A method for 3DP manufacturing of an alumina ceramic part

Abstract

The application relates to the field of additive manufacturing, in particular to a 3DP manufacturing method of an alumina ceramic part, which comprises the following steps: mixing alumina, aluminum dihydrogen phosphate, a curing agent and a mineralizing agent to obtain 3DP pre-preparation powder; printing a ceramic part by using the 3DP pre-preparation powder and water-based ink to obtain a ceramic printed part; integrally baking and curing the ceramic printed part and the powder bed; sequentially performing powder cleaning, vacuum impregnation and drying treatment on the ceramic green body after curing to obtain a ceramic part green body; and sintering the ceramic part green body to obtain a formed ceramic part. The application uses aluminum dihydrogen phosphate as a binder to form a high-performance porous ceramic part, and through a suitable post-processing process, a ceramic part with excellent performance is obtained.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of additive manufacturing, in particular to a 3DP manufacturing method of an alumina ceramic part. BACKGROUND

[0002] Electrically fused corundum has the characteristics of high temperature chemical property stability and high high temperature strength, so it is widely used in the field of investment casting of high temperature alloy, and is widely used as a core and a shell material in the field of investment precision casting. Active alumina has the characteristics of high dispersity, high adsorption performance, high surface activity, excellent thermal stability and reusability, and is widely used in the field of new reusable filters. With the development of engineering technology, the structure of ceramic parts tends to be integrated and complex, mainly in complex shape and complex internal channels. However, because of the high hardness and brittleness of ceramic materials, traditional processing methods need to use molds to process ceramic parts, and the higher the complexity of the parts, the higher the cost of mold opening, and the process flow is complex, the production rate is low, the scrap rate is high and the product iteration speed is slow, so it is difficult to design and manufacture complex ceramic parts.

[0003] Binder Jetting (BJ) technology, also known as 3DP technology, has the advantages of high manufacturing precision, fast printing speed, reusable materials, good manufacturing economy and wide material selection range compared with other additive manufacturing technologies. The principle of this technology is to first convert the CAD model into a two-dimensional model using slicing software, and then spray the ink that can make the sprayed powder stick together according to the predetermined path after each layer of powder laying is completed, and then print layer by layer until completion. However, the current 3DP technology for manufacturing ceramics has the following problems: (1) the binder used is usually organic binder such as furan resin, phenolic resin or silicate binder, but the organic binder has a slow solidification speed, and will pyrolyze and produce harmful gases during high temperature sintering of ceramics, causing environmental pollution; and the silicate binder will soften at a temperature above 1000℃, causing the ceramic part to crack and drift, ultimately resulting in reduced casting precision and service temperature; (2) the carbon residue produced after the shell pyrolysis will cause the surface performance of the casting to decrease, the effective content of alumina in the formed part is low, and the ceramic part may collapse during high temperature sintering, thereby reducing the yield of the product. Therefore, it is of great significance to develop an alumina ceramic 3DP manufacturing method with high precision, high high temperature strength, good high temperature adhesion, no harm to human body and environment during production. SUMMARY

[0004] In order to overcome the above technical problems, the present application provides a 3DP manufacturing method of an alumina ceramic part, and the prepared 3DP ceramic part has the advantages of high precision, high high temperature strength, small high temperature creep, low sintering shrinkage and controllable porosity.

[0005] The application provides a 3DP manufacturing method of an alumina ceramic part, comprising the following steps:

[0006] Mixing alumina, aluminum dihydrogen phosphate, a curing agent and a mineralizing agent to obtain 3DP pre-preparation powder;

[0007] Printing a ceramic part by using the 3DP pre-preparation powder and water-based ink to obtain a ceramic printed part;

[0008] Overall baking and curing the ceramic printed part and the powder bed;

[0009] Carrying out powder cleaning, vacuum impregnation and drying treatment on the ceramic green body after curing to obtain a ceramic part green body;

[0010] Sintering the ceramic part green body to obtain a formed ceramic part.

[0011] Preferably, the content of the aluminum dihydrogen phosphate is 8-12%, the content of the curing agent is 4-8%, the content of the alumina is 76-78.1%, and the content of the mineralizing agent is 4-9.9% based on the total mass of the 3DP pre-preparation powder.

[0012] Preferably, the particle size of the alumina is 150-800 mesh, the particle size of the aluminum dihydrogen phosphate is 120-200 mesh, the particle size of the curing agent is 2000-3000 mesh, and the particle size of the mineralizing agent is 700-800 mesh.

[0013] Preferably, the content of H2O in the water-based ink is greater than 70%, and the apparent viscosity value at 20°C and a shear rate of 1 s -1 -1 is not higher than 10 mPa·s, and the surface tension at 20°C is 30 mN / m.

[0014] Preferably, the alumina, the curing agent and the mineralizing agent are mixed after being dried respectively and then mixed with the aluminum dihydrogen phosphate powder.

[0015] Preferably, the alumina is selected from one or more of white corundum, fused corundum, alpha alumina and active alumina;

[0016] The mineralizing agent is selected from a mixture of one or more of silicon oxide, yttrium oxide, zirconium oxide, boehmite, kyanite and fused mullite powder;

[0017] The curing agent is selected from one or more of magnesium oxide, zinc oxide, magnesium-aluminum spinel, diiron trioxide and copper oxide.

[0018] Preferably, the printing layer is subjected to real-time heating treatment during the printing process, and the heating power is 400-2400 W.

[0019] Preferably, the baking temperature of the baking curing treatment is 170-280 DEG C, and the baking time is 1-2 hours.

[0020] Preferably, the vacuum degree of the vacuum impregnation is less than or equal to 100 Pa, the impregnation time is 60-150 minutes, the drying temperature is 100 DEG C, and the drying time is 30-60 minutes.

[0021] The solution used in the vacuum impregnation is one of a silica sol, a nano-mineralizer particle suspension, a nano-alumina suspension, a silica sol and nano-mineralizer mixed suspension, or a silica sol and nano-alumina mixed suspension.

[0022] Preferably, the sintering is performed in a programmed temperature rising manner, and the programmed temperature rising process is: rising the temperature to 1150 DEG C at a temperature rising rate of 3-5 DEG C / min and keeping for 30-60 min, rising the temperature to 1300 DEG C at a temperature rising rate of 2-5 DEG C / min and keeping for 30-60 min, and then rising the temperature to a sintering temperature point at a temperature rising rate of 2-5 DEG C / min and keeping for 45-80 min.

[0023] Preferably, the printing layer height is 0.05-0.30 mm, and the inkjet concentration is 30%-75% when printing.

[0024] Compared with the prior art, the present application has the following beneficial effects:

[0025] 1. The present application uses aluminum dihydrogen phosphate as a binder, which has the following advantages: (1) the curing time of aluminum dihydrogen phosphate as a binder is shorter than that of traditional resin binders; (2) aluminum dihydrogen phosphate is an inorganic compound, which will not produce harmful gases like resin pyrolysis in a high-temperature sintering environment; (3) aluminum dihydrogen phosphate has a binding property at 1500 DEG C, at which temperature the ceramics have begun to sinter, avoiding the collapse phenomenon between the ceramics during the sintering process and improving the yield of ceramic parts; (4) it is widely available and low in cost, saving manufacturing costs.

[0026] 2. The present application uses water-based ink and aluminum dihydrogen phosphate in the powder bed as a binder, which has the following advantages: (1) the water in the water-based ink can quickly dissolve the powder aluminum dihydrogen phosphate, forming an aluminum dihydrogen phosphate solution and distributing between the particles, and forming a binding bridge after drying; (2) water-based ink has less corrosiveness to the nozzle than solvent-based ink or UV ink, which can improve the service life of the nozzle and reduce the risk of clogging; (3) water-based ink is an environmentally friendly ink, which will not produce carbon dioxide and other harmful gases during the sintering process.

[0027] 3、The mineralizer has the following three advantages: (1) the mineralizer can fill the gaps between the alumina powder particles, improve the packing density of the powder bed, and further improve the density of the product; (2) the mineralizer can form a reinforcing phase with the alumina powder during high-temperature sintering, improving the high-temperature service strength of the product; (3) when used for ceramic core products, the presence of the mineralizer can improve the chemical washing out of the core.

[0028] 4、The curing agent has the following advantages: (1) the curing agent can reduce the curing time and temperature of aluminum dihydrogen phosphate, improve the production rate, and save energy; (2) the curing agent can reduce the water absorption of the sample after sintering and curing, so that the sample has higher strength in the air and is easy to infiltrate; (3) in high-temperature sintering, the presence of the curing agent can improve the high-temperature bonding strength of the binder, prevent the ceramic product from collapsing during sintering, and improve the yield.

[0029] 5、The printed layer is subjected to real-time heating treatment, which has the following two advantages: (1) the temperature rise in the printing area can cause the aluminum dihydrogen phosphate to be preliminarily cured, thereby improving the bonding strength; (2) the temperature rise in the printing area can speed up the evaporation of the ink, reducing the infiltration distance of the ink in the powder bed and thereby improving the printing accuracy.

[0030] 6、The baking process can cause the product to be cured at a lower temperature, and the residual moisture in the ceramic product is released, so that the green body of the ceramic part has the strength to resist damage during powder cleaning, the curing of aluminum dihydrogen phosphate is completed, and the green body is prevented from collapsing during vacuum infiltration.

[0031] 7、The vacuum infiltration process is used, first, the vacuum state infiltration liquid can enter the sample interior more completely, improving the bulk density of the sample and reducing the porosity, thereby improving the bending strength; second, the degree of completeness of the infiltration can be controlled by adjusting the vacuum degree and infiltration time during vacuum infiltration, so as to achieve a ceramic part with controllable porosity; finally, using different infiltration liquids can make the ceramic part have different properties, thereby meeting more use requirements and being applied to more extensive use occasions.

[0032] 8、The ceramic product prepared by the method provided by the present application has the advantages of high precision, high high-temperature strength, small high-temperature creep, low sintering shrinkage, controllable porosity, etc., and good chemical stability during casting after investment casting, thereby avoiding problems such as large shrinkage during sintering, insufficient strength after sintering, and collapse caused by insufficient strength after sintering.

[0033] 9、The ceramic part manufactured by the ceramic 3DP manufacturing method provided by the application can be manufactured into any complex shape and structure, is suitable for ceramic cores for investment casting, ceramic molds for high-temperature casting and porous ceramic filters and other parts with complex structures, can effectively reduce manufacturing cost, shorten product manufacturing cycle and improve product yield, and effectively solve the problem of difficult complex ceramic processing, which includes the difficulties in traditional injection molding ceramic preparation, such as long mold opening time, high cost, precision depending on mold and high scrap rate, and the difficulties in the current stereoscopic photocuring molding, such as the need for support structure, slow printing speed, high cost and high sintering shrinkage rate. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 is a schematic diagram of an alumina ceramic core for hollow turbine blade investment casting in the embodiment 1 of the application;

[0035] Figure 2 is a schematic diagram of an alumina ceramic filter in the embodiment 4 of the application;

[0036] Figure 3 is a schematic diagram of a mold shell for hollow turbine blade casting in the embodiment 8 of the application;

[0037] Figure 4 is a schematic diagram of a printer provided with a traveling heating device in the embodiment of the application; 1, powder laying device; 2, feeding bin; 3, printing head; 4, traveling heating device; 5, powder bed; 11, moving track; 12, mounting frame;

[0038] Figure 5 is a structural schematic diagram of the traveling heating device provided by the embodiment of the application; 6, shell; 7, heating wire; 8, reflective film; 9, heat insulation cotton; 10, stepless control switch. DETAILED DESCRIPTION

[0039] The application will be further described below in combination with the drawings and embodiments.

[0040] The application is realized by the following technical scheme:

[0041] The alumina ceramic 3DP manufacturing method provided by the application comprises the following steps:

[0042] S1, dry the alumina powder, solidifying agent and mineralizing agent respectively, then mix them with freshly opened aluminum dihydrogen phosphate to obtain 3DP molding material; the particle size of the alumina is 150-800 mesh, the particle size of the aluminum dihydrogen phosphate is 120-200 mesh, the particle size of the solidifying agent is 2000-3000 mesh, the particle size of the mineralizing agent is 700-800 mesh, the mass of the alumina powder accounts for 76-78.1% of the total 3DP printing material, the mass of the alumina and the mineralizing agent accounts for 80-88% of the total 3DP printing material, the mass of the aluminum dihydrogen phosphate powder accounts for 8-12% of the total 3DP printing material, and the mass of the solidifying agent accounts for 4-8% of the total 3DP printing material; the powder of 150-200 mesh and the powder of 700-800 mesh are prepared according to the mass ratio of 14:6-14:8.

[0043] S2, import the ceramic part model data to be printed into the 3D printer, use the 3DP molding material prepared in S1 and the water-based printing ink to prepare the ceramic 3DP molding, and obtain the ceramic part green body; during the printing process, the printing layer height is 0.05-0.30 mm, and the inkjet concentration is 30-75%; the heating device works during the printing process, and the heating power is 400-2400 W.

[0044] S3, after S2 is finished, the whole powder bed is moved into the air drying oven for baking and curing, the baking temperature is 170-280℃, and the baking time is 1-2 hours.

[0045] S4, after the powder bed is cooled, the ceramic green body after curing is taken out for powder cleaning treatment, the outer surface is cleaned with a brush, and the inner hole is cleaned with high-pressure gas.

[0046] S5, the ceramic sample after the above powder cleaning is vacuum infiltrated.

[0047] The vacuum degree of the infiltration is ≤100 Pa, and the infiltration time is 60-150 minutes.

[0048] The infiltration solution is one of silicon sol, nano-mineralizing agent particle suspension, nano-alumina suspension, silicon sol and nano-mineralizing agent mixed suspension, and silicon sol and nano-alumina mixed suspension.

[0049] S6, the ceramic sample after the above infiltration is dried, the drying temperature is 100℃, and the time is 30-60 minutes.

[0050] S7. The dried sample is sintered as follows: First, the temperature is increased from room temperature to 1150℃ at a heating rate of 3-5℃ / min and held for 30-60 minutes; then the temperature is increased to 1300℃ at a heating rate of 2-5℃ / min and held for 30-60 minutes; then the temperature is increased to the sintering temperature at a heating rate of 2-5℃ / min and held for 45-80 minutes, and then cooled with the furnace to obtain ceramic parts.

[0051] The sintering temperature is determined by the type of mineralizer and the sintering shrinkage rate. Those skilled in the art can set the sintering temperature according to the specific mineralizer and sintering shrinkage rate selected in specific embodiments. For example, for the alumina ceramic parts in this invention, the sintering temperature is between 1450 and 1700°C, with the specific sintering temperature selected based on the mineralizer. For instance, if the mineralizer is silicon dioxide, a sintering temperature of 1350–1500°C is recommended, with mullite as the reinforcing phase; if the mineralizer is calcium oxide, a sintering temperature of [missing information] is recommended.

[0052] 1500–1700℃, the reinforcing phase is CaAl 12 O 19 If the mineralizer is magnesium oxide, the recommended sintering temperature is 1350-1550℃, and the reinforcing phase is magnesium aluminum spinel, etc. Different sintering temperatures and times will regulate the shrinkage rate and porosity. Generally speaking, the higher the temperature and the longer the time, the greater the shrinkage rate, the lower the porosity, and the higher the strength.

[0053] The accompanying heating device is installed on an existing printer. This embodiment of the invention uses the Wuhan Easy3DP-M450 printer, which has a moving track 11 on which the accompanying heating device is mounted. Figure 4 As shown.

[0054] Specific structure of the accompanying heating device in this embodiment of the invention ( Figure 5 The portable heating device includes an aluminum alloy housing 6, inside which are six 400W heating wires 7. A reflective film 8 is affixed to the inner wall of the aluminum alloy housing 6. A stepless power control switch 10 is installed on the aluminum alloy housing 6 to control the operation of the heating wires 7. Heat insulation cotton 9 (10mm thick, from Jinchan Insulation Materials Co., Ltd.) is also provided between the reflective film 8 and the inner wall of the aluminum alloy housing 6. The aluminum alloy housing 6 slides along the moving track 11 via a mounting bracket 12 that slides on the moving track 11.

[0055] The parameters are as follows: Heating wire 7 (brand: Tempered Glass; material: iron-chromium-aluminum; power: 400W; voltage: 220V; length: 360mm; outer diameter: 3.9mm), control switch 10 (single-phase AC fan speed controller); housing 6 material: aluminum alloy 5052-H112. Reflective film 8 uses heat-insulating aluminum sheet, resistant to high temperature of 500℃.

[0056] Working principle: the control switch 10 controls six heating wires 7 respectively, so that the heating power changes from 400 to 2400 W; the reflective film 8 makes the heat concentrate downward; the heat insulation cotton 9 protects the shell and makes the equipment more safe during working. The whole is fixed by the mounting frame 12, so that the heating function is realized on the moving track 11.

[0057] The alumina powder used in the application can be mixed with different particle size grades of one material or different particle size grades of several materials to obtain.

[0058] The mineralizer used in the application can be one or a mixture of several of silicon oxide, magnesium oxide, yttrium oxide, zirconium oxide, boehmite, kyanite and fused mullite powder.

[0059] The application will be described below in conjunction with specific examples.

[0060] Example 1

[0061] The 3DP manufacturing method provided by the application is used to manufacture a hollow turbine blade ceramic mold core for investment casting with thin-walled curved surface structure and fine features, which comprises the following steps:

[0062] S1, the electrically fused corundum powder with particle size of 150-200 mesh, the electrically fused corundum powder with particle size of 700-800 mesh and the silicon dioxide powder with particle size of 700-800 mesh are mixed uniformly in a mass ratio of 14:5:1, and then are baked and dried with the magnesium oxide powder with particle size of 2000-3000 mesh, and then are mixed uniformly with the aluminum dihydrogen phosphate powder with particle size of 120-200 mesh and effective component of 95%, to obtain 3DP pre-prepared powder. The mass ratio of the alumina and silicon dioxide graded mixed powder, the aluminum dihydrogen phosphate powder and the magnesium oxide powder is 80:12:8.

[0063] S2, the model data of the hollow turbine blade investment casting alumina ceramic mold core shown in Figure 1 is imported into the 3D printer, and the water-based ink is used as the printing ink to perform 3DP forming preparation of the ceramic, to obtain a ceramic mold core green body; during the printing process, the printing layer height is 0.05mm, the inkjet concentration is 30%, and the printing process uses the traveling heating device to perform real-time heating treatment on the printing layer, and the heating power is 400W.

[0064] S3, after S2 is finished, the whole powder bed is moved into the air drying oven for heating and curing, the heating temperature is 170 DEG C, and the baking time is 2 hours.

[0065] S4, after the powder bed is cooled with the furnace, the already cured ceramic mold core is taken out, and the powder is cleaned, the outer surface is cleaned using a brush, and the inner hole can be cleaned using high-pressure gas.

[0066] S5. After the above-mentioned powder cleaning is completed, the ceramic parts are subjected to vacuum impregnation. The impregnation vacuum degree is 100Pa, the impregnation liquid is nano mullite suspension, and the impregnation time is 60 minutes.

[0067] S6. After impregnation, the parts are baked and dried at 100°C for 30 minutes.

[0068] S7. The sintering temperature of the dried ceramic parts is 1550℃. The temperature is increased from room temperature to 1150℃ at a heating rate of 5℃ / min and held for 60 minutes. Then the temperature is increased to 1300℃ at a heating rate of 5℃ / min and held for 60 minutes. Finally, the temperature is increased to 1550℃ at a heating rate of 5℃ / min and held for 80 minutes. After that, the parts are cooled in the furnace to obtain high-performance ceramic core parts.

[0069] Example 2

[0070] The ceramic core for investment casting of hollow turbine blades, which has a thin-walled curved surface structure and fine features, is manufactured using the 3DP manufacturing method provided by this invention, comprising the following steps:

[0071] S1. Fused alumina powder with a particle size of 150-200 mesh, fused alumina powder with a particle size of 700-800 mesh, and silica powder with a particle size of 700-800 mesh are mixed evenly in a mass ratio of 16.3:5:2. This mixture is then baked and dried separately with magnesium oxide powder with a particle size of 2000-3000 mesh. Finally, it is mixed evenly with aluminum dihydrogen phosphate powder with a particle size of 120-200 mesh and an effective component content of 95%, to obtain the 3DP preform powder. The mass ratio of the alumina and silica powder, aluminum dihydrogen phosphate powder, and magnesium oxide powder is 84:10:6.

[0072] S2, will be as follows Figure 1 The data of the alumina ceramic core model for investment casting of hollow turbine blades was imported into a 3D printer. Water-based ink was used as the printing ink to prepare the ceramic 3DP molding, and a ceramic core blank was obtained. During the printing process, the printing layer height was 0.05mm, the ink density was 40%, and the printing layer was heated in real time using a traveling heating device with a heating power of 800W.

[0073] S3. After S2 is completed, the powder bed is moved into a forced-air drying oven for heating and curing at 200℃ for 1.5 hours.

[0074] S4. After the powder bed cools down with the furnace, the solidified ceramic core is removed and cleaned. The outer surface is cleaned with a brush, and the inner hole is cleaned with high-pressure gas.

[0075] S5. After the above-mentioned powder cleaning is completed, the ceramic parts are subjected to vacuum impregnation. The impregnation vacuum degree is 90 Pa, the impregnation solution is 30% silica sol, and the impregnation time is 90 minutes.

[0076] S6. After impregnation, the parts are baked and dried at a temperature of 100°C for 45 minutes.

[0077] S7. The sintering temperature of the dried ceramic parts is 1550℃. The temperature is increased from room temperature to 1150℃ at a heating rate of 3℃ / min and held for 30 minutes. Then the temperature is increased to 1300℃ at a heating rate of 2℃ / min and held for 30 minutes. Finally, the temperature is increased to 1550℃ at a heating rate of 2℃ / min and held for 45 minutes. After that, the parts are cooled in the furnace to obtain high-performance ceramic core parts.

[0078] Example 3

[0079] The ceramic core for investment casting of hollow turbine blades, which has a thin-walled curved surface structure and fine features, is manufactured using the 3DP manufacturing method provided by this invention, comprising the following steps:

[0080] S1. Fused alumina powder with a particle size of 150-200 mesh, fused alumina powder with a particle size of 700-800 mesh, and silica powder with a particle size of 700-800 mesh are mixed evenly in a mass ratio of 18.6:5:3. This mixture is then baked and dried separately with magnesium oxide powder with a particle size of 2000-3000 mesh. Finally, it is mixed evenly with aluminum dihydrogen phosphate powder with a particle size of 120-200 mesh and an effective component content of 95%, to obtain the 3DP preform powder. The mass ratio of the alumina and silica powder, aluminum dihydrogen phosphate powder, and magnesium oxide powder is 88:8:4.

[0081] S2, will be as follows Figure 1 The data of the alumina ceramic core model for investment casting of hollow turbine blades was imported into a 3D printer. Water-based ink was used as the printing ink to prepare the ceramic 3DP molding, and a ceramic core blank was obtained. During the printing process, the printing layer height was 0.1 mm, the ink density was 50%, and the printing layer was heated in real time using a traveling heating device with a heating power of 1200W.

[0082] S3. After S2 is completed, the powder bed is moved into a forced-air drying oven for heating and curing at 240℃ for 1.2 hours.

[0083] S4. After the powder bed cools down with the furnace, the solidified ceramic core is removed and cleaned. The outer surface is cleaned with a brush, and the inner hole is cleaned with high-pressure gas.

[0084] S5, vacuum infiltration is performed on the ceramic part after the powder cleaning, the vacuum degree of the infiltration is 100 Pa, the infiltration liquid is a nano-alumina turbid liquid, and the infiltration time is 120 minutes.

[0085] S6, baking and drying are performed on the part after the infiltration, the drying temperature is 100 DEG C, and the drying time is 50 minutes.

[0086] S7, the sintering temperature of the ceramic part after the drying is 1550 DEG C, the temperature is raised from room temperature to 1150 DEG C at a rate of 4 DEG C / min, kept for 45 minutes, then raised to 1300 DEG C at a rate of 4 DEG C / min, kept for 45 minutes, finally raised to 1550 DEG C at a rate of 4 DEG C / min, kept for 60 minutes, and then cooled in the furnace to obtain a high-performance ceramic core part.

[0087] Example 4

[0088] The 3DP manufacturing method provided by the application is used to manufacture the reusable alumina ceramic filter with high porosity, which comprises the following steps:

[0089] S1, active alumina powder with a particle size of 150-200 mesh, active alumina powder with a particle size of 700-800 mesh and mullite powder with a particle size of 700-800 mesh are uniformly graded mixed in a mass ratio of 14:5:1, and then baked and dried with magnesium oxide powder with a particle size of 2000-3000 mesh, and then mixed with aluminum dihydrogen phosphate powder with a particle size of 120-200 mesh and an effective component of 90%, to obtain 3DP pre-powder. The mass ratio of the graded mixed powder of alumina and mullite, aluminum dihydrogen phosphate powder and magnesium oxide powder is 80:12:8.

[0090] S2, as shown in Figure 2 The model data of the reusable alumina ceramic filter with high porosity is imported into the 3D printer, water-based ink is used as the printing ink for 3DP forming and preparation of the ceramic, and the ceramic core green body is obtained; during the printing process, the printing layer height is 0.2 mm, the inkjet concentration is 60%, and the printing layer is treated by real-time heating using a heating device during the printing process, and the heating power is 1600 W.

[0091] S3, after S2 is finished, the whole powder bed is moved into the air drying oven for heating and curing, the heating temperature is 170 DEG C, and the baking time is 2 hours.

[0092] S4, after the powder bed is cooled in the furnace, the cured ceramic core is taken out, and the powder is cleaned, the outer surface is cleaned with a brush, and the inner hole can be cleaned with high-pressure gas.

[0093] S5, vacuum impregnation is performed on the ceramic part after the above powder cleaning, the impregnation liquid is 30% silica sol, and the impregnation time is 120 minutes.

[0094] S6, baking and drying are performed on the part after impregnation, the drying temperature is 100 DEG C, and the drying time is 60 minutes.

[0095] S7, the sintering temperature of the dried ceramic part is 1550 DEG C, the temperature is raised from room temperature to 1150 DEG C at a rate of 5 DEG C / min, maintained for 60 minutes, then raised to 1300 DEG C at a rate of 5 DEG C / min, maintained for 60 minutes, finally raised to 1450 DEG C at a rate of 5 DEG C / min, maintained for 80 minutes, and then cooled in the furnace to obtain a high-performance ceramic core part.

[0096] Example 5

[0097] The 3DP manufacturing method provided by the application is used to manufacture the high-porosity alumina ceramic filter which can be reused, comprising the following steps:

[0098] S1, active alumina powder with a particle size of 150-200 mesh, active alumina powder with a particle size of 700-800 mesh and silica powder with a particle size of 700-800 mesh are uniformly graded mixed in a mass ratio of 16.3:5:2, and then dried with zinc oxide powder with a particle size of 2000-3000 mesh, and then mixed with aluminum dihydrogen phosphate powder with a particle size of 120-200 mesh and an effective component of 90%, to obtain 3DP pre-powder. The mass ratio of the graded mixed powder of fused alumina and silica, aluminum dihydrogen phosphate powder and zinc oxide powder is 84:10:6.

[0099] S2, as shown in Figure 2 The model data of the high-porosity alumina ceramic filter which can be reused is imported into the 3D printer, water-based ink is used as printing ink for 3DP forming and preparation of ceramics, and a ceramic core green body is obtained; during printing, the printing layer height is 0.3mm, the inkjet concentration is 75%, and the printing layer is treated by real-time heating during printing by using a heating device, and the heating power is 2400W.

[0100] S3, after S2 is finished, the whole powder bed is moved into the air drying oven for heating and curing, the heating temperature is 280 DEG C, and the baking time is 1.5 hours.

[0101] S4, after the powder bed is cooled in the furnace, the cured ceramic core is taken out, and the powder is cleaned, the outer surface is cleaned with a brush, and the inner hole can be cleaned with high-pressure gas.

[0102] S5, vacuum infiltration is performed on the ceramic part after the above-mentioned powder cleaning, the infiltration liquid is 30% silica sol, and the infiltration time is 120 minutes.

[0103] S6, baking and drying is performed on the part after infiltration, the drying temperature is 100 DEG C, and the drying time is 60 minutes.

[0104] S7, the sintering temperature of the ceramic part after drying is 1550 DEG C, the temperature is raised from room temperature to 1150 DEG C at a rate of 3 DEG C / min, kept for 30 minutes, then raised to 1300 DEG C at a rate of 2 DEG C / min, kept for 30 minutes, finally raised to 1450 DEG C at a rate of 2 DEG C / min, kept for 45 minutes, and then cooled in the furnace to obtain a high-performance ceramic core part.

[0105] Example 6

[0106] The 3DP manufacturing method provided by the application is used to manufacture the re-usable high-porosity alumina ceramic filter, which comprises the following steps:

[0107] S1, active alumina powder with a particle size of 150-200 mesh, active alumina powder with a particle size of 700-800 mesh and silica powder with a particle size of 700-800 mesh are uniformly graded mixed in a mass ratio of 18.6:5:3, and then baked and dried with zinc oxide powder with a particle size of 2000-3000 mesh, and then mixed with aluminum dihydrogen phosphate powder with a particle size of 120-200 mesh and an effective component of 90%, to obtain 3DP pre-powder. The mass ratio of the graded mixed powder of fused alumina and silica, aluminum dihydrogen phosphate powder and zinc oxide powder is 88:8:4.

[0108] S2, as shown in Figure 2 The model data of the re-usable high-porosity alumina ceramic filter is imported into the 3D printer, water-based ink is used as the printing ink for 3DP forming of the ceramic, and a ceramic core green body is obtained; during the printing process, the printing layer height is 0.1 mm, the inkjet concentration is 40%, and the printing layer is treated by real-time heating using a traveling heating device during the printing process, and the heating power is 1400 W.

[0109] S3, after S2 is completed, the whole powder bed is moved into the air drying oven for heating and curing, the heating temperature is 280 DEG C, and the baking time is 1 hour.

[0110] S4, after the powder bed is cooled in the furnace, the cured ceramic core is taken out, powder cleaning is performed, the outer surface is cleaned with a brush, and the inner hole can be cleaned with high-pressure gas.

[0111] S5, vacuum infiltration is performed on the ceramic part after the above-mentioned powder cleaning, the infiltration liquid is 30% silica sol, and the infiltration time is 120 minutes.

[0112] S6. After impregnation, the parts are baked and dried at a temperature of 100°C for 45 minutes.

[0113] S7. The sintering temperature of the dried ceramic parts is 1550℃. The temperature is increased from room temperature to 1150℃ at a heating rate of 4℃ / min and held for 45 minutes. Then the temperature is increased to 1300℃ at a heating rate of 4℃ / min and held for 45 minutes. Finally, the temperature is increased to 1450℃ at a heating rate of 4℃ / min and held for 60 minutes. After that, the parts are cooled in the furnace to obtain high-performance ceramic core parts.

[0114] Example 7

[0115] The reusable alumina ceramic filter with high porosity, manufactured using the 3DP manufacturing method provided by this invention, comprises the following steps:

[0116] S1. Activated alumina powder with a particle size of 150-200 mesh, activated alumina powder with a particle size of 700-800 mesh, and yttrium oxide powder with a particle size of 700-800 mesh are uniformly mixed in a mass ratio of 18.6:5:3. This mixture is then baked and dried separately with zinc oxide powder with a particle size of 2000-3000 mesh. Finally, it is mixed uniformly with aluminum dihydrogen phosphate powder with a particle size of 120-200 mesh and an effective component content of 90%, to obtain 3DP preformed powder. The mass ratio of the electrofused alumina and silica graded mixed powder, aluminum dihydrogen phosphate powder, and zinc oxide powder is 88:8:4.

[0117] S2, will be as follows Figure 2 The model data of a reusable alumina ceramic filter with high porosity was imported into a 3D printer. Water-based ink was used as the printing ink to prepare the ceramic 3DP molding, resulting in a ceramic core green body. During the printing process, the printing layer height was 0.15 mm, the ink concentration was 50%, and a traveling heating device was used to heat the printing layer in real time with a heating power of 2000 W.

[0118] S3. After S2 is completed, the powder bed is moved into a forced-air drying oven for heating and curing at 280℃ for 1 hour.

[0119] S4. After the powder bed cools down with the furnace, the solidified ceramic core is removed and cleaned. The outer surface is cleaned with a brush, and the inner hole is cleaned with high-pressure gas.

[0120] S5. After the above-mentioned powder cleaning is completed, the ceramic parts are vacuum impregnated with nano-alumina turbid liquid for 90 minutes.

[0121] S6. After impregnation, the parts are baked and dried at a temperature of 100°C for 45 minutes.

[0122] S7. The sintering temperature of the dried ceramic parts is 1550℃. The temperature is increased from room temperature to 1150℃ at a heating rate of 5℃ / min and held for 60 minutes. Then the temperature is increased to 1300℃ at a heating rate of 5℃ / min and held for 60 minutes. Finally, the temperature is increased to 1450℃ at a heating rate of 5℃ / min and held for 80 minutes. After that, the parts are cooled in the furnace to obtain high-performance ceramic core parts.

[0123] Example 8

[0124] The integral core mold shell for casting hollow turbine blades, manufactured using the 3DP manufacturing method provided by this invention, includes the following steps:

[0125] S1. White corundum powder with a particle size of 150-200 mesh, white corundum powder with a particle size of 700-800 mesh, and silica powder with a particle size of 700-800 mesh are mixed evenly in a mass ratio of 14:5:1. This mixture is then baked and dried separately with magnesium oxide powder with a particle size of 2000-3000 mesh. Finally, it is mixed evenly with aluminum dihydrogen phosphate powder with a particle size of 120-200 mesh and an effective component content of 90%, to obtain 3DP preformed powder. The mass ratio of the fused alumina and silica powder, aluminum dihydrogen phosphate powder, and magnesium oxide powder is 80:12:8.

[0126] S2, will be as follows Figure 3 The data of the integrated core mold shell model for hollow turbine blade casting shown is imported into a 3D printer. Water-based ink is used as the printing ink to prepare the ceramic 3DP molding, and a ceramic core blank is obtained. During the printing process, the printing layer height is 0.05mm, the ink density is 30%, and the printing layer is heated in real time by a traveling heating device with a heating power of 600W.

[0127] S3. After S2 is completed, the powder bed is moved into a forced-air drying oven for heating and curing at 170℃ for 2 hours.

[0128] S4. After the powder bed cools down with the furnace, the solidified ceramic core is removed and cleaned. The outer surface is cleaned with a brush, and the inner hole is cleaned with high-pressure gas.

[0129] S5. After the above-mentioned powder cleaning is completed, the ceramic parts are subjected to vacuum impregnation. The impregnation solution is 30% silica sol, and the impregnation time is 60 minutes.

[0130] S6. After impregnation, the parts are baked and dried at 100°C for 30 minutes.

[0131] S7, the sintering temperature of the ceramic part after drying is 1550℃, the temperature is raised from room temperature to 1150℃ at a rate of 5℃ / min, kept for 60 minutes, then raised to 1300℃ at a rate of 5℃ / min, kept for 60 minutes, finally raised to 1550℃ at a rate of 5℃ / min, kept for 80 minutes, then cooled with the furnace, to obtain a high-performance ceramic core part.

[0132] Example 9

[0133] The hollow turbine blade integrated core shell for casting manufactured by the 3DP manufacturing method provided by the application comprises the following steps:

[0134] S1, white corundum powder with a particle size of 150-200 mesh, white corundum powder with a particle size of 700-800 mesh, and silicon dioxide powder with a particle size of 700-800 mesh are uniformly graded mixed in a mass ratio of 16.3:5:2, and then dried with magnesium oxide powder with a particle size of 2000-3000 mesh, and then mixed with aluminum dihydrogen phosphate powder with a particle size of 120-200 mesh and an effective component of 90%, to obtain 3DP pre-prepared powder. The mass ratio of the graded mixed powder of fused corundum and silicon dioxide, aluminum dihydrogen phosphate powder, and magnesium oxide powder is 84:10:6.

[0135] S2, as shown in the hollow turbine blade integrated core shell model data for casting is imported into the 3D printer, and water-based ink is used as the printing ink for the 3DP forming preparation of the ceramic, to obtain a ceramic core green body; during the printing process, the printing layer height is 0.1mm, the inkjet concentration is 50%, and the printing layer is treated by real-time heating during the printing process by using a traveling heating device, and the heating power is 1200W. Figure 3

[0136] S3, after S2 is finished, the whole powder bed is moved into the air drying oven for heating and curing, the heating temperature is 240℃, and the baking time is 1.5 hours.

[0137] S4, after the powder bed is cooled with the furnace, the already cured ceramic core is taken out for powder cleaning treatment, the outer surface is cleaned by using a brush, and the inner hole can be cleaned by using high-pressure gas.

[0138] S5, the ceramic part after the above powder cleaning is finished is vacuum infiltrated, the infiltration liquid is nano yttrium oxide turbid liquid, and the infiltration time is 150 minutes.

[0139] S6, the part after infiltration is baked and dried, the drying temperature is 100℃, and the drying time is 60 minutes.

[0140] ​S7. The sintering temperature of the dried ceramic parts is 1550℃. The temperature is increased from room temperature to 1150℃ at a heating rate of 3℃ / min and held for 30 minutes. Then the temperature is increased to 1300℃ at a heating rate of 2℃ / min and held for 30 minutes. Finally, the temperature is increased to 1550℃ at a heating rate of 2℃ / min and held for 45 minutes. After that, the parts are cooled in the furnace to obtain high-performance ceramic core parts.

[0141] Example 10

[0142] The integral core mold shell for casting hollow turbine blades, manufactured using the 3DP manufacturing method provided by this invention, includes the following steps:

[0143] S1. White corundum powder with a particle size of 150-200 mesh, white corundum powder with a particle size of 700-800 mesh, and silica powder with a particle size of 700-800 mesh are mixed evenly in a mass ratio of 18.6:5:3. This mixture is then baked and dried separately with magnesium oxide powder with a particle size of 2000-3000 mesh. Finally, it is mixed evenly with aluminum dihydrogen phosphate powder with a particle size of 120-200 mesh and an effective component content of 90%, to obtain the 3DP preform powder. The mass ratio of the fused alumina and silica powder, aluminum dihydrogen phosphate powder, and magnesium oxide powder is 88:8:4.

[0144] S2, will be as follows Figure 3 The data of the integrated core mold shell model for hollow turbine blade casting shown is imported into a 3D printer. Water-based ink is used as the printing ink to prepare the ceramic 3DP molding, and a ceramic core blank is obtained. During the printing process, the printing layer height is 0.15mm, the ink density is 60%, and the printing layer is heated in real time by a traveling heating device with a heating power of 2000W.

[0145] S3. After S2 is completed, the powder bed is moved into a forced-air drying oven for heating and curing at 280℃ for 1 hour.

[0146] S4. After the powder bed cools down with the furnace, the solidified ceramic core is removed and cleaned. The outer surface is cleaned with a brush, and the inner hole is cleaned with high-pressure gas.

[0147] S5. After the above-mentioned powder cleaning is completed, the ceramic parts are vacuum impregnated with nano-alumina turbid liquid for 90 minutes.

[0148] S6. After impregnation, the parts are baked and dried at a temperature of 100°C for 45 minutes.

[0149] S7. The sintering temperature of the dried ceramic parts is 1550℃. The temperature is increased from room temperature to 1150℃ at a heating rate of 4℃ / min and held for 40 minutes. Then the temperature is increased to 1300℃ at a heating rate of 3℃ / min and held for 50 minutes. Finally, the temperature is increased to 1550℃ at a heating rate of 4℃ / min and held for 60 minutes. After that, the parts are cooled in the furnace to obtain high-performance ceramic core parts.

[0150] Example 11

[0151] The integral core mold shell for casting hollow turbine blades, manufactured using the 3DP manufacturing method provided by this invention, includes the following steps:

[0152] S1. White corundum powder with a particle size of 150-200 mesh, white corundum powder with a particle size of 700-800 mesh, and yttrium oxide powder with a particle size of 700-800 mesh are graded and mixed evenly in a mass ratio of 18.6:5:3. This mixture is then baked and dried separately with magnesium oxide powder with a particle size of 2000-3000 mesh. Finally, it is mixed evenly with aluminum dihydrogen phosphate powder with a particle size of 120-200 mesh and an effective component content of 90%, to obtain 3DP pre-formed powder. The mass ratio of the graded mixture of fused alumina and yttrium oxide powder, aluminum dihydrogen phosphate powder, and magnesium oxide powder is 88:8:4.

[0153] S2, will be as follows Figure 3 The data of the integrated core mold shell model for hollow turbine blade casting shown is imported into a 3D printer. Water-based ink is used as the printing ink to prepare the ceramic 3DP molding, and a ceramic core blank is obtained. During the printing process, the printing layer height is 0.20mm, the ink density is 65%, and the printing layer is heated in real time by a traveling heating device with a heating power of 2200W.

[0154] S3. After S2 is completed, the powder bed is moved into a forced-air drying oven for heating and curing at 280℃ for 1 hour.

[0155] S4. After the powder bed cools down with the furnace, the solidified ceramic core is removed and cleaned. The outer surface is cleaned with a brush, and the inner hole is cleaned with high-pressure gas.

[0156] S5. After the above-mentioned powder cleaning is completed, the ceramic parts are vacuum impregnated with nano-alumina turbid liquid for 120 minutes.

[0157] S6. After impregnation, the parts are baked and dried at a temperature of 100°C for 50 minutes.

[0158] S7. The sintering temperature of the dried ceramic parts is 1550℃. The temperature is increased from room temperature to 1150℃ at a heating rate of 4℃ / min and held for 40 minutes. Then the temperature is increased to 1300℃ at a heating rate of 3℃ / min and held for 50 minutes. Finally, the temperature is increased to 1550℃ at a heating rate of 4℃ / min and held for 60 minutes. After that, the parts are cooled in the furnace to obtain high-performance ceramic core parts.

[0159] Example 12

[0160] The integral core mold shell for casting hollow turbine blades, manufactured using the 3DP manufacturing method provided by this invention, includes the following steps:

[0161] S1. White fused alumina powder with a particle size of 150-200 mesh, white fused alumina powder with a particle size of 700-800 mesh, and yttrium oxide powder with a particle size of 700-800 mesh are mixed evenly in a mass ratio of 16.3:5:2. This mixture is then baked and dried separately with magnesium oxide powder with a particle size of 2000-3000 mesh. Finally, it is mixed evenly with aluminum dihydrogen phosphate powder with a particle size of 120-200 mesh and an effective component content of 90%, to obtain the 3DP pre-formed powder. The mass ratio of the white fused alumina and yttrium oxide powder, aluminum dihydrogen phosphate powder, and magnesium oxide powder is 88:8:4.

[0162] S2, will be as follows Figure 3 The data of the integrated core mold shell model for hollow turbine blade casting shown is imported into the 3D printer. Water-based ink is used as the printing ink to prepare the ceramic 3DP molding and obtain the ceramic core blank. During the printing process, the printing layer height is 0.20mm, the ink density is 75%, and the printing layer is heated in real time by a traveling heating device with a heating power of 2400W.

[0163] S3. After S2 is completed, the powder bed is moved into a forced-air drying oven for heating and curing at 280℃ for 1 hour.

[0164] S4. After the powder bed cools down with the furnace, the solidified ceramic core is removed and cleaned. The outer surface is cleaned with a brush, and the inner hole is cleaned with high-pressure gas.

[0165] S5. Vacuum impregnation is performed on the ceramic parts after the above-mentioned powder cleaning is completed. The impregnation solution is 30% silica sol, and the impregnation time is 120 minutes.

[0166] S6. After impregnation, the parts are baked and dried at a temperature of 100°C for 50 minutes.

[0167] S7, the sintering temperature of the ceramic part after drying is 1550℃, the temperature is raised from room temperature to 1150℃ at a rate of 3℃ / min, kept for 30 minutes, then raised to 1300℃ at a rate of 3℃ / min, kept for 40 minutes, finally raised to 1550℃ at a rate of 5℃ / min, kept for 80 minutes, then cooled with the furnace, to obtain a high-performance ceramic core part.

[0168] Since the properties of the ceramic parts prepared in Examples 1-12 are basically the same, the effect is illustrated only by the ceramic core provided in Example 1.

[0169] 1. Precision test

[0170] The precision is tested according to GB / T6414-1999.

[0171] The length of the sample is greater than 40mm and less than 63mm, and the errors in eight measurements are 0.27, 0.03, 0.15, 0.23, 0.21, 0.23, 0.20, 0.23mm, the average error is 0.19375mm, which is between 0.18-0.26, and is CT 3 level.

[0172] The test shows that the dimensional accuracy in the sample can reach ±0.25mm.

[0173] 2. Roughness test

[0174] The experimental instrument for measuring roughness is a surface roughness tester (manufacturer: Jiangxi Zhenyang Precision Machinery Manufacturing Co., Ltd., model: TR200). The size of the sample is 60x10x4mm 3 , the top surface size is 60x10mm 2 , and the side surface size is 60x4mm 2 . The top surface and end surface of eight samples are measured.

[0175] The top surface roughness measurement results are: Ra9.45, Ra9.36, Ra11.41, Ra7.21, Ra8.33, Ra8.97, Ra7.89, Ra9.23, and the average value is Ra8.98μm.

[0176] The end surface roughness measurement results are: Ra17.65, Ra22.09, Ra21.04, Ra12.41, Ra19.88, Ra20.99, Ra21.32, Ra20.76, and the average value is Ra19.52μm.

[0177] 3. High temperature strength test

[0178] The experimental instrument is a universal testing machine, the test method is a three-point bending test, six groups of experiments are carried out, the loading speed is 7mm / min, the span is 30mm, and the width is 10.28mm, 10.16mm, 10.34mm, 10.40mm, 10.24mm and 10.20mm respectively, and the thickness is 4.24mm, 4.12mm, 4.20mm, 4.22mm, 4.08mm and 4.18mm respectively.

[0179] The test results show that the bending strength is 12.342MPa, 11.243MPa, 13.423MPa, 12.223MPa, 11.256MPa and 13.984MPa respectively, and the average value is 12.413MPa. The high-temperature strength can reach more than 10MPa. The high-temperature creep is small, the sintering shrinkage is low, and the sintering shrinkage in the x, y and z directions is less than 1.8%.

[0180] By adopting the method disclosed in the application, a high-performance alumina ceramic core with high strength at high temperature, high precision, controllable porosity, small high-temperature shrinkage, can be prepared, the problems of insufficient casting precision and frequent defects caused by high-temperature fracture and high-temperature creep of the core are avoided, and the use of organic binder is also avoided, and carbon residues in the core after high-temperature pyrolysis. The application is a high-performance ceramic preparation technology with high productivity, high quality and low cost, and has wide market space and great engineering application value.

[0181] The above description is only a preferred embodiment of the application, and those skilled in the art can make various corresponding changes and modifications according to the technical solutions and technical concepts of the application, and all these changes and modifications shall belong to the protection scope of the claims of the application.

Claims

1. A method of 3DP manufacturing of an alumina ceramic part, characterized in that, The method comprises the following steps: Mixing alumina, aluminum dihydrogen phosphate, a curing agent and a mineralizing agent to obtain 3DP pre-preparation powder; the content of aluminum dihydrogen phosphate is 8-12%, the content of the curing agent is 4-8%, the content of alumina is 76-78.1%, and the content of the mineralizing agent is 4-9.9% based on the total mass of the 3DP pre-preparation powder; Ceramic parts are printed using the 3DP pre-formed powder and water-based ink; the water-based ink is used at 20°C and a shear rate of [missing information]. The apparent viscosity value at that time is not higher than 10 m. The surface tension at 20℃ is 30. Furthermore, the H2O content in water-based inks is greater than 70%. Overall baking and curing of the ceramic print and the powder bed; After curing, the ceramic green body is sequentially subjected to powder cleaning, vacuum infiltration and drying treatment to obtain a ceramic product green body; the vacuum degree of vacuum infiltration is ≤100 Pa, the infiltration time is 60-150 minutes, the drying temperature is 100°C, and the time is 30-60 minutes; the solution used for vacuum infiltration is one of a silica sol, a nano-mineralizing agent particle suspension, a nano-alumina suspension, a silica sol and nano-mineralizing agent mixed suspension, or a silica sol and nano-alumina mixed suspension; Sintering the ceramic product green body to obtain a formed ceramic product.

2. The 3DP manufacturing method of claim 1, wherein, The particle size of the alumina is 150-800 mesh, the particle size of the aluminum dihydrogen phosphate is 120-200 mesh, the particle size of the curing agent is 2000-3000 mesh, and the particle size of the mineralizing agent is 700-800 mesh.

3. The 3DP fabrication method of claim 1, wherein, The alumina is selected from one or more of white corundum, fused corundum, alpha alumina and active alumina; The mineralizing agent is selected from one or more of a mixture of silicon oxide, magnesium oxide, yttrium oxide, zirconium oxide, boehmite, kyanite and fused mullite powder; The curing agent is selected from one or more of magnesium oxide, zinc oxide, magnesium aluminate spinel, diiron trioxide and copper oxide.

4. The 3DP fabrication method of claim 1, wherein, Real-time heating treatment is performed on the printing layer during printing, and the heating power is 400-2400 W.

5. The 3DP fabrication method of claim 1, wherein, The baking temperature of the baking and curing treatment is 170-280°C, and the baking time is 1-2 hours.

6. The 3DP fabrication method of claim 1, wherein, The sintering is performed in a programmed heating manner, and the programmed heating process is: heating at a heating rate of 3-5°C / min to 1150°C, maintaining for 30-60 min; then heating at a heating rate of 2-5°C / min to 1300°C, maintaining for 30-60 min; then heating at a heating rate of 2-5°C / min to a sintering temperature point, maintaining for 45-80 min.

7. The 3DP fabrication method of claim 1 wherein, During printing, the printing layer height is 0.05-0.30 mm, and the inkjet concentration is 30-75%.

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