A photocuring additive manufacturing aluminum-based ceramic core material with zero sintering shrinkage

Abstract

The present invention discloses a photocurable additive manufacturing aluminum-based ceramic core material with zero sintering shrinkage. Its slurry is composed of a photosensitive resin, a dispersant, and ceramic powder. Among them, the photosensitive resin accounts for 35-45 vol% by volume, the ceramic powder accounts for 55-60 vol% by volume, and the dispersant is added according to 1-5% of the mass of the ceramic powder. Moreover, the photosensitive resin contains 0.4-1% of a photoinitiator. The components of the ceramic powder include alumina, cyanite, and silica. The present invention relates to the technical field of additive manufacturing of ceramic materials. For this photocurable additive manufacturing aluminum-based ceramic core material with zero sintering shrinkage, by adding cyanite to the photocurable ceramic slurry, the expansion generated by the decomposition of cyanite at high temperature compensates for the shrinkage of the ceramic core during the sintering stage. Under the combined action of the decomposition expansion of cyanite and the sintering shrinkage of alumina, zero sintering shrinkage of the ceramic core at a sintering temperature of 1600 degrees is achieved. The present invention can prepare complex ceramic cores with a zero sintering shrinkage rate and excellent comprehensive properties.

Description

Technical Field

[0001] The present invention relates to the technical field of additive manufacturing of ceramic materials, and particularly to a photocuring additive manufacturing zero-sintering shrinkage aluminum-based ceramic core material. Background Art

[0002] Cores made of ceramic materials have good high-temperature mechanical properties and chemical stability, and can be used in the manufacture of high-precision hollow turbine blades. At present, with the progress of technology, the traditional hot injection method has gradually become difficult to meet the processing requirements of ceramic cores with high complexity. The development of additive manufacturing technology makes it possible to obtain ceramic cores with higher complexity and shorter production cycles through additive methods. Among them, the additive manufacturing process based on photocuring has the advantage of high forming accuracy and can be used to manufacture ceramic cores with high-precision complex shapes. However, in the additive manufacturing process based on stereolithography technology, due to the relatively high content of binder in the printing material, the sintering shrinkage rate of the obtained ceramic core is relatively high, which has an adverse effect on the control of the dimensional accuracy of the core and limits the further popularization of ceramic cores in industrial applications.

[0003] The first prior art is a photocuring 3D printing alumina-based ceramic core and its preparation method with the patent publication number CN114853450A, which discloses a photocuring 3D printing alumina-based ceramic core and its preparation method. By using three types of alumina ceramic powders, namely coarse, medium, and fine, for grading, a photocuring alumina-based ceramic core slurry with a high solid content and powder grading is obtained. After that, a ceramic core with excellent mechanical properties is obtained through photocuring 3D printing, debinding, and sintering.

[0004] The disadvantage of the first prior art is that although the mechanical properties of the high-porosity ceramic core are improved, the sintering shrinkage performance of the ceramic slurry is not optimized.

[0005] The second prior art is a photocuring 3D printing aluminum-based ceramic core and its preparation method with the patent publication number CN114082896A, which proposes a photocuring 3D printing aluminum-based ceramic core and its preparation method. By mixing and drying an organic fiber through-hole agent and a starch pore-forming agent to obtain a mixed fiber material, and then mixing the mixed fiber material, a mixed powder containing a skeleton powder and a filler, and a photocuring resin prepolymer solution, an aluminum-based ceramic core slurry is obtained. After photocuring 3D printing, debinding, and sintering, an aluminum-based ceramic core with a higher open porosity and better removal performance is obtained.

[0006] The disadvantage of the second prior art is that although the sintering accuracy problem of the current ceramic core is considered and the material is improved to reduce the sintering cracking tendency of the aluminum-based ceramic core by increasing the through-hole agent, the sintering shrinkage performance of the ceramic slurry itself is not improved. Summary of the Invention

[0007] (1) Technical Problem to be Solved

[0008] Aiming at the deficiencies of the prior art, the present invention provides a photocuring additive manufacturing aluminum-based ceramic core material with zero sintering shrinkage, which can prepare complex ceramic cores with a zero sintering shrinkage rate and excellent comprehensive performance.

[0009] (2) Technical Solution

[0010] To achieve the above object, the present invention is realized through the following technical solutions: A photocuring additive manufacturing aluminum-based ceramic core material with zero sintering shrinkage, the slurry of which is composed of a photosensitive resin, a dispersant and ceramic powder. Among them, the photosensitive resin accounts for 35-45 vol% by volume, the ceramic powder accounts for 55-60 vol% by volume, and the dispersant is added according to 1-5% of the mass of the ceramic powder, and the photosensitive resin contains 0.4-1% of a photoinitiator.

[0011] The components of the ceramic powder include, by mass percentage: 70 wt% alumina, 8 wt% cyanite and 22 wt% silica.

[0012] The photosensitive resin is composed of HDDA resin, PPTTA resin, PEG400DA resin and HEMA resin, and the content ratio of HDDA resin, PPTTA resin, PEG400DA resin and HEMA resin is: HDDA:PPTTA:PEG400DA:HEMA = 1:2:3:1.

[0013] Preferably, the HDDA resin and the PPTTA resin are difunctional and tetrafunctional UV monomers respectively, which are important components for constructing the curing strength.

[0014] Preferably, the PEG400DA resin is used as a difunctional long-chain UV monomer to increase the flexibility of the printed green body and reduce the cracking during the debinding process.

[0015] Preferably, the HEMA resin is a low-viscosity active diluent, which is used to reduce the viscosity of the slurry.

[0016] Preferably, the particle size of the alumina is 10-30 um, the particle size of the cyanite is 10-30 um, and the particle size of the silica is 30-50 um.

[0017] Preferably, the photoinitiator is TPO.

[0018] The present invention also provides a forming process for a photocuring additive manufacturing aluminum-based ceramic core material with zero sintering shrinkage, which specifically includes the following steps:

[0019] S1. Add photosensitive resin, photoinitiator, and dispersant into a container and mix them evenly to obtain a UV adhesive; the mechanical stirring time shall be no less than 10 min, the room temperature shall not be higher than 35 °C, and the environmental humidity shall not be higher than 40%;

[0020] S2. Add ceramic powder and the UV adhesive into a container in proportion and stir them evenly by mechanical stirring to obtain a ceramic slurry;

[0021] S3. Transfer the ceramic slurry obtained in step S2 into a nylon ball mill pot, add corundum grinding balls, and perform ball milling with a planetary ball mill;

[0022] S4. Perform vacuum degassing on the ball-milled ceramic slurry in step S3 to obtain the ceramic slurry for printing, and the vacuum degassing time is 3 - 5 min;

[0023] S5. Use the ceramic slurry prepared in step S4 to work with a photocuring ceramic 3D printer to obtain a green ceramic part. The printer includes an inverted DLP ceramic printer (Autocera-L, Autocera-M, Autocera-R of Beijing Shiwei Technology Co., Ltd.) or an upright DLP ceramic printer (Autocera-U, Autocera-XL of Beijing Shiwei Technology Co., Ltd.). The printing layer thickness is 25 - 100 μm, the exposure power is 5 - 20 mW / cm 2 , and the single-layer exposure time is 5 - 12 s;

[0024] S6. Clean the surface of the green ceramic part printed in step S5 with isopropyl alcohol and dry it;

[0025] S7. Put the green ceramic part in step S6 into a ceramic crucible and place it in a muffle furnace for sintering. After sintering, a ceramic core with zero sintering shrinkage is obtained.

[0026] Preferably, in step S7, the heating rate is not more than 10 °C / min below 1000 °C, not more than 5 °C / min above 1000 °C, the final sintering temperature is 1600 °C, and the holding time is not more than 4 h.

[0027] Preferably, in step S3, the ball-to-material ratio is 3:2, the ball milling speed is 400 r / min, and the ball milling time is 4 - 12 h.

[0028] Preferably, in step S2, the mechanical stirring time is not less than 10 min, the rotor speed is 300 - 600 r / min, the room temperature is not higher than 35 °C, and the environmental humidity is not higher than 40%.

[0029] (III) Beneficial effects

[0030] The present invention provides a photocuring additive manufacturing aluminum-based ceramic core material with zero sintering shrinkage. Compared with the prior art, it has the following beneficial effects: the photocuring additive manufacturing aluminum-based ceramic core material with zero sintering shrinkage, the slurry of which is composed of a photosensitive resin, a dispersant and ceramic powder. Among them, the photosensitive resin accounts for 35-45 vol% by volume, the ceramic powder accounts for 55-60 vol% by volume, and the dispersant is added according to 1-5% of the mass of the ceramic powder. And the photosensitive resin contains 0.4-1% of a photoinitiator. The components of the ceramic powder include, by mass percentage: 70 wt% of alumina, 8 wt% of cyanite and 22 wt% of silica. The photosensitive resin is composed of HDDA resin, PPTTA resin, PEG400DA resin and HEMA resin, and the content ratio of HDDA resin, PPTTA resin, PEG400DA resin and HEMA resin is: HDDA:PPTTA:PEG400DA:HEMA = 1:2:3:1. By adding cyanite to the photocuring ceramic slurry, the expansion generated by the decomposition of cyanite at high temperature compensates for the shrinkage of the ceramic core during the sintering stage. Under the combined action of the decomposition expansion of cyanite and the sintering shrinkage of alumina, zero sintering shrinkage of the ceramic core at a sintering temperature of 1600 degrees is achieved. The present invention can prepare a complex ceramic core with a sintering shrinkage rate of zero and excellent comprehensive performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a flowchart of the forming process of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0033] Please refer to Figure 1 , the embodiments of the present invention provide three technical solutions: a photocuring additive manufacturing aluminum-based ceramic core material with zero sintering shrinkage, specifically including the following embodiments:

[0034] Example 1

[0035] A photocuring additive manufacturing aluminum-based ceramic core material with zero sintering shrinkage, the slurry of which is composed of a photosensitive resin, a dispersant and ceramic powder. Among them, the photosensitive resin accounts for 40 vol% by volume, the ceramic powder accounts for 58 vol% by volume, and the dispersant is added according to 1.3% of the mass of the ceramic powder. And the photosensitive resin contains 0.7% of a photoinitiator, and the photoinitiator is TPO;

[0036] The components of the ceramic powder include, by mass percentage: 70 wt% alumina, 8 wt% kyanite, and 22 wt% silica. The particle size of alumina is 20 um, the particle size of kyanite is 20 um, and the particle size of silica is 40 um;

[0037] The photosensitive resin is composed of HDDA resin, PPTTA resin, PEG400DA resin, and HEMA resin, and the content ratio of HDDA resin, PPTTA resin, PEG400DA resin, and HEMA resin is: HDDA:PPTTA:PEG400DA:HEMA = 1:2:3:1. HDDA resin and PPTTA resin are bifunctional and tetrafunctional UV monomers respectively, which are important components for building curing strength. PEG400DA resin, as a bifunctional long-chain UV monomer, increases the flexibility of the printed green body and reduces cracking during the debinding process. HEMA resin is a low-viscosity active diluent, which is used to reduce the viscosity of the slurry.

[0038] The embodiment of the present invention also provides a forming process of a photocurable additive manufacturing zero-sintering shrinkage aluminum-based ceramic core material, which specifically includes the following steps:

[0039] S1. Add the photosensitive resin, photoinitiator, and dispersant into a container and mix them evenly to obtain a UV adhesive; the mechanical stirring time is 10 min, the room temperature is 35 °C, and the environmental humidity is 40%;

[0040] S2. Add the ceramic powder and the UV adhesive into a container in proportion and stir them evenly mechanically to obtain a ceramic slurry. The mechanical stirring time is 10 min, the rotor speed is 450 r / min, the room temperature is 35 °C, and the environmental humidity is 40%;

[0041] S3. Transfer the ceramic slurry obtained in step S2 to a nylon ball mill jar, add corundum grinding balls, and perform ball milling with a planetary ball mill. The ball-to-material ratio is 3:2, the ball milling speed is 400 r / min, and the ball milling time is 8 h;

[0042] S4. Perform vacuum degassing on the ball-milled ceramic slurry in step S3 to obtain the ceramic slurry for printing. The vacuum degassing time is 4 min;

[0043] S5. Obtain a green body of a ceramic part by working the ceramic slurry prepared in step S4 with a photocurable ceramic 3D printer. The printer includes an inverted DLP ceramic printer (Autocera-L, Autocera-M, Autocera-R of Beijing Shiwei Technology Co., Ltd.) or an upright DLP ceramic printer (Autocera-U, Autocera-XL of Beijing Shiwei Technology Co., Ltd.). The printing layer thickness is 60 um, and the exposure power is 12 mW / cm 2 and the single-layer exposure time is 8 s;

[0044] S6. Clean the surface of the green ceramic part completed in step S5 with isopropanol and dry it.

[0045] S7. Place the green ceramic blank in step S6 into a ceramic crucible and then sinter it in a muffle furnace to obtain a ceramic core with zero sintering shrinkage. The heating rate is 10 °C / min below 1000 °C, 5 °C / min above 1000 °C, the final sintering temperature is 1600 °C, and the holding time is 4 h.

[0046] Example 2

[0047] A photocuring additive manufacturing aluminum-based ceramic core material with zero sintering shrinkage, whose slurry is composed of a photosensitive resin, a dispersant, and ceramic powder. Among them, the photosensitive resin accounts for 40 vol% by volume, the ceramic powder accounts for 55 vol% by volume, and the dispersant is added according to 4.6% of the mass of the ceramic powder. And the photosensitive resin contains 0.4% of a photoinitiator, and the photoinitiator is TPO.

[0048] The components of the ceramic powder include, by mass percentage: 70 wt% alumina, 8 wt% kyanite, and 22 wt% silica. The particle size of alumina is 10 μm, the particle size of kyanite is 10 μm, and the particle size of silica is 30 μm.

[0049] The photosensitive resin is composed of HDDA resin, PPTTA resin, PEG400DA resin, and HEMA resin. And the content ratio of HDDA resin, PPTTA resin, PEG400DA resin, and HEMA resin is: HDDA:PPTTA:PEG400DA:HEMA = 1:2:3:1. HDDA resin and PPTTA resin are bifunctional and tetrafunctional UV monomers respectively, which are important components for building curing strength. PEG400DA resin is used as a bifunctional long-chain UV monomer to increase the flexibility of the printed green body and reduce cracking during the debinding process. HEMA resin is a low-viscosity reactive diluent, which is used to reduce the viscosity of the slurry.

[0050] The embodiment of the present invention also provides a forming process for a photocuring additive manufacturing aluminum-based ceramic core material with zero sintering shrinkage, which specifically includes the following steps:

[0051] S1. Add the photosensitive resin, photoinitiator, and dispersant into a container and mix them evenly to obtain a UV adhesive; the mechanical stirring time is 11 min, the room temperature is 34 °C, and the environmental humidity is 39%.

[0052] S2. Add the ceramic powder and the UV adhesive into the container according to a ratio and stir them evenly mechanically to obtain a ceramic slurry. The mechanical stirring time is 11 min, the rotor speed is 300 r / min, the room temperature is 34 °C, and the environmental humidity is 39%.

[0053] S3. Transfer the ceramic slurry obtained in step S2 to a nylon ball mill tank, add corundum grinding balls, and perform ball milling with a planetary ball mill. The ball-to-material ratio is 3:2, the ball milling speed is 400 r / min, and the ball milling time is 4 h.

[0054] S4. Perform vacuum degassing on the ball-milled ceramic slurry in step S3 to obtain the ceramic slurry for printing. The vacuum degassing time is 3 min.

[0055] S5. Use the ceramic slurry prepared in step S4 to work with a photocuring ceramic 3D printer to obtain a green body of a ceramic part. The printer includes an inverted DLP ceramic printer (Autocera-L, Autocera-M, Autocera-R of Beijing Shiwei Technology Co., Ltd.) or an upright DLP ceramic printer (Autocera-U, Autocera-XL of Beijing Shiwei Technology Co., Ltd.). The printing layer thickness is 25 μm, the exposure power is 5 mW / cm 2 , and the single-layer exposure time is 5 s.

[0056] S6. Clean the surface of the green body of the ceramic part printed in step S5 with isopropyl alcohol and dry it.

[0057] S7. Place the green body of the ceramic in a ceramic crucible and then sinter it in a muffle furnace to obtain a ceramic core with zero sintering shrinkage. The heating rate is 9 °C / min below 1000 °C, 4 °C / min above 1000 °C, the final sintering temperature is 1600 °C, and the holding time is 3 h.

[0058] Example 3

[0059] A photocuring additive manufacturing aluminum-based ceramic core material with zero sintering shrinkage, whose slurry is composed of a photosensitive resin, a dispersant, and ceramic powder. Among them, the photosensitive resin accounts for 36 vol% by volume, the ceramic powder accounts for 60 vol% by volume, and the dispersant is added according to 3% of the mass of the ceramic powder. And the photosensitive resin contains 1% of a photoinitiator, and the photoinitiator is TPO.

[0060] The components of the ceramic powder include, by mass percentage: 70 wt% alumina, 8 wt% kyanite, and 22 wt% silica. The particle size of alumina is 30 μm, the particle size of kyanite is 30 μm, and the particle size of silica is 50 μm.

[0061] The photosensitive resin is composed of HDDA resin, PPTTA resin, PEG400DA resin and HEMA resin, and the content ratio of HDDA resin, PPTTA resin, PEG400DA resin and HEMA resin is: HDDA:PPTTA:PEG400DA:HEMA = 1:2:3:1. HDDA resin and PPTTA resin are bifunctional and tetrafunctional UV monomers respectively, which are important components for constructing the curing strength. PEG400DA resin, as a bifunctional long-chain UV monomer, increases the flexibility of the printed green body and reduces cracking during the debinding process. HEMA resin is a low-viscosity active diluent, which is used to reduce the viscosity of the slurry.

[0062] The embodiment of the present invention also provides a forming process for a photocuring additive manufacturing zero-sintering shrinkage aluminum-based ceramic core material, which specifically includes the following steps:

[0063] S1. Add the photosensitive resin, photoinitiator and dispersant into a container and mix them evenly to obtain a UV adhesive; the mechanical stirring time is 12 min, the room temperature is 33 °C, and the environmental humidity is 38%;

[0064] S2. Add the ceramic powder and the UV adhesive into a container according to a ratio and stir them mechanically and evenly to obtain a ceramic slurry. The mechanical stirring time is 12 min, the rotor speed is 600 r / min, the room temperature is 33 °C, and the environmental humidity is 38%;

[0065] S3. Transfer the ceramic slurry obtained in step S2 to a nylon ball mill jar, add corundum grinding balls, and carry out ball milling with a planetary ball mill. The ball-to-material ratio is 3:2, the ball milling speed is 400 r / min, and the ball milling time is 12 h;

[0066] S4. Carry out vacuum degassing on the ball-milled ceramic slurry in step S3 to obtain a ceramic slurry for printing. The vacuum degassing time is 5 min;

[0067] S5. Obtain a green body of a ceramic part by working the ceramic slurry prepared in step S4 with a photocuring ceramic 3D printer. The printer includes an inverted DLP ceramic printer (Autocera-L, Autocera-M, Autocera-R of Beijing Shiwei Technology Co., Ltd.) or an upright DLP ceramic printer (Autocera-U, Autocera-XL of Beijing Shiwei Technology Co., Ltd.). The printing layer thickness is 100 μm, and the exposure power is 20 mW / cm 2 , and the single-layer exposure time is 12 s;

[0068] S6. Wash the surface of the printed green body of the ceramic part in step S5 with isopropyl alcohol and dry it;

[0069] S7. Place the green ceramic body in step S6 into a ceramic sagger and then sinter it in a muffle furnace to obtain a ceramic core with zero sintering shrinkage. The heating rate is 8 °C / min below 1000 °C and 3 °C / min above 1000 °C. The final sintering temperature is 1600 °C and the holding time is 2 h.

[0070] When preparing the ceramic powder, the D50 of the powder is shown in Table 1.

[0071] Table 1 Median particle size of ceramic raw materials

[0072]

[0073] When sintering the specimen, in order to prevent crack defects from occurring in the specimen after debinding and sintering, it is set that the heating rate does not exceed 10 °C / min below 1000 °C and does not exceed 5 °C / min above 1000 °C. The heating rate is slowed down in the range of 200 °C - 500 °C, and multiple holding steps are added to ensure the complete removal of organic matter in stages. The final sintering temperature is set according to experimental requirements and material properties, and the holding time does not exceed 4 h.

[0074] After multiple experiments, it is found that when the sintering temperature is 1600 °C, the shrinkage rate of the sample sintered from the formulation with 70% alumina content, 8% kyanite content and 22% silica content is 0.

[0075] Table 2 Shrinkage rate of alumina - kyanite - silica sample after sintering at 1600 °C

[0076]

[0077] In summary, in the present invention, by adding kyanite to the photocurable ceramic slurry, the expansion generated by the decomposition of kyanite at high temperature compensates for the shrinkage of the ceramic core during the sintering stage. Under the combined action of the decomposition expansion of kyanite and the sintering shrinkage of alumina, zero sintering shrinkage of the ceramic core at a sintering temperature of 1600 °C is achieved. The present invention can prepare a complex ceramic core with a zero sintering shrinkage rate and excellent comprehensive properties.

[0078] Meanwhile, the content not described in detail in this specification belongs to the prior art well-known to those skilled in the art.

[0079] It should be noted that in this text, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, such that a process, method, article or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article or device.

[0080] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A photocurable additive manufacturing aluminum-based ceramic core material with zero sintering shrinkage, characterized in that: Its slurry is composed of a photosensitive resin, a dispersant, and ceramic powder. Among them, the photosensitive resin accounts for 35-45 vol% by volume, the ceramic powder accounts for 55-60 vol% by volume, and the dispersant is added at 1-5% of the mass of the ceramic powder. And the photosensitive resin contains 0.4-1% of a photoinitiator; The components of the ceramic powder include, by mass percentage: 70 wt% alumina, 8 wt% cyanite, and 22 wt% silica; The photosensitive resin is composed of HDDA resin, PPTTA resin, PEG400DA resin, and HEMA resin, and the content ratio of HDDA resin, PPTTA resin, PEG400DA resin, and HEMA resin is: HDDA:PPTTA:PEG400DA:HEMA = 1:2:3:

1.

2. The photocuring additive manufacturing zero-sintering shrinkage aluminum-based ceramic core material according to claim 1, wherein: The HDDA resin and PPTTA resin are bifunctional and tetrafunctional UV monomers respectively, which are important components for constructing the curing strength.

3. The aluminosilicate-based ceramic core material for photocuring additive manufacturing with zero sintering shrinkage according to claim 1, wherein: The PEG400DA resin, as a bifunctional long-chain UV monomer, increases the flexibility of the printed green body and reduces cracking during the debinding process.

4. The aluminide-based ceramic core material for photocuring additive manufacturing with zero sintering shrinkage according to claim 1, characterized in that: The HEMA resin is a low-viscosity active diluent, which is used to reduce the viscosity of the slurry.

5. The aluminide ceramic core material for photocuring additive manufacturing with zero sintering shrinkage according to claim 1, characterized in that: The particle size of the alumina is 10-30 um, the particle size of the cyanite is 10-30 um, and the particle size of the silica is 30-50 um.

6. The aluminide-based ceramic core material for photocuring additive manufacturing with zero sintering shrinkage according to claim 1, characterized in that: The photoinitiator is TPO.

7. A forming process for the photocuring additive manufacturing zero-sintering shrinkage aluminum-based ceramic core material according to any one of claims 1-6, characterized in that: Specifically, it includes the following steps: S1. Add the photosensitive resin, photoinitiator, and dispersant into a container and mix them evenly to obtain a UV adhesive; the mechanical stirring time is not less than 10 min, the room temperature is not higher than 35 °C, and the environmental humidity is not higher than 40%; S2. Add the ceramic powder and the UV adhesive into a container in proportion and stir them mechanically and evenly to obtain a ceramic slurry; S3. Transfer the ceramic slurry obtained in step S2 to a nylon ball mill tank, add corundum grinding balls, and use a planetary ball mill for ball milling; S4. Carry out vacuum degassing on the ball-milled ceramic slurry in step S3 to obtain a ceramic slurry for printing, and the vacuum degassing time is 3-5 min; S5. Obtain a green ceramic part by operating a photocuring ceramic 3D printer on the ceramic slurry prepared in step S4. The printer includes an inverted DLP ceramic printer or an upright DLP ceramic printer. The printing layer thickness is 25 - 100 μm, the exposure power is 5 - 20 mW / cm 2 , and the single-layer exposure time is 5 - 12 s; S6. Wash the surface of the printed green body of the ceramic part in step S5 with isopropyl alcohol and dry it; S7. Put the ceramic green body in step S6 into a ceramic crucible and place it in a muffle furnace for sintering. After sintering, a ceramic core with zero sintering shrinkage is obtained.

8. The forming process of a photocuring additive manufacturing zero-sintering shrinkage aluminum-based ceramic core material according to claim 7, characterized in that: In step S7, the heating rate is not more than 10 °C / min below 1000 °C, not more than 5 °C / min above 1000 °C, the final sintering temperature is 1600 °C, and the holding time is not more than 4 h.

9. The forming process of a photocuring additive manufacturing zero-sintering shrinkage aluminum-based ceramic core material according to claim 7, characterized in that: In step S3, the ball-to-material ratio is 3:2, the ball milling speed is 400 r / min, and the ball milling time is 4-12 h.

10. The forming process of a photocuring additive manufacturing aluminum-based ceramic core material with zero sintering shrinkage according to claim 7, characterized in that: In step S2, the mechanical stirring time is not less than 10 min, the rotor speed is 300-600 r / min, the room temperature is not higher than 35 °C, and the environmental humidity is not higher than 40%.

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