阅读说明：本技术 一种3d打印用陶瓷型芯浆料及其制备方法和应用 (Ceramic core slurry for 3D printing and preparation method and application thereof ) 是由 任忠鸣 陈超越 王江 玄伟东 殷宇豪 于 2021-08-23 设计创作，主要内容包括：本发明属于3D打印用材料技术领域,特别涉及一种3D打印用陶瓷型芯浆料及其制备方法和应用。本发明提供的3D打印用陶瓷型芯浆料,由包括以下组分的原料制备得到：丙烯酸酯类单体、丙烯酸酯低聚物、二氧化硅粉、硅酸锆粉、光引发剂、水性流平剂和分散剂；所述丙烯酸酯类单体和丙烯酸酯低聚物的体积比为(2～10)：1；所述二氧化硅粉和硅酸锆粉的质量比为100：(5～20)；所述丙烯酸酯类单体和丙烯酸酯低聚物的总体积与二氧化硅粉的质量的比为(80～600)mL：(200～1000)g。本发明提供的3D打印用陶瓷型芯浆料固含量高且流动性优良,所得3D打印陶瓷型芯抗弯曲强度高、抗高温蠕变性优异、收缩率小且表面质量好。(The invention belongs to the technical field of materials for 3D printing, and particularly relates to ceramic core slurry for 3D printing and a preparation method and application thereof. The ceramic core slurry for 3D printing provided by the invention is prepared from the following raw materials: acrylate monomer, acrylate oligomer, silicon dioxide powder, zirconium silicate powder, photoinitiator, aqueous flatting agent and dispersant; the volume ratio of the acrylate monomer to the acrylate oligomer is (2-10): 1; the mass ratio of the silicon dioxide powder to the zirconium silicate powder is 100: (5-20); the ratio of the total volume of the acrylate monomer and the acrylate oligomer to the mass of the silicon dioxide powder is (80-600) mL: (200-1000) g. The ceramic core slurry for 3D printing provided by the invention has high solid content and excellent fluidity, and the obtained 3D printing ceramic core has high bending strength, excellent high-temperature creep resistance, small shrinkage and good surface quality.)

1. The ceramic core slurry for 3D printing is prepared from the following raw materials:

acrylate monomer, acrylate oligomer, silicon dioxide powder, zirconium silicate powder, photoinitiator, aqueous flatting agent and dispersant;

the volume ratio of the acrylate monomer to the acrylate oligomer is (2-10): 1;

the mass ratio of the silicon dioxide powder to the zirconium silicate powder is 100: (5-20);

the ratio of the total volume of the acrylate monomer and the acrylate oligomer to the mass of the silicon dioxide powder is (80-600) mL: (200-1000) g.

2. The ceramic core paste for 3D printing according to claim 1, wherein the acrylate monomer is one or more of 1, 6-hexanediol diacrylate, dipropylene glycol diacrylate, oxidized neopentyl glycol diacrylate, and tripropylene glycol diacrylate.

3. The ceramic core paste for 3D printing according to claim 1, wherein the acrylate oligomer is one or more of trimethylolpropane triacrylate, ethoxylated pentaerythritol tetraacrylate and di-trimethylolpropane tetraacrylate.

4. The ceramic core paste for 3D printing according to claim 1, wherein the photoinitiator is benzoin bis methyl ether or trimethylbenzoyl-diphenyl phosphine oxide;

the mass of the photoinitiator is 0.5-1.5% of the total mass of the acrylate monomer and the acrylate oligomer.

5. The ceramic core slurry for 3D printing according to claim 1, wherein the aqueous leveling agent is BYK-333;

the mass of the water-based leveling agent is 0.1-1% of the total mass of the acrylate monomer and the acrylate oligomer.

6. The ceramic core slurry for 3D printing according to claim 1, wherein the dispersant is ammonium polyacrylate, oleic acid, Disperbyk, or polyvinyl alcohol;

the mass of the dispersing agent is 0.5-2% of the total mass of the silicon dioxide powder and the zirconium silicate powder.

7. The ceramic core slurry for 3D printing according to claim 1, wherein the silica powder has a median particle size of 10 to 30 μm and a particle size distribution of 5 to 80 μm;

the particle size of the zirconium silicate powder is 10-40 mu m.

8. The method for preparing the ceramic core slurry for 3D printing according to any one of claims 1 to 7, comprising the following steps:

mixing an acrylate monomer, an acrylate oligomer, a photoinitiator and a water-based leveling agent to obtain a photosensitive resin material;

and mixing the photosensitive resin material, silicon dioxide powder, zirconium silicate powder and a dispersing agent to obtain the ceramic core slurry for 3D printing.

9. Use of the ceramic core slurry for 3D printing according to any one of claims 1 to 7 or the ceramic core slurry for 3D printing obtained by the preparation method according to claim 8 as a 3D printing material in a ceramic core for 3D printing.

10. Use according to claim 9, wherein the 3D printed ceramic core comprises the steps of:

3D printing is carried out on the ceramic core slurry for 3D printing to obtain a biscuit;

degreasing and sintering the biscuit to obtain a 3D printing ceramic core;

the degreasing sintering comprises the following steps: raising the temperature from room temperature to the first-stage temperature of 100-130 ℃, raising the temperature from the first-stage temperature to the second-stage temperature of 500-550 ℃, and preserving heat for 2-2.5 h, and raising the temperature from the second-stage temperature to the third-stage temperature of 1200-1250 ℃, and preserving heat for 2-2.5 h.

Technical Field

The invention belongs to the technical field of materials for 3D printing, and particularly relates to ceramic core slurry for 3D printing and a preparation method and application thereof.

Background

The 3D printing technology is a technology for generating a three-dimensional entity by adding materials layer by layer in a layered processing and stacking formation manner by using an adhesive material such as powdered metal or plastic based on a digital model file, and is an Additive Manufacturing (AM) technology. The 3D printing technology does not need a complex forming process, does not need a blank and a die in the manufacturing process, and does not need lots of manpower, so that the manufacturing procedure of the product is simplified, the development period of the product is shortened, the production efficiency is improved, the cost is reduced, the product manufacturing is more intelligent, accurate and efficient, and a thought is provided for manufacturing ceramic cores with complex structures.

According to the form of the printing raw material, the 3D printing suitable for the ceramic core can be mainly divided into ceramic 3D printing based on ceramic powder and ceramic 3D printing technology based on ceramic slurry, wherein the ceramic 3D printing technology based on liquid or semi-liquid ceramic slurry mainly relates to the photo-curing 3D printing technology, which is called Stereolithography (SL).

The slurries used in conventional non-3D methods to make ceramic cores typically consist of a matrix material, a mineralizer, a plasticizer, and a surfactant. The ceramic slurry suitable for 3D photocuring molding is different from the ceramic slurry molded by the traditional non-3D method in components, and ceramic powder needs to be added into a photocuring solution and is uniformly dispersed in the solution through high-speed stirring. Currently, ceramic slurry systems suitable for 3D printing photocuring can be broadly classified into three categories: a water-based ceramic photocuring slurry system, a resin-based ceramic photocuring slurry system and a precursor ceramic photocuring system.

A large amount of suspended ceramic particles exist in the resin-based photocuring ceramic slurry, and high solid content and good fluidity cannot be both considered, so that the finally obtained 3D printing ceramic core has poor mechanical property, poor high-temperature creep resistance and high shrinkage rate, and cannot meet the preparation requirements of ceramic cores with complex structures and high requirements on mechanical property, such as aircraft engine blades and the like.

Disclosure of Invention

In view of the above, the invention aims to provide ceramic core slurry for 3D printing and a preparation method thereof, and the ceramic core slurry for 3D printing provided by the invention has high solid content and excellent fluidity, so that a 3D printing ceramic core obtained from the ceramic core slurry for 3D printing has the characteristics of high bending strength, excellent high-temperature creep resistance, small shrinkage and good surface quality.

In order to achieve the purpose of the invention, the invention provides the following technical scheme:

the invention provides ceramic core slurry for 3D printing, which is prepared from the following raw materials:

acrylate monomer, acrylate oligomer, silicon dioxide powder, zirconium silicate powder, photoinitiator, aqueous flatting agent and dispersant;

the volume ratio of the acrylate monomer to the acrylate oligomer is (2-10): 1;

the mass ratio of the silicon dioxide powder to the zirconium silicate powder is 100: (5-20);

the ratio of the total volume of the acrylate monomer and the acrylate oligomer to the mass of the silicon dioxide powder is (80-600) mL: (200-1000) g.

Preferably, the acrylate monomer is one or more of 1, 6-hexanediol diacrylate, dipropylene glycol diacrylate, oxidized neopentyl glycol diacrylate and tripropylene glycol diacrylate.

Preferably, the acrylate oligomer is one or more of trimethylolpropane triacrylate, ethoxylated pentaerythritol tetraacrylate and di-trimethylolpropane tetraacrylate.

Preferably, the photoinitiator is benzoin bis methyl ether or trimethylbenzoyl-diphenylphosphine oxide;

the mass of the photoinitiator is 0.5-1.5% of the total mass of the acrylate monomer and the acrylate oligomer.

Preferably, the aqueous leveling agent is BYK-333;

the mass of the water-based leveling agent is 0.1-1% of the total mass of the acrylate monomer and the acrylate oligomer.

Preferably, the dispersant is ammonium polyacrylate, oleic acid, Disperbyk or polyvinyl alcohol;

the mass of the dispersing agent is 0.5-2% of the total mass of the silicon dioxide powder and the zirconium silicate powder.

Preferably, the median particle size of the silicon dioxide powder is 10-30 μm, and the particle size is distributed in the range of 5-80 μm;

the particle size of the zirconium silicate powder is 10-40 mu m.

The invention also provides a preparation method of the ceramic core slurry for 3D printing, which comprises the following steps:

mixing an acrylate monomer, an acrylate oligomer, a photoinitiator and a water-based leveling agent to obtain a photosensitive resin material;

and mixing the photosensitive resin material, silicon dioxide powder, zirconium silicate powder and a dispersing agent to obtain the ceramic core slurry for 3D printing.

The invention also provides application of the ceramic core slurry for 3D printing or the ceramic core slurry for 3D printing obtained by the preparation method in the technical scheme as a 3D printing material in a 3D printing ceramic core.

Preferably, the 3D printed ceramic core comprises the steps of:

3D printing is carried out on the ceramic core slurry for 3D printing to obtain a biscuit;

degreasing and sintering the biscuit to obtain a 3D printing ceramic core;

the degreasing sintering comprises the following steps: raising the temperature from room temperature to the first-stage temperature of 100-130 ℃, raising the temperature from the first-stage temperature to the second-stage temperature of 500-550 ℃, and preserving heat for 2-2.5 h, and raising the temperature from the second-stage temperature to the third-stage temperature of 1200-1250 ℃, and preserving heat for 2-2.5 h.

The invention provides ceramic core slurry for 3D printing, which is prepared from the following raw materials: acrylate monomer, acrylate oligomer, silicon dioxide powder, zirconium silicate powder, photoinitiator, aqueous flatting agent and dispersant; the volume ratio of the acrylate monomer to the acrylate oligomer is (2-10): 1; the mass ratio of the silicon dioxide powder to the zirconium silicate powder is 100: (5-20); the ratio of the total volume of the acrylate monomer and the acrylate oligomer to the mass of the silicon dioxide powder is (80-600) mL: (200-1000) g.

In the invention, the acrylate oligomer is a main body in the ceramic core slurry for 3D printing, and once the acrylate oligomer is initiated to polymerize, the molecular weight can be rapidly increased, and the acrylate oligomer is rapidly cured to form a solid; the acrylate monomer plays a role of an active diluent and is an important component in the ceramic core slurry for 3D printing, a polymerization functional group in the acrylate monomer can perform polymerization reaction under the action of illumination, and in addition, the acrylate monomer can dissolve and dilute acrylate oligomer, so that the viscosity of the ceramic core slurry for 3D printing is reduced, and the flowability of the ceramic core slurry for 3D printing is improved; the silicon dioxide powder is a matrix material, has small thermal expansion coefficient and good thermal shock resistance and is easy to remove by a chemical depoling method; the zirconium silicate powder has high melting point and good chemical stability, is not influenced by ceramic sintering, can fill gaps among large particles through viscous flow during sintering, improves the compactness and the bending strength of the ceramic core, and can further improve the bending strength of the ceramic core as a skeleton structure material; the aqueous leveling agent is beneficial to improving the leveling property of the ceramic core slurry for 3D printing; the dispersing agent can improve the dispersion uniformity of materials in the ceramic core slurry for 3D printing and improve the stability of the ceramic core slurry for 3D printing; according to the ceramic core slurry for 3D printing, the components are reasonably matched, so that the stability of the ceramic core slurry for 3D printing is improved, and the solid content of the ceramic core slurry for 3D printing is further improved; the photoinitiator is a compound capable of causing polymerization, and can be excited to produce chemical change by absorbing the radiation energy of ultraviolet light or visible laser to generate an active intermediate with the effect of causing polymerization, so that the photocuring speed and the quality of a ceramic core product are improved.

The test result of the embodiment shows that the solid content of the ceramic core slurry for 3D printing provided by the invention is 44-50 vol.%, the viscosity is 250-280 mPa.s, and no obvious agglomeration or precipitation occurs after standing for 0.5h at room temperature; the ceramic core slurry for 3D printing is subjected to 3D printing to obtain a ceramic core with an average value of 13.7-15.2 MPa in room temperature bending strength test, an average value of 29.8-33.5 MPa in 1550 ℃ high temperature bending resistance test, an average value of 30.8-33.9% in porosity and an average value of 1.72-1.75 g/cm in density³And the requirements of high-temperature blade casting are met.

Drawings

FIG. 1 is a particle size distribution diagram of the silica powder used in example 1;

FIG. 2 is a sample object of a ceramic core prepared in application example 1;

fig. 3 is a sample object diagram of the ceramic core prepared in application example 1.

Detailed Description

The invention provides ceramic core slurry for 3D printing, which is prepared from the following raw materials:

acrylate monomer, acrylate oligomer, silicon dioxide powder, zirconium silicate powder, photoinitiator, aqueous flatting agent and dispersant;

the volume ratio of the acrylate monomer to the acrylate oligomer is (2-10): 1;

the mass ratio of the silicon dioxide powder to the zirconium silicate powder is 100: (5-20);

the ratio of the total volume of the acrylate monomer and the acrylate oligomer to the mass of the silicon dioxide powder is (80-600) mL: (200-1000) g.

In the present invention, all the components are commercially available products well known to those skilled in the art unless otherwise specified.

In the invention, the raw material for preparing the ceramic core slurry for 3D printing comprises an acrylate monomer. In the present invention, the acrylate-based monomer is preferably one or more of 1, 6-hexanediol diacrylate, dipropylene glycol diacrylate, oxidized neopentyl glycol diacrylate and tripropylene glycol diacrylate.

In the present invention, the preparation raw material of the ceramic core paste for 3D printing includes an acrylate oligomer. In the present invention, the acrylate oligomer is preferably one or more of trimethylolpropane triacrylate, ethoxylated pentaerythritol tetraacrylate and di-trimethylolpropane tetraacrylate.

In the invention, the volume ratio of the acrylate monomer to the acrylate oligomer is (2-10): 1, preferably (3-9): 1, more preferably (4-8): 1.

in the invention, the raw material for preparing the ceramic core slurry for 3D printing comprises silicon dioxide powder. In the invention, the median particle diameter of the silicon dioxide powder is preferably 10-30 μm, and more preferably 14-20 μm. In the invention, the particle size distribution of the silicon dioxide powder is preferably 5-80 μm. In the present invention, the silica powder is preferably commercially available or prepared by ball milling quartz glass. In the present invention, the ball-milling grinding balls are preferably zirconia grinding balls. In the present invention, the mass ratio of the quartz glass to the grinding balls in the ball milling is preferably 1: 2; the time for ball milling is preferably 50 h; the rate of ball milling is not particularly limited in the present invention and may be any rate known to those skilled in the art.

In the invention, the raw material for preparing the ceramic core slurry for 3D printing comprises zirconium silicate powder. In the invention, the particle size of the zirconium silicate powder is preferably 10-40 μm.

In the invention, the mass ratio of the silicon dioxide powder to the zirconium silicate powder is 100: (5-20), preferably 100: (7-18), more preferably 100: (10-15).

In the invention, the ratio of the total volume of the acrylate monomer and the acrylate oligomer to the mass of the silicon dioxide powder is (80-600) mL: (200-1000) g, preferably (100-550) mL: (250-950) g, more preferably (150-500) mL: (300-900) g, more preferably (200-450) mL: (350-850) g.

In the invention, the raw material for preparing the ceramic core slurry for 3D printing comprises a photoinitiator. In the present invention, the photoinitiator is preferably benzoin bis methyl ether or trimethylbenzoyl-diphenylphosphine oxide. In the invention, the mass of the photoinitiator is preferably 0.5-1.5%, more preferably 0.7-1.3%, and still more preferably 0.8-1.2% of the total mass of the acrylate monomer and the acrylate oligomer.

In the invention, the raw materials for preparing the ceramic core slurry for 3D printing comprise an aqueous leveling agent. In the present invention, the aqueous leveling agent is preferably BYK-333. In the invention, the mass of the aqueous leveling agent is preferably 0.1-1%, more preferably 0.3-0.7%, and still more preferably 0.4-0.6% of the total mass of the acrylate monomer and the acrylate oligomer.

In the invention, the raw material for preparing the ceramic core slurry for 3D printing comprises a dispersing agent. In the present invention, the dispersant is preferably ammonium polyacrylate, oleic acid, Disperbyk or polyvinyl alcohol. In the invention, the mass of the dispersing agent is preferably 0.5-2%, more preferably 0.8-1.7%, and still more preferably 1-1.5% of the total mass of the silicon dioxide powder and the zirconium silicate powder.

The invention also provides a preparation method of the ceramic core slurry for 3D printing, which comprises the following steps:

mixing an acrylate monomer, an acrylate oligomer, a photoinitiator and a water-based leveling agent to obtain a photosensitive resin material;

and mixing the photosensitive resin material, silicon dioxide powder, zirconium silicate powder and a dispersing agent to obtain the ceramic core slurry for 3D printing.

In the invention, the species and the amount of the substances in the preparation method are consistent with those in the ceramic core slurry for 3D printing in the technical scheme, and are not described again here.

The invention mixes the acrylate monomer, the acrylate oligomer, the photoinitiator and the aqueous flatting agent to obtain the photosensitive resin material.

The present invention does not specifically limit the mixing of the acrylate monomer, the acrylate oligomer, the photoinitiator and the aqueous leveling agent, and the mixing is well known to those skilled in the art, specifically, stirring.

After the photosensitive resin material is obtained, the photosensitive resin material, silicon dioxide powder, zirconium silicate powder and a dispersing agent are mixed to obtain the ceramic core slurry for 3D printing.

In the invention, the photosensitive resin material, the silicon dioxide powder, the zirconium silicate powder and the dispersing agent are preferably mixed by vacuum stirring; the air pressure of the vacuum stirring is preferably 50 to 100Pa, and more preferably 60 to 90 Pa. In the invention, the vacuum stirring time is preferably 4-5 h, and more preferably 4-4.5 h; the rate of the vacuum agitation is not particularly limited in the present invention, and may be any rate known to those skilled in the art. In the present invention, the mixing of the photosensitive resin material, the silica powder, the zirconium silicate powder and the dispersant is preferably performed in the dark.

The invention also provides application of the ceramic core slurry for 3D printing or the ceramic core slurry for 3D printing obtained by the preparation method in the technical scheme as a 3D printing material in a 3D printing ceramic core.

In the present invention, the 3D printed ceramic core preferably comprises the steps of:

3D printing is carried out on the ceramic core slurry for 3D printing to obtain a biscuit;

degreasing and sintering the biscuit to obtain a 3D printing ceramic core;

the degreasing sintering comprises the following steps: raising the temperature from room temperature to the first-stage temperature of 100-130 ℃, raising the temperature from the first-stage temperature to the second-stage temperature of 500-550 ℃, and preserving heat for 2-2.5 h, and raising the temperature from the second-stage temperature to the third-stage temperature of 1200-1250 ℃, and preserving heat for 2-2.5 h.

According to the invention, the ceramic core slurry for 3D printing is used for 3D printing to obtain a biscuit.

In the invention, the ceramic core slurry for 3D printing in the application is the ceramic core slurry for 3D printing according to the above technical scheme, and is not described herein again.

The 3D printing is not particularly limited in the present invention, and may be performed by 3D printing known to those skilled in the art, specifically, by DLP lithography.

After a biscuit is obtained, the biscuit is subjected to degreasing sintering to obtain the 3D printing ceramic core.

In the present invention, the degreasing sintering preferably includes: raising the temperature from room temperature to the first-stage temperature of 100-130 ℃, raising the temperature from the first-stage temperature to the second-stage temperature of 500-550 ℃, and preserving heat for 2-2.5 h, and raising the temperature from the second-stage temperature to the third-stage temperature of 1200-1250 ℃, and preserving heat for 2-2.5 h.

In the invention, the temperature of the first stage is preferably 100-130 ℃, and more preferably 100-125 ℃. In the invention, the heating rate from room temperature to the first stage temperature is preferably 2-2.5 ℃/min, and more preferably 2-2.3 ℃/min.

In the invention, the temperature of the second stage is preferably 500-550 ℃, more preferably 500-545 ℃, and further preferably 500-540 ℃; the heat preservation time is preferably 2-2.5 h, and more preferably 2-2.3 h. In the invention, the heating rate from the first stage temperature to the second stage temperature is preferably 0.5-1 ℃/min, and more preferably 0.7-1 ℃/min.

In the invention, the temperature of the third stage is preferably 1200-1250 ℃, more preferably 1200-1245 ℃, and still more preferably 1200-1240 ℃; the heat preservation time is preferably 2-2.5 h, and more preferably 2-2.3 h. In the invention, the heating rate from the second stage temperature to the third stage temperature is preferably 1-2 ℃/min, and more preferably 1.5-2 ℃/min.

After degreasing and sintering, the degreasing and sintering product is preferably cooled to obtain the 3D printing ceramic core. In the present invention, the cooling is preferably furnace cooling.

In order to further illustrate the present invention, the following will describe in detail a ceramic core slurry for 3D printing, a preparation method and applications thereof, which are provided by the present invention, with reference to the examples, but they should not be construed as limiting the scope of the present invention. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

Mixing 282mL (284.82g) of 1, 6-hexanediol diacrylate, 70.5mL (78.114g) of trimethylolpropane triacrylate, 3.5g of photoinitiator trimethylbenzoyl-diphenylphosphine oxide and 1g of an aqueous leveling agent BYK-333 to obtain a photosensitive resin material;

the photosensitive resin material, 800g of silica powder having a D50 value of 15.8 μm (the particle size distribution of the silica powder used in this example is shown in fig. 1), 80g of zirconium silicate powder having a 325 mesh size, and 5.5g of ammonium polyacrylate as a dispersant were mixed in the dark and stirred under vacuum at 100MPa for 4 hours to obtain the ceramic core slurry for 3D printing having a solid content of 50 vol.% and a viscosity of 280MPa · s.

And standing the obtained ceramic core slurry for 3D printing at room temperature for 0.5h, wherein the ceramic core slurry for 3D printing does not obviously cake and precipitate.

Application example 1

DLP photoetching printing is carried out by using the ceramic core slurry for 3D printing obtained in the embodiment 1 to obtain a sample strip and a small-leaflet ceramic core biscuit, wherein the sample strip and the small-leaflet ceramic core biscuit are printed by 50mm multiplied by 10mm multiplied by 5 mm; degreasing and sintering the biscuit: and heating the temperature from room temperature to 100 ℃ at the rate of 2 ℃/min, heating the temperature from the first stage to 500 ℃ at the rate of 1 ℃/min, keeping the temperature for 2h, heating the temperature from the second stage to 1200 ℃ at the rate of 2 ℃/min, keeping the temperature for 2h, and cooling along with the furnace to obtain the 3D printing ceramic core.

The 3D printing ceramic core sample object diagram prepared by the small-blade ceramic core biscuit is shown in fig. 2 and 3, and as can be seen from fig. 2 and 3, the small-blade ceramic core prepared by the ceramic core slurry for 3D printing provided by the invention has smooth surface and good surface quality; no obvious crack defects were found inside the small-leaflet ceramic cores using industrial CT for scan reconstruction.

The 3D printed ceramic core sample strips prepared from the sample strips of 50mm x 10mm x 5mm in example 1 were tested by measuring the room temperature bending strength using a room temperature bending strength tester using a three point bending method, and the formula (1) was calculated:

in the formula (1), σ_wIs the flexural strength (in MPa), P is the load at break of the sample (in N), L is the span between two points (in mm), b is the width of the sample (in mm), and h is the thickness of the sample (in mm);

in the high-temperature bending resistance test, the temperature of a sample is increased to 1550 ℃ at the heating rate of 5 ℃/min, the temperature is kept for 0.5h, and the breaking strength is calculated according to the formula (1);

the porosity and the density are measured by an Archimedes drainage method.

The average value of the room-temperature bending strength test of the 3D printing ceramic core provided in the application example 1 is 13.7MPa, the average value of the high-temperature bending resistance test at 1550 ℃ is 29.8MPa, the average value of the porosity is 30.8%, and the average value of the density is 1.75g/cm³And the requirements of high-temperature blade casting are met.

Example 2

Mixing 64mL (64.64g) of 1, 6-hexanediol diacrylate, 16mL (17.728g) of trimethylolpropane triacrylate, 8g of photoinitiator trimethylbenzoyl-diphenylphosphine oxide and 0.25g of an aqueous leveling agent BYK-333 to obtain a photosensitive resin material;

and mixing the photosensitive resin material, 200g of silica powder with D50 of 15.8 mu m, 30g of zirconium silicate powder with 325 meshes and 1.15g of dispersant ammonium polyacrylate under dark conditions, and stirring in vacuum at 100MPa for 4 hours to obtain the ceramic core slurry for 3D printing, wherein the solid content of the slurry is 44 vol% and the viscosity of the slurry is 250mPa & s.

And standing the obtained ceramic core slurry for 3D printing at room temperature for 0.5h, wherein the ceramic core slurry for 3D printing does not obviously cake and precipitate.

Application example 2

DLP photoetching printing is carried out by using the ceramic core slurry for 3D printing obtained in the embodiment 2, and sample strips and small-leaflet ceramic core biscuits with the printing size of 50mm multiplied by 10mm multiplied by 5mm are obtained; degreasing and sintering the biscuit: and heating the temperature from room temperature to 100 ℃ at the rate of 2 ℃/min, heating the temperature from the first stage to 500 ℃ at the rate of 1 ℃/min, keeping the temperature for 2h, heating the temperature from the second stage to 1200 ℃ at the rate of 2 ℃/min, keeping the temperature for 2h, and cooling along with the furnace to obtain the 3D printing ceramic core.

The 3D printing ceramic core sample prepared from the small-blade ceramic core biscuit has a smooth surface and good surface quality; no obvious crack defects were found inside the small-leaflet ceramic cores using industrial CT for scan reconstruction.

The 3D printed ceramic core bars prepared from the 50mm x 10mm x 5mm bars of example 2 were tested according to the method of application example 1.

The average value of the room-temperature bending strength test of the 3D printing ceramic core provided in application example 2 is 15.2MPa, the average value of the high-temperature bending resistance test at 1550 ℃ is 33.5MPa, the average value of the porosity is 33.9%, and the average value of the density is 1.72g/cm³And the requirements of high-temperature blade casting are met.

Comparative example 1

Mixing 64mL (64.64g) of 1, 6-hexanediol diacrylate, 16mL (17.728g) of trimethylolpropane triacrylate, 8g of photoinitiator trimethylbenzoyl-diphenylphosphine oxide and 0.25g of an aqueous leveling agent BYK-333 to obtain a photosensitive resin material;

and mixing the photosensitive resin material, 200g of silica powder with D50 of 15.8 mu m and 1g of dispersant ammonium polyacrylate under dark conditions, and stirring for 4 hours under vacuum at 100MPa to obtain the ceramic core slurry for 3D printing, wherein the solid content of the ceramic core slurry is 40 vol% and the viscosity of the ceramic core slurry is 230mPa & s.

And standing the obtained ceramic core slurry for 3D printing at room temperature for 0.5h, wherein the ceramic core slurry for 3D printing does not obviously cake and precipitate.

Comparative application example 1

DLP photoetching printing is carried out by using the ceramic core slurry for 3D printing obtained in the comparative example 1, and sample strips and small-leaflet ceramic core biscuits with the printing size of 50mm multiplied by 10mm multiplied by 5mm are obtained; degreasing and sintering the biscuit: and heating the temperature from room temperature to 100 ℃ at the rate of 2 ℃/min, heating the temperature from the first stage to 500 ℃ at the rate of 1 ℃/min, keeping the temperature for 2h, heating the temperature from the second stage to 1200 ℃ at the rate of 2 ℃/min, keeping the temperature for 2h, and cooling along with the furnace to obtain the 3D printing ceramic core.

The 3D printed ceramic core bars prepared from 50mm x 10mm x 5mm bars in comparative application example 1 were tested as in application example 1.

The average value of the room-temperature bending strength test of the 3D printing ceramic core provided in the comparative application example 1 is 7.5MPa, the average value of the high-temperature bending resistance test at 1550 ℃ is 17.2MPa, the average value of the porosity is 39.5%, and the average value of the density is 1.55g/cm³The strength at room temperature and the strength at high temperature are relatively weak, so the blade is easy to damage in the transportation and storage links, and is not suitable for casting the engine blade.

Comparative example 2

Mixing 72mL (72.72g) of 1, 6-hexanediol diacrylate, 20mL (22.16g) of trimethylolpropane triacrylate, 8g of photoinitiator trimethylbenzoyl-diphenylphosphine oxide and 0.25g of an aqueous leveling agent BYK-333 to obtain a photosensitive resin material;

and mixing the photosensitive resin material, 200g of silica powder with D50 of 15.8 mu m, 50g of zirconium silicate powder with 325 meshes and 1.2g of dispersant ammonium polyacrylate under dark conditions, and stirring in vacuum at 100MPa for 4 hours to obtain the ceramic core slurry for 3D printing, wherein the solid content of the slurry is 44 vol% and the viscosity of the slurry is 300mPa & s.

And standing the obtained ceramic core slurry for 3D printing at room temperature for 0.5h, wherein the ceramic core slurry for 3D printing does not obviously cake and precipitate.

Comparative application example 2

DLP photoetching printing is carried out by using the ceramic core slurry for 3D printing obtained in the comparative example 2, and sample strips and small-leaflet ceramic core biscuits with the printing size of 50mm multiplied by 10mm multiplied by 5mm are obtained; degreasing and sintering the biscuit: and heating the temperature from room temperature to 100 ℃ at the rate of 2 ℃/min, heating the temperature from the first stage to 500 ℃ at the rate of 1 ℃/min, keeping the temperature for 2h, heating the temperature from the second stage to 1200 ℃ at the rate of 2 ℃/min, keeping the temperature for 2h, and cooling along with the furnace to obtain the 3D printing ceramic core.

The 3D printed ceramic core bars prepared from 50mm x 10mm x 5mm bars in comparative application example 2 were tested as in application example 1.

The average value of the room-temperature bending strength test of the 3D printing ceramic core provided in the comparative application example 2 is 9.5MPa, the average value of the high-temperature bending resistance test at 1550 ℃ is 16.5MPa, the average value of the porosity is 36.2%, and the average value of the density is 1.6g/cm³Because the zirconium silicate powder is too much, the excessive zirconium silicate powder blocks the viscous flow between the silicon dioxide powder during sintering, large particles cannot be formed by the blockage of the zirconium silicate powder between the silicon dioxide ceramic particles at high temperature, the high-temperature (bending resistance) strength is reduced, the damage is easily caused in the transportation and storage link, and the engine blade is not suitable for being cast and used.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.