阅读说明：本技术 一种陶瓷前驱体浆料及多孔陶瓷件的3d打印反应成形方法 (Ceramic precursor slurry and 3D printing reaction forming method of porous ceramic piece ) 是由 陈张伟 刘雨 劳长石 林路平 于 2020-04-10 设计创作，主要内容包括：本发明公开了一种陶瓷前驱体浆料及多孔陶瓷件的3D打印反应成形方法,所述方法包括：制备用于光固化3D打印的正硅酸锂前驱体陶瓷浆料；通过光固化3D打印技术打印出材料和结构均匀的前驱体陶瓷素坯结构；将所述前驱体陶瓷素坯通过两步烧结的方式获得正硅酸锂多孔陶瓷样件。本发明通过3D打印技术制备正硅酸锂陶瓷件,并且不通过直接使用昂贵且难以获取的正硅酸锂粉末,而是采用价格低廉的前驱体粉末经过3D打印和高温烧结反应生成正硅酸锂材料的多孔陶瓷结构,所制备的正硅酸锂陶瓷纯度高、晶粒分布均匀、可实现任意复杂结构,从而实现更大的比表面积,有助于改善氚增殖陶瓷部件的产氚效率及使用寿命。(The invention discloses a ceramic precursor slurry and a 3D printing reaction forming method of a porous ceramic piece, which comprises the following steps: preparing lithium orthosilicate precursor ceramic slurry for photocuring 3D printing; printing a precursor ceramic biscuit structure with uniform material and structure by a photocuring 3D printing technology; and (3) obtaining the lithium orthosilicate porous ceramic sample by sintering the precursor ceramic biscuit in a two-step way. According to the invention, the lithium orthosilicate ceramic part is prepared by a 3D printing technology, expensive and difficultly-obtained lithium orthosilicate powder is not directly used, but a precursor powder with low price is adopted to generate a porous ceramic structure of a lithium orthosilicate material through 3D printing and high-temperature sintering reaction, and the prepared lithium orthosilicate ceramic has high purity and uniform crystal grain distribution, can realize any complex structure, thus realizing larger specific surface area, and is beneficial to improving the tritium production efficiency and the service life of the tritium multiplication ceramic part.)

1. A method of 3D printing reactive forming of a ceramic precursor slurry and a porous ceramic part, the method comprising:

preparing lithium orthosilicate precursor ceramic slurry for photocuring 3D printing;

printing a precursor ceramic biscuit structure with uniform material and structure by a photocuring 3D printing technology;

and (3) obtaining the lithium orthosilicate porous ceramic sample by sintering the precursor ceramic biscuit in a two-step way.

2. The ceramic precursor paste and the method for 3D printing reactive forming of a porous ceramic part according to claim 1, wherein the preparing a lithium orthosilicate precursor ceramic paste for photocuring 3D printing comprises:

mixing lithium carbonate powder and silicon dioxide powder in a molar ratio of 2: 1, uniformly mixing to obtain inorganic precursor mixed ceramic powder;

mixing and stirring the inorganic precursor mixed powder, the pre-photocuring resin premix, the surfactant and the dispersant to obtain a mixture;

putting the mixture into a planetary ball mill, fully grinding, mixing and stirring, and then adding a photoinitiator to obtain primary slurry;

and (3) putting the preliminary slurry into a planetary ball mill, fully grinding, mixing and stirring, filtering, and defoaming through a defoaming machine to obtain the lithium orthosilicate precursor ceramic slurry.

3. The method of claim 1, wherein the printing of the precursor ceramic biscuit structure with uniform material and structure by photocuring 3D printing technique comprises:

pouring the lithium orthosilicate precursor ceramic slurry into a material groove of a photocuring 3D printer;

and (4) introducing the designed porous structure model into a printer computer system, and printing a precursor ceramic biscuit structure.

4. The ceramic precursor slurry and the 3D printing reaction forming method of the porous ceramic piece according to claim 1, wherein the precursor ceramic biscuit is sintered in two steps to obtain the lithium orthosilicate porous ceramic sample piece, and the method comprises the following steps:

putting the precursor ceramic biscuit into a degreasing sintering furnace, heating to 750 ℃ from room temperature, and naturally cooling to room temperature to obtain a degreased sample piece;

and putting the degreased sample piece into a high-temperature sintering furnace, heating the sample piece to 950 ℃ from room temperature, and naturally cooling the sample piece to the room temperature to obtain the lithium orthosilicate porous ceramic sample piece.

5. The method of claim 2, wherein the photocurable resin premix comprises: 70-80 parts of trimethylolpropane triacrylate and 20-30 parts of ethylene glycol diacrylate in parts by weight.

6. The ceramic precursor slurry and the 3D printing reaction forming method of a porous ceramic part according to claim 2, wherein the particle size of the lithium carbonate powder is 0.1-20 μm and the particle size of the silica powder is 0.1-20 μm in the precursor mixed powder.

7. The ceramic precursor slurry and the method for 3D printing reactive forming of a porous ceramic article according to claim 2, wherein the lithium orthosilicate precursor ceramic slurry has a solid content of 35 to 55 vol%; the dispersant accounts for 2 to 6 percent of the inorganic precursor mixed powder; the surfactant accounts for 1% -3% of the mixture; the volume ratio of the inorganic precursor mixed powder to the light-cured resin premix is 3.5-5.5: 4.5-6.5.

8. The method of 3D printing reactive forming of ceramic precursor paste and porous ceramic part according to claim 2, wherein the photoinitiator is a radical photoinitiator comprising: 2,4, 6-trimethylbenzoyl-diphenylphosphine oxide, 2-dimethoxybenzil ketal, 2-methyl-1- (4-methylmercaptophenyl) 2-morpholinopropanone-1, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1, 2,4, 6-trimethylbenzoyl-ethoxy-phenylphosphine oxide.

9. The method of claim 2, wherein the surfactant is a silane-based active agent or coupling agent, and comprises: propyl trimethoxy silane, vinyl triethoxy silane, and gamma- (methacryloxy) silane.

10. The method for 3D printing, reacting and forming of the ceramic precursor slurry and the porous ceramic piece according to claim 4, wherein the heating rate of the degreasing sintering furnace is 0.1-1 ℃/min during degreasing, and the holding time is 4-8 h; the temperature rise rate of the high-temperature sintering furnace during sintering is 1-5 ℃/min, and the heat preservation time is 1-2 h.

Technical Field

The invention relates to the technical field of 3D printing, in particular to a ceramic precursor slurry and a 3D printing reaction forming method of a porous ceramic piece.

Background

The tritium production experimental cladding (TBM) module is one of three major engineering goals of the international thermonuclear experimental fusion reactor ITER. Meanwhile, the reactor is also a core component of fusion engineering experimental reactors, demonstration reactors and commercial fusion power stations, and plays a role in breeding tritium fuel, extracting fusion energy and the like in various reactor types. As the most important functional material in the TBM module, the lithium-based ceramic is widely concerned by domestic and foreign researches due to good stability, higher safety and no magnetic fluid dynamic effect, and is a main research object in the current domestic and foreign solid tritium breeding materials; lithium orthosilicate (Li4SiO4) material is considered to be one of the most attractive tritium breeding materials in lithium-based ceramic systems because of high lithium-containing density, good chemical stability, mechanical stability and irradiation stability, capability of releasing tritium at a lower temperature and capability of reducing tritium retention by raising temperature.

At present, the Li4SiO4 tritium breeder unit is generally piled up in a tritium breeding area in a cladding in a microsphere form to form a ball bed structure. The manufacturing process faces the problems of microsphere thermal stress concentration, easy material fracture, poor structure and performance uniformity and controllability and the like, the structure-function integrated design and manufacturing process is urgently needed to be developed, and the 3D printing technology provides possibility for solving the problems. Nowadays, the 3D printing integrated manufacturing technology obtains specially designed lithium orthosilicate porous ceramics to solve various problems faced by ceramic microspheres. But 3D printing directly using lithium orthosilicate powder also presents significant challenges. On one hand, the lithium orthosilicate powder preparation process has complex procedures, low yield and high cost, and a direct-sale commercial powder product is difficult to find in the market; on the other hand, the requirements of 3D printing on the specification of ceramic powder are high, and particularly, micro-nano-grade powder materials are needed for photocuring 3D printing, and the micro-nano-grade powder materials are not easy to obtain for lithium orthosilicate. In addition, lithium orthosilicate powder is easy to react with carbon dioxide and moisture in the air at room temperature, which affects the phase purity of lithium orthosilicate materials and is not beneficial to the subsequent printing process.

Accordingly, the prior art is yet to be improved and developed.

Disclosure of Invention

The technical problem to be solved by the invention is to provide a ceramic precursor slurry and a 3D printing reaction forming method of a porous ceramic piece aiming at preparing a lithium orthosilicate precursor ceramic slurry which can be applied to photocuring 3D printing, aiming at overcoming the defects in the prior art; designing a porous structure model with a special structure, and printing a biscuit by a photocuring 3D printing technology; finally, the printed precursor biscuit is converted into a lithium orthosilicate ceramic sample by degreasing and sintering.

The technical scheme adopted by the invention for solving the technical problem is as follows:

the embodiment of the invention provides a ceramic precursor slurry and a 3D printing reaction forming method of a porous ceramic piece, wherein the method comprises the following steps:

preparing lithium orthosilicate precursor ceramic slurry for photocuring 3D printing;

printing a precursor ceramic biscuit structure with uniform material and structure by a photocuring 3D printing technology;

and (3) obtaining the lithium orthosilicate porous ceramic sample by sintering the precursor ceramic biscuit in a two-step way.

In one embodiment, the preparing a lithium orthosilicate precursor ceramic slurry for photocuring 3D printing includes:

mixing lithium carbonate powder and silicon dioxide powder in a molar ratio of 2: 1, uniformly mixing to obtain inorganic precursor mixed ceramic powder;

mixing and stirring the inorganic precursor mixed powder, the pre-photocuring resin premix, the surfactant and the dispersant to obtain a mixture;

putting the mixture into a planetary ball mill, fully grinding, mixing and stirring, and then adding a photoinitiator to obtain primary slurry;

and (3) putting the preliminary slurry into a planetary ball mill, fully grinding, mixing and stirring, filtering, and defoaming through a defoaming machine to obtain the lithium orthosilicate precursor ceramic slurry.

In one embodiment, the printing of the precursor ceramic biscuit structure with uniform material and structure by the photocuring 3D printing technique comprises:

pouring the lithium orthosilicate precursor ceramic slurry into a material groove of a photocuring 3D printer;

and (4) introducing the designed porous structure model into a printer computer system, and printing a precursor ceramic biscuit structure.

In one embodiment, the lithium orthosilicate porous ceramic sample is obtained by sintering the precursor ceramic biscuit in two steps, and comprises:

putting the precursor ceramic biscuit into a degreasing sintering furnace, heating to 750 ℃ from room temperature, and naturally cooling to room temperature to obtain a degreased sample piece;

and putting the degreased sample piece into a high-temperature sintering furnace, heating the sample piece to 950 ℃ from room temperature, and naturally cooling the sample piece to the room temperature to obtain the lithium orthosilicate porous ceramic sample piece.

In one embodiment, the photocurable resin premix comprises: 70-80 parts of trimethylolpropane triacrylate and 20-30 parts of ethylene glycol diacrylate in parts by weight.

In one embodiment, the particle size of the lithium carbonate powder is 0.1 to 20 μm, and the particle size of the silica powder is 0.1 to 20 μm.

In one embodiment, the lithium orthosilicate precursor ceramic slurry has a solid phase content of 35 to 55 vol%; the dispersant accounts for 2 to 6 percent of the inorganic precursor mixed powder; the surfactant accounts for 1% -3% of the mixture; the volume ratio of the inorganic precursor mixed powder to the light-cured resin premix is 3.5-5.5:4.5-6.5

In one embodiment, the photoinitiator is a free radical photoinitiator comprising: 2,4, 6-trimethylbenzoyl-diphenylphosphine oxide, 2-dimethoxybenzil ketal, 2-methyl-1- (4-methylmercaptophenyl) 2-morpholinopropanone-1, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1, 2,4, 6-trimethylbenzoyl-ethoxy-phenylphosphine oxide.

In one embodiment, the surfactant is a silane-based active agent or coupling agent comprising: propyl trimethoxy silane, vinyl triethoxy silane, and gamma- (methacryloxy) silane.

In one embodiment, the heating rate of the degreasing sintering furnace during degreasing is 0.1-1 ℃/min, and the heat preservation time is 4-8 h; the temperature rise rate of the high-temperature sintering furnace during sintering is 1-5 ℃/min, and the heat preservation time is 1-2 h.

The invention has the beneficial effects that: according to the invention, the lithium orthosilicate ceramic part is prepared by a 3D printing technology, expensive and difficultly-obtained lithium orthosilicate powder is not directly used, but a precursor powder with low price is adopted to generate a porous ceramic structure of a lithium orthosilicate material through 3D printing and high-temperature sintering reaction, and the prepared lithium orthosilicate ceramic has high purity and uniform crystal grain distribution, can realize any complex structure, thus realizing larger specific surface area, and is beneficial to improving the tritium production efficiency and the service life of the tritium multiplication ceramic part.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments described in the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.

Fig. 1 is a flow chart of a ceramic precursor slurry and a method for 3D printing reactive forming of a porous ceramic part according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of a lithium orthosilicate precursor ceramic slurry prepared in the ceramic precursor slurry and the 3D printing reaction forming method for a porous ceramic piece according to the embodiment of the invention.

Fig. 3 shows a CAD model, a printed biscuit and a sintered lithium orthosilicate structure in a method for 3D printing reactive forming of a ceramic precursor slurry and a porous ceramic part according to an embodiment of the invention.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. 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.

The present embodiment provides a method for 3D printing reaction forming of a ceramic precursor slurry and a porous ceramic part, specifically as shown in fig. 1, the method includes the following steps:

and S100, preparing lithium orthosilicate precursor ceramic slurry for photocuring 3D printing.