 2.1 ),j 2.2 :(x 2.2 :y 2.2 :z 2.2 ); Zone 3 J 3.1 Calibration column: j 3.1 :(x 3.1 :y 3.1 :z 3.1 ). Calculate the firing shrinkage according to the formula:

[0065] Zone 1: X-axis firing shrinkage: A1=[(X 1.1 -x 1.1 )×100% / X 1.1 +(X 1.2 -x 1.2 )×100% / X 1.2 ] / 2=15.3%;

[0066] Y-axis firing shrinkage: B1=[(Y 1.1 -y 1.1 )×100% / Y 1.1 + (Y 1.2 -y 1.2 )×100% / Y 1.2 ] / 2=15.3%;

[0067] Z-axis firing shrinkage: C1=[(Z 1.1 -z 1.1 )×100% / Z 1.1 +(Z 1.2 -z 1.2 )×100% / Z 1.2 ] / 2=15.4%;

[0068] Zone 2: X-axis firing shrinkage: A2=[(X 2.1 -x 1.1 )×100% / X 2.1+(X 2.2 -x 2.2 )×100% / X 2.2 ] / 2=15.4%;

[0069] Y-axis firing shrinkage: B2=[(Y 2.1 -y 1.1 )×100% / Y 2.1 + (Y 2.2 -y 2.2 )×100% / Y 2.2 ] / 2=15.4%;

[0070] Z-axis firing shrinkage: C2=[(Z 2.1 -z 2.1 )×100% / Z 2.1 +(Z 2.2 -z 2.2 )×100% / Z 2.2 ] / 2=15.4%;

[0071] Zone 3: X-axis firing shrinkage: A3 = (X 3.1 -x 3.1 )×100% / X 3.1 =15.1%;

[0072] Y-axis firing shrinkage: B3= (Y 3.1 -y 3.1 )×100% / Y 3.1 =15.1%;

[0073] Z-axis firing shrinkage: C3=(Z 3.1 -z 3.1 )×100% / Z 3.1 =15.4%.

[0074] Since each of the three partitions has a calibration column, the firing shrinkage rate of each partition is taken as the average firing shrinkage rate of the calibration columns in the respective partition according to the different number of calibration columns.

[0075] According to the shrinkage rate corresponding to the partition where the positioning column is located, calculate the corresponding position of the positioning column: as shown in the figure: positioning column D1: (DX1: DY1: DZ1), D2: (DX2: DY2: DZ2) are located in zone 1, positioning column D3: (DX3: DY3: DZ3), D4: (DX4: DY4: DZ4) are located in zone 2, and D5: (DX5: DY5: DZ5) is located in zone 3.

[0076] D1 positioning column blank position:

[0077] DX1=x1 / (100%-A1)=170.01;

[0078] DY1=y1 / (100%-B1)=17.71;

[0079] DZ1=z1 / (100%-C1)=29.55;

[0080] D2 positioning column blank position:

[0081] DX2=x2 / (100%-A1)=82.64;

[0082] DY2=y2 / (100%-B1)=167.65;

[0083] DZ2=z2 / (100%-C1)=29.55;

[0084] D3 positioning column blank position:

[0085] DX3=x3 / (100%-A2)=23.64;

[0086] DY3=y3 / (100%-B2)=76.83;

[0087] DZ3=z3 / (100%-C2)=29.55;

[0088] D4 positioning column blank position:

[0089] DX4=x4 / (100%-A2)=94.56;

[0090] DY4=y4 / (100%-B2)=35.46;

[0091] DZ4=z4 / (100%-C2)=29.55;

[0092] D5 positioning column blank position:

[0093] DX5=x5 / (100%-A3)=0;

[0094] DY5=y5 / (100%-B3)=0;

[0095] DZ5=z5 / (100%-C3)=29.55.

[0096] According to calculation, the coordinates of the positioning columns of the blank before firing of alumina ceramic are: D1 (-170.01: 17.71: 29.55), D2 (82.64: -167.65: 29.55), D3 (-23.64: -76.83: 29.55), D4 (94.56: 35.46: 29.55), D5 (0: 0: 29.55). Two circles of through holes and positioning columns are processed in sequence on the alumina ceramic blank plate. The processing technology is the same as that of the calibration piece.

[0097] Processing parameters: Use a Φ25mm vertical milling cutter to set the spindle speed to 6000r / min, feed rate to 1500mm / min, cutter speed to 300mm / min, cutting direction: down milling, cutting depth 1mm / layer, XY stepping amount: 1mm, tool diameter 45%, Z layer maximum rough cutting stepping amount: 2mm, entry method: oblique insertion, safety height: 100mm, reference height: 10mm, cutter position: 3mm, cutter depth: 1mm, and processing time 30min. According to this processing parameter, the total processing time is 532min.

[0098] The product is fired at high temperature, and the firing temperature is the same as that of the calibration part.

[0099] Comparative Example 1

[0100] The prepared ceramic special-shaped part is the same as that in Example 1, and the preparation process is as follows:

[0101] First, the ceramic blank is processed into thickness and outer diameter. The thickness is the sum of the thickness of the disc and the height of the positioning column. After being fired at a high temperature of 1600℃, the ceramic part is: a disc with a diameter of Φ300mm and a diameter of H25mm.

[0102] The fired alumina ceramic disc is marked on the drawing and two circles of through holes and five positioning columns are processed on the engraving machine. Since the fired ceramic product has high strength and hardness and is difficult to process, a high speed and low feed rate processing method should be used during processing.

[0103] Processing parameters: Use Φ25mm grinding rod to set the spindle speed to 18000r / min, feed rate to 2000mm / min, cutter speed to 50mm / min, cutting direction: down milling, XY stepping amount: 1mm, tool diameter 45%, Z layer maximum rough cutting stepping amount: 0.01mm, entry method: oblique insertion, safety height: 100mm, reference height: 10mm, cutter position: 3mm, cutter depth: 1mm. Processing time: 180min. According to this processing parameter, the total processing time is: 2700min.

[0104] Example 2

[0105] The prepared ceramic special-shaped part is a zirconia circular ceramic disk, and the preparation method comprises the following steps:

[0106] The zirconia circular ceramic disk (Φ600mm, H20mm) has 4 evenly distributed 80×80mm ear-shaped protrusions on the outside, and 6 evenly distributed special-shaped through holes are opened between Φ200mm and Φ400mm. There are 8 positioning columns (Φ20mm, H35mm) on the ceramic disk. The center position of the bottom circle is calibrated as the center origin. The corresponding center coordinates of the upper surface of the positioning columns are: D1 (0:-340:55), D2 (0:340:55), D3 (150:-190:55), D4 (-240:50:55), D5 (-150:0:55), D6 (60:140:55), D7 (-50:50:55), D8 (50:40:55), such as Figure 3 As shown in Figures c and d.

[0107] According to the drawing, the special-shaped partitions of the ceramic plate are divided into four zones from the outside to the inside: Zone 1, Zone 2, Zone 3, and Zone 4. Figure 4 shown.

[0108] like Figure 4 As shown, four evenly distributed ear-shaped protrusions are first machined on the ceramic disk, and then six evenly distributed special-shaped through holes are punched in the middle, and then calibration columns are machined in each partition, namely: Zone 1 J1 (X1: Y1: Z1) calibration column; Zone 2 J2 (X2: Y2: Z2) calibration column; Zone 3 J3 (X3: Y3: Z3) calibration column, Zone 4 J4 (X4: Y4: Z4) calibration column. Since the ceramic green body has low strength and is easy to crack, a low-speed, large-feed processing method is used.

[0109] Processing parameters: Use a 20mm vertical milling cutter to set the spindle speed to 6000r / min, feed rate to 1500mm / min, cutter speed: 300mm / min, cutting direction: down milling, cutting depth 1mm / layer, XY stepping amount: 2mm, tool diameter 40%, Z layer maximum rough cutting stepping amount: 1mm, entry method: oblique insertion, safety height: 100mm, reference height: 10mm, cutter position: 3mm, cutter depth: 1mm.

[0110] The ceramic calibration piece is fired at 1500℃.

[0111] The positions of the calibration posts are measured respectively, which are: Zone 1 j1 calibration post: j1: (x1: y1: z1); Zone 2 j 2. Calibration column: j2: (x2: y2: z2); Zone 3 J3 calibration column: j3: (x3: y3: z3), Zone 4 J4 calibration column: j4: (x4: y4: z4). Calculate the firing shrinkage according to the formula:

[0112] Zone 1: X-axis firing shrinkage: A1=(X1-x1)×100% / X1=20.3%;

[0113] Y-axis firing shrinkage: B1=(Y1-y1)×100% / Y1=20.0%;

[0114] Z-axis firing shrinkage: C1=(Z1-z1)×100% / Z1=20.0%;

[0115] Zone 2: X-axis firing shrinkage: A2=(X2-x2)×100% / X2=19.8%;

[0116] Y-axis firing shrinkage: B2=(Y2-y2)×100% / Y2=19.8%;

[0117] Z-axis firing shrinkage: C2 = (Z2-z2) × 100% / Z2 = 20.0%;

[0118] Zone 3: X-axis firing shrinkage: A3=(X3-x3)×100% / X3=20.2%;

[0119] Y-axis firing shrinkage: B3=(Y3-y3)×100% / Y3=20.0%;

[0120] Z-axis firing shrinkage: C3=(Z3-z3)×100% / Z3=20.0%;

[0121] Zone 4: X-axis firing shrinkage: A4=(X4-x4)×100% / X4=19.6%;

[0122] Y-axis firing shrinkage: B4=(Y4-y4)×100% / Y4=19.8%;

[0123] Z-axis firing shrinkage: C4=(Z4-z4)×100% / Z4=20.0%.

[0124] According to the shrinkage rate corresponding to the partition where the positioning column is located, calculate the corresponding position of the positioning column: as shown in the figure: positioning column D1: (DX1: DY1: DZ1), D2: (DX2: DY2: DZ2) are located in zone 1, positioning column D3: (DX3: DY3: DZ3), D4: (DX4: DY4: DZ4) are located in zone 2, D5: (DX5: DY5: DZ5), D6: (DX6: DY6: DZ6) are located in zone 3, D7: (DX7: DY7: DZ7), D8: (DX8: DY8: DZ8) are located in zone 4.

[0125] D1 positioning column blank position:

[0126] DX1=x1 / (100%-A1)=0;

[0127] DY1=y1 / (100%-B1)=425;

[0128] DZ1=z1 / (100%-C1)=68.75;

[0129] D2 positioning column blank position: DX2=x2 / (100%-A1)=0;

[0130] DY2=y2 / (100%-B1)=425;

[0131] DZ2=z2 / (100%-C1)=68.75;

[0132] D3 positioning column blank position:

[0133] DX3=x3 / (100%-A2)=187.03;

[0134] DY3=y3 / (100%-B2)=236.91;

[0135] DZ3=z3 / (100%-C2)=68.75;

[0136] D4 positioning column blank position:

[0137] DX4=x4 / (100%-A2)=299.25;

[0138] DY4=y4 / (100%-B2)=62.34;

[0139] DZ4=z4 / (100%-C2)=68.75;

[0140] D5 positioning column blank position:

[0141] DX5=x5 / (100%-A3)=187.97;

[0142] DY5=y5 / (100%-B3)=0;

[0143] DZ5=z5 / (100%-C3)=68.75;

[0144] D6 positioning column blank position:

[0145] DX6=x6 / (100%-A3)=75.19;

[0146] DY6=y6 / (100%-B3)=175;

[0147] DZ6=z6 / (100%-C3)=68.75.

[0148] D7 positioning column blank position:

[0149] DX7=x7 / (100%-A4)=62.19;

[0150] DY7=y7 / (100%-B4)=62.34;

[0151] DZ7=z7 / (100%-C4)=68.75;

[0152] D8 positioning column blank position:

[0153] DX8=x8 / (100%-A4)=62.19;

[0154] DY8=y8 / (100%-B4)=49.88;

[0155] DZ8=z8 / (100%-C4)=68.75.

[0156] According to the calculation, the coordinates of the positioning columns of the blank of the zirconia ceramic parts before firing are: D1 (0: -425: 68.75), D2 (0: 425: 68.75), D3 (187.03: -236.91: 68.75), D4 (-299.25: 62.34: 68.75), D5 (-187.97: 0: 68.75), D6 (75.19: 175: 68.75), D7 (-62.19: 62.34: 68.75), D8 (62.19: 49.88: 68.75). Four evenly distributed ear-shaped protrusions are processed on the zirconia ceramic blank plate in sequence, and then six evenly divided special-shaped through holes are processed in the middle, and finally eight positioning columns are processed. The processing technology is the same as that of the calibration piece.

[0157] Processing parameters: Use a 20mm vertical milling cutter to set the spindle speed to 6000r / min, feed rate to 1500mm / min, cutter speed to 300mm / min, cutting direction: down milling, cutting depth to 1mm / layer, XY stepping amount to 2mm, tool diameter to 40%, Z layer maximum rough cutting stepping amount to 1mm, entry method to oblique insertion, safety height to 100mm, reference height to 10mm, cutter position to 3mm, cutter depth to 1mm, and processing time to 60mm. According to these processing parameters, the total processing time is 2625min.

[0158] The product is fired at high temperature, and the firing temperature is the same as that of the calibration part.

[0159] Comparative Example 2

[0160] The prepared ceramic special-shaped part is the same as that in Example 2, and the preparation process is as follows:

[0161] First, the ceramic blank is processed into thickness and outer contour size, the thickness is the sum of the thickness of the disc and the height of the positioning column. After being fired at a high temperature of 1500℃, the ceramic part is: a disc of Φ760mm and H55mm.

[0162] The fired zirconia ceramic disc is processed with 4 evenly distributed ear-shaped protrusions on the engraving machine according to the marked positions on the drawing, 6 evenly distributed special-shaped through holes in the middle, and finally 8 positioning columns. Since the fired ceramic product has high strength and hardness and is difficult to process, high speed and low feed rate processing methods should be adopted during processing.

[0163] Processing parameters: Use 25mm grinding rod to set the spindle speed to 18000r / min, feed rate to 1200mm / min, cutter rate to 50mm / min, cutting direction to down milling, XY stepping amount to 2mm, tool diameter to 30%, Z layered maximum rough cutting stepping amount to 0.01mm, entry method to oblique insertion, safety height to 100mm, reference height to 10mm, cutter position to 2mm, cutter depth to 0.5mm, and processing time to 360min. According to these processing parameters, the total processing time is 12600min.

[0164] Example 3

[0165] The prepared ceramic special-shaped part is a silicon nitride ceramic square disk, and the preparation method comprises the following steps:

[0166] On the silicon nitride ceramic square disk (400×400mm, H25mm), there is a 50×50mm square hole at the center, and there are 4 evenly distributed 50×50mm square holes outside. There are 5 positioning columns (Φ35mm, H50mm) on the ceramic disk. The center of the bottom circle is calibrated as the center origin. The corresponding center coordinates of the upper surface of the positioning columns are: D1 (-185:-185:75), D2 (185:185:75), D3 (0:-100:75), D4 (0:100:75), D5 (-60:0:75), such as Figure 5 As shown in Figures e and f.

[0167] According to the drawing, the special-shaped partitions of the ceramic plate are divided into three zones from the outside to the inside: Zone 1, Zone 2, and Zone 3. Figure 6 shown.

[0168] like Figure 6 As shown, five square holes are first machined on the ceramic plate, and then calibration columns are machined in each partition, namely: Zone 1 J 1.1 (X 1.1 : Y 1.1 :Z 1.1 )、J 1.2(X 1.2 : Y 1.2 :Z 1.2 ) calibration column; zone 2 J 2.1 (X 2.1 : Y 2.1 :Z 2.1 )、J 2.2 (X 2.2 : Y 2.2 :Z 2.2 ) calibration column; zone 3 J 3.1 (X 3.1 : Y 3.1 :Z 3.1 )Calibration column. Since the ceramic green body has low strength and is easy to crack, a low speed and large feed processing method is adopted.

[0169] Processing parameters: Use Φ25mm vertical milling cutter to set the spindle speed to 8000r / min, feed rate to 1200r / min, cutter speed: 200mm / min, cutting direction: down milling, XY stepping amount: 1mm, tool diameter 35%, Z layer maximum rough cutting stepping amount: 1mm, entry method: oblique insertion, safety height: 100mm, reference height: 10mm, cutter position: 3mm, cutter depth: 0.5mm.

[0170] The ceramic calibration piece is fired at 1700℃.

[0171] Measure the positions of the calibration columns respectively: Zone 1 calibration column: j 1.1 :(x 1.1 :y 1.1 :z 1.1 ),j 1.2 :(x 1.2 :y 1.2 :z 1.2 ); Zone 2 calibration column: j 2.1 :(x 2.1 :y 2.1 :z 2.1 ),j 2.2 :(x 2.2 :y 2.2 :z 2.2 ); 3-zone calibration column: j 3.1 :(x 3.1 :y 3.1 :z 3.1 ). Calculate the firing shrinkage according to the formula:

[0172] Zone 1: X-axis firing shrinkage: A1=[(X 1.1 -x 1.1 )×100% / X 1.1 +(X 1.2 -x 1.2)×100% / X 1.2 ] / 2=20.5%;

[0173] Y-axis firing shrinkage: B1=[(Y 1.1 -y 1.1 )×100% / Y 1.1 + (Y 1.2 -y 1.2 )×100% / Y 1.2 ] / 2=20.5%;

[0174] Z-axis firing shrinkage: C1=[(Z 1.1 -z 1.1 )×100% / Z 1.1 +(Z 1.2 -z 1.2 )×100% / Z 1.2 ] / 2=20.8%;

[0175] Zone 2: X-axis firing shrinkage: A2=[(X 2.1 -x 1.1 )×100% / X 2.1 +(X 2.2 -x 2.2 )×100% / X 2.2 ] / 2=19.8%;

[0176] Y-axis firing shrinkage: B2=[(Y 2.1 -y 1.1 )×100% / Y 2.1 + (Y 2.2 -y 2.2 )×100% / Y 2.2 ] / 2=19.9%;

[0177] Z-axis firing shrinkage: C2=[(Z 2.1 -z 2.1 )×100% / Z 2.1 +(Z 2.2 -z 2.2 )×100% / Z 2.2 ] / 2=20.8%;

[0178] Zone 3: X-axis firing shrinkage: A3 = (X 3.1 -x 3.1 )×100% / X 3.1 =20.4%;

[0179] Y-axis firing shrinkage: B3= (Y 3.1 -y 3.1 )×100% / Y 3.1 =20.6%;

[0180] Z-axis firing shrinkage: C3=(Z 3.1 -z 3.1 )×100% / Z 3.1 =20.8%.

[0181] According to the shrinkage rate corresponding to the partition where the positioning column is located, calculate the corresponding position of the positioning column: as shown in the figure: positioning column D1: (DX1: DY1: DZ1), D2: (DX2: DY2: DZ2) are located in zone 1, positioning column D3: (DX3: DY3: DZ3), D4: (DX4: DY4: DZ4) are located in zone 2, and D5: (DX5: DY5: DZ5) is located in zone 3.

[0182] D1 positioning column blank position:

[0183] DX1=x1 / (100%-A1)=232.70;

[0184] DY1=y1 / (100%-B1)=232.70;

[0185] DZ1=z1 / (100%-C1)=94.70;

[0186] D2 positioning column blank position:

[0187] DX2=x2 / (100%-A1)=232.70;

[0188] DY2=y2 / (100%-B1)=232.70;

[0189] DZ2=z2 / (100%-C1)=94.70;

[0190] D3 positioning column blank position:

[0191] DX3=x3 / (100%-A2)=0;

[0192] DY3=y3 / (100%-B2)=124.84;

[0193] DZ3=z3 / (100%-C2)=94.70;

[0194] D4 positioning column blank position:

[0195] DX4=x4 / (100%-A2)=0;

[0196] DY4=y4 / (100%-B2)=124.84;

[0197] DZ4=z4 / (100%-C2)=94.70;

[0198] D5 positioning column blank position:

[0199] DX5=x5 / (100%-A3)=75.38;

[0200] DY5=y5 / (100%-B3)=0;

[0201] DZ5=z5 / (100%-C3)=94.70.

[0202] According to calculation, the coordinates of the positioning columns of the blank before firing of the silicon nitride ceramic part are: D1 (-232.70: -232.70: 94.70), D2 (232.70: 232.70: 94.70), D3 (0: -124.84: 94.70), D4 (0: 124.84: 94.70), D5 (-75.38: 0: 94.70). Five square holes are processed on the silicon nitride ceramic blank plate in sequence, and finally five positioning columns are processed. The processing technology is the same as that of the calibration part.

[0203] Processing parameters: Use a Φ25mm vertical milling cutter to set the spindle speed to 8000r / min, feed rate to 1200r / min, cutter rate to 200mm / min, cutting direction: down milling, XY stepping amount: 1mm, tool diameter 35%, Z layered maximum rough cutting stepping amount: 1mm, entry method: oblique insertion, safety height: 100mm, reference height: 10mm, cutter position: 3mm, cutter depth: 0.5mm, and processing time 40min. According to this processing parameter, the total processing time is: 2525min.

[0204] The product is fired at high temperature, and the firing temperature is the same as that of the calibration part.

[0205] Comparative Example 3

[0206] The prepared ceramic special-shaped part is the same as that in Example 3, and the preparation process is as follows:

[0207] First, the ceramic blank is processed into thickness and outer contour size. The thickness is the sum of the thickness of the disc and the height of the positioning column. After being fired at a high temperature of 1700℃, the ceramic piece is a square plate of 400×400mm and H55mm. H represents thickness.

[0208] The fired silicon nitride ceramic plate is processed with 5 square holes in sequence on the engraving machine according to the marked positions on the drawing, and then 5 positioning columns are processed. Since the fired ceramic product has high strength, high hardness and is difficult to process, a high speed and low feed rate processing method should be used during processing.

[0209] Processing parameters: Use 25mm grinding rod to set the spindle speed to 20000r / min, feed rate to 2000r / min, cutter rate to 500mm / min, cutting direction to down milling, XY stepping amount to 1mm, tool diameter to 30%, Z layered maximum rough cutting stepping amount to 1mm, entry method to oblique insertion, safety height to 100mm, reference height to 10mm, cutter position to 0.2mm, cutter depth to 0.15mm, and processing time to 240min. According to these processing parameters, the total processing time is 12000min.

[0210] The ceramic products prepared in the above embodiments and comparative examples were tested using a three-coordinate measuring machine, and the test results are shown in Table 1. At the same time, the processing time was analyzed, and the results are shown in Table 1.

[0211] Table 1 Test results

[0212]

[0213] As can be seen from the above, compared with the comparative example, the flatness and verticality of the processed products of the embodiments of the present invention are almost the same, and the same processing effect can be achieved. However, in the comparative example, after the regular whole ceramic piece with processing allowance is fired, holes are opened at the corresponding positions of the ceramic plate blank according to the drawings, and special-shaped or positioning columns are processed. This method results in a large processing allowance, and due to the high hardness of the ceramic after firing, it leads to low processing efficiency, long processing time, and low processing yield rate. Therefore, compared with the comparative example, the processing time of the embodiment is shortened and the processing efficiency is high.

Claims

1. A process for preparing a ceramic special-shaped part, characterized in that: The following steps are involved: (1) Preparing calibration parts and calculating firing shrinkage: According to the drawings, the ceramic green body block is divided into a plurality of partitions, and the center position of the ceramic green body block is calibrated as the origin of each partition. The special-shaped parts of each partition are arranged in an axisymmetric manner. The special-shaped parts are processed. The outer contour, holes, and special-shaped parts are processed by a precision engraving machine or a CNC machine. Calibration columns are processed on different partitions. Each partition has at least one calibration column. The coordinate positions of the calibration columns are recorded. The number of calibration columns is ≥ the number of partitions. After firing, the coordinate positions of the calibration columns are measured to obtain calibration parts, and the firing shrinkage rates of the calibration columns of different partitions are calculated respectively. The special-shaped parts include holes and / or ear-shaped protrusions of different shapes. (2) According to the firing shrinkage rates of the calibration columns in different partitions, the relative positions of the different positioning columns and the relative positions of the special-shaped parts are calculated respectively; (3) Processing ceramic special-shaped parts: taking the same batch of ceramic green blocks as in step (1), processing all positioning posts according to the relative positions of different positioning posts, first calibrating the relative positions of the special-shaped parts, then processing the special-shaped parts, and finally firing to obtain ceramic special-shaped parts; the processing technology of the different positioning posts and special-shaped parts in step (3) is the same as the processing technology of the special-shaped parts and calibration posts in step (1); The sintering temperature in step (3) is the same as that in step (1), which is 1500-1700° C. The processing technology for processing the special-shaped parts and the calibration column in step (1) is: use a Φ20-25mm vertical milling cutter, set the spindle speed to 6000-8000r / min, the feed rate to 1200-1500mm / min, the cutting rate to 200-400mm / min, the cutting direction to down milling, the XY stepping amount to 1-2mm, the tool diameter to 35-45%, the maximum rough cutting stepping amount of the Z layer to 1-2mm, the entry method to oblique insertion, and the cutting depth to 0.5-1mm.

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