A preparation method of a 3D printed opacified crackled celadon ceramic product

Abstract

The present invention discloses a preparation method of a 3D printed opalescent crackled celadon ceramic product, and the steps are as follows: (1) preparing a 3D printing slurry: the components of the slurry include clay powder, pulp and water; the components of the clay powder include purple gold clay, kaolin, iron oxide and grog; (2) preparing a glazing slurry: the components of the glaze include Huangtang stone, quartz, calcined kaolin, calcite, talc, iron oxide; (3) 3D printing the blank to form; (4) biscuit firing the blank; (5) dipping the glaze; (6) firing. The present invention selects blank components with a similar expansion coefficient to the glaze, and adds grog with specific components to the blank, so that the blank can be formed by 3D printing through the LDM method without adding an organic binder, and the prepared ceramic product has good blank-glaze bonding and good glaze surface quality, and can realize the rapid and large-scale industrial production of Longquan celadon.

Description

Technical Field

[0001] The present invention relates to the technical field of 3D printing ceramic materials, and particularly to a preparation method for 3D printing semi-opalescent crackle celadon ceramic products. Background Art

[0002] Traditional Longquan celadon is a traditional ceramic product made from natural minerals, mainly formed by manual throwing, decorated with thick glazes using family heirloom glaze formulas, and fired at high temperatures. The preparation process is relatively single, it is difficult to form complex structures through traditional processes, and its production cycle is long, unable to meet the personalized needs of modern consumers for Longquan celadon, and unable to carry out large-scale industrial production.

[0003] 3D printing technology is an additive manufacturing method that can quickly generate ceramic bodies with complex structures. Compared with traditional ceramic forming technologies, this technology is not restricted by mold making or processing techniques, provides a way for the forming of complex ceramic products, and greatly reduces the processing procedures and shortens the processing cycle. Printing materials are one of the key factors restricting the development of ceramic 3D printing technology. When using 3D printing technology to prepare ceramic products, on the one hand, it is necessary to ensure that the ceramic slurry meets the forming requirements of 3D printing, and on the other hand, it is necessary to ensure good bonding between the formed green body and the glaze to improve the glaze quality of the product.

[0004] Currently, most ceramic slurries for 3D printing need to use organic materials such as organic binders or photosensitive resins to bond ceramic powders so that they can be formed by 3D printing. The addition of these organic materials reduces the density of the green body. During firing, the removal of organic materials causes the green body to shrink and deform easily. When making Longquan celadon with it, the expansion coefficients of the green body and the glaze do not match, resulting in poor bonding between the green body and the glaze, and prone to problems such as glaze peeling and glaze cracking. Therefore, developing a preparation method that can not only make the ceramic slurry meet the forming requirements of 3D printing but also have good bonding with the glaze of Longquan celadon is of great significance for the rapid and large-scale industrial production of Longquan celadon with complex shapes. Summary of the Invention

[0005] The present invention aims to overcome the above problems existing in the preparation of Longquan celadon using 3D printing technology, and provides a preparation method for 3D printing semi-opalescent crackle celadon ceramic products. By selecting blank components with expansion coefficients similar to those of the glaze and adding clinker with specific components to the blank, the blank can be formed by LDM 3D printing without adding organic binders, and the resulting ceramic products have good blank-glaze bonding and excellent glaze quality, enabling the rapid and large-scale industrial production of Longquan celadon.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A preparation method of a 3D printed opacified crackled celadon ceramic product, comprising the following steps:

[0008] (1) Prepare 3D printing slurry: Mix clay powder and pulp in a mass ratio of 100:10 - 15, stir evenly, and then add water and stir until the water content of the slurry is 25 - 30 wt%, to obtain 3D printing slurry; calculated by weight, the components of the clay powder include: 60 - 65 parts of purple gold clay, 25 - 35 parts of kaolin, 3 - 5 parts of iron oxide, and 5 - 8 parts of grog; the grog is sintered from kaolin, MgO, ZrO2 and Nd2O3 in a mass ratio of 10 - 15:5 - 8:3 - 5:1;

[0009] (2) Prepare glazing slurry: Ball mill the glaze components with water to obtain glazing slurry; calculated by weight, the glaze components include: 40 - 60 parts of Huangtang stone, 10 - 15 parts of quartz, 10 - 15 parts of calcined kaolin, 10 - 15 parts of calcite, 15 - 20 parts of talc, and 0.5 - 1 part of iron oxide;

[0010] (3) 3D print the blank to form: Use the 3D printer of the LDM method to print and form the prepared 3D printing slurry to obtain a blank;

[0011] (4) Bisque-fire the blank: Bisque-fire the blank at 800 - 900 °C to obtain a bisque;

[0012] (5) Dip glazing: Place the bisque in the glazing slurry for dip glazing;

[0013] (6) Fire: Fire the dip-glazed blank to obtain the 3D printed opacified crackled celadon ceramic product.

[0014] In the present invention, Huangtang stone is used as the main component, and together with quartz, calcined kaolin, calcite, talc and iron oxide, it is formulated into glaze components. After firing, an opacified crackled celadon glaze with a crackled effect, green color and high gloss can be obtained. At the same time, the present invention uses a certain proportion of purple gold clay and kaolin as the main raw materials of the blank, which can make the blank and the glaze have similar expansion coefficients, so that the body and glaze have good adaptability and avoid the phenomenon of glaze peeling off in the fired product.

[0015] The blank in the present invention is made by 3D printing technology, which is not restricted by mold making or processing techniques, is suitable for the forming of complex ceramic products, greatly reduces the processing procedures, shortens the processing cycle, and enables large-scale industrial production of Longquan celadon. To make the blank meet the forming requirements of 3D printing, the present invention introduces grog made by mixing and sintering kaolin, MgO, ZrO2 and Nd2O3 and an appropriate amount of pulp into the blank. The grog can improve the plasticity of the blank, and after being made into a slurry by adding water, it can be formed by 3D printing using the LDM method without adding an organic binder, and the obtained green body has a high density; the pulp can reduce the shrinkage and deformation rate of the green body, and the fired product is not prone to cracking, deformation, or collapse, improving the quality of Longquan celadon products.

[0016] Meanwhile, the present invention has found through research that the doping of the three phases of MgO, ZrO2 and Nd2O3 in the grog is beneficial to the mutual diffusion and penetration between the glaze and the blank components during the firing process, forming a blank-glaze intermediate layer with an appropriate thickness. The chemical composition and crystal properties of the intermediate layer gradually transition from the blank to the glaze, reconciling the property differences between the glaze and the blank, enhancing the bonding force between the blank and the glaze, thereby avoiding phenomena such as product deformation, glaze peeling, and late-stage cracking, and improving the quality stability of the product.

[0017] Preferably, the sintering method of the grog in step (1) is: mixing kaolin, MgO, ZrO2 and Nd2O3 in proportion and placing them in an electric kiln, heating to 300 °C within 50 - 70 min, then heating to 600 °C within 100 - 130 min and stopping the fire, taking out after cooling to room temperature to obtain the grog. By sintering kaolin, MgO, ZrO2 and Nd2O3, their crystal forms and physical properties can be changed, the plasticity of the blank can be improved, the drying shrinkage and deformation of the green body made by 3D printing can be reduced, and product cracking can be decreased.

[0018] Preferably, the preparation method of the clay powder in step (1) is: mixing purple gold clay, kaolin, iron oxide and grog in proportion to obtain a mixture, adding an additive and water to the mixture and then ball milling; after the ball milling is completed, the mixture is subjected to pressure filtration, vacuum clay refining, and aging to obtain a clay material; the clay material is dried to obtain the clay powder. The fineness of ceramic powder can affect the plasticity of the clay powder and the density of the green body. Finer powder can endow the clay powder with better forming properties, improve the accuracy and density of the printed product. The present invention reduces the fineness of the blank by ball milling to improve its plasticity and the density of the green body.

[0019] Preferably, the preparation method of the additive is as follows: A) Mix sebac diamine with sodium methoxide catalyst, then heat up to 70-90 °C, and dropwise add dimethyl maleate under nitrogen protection, and keep the temperature for reaction for 12-24 h to obtain aspartic acid ester; the molar ratio of sebac diamine to dimethyl maleate is 1:2-2.2, and the addition amount of sodium methoxide catalyst is 0.5-1% of the total mass of sebac diamine and dimethyl maleate; B) Mix the obtained aspartic acid ester with methoxypolyethylene glycol, add sodium methoxide catalyst, and react at 130-150 °C for 5-8 h to obtain the additive; the molecular weight of methoxypolyethylene glycol is 300-500, the mass ratio of aspartic acid ester to methoxypolyethylene glycol is 1:3-5, and the addition amount of sodium methoxide catalyst is 0.5-1% of the total mass of aspartic acid ester and methoxypolyethylene glycol.

[0020] In order to improve the 3D printing forming performance of the blank and improve the quality of the green body, the present invention adds an additive during the ball milling process. During the preparation process of the additive of the present invention, aspartic acid ester is first prepared by the Michael addition reaction of sebac diamine and dimethyl maleate; then, through the transesterification reaction of aspartic acid ester and methoxypolyethylene glycol, aspartic acid ester with both hydrophilic and hydrophobic segments in the molecule is obtained. When used as an additive, during the ball milling process, the hydrophobic segment adsorbs on the surface of the powder, and the hydrophilic group stretches outwards, which can reduce the surface energy of the powder, prevent the agglomeration of the powder, reduce the viscosity of the slurry, improve its fluidity, and improve the ball milling efficiency; at the same time, the molecular chains of the additive wrapped on the surface of the powder can be intertwined with each other, play a bridging role between the powders, form a three-dimensional network structure, and make the powder particles more closely combined, thereby improving the density and strength of the green body.

[0021] Preferably, the addition amount of the additive is 3-5% of the mass of the mixture.

[0022] Preferably, the mass ratio of ball stones: mixture: water during ball milling is 2-3:1:0.5-1, and the ball milling time is 10-15 h.

[0023] Preferably, the moisture content of the pulp in step (1) is 40-60 wt%.

[0024] Preferably, the preparation method of the calcined kaolin in step (2) is: place kaolin in an electric kiln, heat up to 300 °C within 50-70 min, then heat up to 600 °C within 100-130 min and stop firing, and take it out after cooling to room temperature to obtain the calcined kaolin.

[0025] Preferably, during ball milling in step (2), the mass ratio of ball stones: glaze components: water is 1-2:1:0.5-1, and the ball milling time is 10-15 h; after ball milling, it is sieved through a 100-200 mesh sieve to obtain the glazing slurry.

[0026] Preferably, in step (3), the nozzle diameter during 3D printing is 0.4 - 0.6 mm, the layer height is set to 0.3 - 0.5 mm, and the air pump air pressure is 5 - 6 MPa.

[0027] Preferably, in step (4), the biscuit firing time is 4 - 6 h.

[0028] Preferably, the firing method in step (6) is as follows: first, heat up to 950 - 1000 °C within 4 - 6 h; then heat up to 1050 - 1100 °C and hold for 1 - 2 h; continue to heat up to 1280 - 1300 °C within 3 - 5 h; finally, heat up to 1300 - 1310 °C, hold for 40 - 50 min, and cool naturally before taking out of the kiln.

[0029] Therefore, the present invention has the following beneficial effects:

[0030] (1) Through the selection of glaze components, after firing, a semi - opaque crackle Longquan celadon glaze with crackle effect, blue - green color, and high gloss can be obtained; at the same time, a blank with a coefficient of thermal expansion similar to that of the glaze is selected to make the glaze and the blank have good adaptability and avoid the phenomenon of glaze peeling off after firing.

[0031] (2) The blank is made by 3D printing technology, which is not restricted by mold making or processing technology, is suitable for the forming of complex ceramic products, greatly reduces the processing procedures, shortens the processing cycle, and can realize the large - scale industrial production of Longquan celadon.

[0032] (3) Adding pulp to the blank can reduce the shrinkage and deformation rate of the blank body, and the fired products are not easy to crack, deform, or collapse, improving the quality of Longquan celadon products.

[0033] (4) Introducing grog made by mixing and sintering kaolin, MgO, ZrO2, and Nd2O3 into the blank can improve the plasticity of the blank and is beneficial to the formation of an appropriate - thickness intermediate layer between the blank and the glaze during firing, enhancing the bonding force between the blank and the glaze, thus avoiding phenomena such as product deformation, glaze peeling, and late cracking, and improving the quality stability of the products.

[0034] (5) Adding aspartic acid ester with both hydrophilic and hydrophobic segments in the molecule as an additive during the ball - milling process of the blank can avoid powder agglomeration, improve the fluidity of the slurry, and enhance the density and strength of the blank body. Specific Embodiments

[0035] The following further describes the present invention in combination with specific embodiments.

[0036] In the present invention, unless otherwise specified, all equipment and raw materials can be purchased from the market or are commonly used in this industry. The methods in the following embodiments, unless otherwise specified, are conventional methods in this field.

[0037] General Embodiment

[0038] A preparation method of a 3D printed opacified cracked celadon ceramic product, comprising the following steps:

[0039] (1) Prepare the clinker: Mix kaolin, MgO, ZrO2 and Nd2O3 in a mass ratio of 10 - 15:5 - 8:3 - 5:1, place them in an electric kiln, heat up to 300 °C within 50 - 70 min, then heat up to 600 °C within 100 - 130 min and stop firing, take out after cooling to room temperature to obtain the clinker;

[0040] (2) Prepare the additive: A) Mix decanediamine with sodium methoxide catalyst, then heat up to 70 - 90 °C, dropwise add dimethyl maleate under nitrogen protection, keep the temperature for reaction for 12 - 24 h to obtain aspartic acid ester; the molar ratio of decanediamine to dimethyl maleate is 1:2 - 2.2, and the addition amount of sodium methoxide catalyst is 0.5 - 1% of the total mass of decanediamine and dimethyl maleate; B) Mix the obtained aspartic acid ester with methoxypolyethylene glycol, add sodium methoxide catalyst, and react at 130 - 150 °C for 5 - 8 h to obtain the additive; the molecular weight of methoxypolyethylene glycol is 300 - 500, the mass ratio of aspartic acid ester to methoxypolyethylene glycol is 1:3 - 5, and the addition amount of sodium methoxide catalyst is 0.5 - 1% of the total mass of aspartic acid ester and methoxypolyethylene glycol;

[0041] (3) Prepare the mud powder: By weight, mix 60 - 65 parts of purple gold clay, 25 - 35 parts of kaolin, 3 - 5 parts of iron oxide and 5 - 8 parts of clinker to obtain a mixture, add 3 - 5% of the additive and water based on the mass of the mixture to the mixture and then ball mill it, the mass ratio of ball stones: mixture: water is 2 - 3:1:0.5 - 1, and the ball milling time is 10 - 15 h; after the ball milling is completed, obtain the mud material through pressure filtration, vacuum pugging and aging; dry the mud material to obtain the mud powder;

[0042] (4) Prepare the 3D printing slurry: Mix the mud powder and pulp (water content 40 - 60 wt%) in a mass ratio of 100:10 - 15, stir evenly, and then add water and stir until the water content of the slurry is 25 - 30 wt% to obtain the 3D printing slurry;

[0043] (5) Prepare the calcined kaolin: Place kaolin in an electric kiln, heat up to 300 °C within 50 - 70 min, then heat up to 600 °C within 100 - 130 min and stop firing, take out after cooling to room temperature to obtain the calcined kaolin;

[0044] (6) Preparation of glazing slurry: The glaze components are ball-milled with water and then screened through a 100-200 mesh sieve to obtain the glazing slurry; calculated by weight, the glaze components include: 40-60 parts of Huangtang stone, 10-15 parts of quartz, 10-15 parts of calcined kaolin, 10-15 parts of calcite, 15-20 parts of talc, and 0.5-1 part of iron oxide; during ball-milling, the mass ratio of ball stones: glaze components: water is 1-2:1:0.5-1, and the ball-milling time is 10-15 h;

[0045] (7) 3D printing green body forming: The prepared 3D printing slurry is printed and formed with an LDM method 3D printer to obtain a green body; the nozzle diameter during 3D printing is 0.4-0.6 mm, the layer height is set to 0.3-0.5 mm, and the air pump air pressure is 5-6 MPa;

[0046] (8) Biscuit firing of the green body: The green body is biscuit-fired at 800-900 °C for 4-6 h to obtain a biscuit body;

[0047] (9) Glazing: The biscuit body is placed in the glazing slurry for glazing;

[0048] (10) Firing: The glazed green body is fired to obtain the 3D printed semi-opalescent crackled celadon ceramic product; the firing method is as follows: first, it is heated to 950-1000 °C within 4-6 h; then it is further heated to 1050-1100 °C and held for 1-2 h; it is continuously heated to 1280-1300 °C within 3-5 h; finally, it is heated to 1300-1310 °C and held for 40-50 min, and then taken out of the kiln after natural cooling.

[0049] Example 1:

[0050] A preparation method of a 3D printed semi-opalescent crackled celadon ceramic product, comprising the following steps:

[0051] (1) Preparation of clinker: Kaolin, MgO, ZrO2 and Nd2O3 are mixed in a mass ratio of 12:6:4:1 and placed in an electric kiln, heated to 300 °C within 60 min, then heated to 600 °C within 120 min and stopped firing, and taken out after cooling to room temperature to obtain the clinker;

[0052] (2) Preparation of additives: A) Mix sebac diamine with sodium methoxide catalyst, then heat up to 80 °C, and dropwise add dimethyl maleate under nitrogen protection, keep the temperature for reaction for 18 h to obtain aspartic acid ester; the molar ratio of sebac diamine to dimethyl maleate is 1:2.1, and the addition amount of sodium methoxide catalyst is 0.5% of the total mass of sebac diamine and dimethyl maleate; B) Mix the obtained aspartic acid ester with polyethylene glycol monomethyl ether (average molecular weight 350), add sodium methoxide catalyst, and react at 140 °C for 6 h to obtain the additive; the mass ratio of aspartic acid ester to polyethylene glycol monomethyl ether is 1:4, and the addition amount of sodium methoxide catalyst is 0.5% of the total mass of aspartic acid ester and polyethylene glycol monomethyl ether;

[0053] (3) Preparation of mud powder: By weight, mix 62 parts of Baoxi purple gold clay, 30 parts of Longquan kaolin, 3 parts of iron oxide and 5 parts of clinker to obtain a mixture. Add 4% of the additive and water based on the mass of the mixture to the mixture and then carry out ball milling. The mass ratio of ball stones: mixture: water is 2:1:0.8, and the ball milling time is 12 h; after the ball milling is completed, obtain the mud material through pressure filtration, vacuum clay refining and aging; dry the mud material to obtain the mud powder;

[0054] (4) Preparation of 3D printing slurry: Mix the mud powder and pulp (water content 50 wt%) with a mass ratio of 100:12, stir evenly, and then add water and stir until the water content of the slurry is 30 wt% to obtain the 3D printing slurry;

[0055] (5) Preparation of calcined kaolin: Place Longquan kaolin in an electric kiln, heat up to 300 °C within 60 min, then heat up to 600 °C within 120 min and stop firing, and take it out after cooling to room temperature to obtain the calcined kaolin;

[0056] (6) Preparation of glazing slurry: Add water to the glaze components and carry out ball milling, then pass through a 150-mesh sieve to obtain the glazing slurry; by weight, the glaze components include: 50 parts of Huangtang stone, 10 parts of quartz, 12 parts of calcined kaolin, 12 parts of calcite, 16 parts of talc, 0.5 part of iron oxide; during ball milling, the mass ratio of ball stones: glaze components: water is 1.5:1:0.8, and the ball milling time is 12 h;

[0057] (7) 3D printing of green body forming: Use the prepared 3D printing slurry to print and form with an LDM method 3D printer to obtain a green body; the nozzle diameter during 3D printing is 0.5 mm, the layer height is set to 0.4 mm, and the air pump air pressure is 5 MPa;

[0058] (8) Biscuit firing of green body: Biscuit fire the green body at 860 °C for 5 h to obtain a biscuit body;

[0059] (9) Glazing: Dip the biscuit body into the glazing slurry twice;

[0060] (10) Firing: Fire the glazed green body to obtain the 3D printed semi - opalescent crackled celadon ceramic product; the firing method is as follows: First, heat it to 980 °C in 5 h; then heat it to 1080 °C and hold for 1.5 h; continue to heat to 1290 °C in 4 h; finally heat to 1300 °C and hold for 40 min, and then cool naturally and take it out of the kiln.

[0061] Example 2:

[0062] A preparation method of a 3D printed semi - opalescent crackled celadon ceramic product, comprising the following steps:

[0063] (1) Preparation of clinker: Mix kaolin, MgO, ZrO2 and Nd2O3 in a mass ratio of 10:8:3:1, place them in an electric kiln, heat to 300 °C in 60 min, then heat to 600 °C in 120 min, stop firing, cool to room temperature and take out to obtain the clinker;

[0064] (2) Preparation of additives: A) Mix decanediamine with sodium methoxide catalyst, then heat to 80 °C, dropwise add dimethyl maleate under nitrogen protection, and hold for 18 h to obtain aspartic acid ester; the molar ratio of decanediamine to dimethyl maleate is 1:2.1, and the addition amount of sodium methoxide catalyst is 0.5% of the total mass of decanediamine and dimethyl maleate; B) Mix the obtained aspartic acid ester with polyethylene glycol monomethyl ether (average molecular weight 350), add sodium methoxide catalyst, and react at 140 °C for 6 h to obtain the additive; the mass ratio of aspartic acid ester to polyethylene glycol monomethyl ether is 1:4, and the addition amount of sodium methoxide catalyst is 0.5% of the total mass of aspartic acid ester and polyethylene glycol monomethyl ether;

[0065] (3) Preparation of mud powder: By weight, mix 60 parts of Baoxi purple gold clay, 25 parts of Longquan kaolin, 3 parts of iron oxide and 5 parts of clinker to obtain a mixture. Add 3% of the additive and water based on the mass of the mixture, and then ball - mill. The mass ratio of ball stones: mixture: water is 2:1:0.8, and the ball - milling time is 12 h; after ball - milling, obtain mud through pressure filtration, vacuum clay refining and aging; dry the mud to obtain mud powder;

[0066] (4) Preparation of 3D printing slurry: Mix mud powder and pulp (water content 50 wt%) in a mass ratio of 100:10, stir evenly, and then add water and stir until the water content of the slurry is 25 wt% to obtain 3D printing slurry;

[0067] (5) Preparation of calcined kaolin: Place Longquan kaolin in an electric kiln, heat to 300 °C in 60 min, then heat to 600 °C in 120 min, stop firing, cool to room temperature and take out to obtain the calcined kaolin;

[0068] (6) Preparation of glazing slurry: The glaze components are ball-milled with water and then screened through a 150-mesh sieve to obtain the glazing slurry; calculated by weight, the glaze components include: 40 parts of Huangtang stone, 10 parts of quartz, 10 parts of calcined kaolin, 10 parts of calcite, 15 parts of talc, and 0.5 part of iron oxide; during ball-milling, the mass ratio of ball stones: glaze components: water is 1.5:1:0.8, and the ball-milling time is 12 h;

[0069] (7) 3D printing of green body forming: The prepared 3D printing slurry is printed and formed by an LDM method 3D printer to obtain a green body; the nozzle diameter during 3D printing is 0.5 mm, the layer height is set to 0.4 mm, and the air pump air pressure is 5 MPa;

[0070] (8) Biscuit firing of green body: The green body is biscuit-fired at 860 °C for 5 h to obtain a biscuit body;

[0071] (9) Glaze dipping: The biscuit body is dipped into the glazing slurry twice;

[0072] (10) Firing: The dipped green body is fired to obtain the 3D printed semi-opalescent crackled celadon ceramic product; the firing method is as follows: first, it is heated to 980 °C in 5 h; then it is further heated to 1080 °C and held for 1.5 h; it is continuously heated to 1290 °C in 4 h; finally, it is heated to 1300 °C and held for 40 min, and then taken out of the kiln after natural cooling.

[0073] Example 3:

[0074] A preparation method of a 3D printed semi-opalescent crackled celadon ceramic product, comprising the following steps:

[0075] (1) Preparation of clinker: Kaolin, MgO, ZrO2 and Nd2O3 are mixed according to a mass ratio of 15:5:5:1 and placed in an electric kiln, heated to 300 °C within 60 min, then heated to 600 °C within 120 min and stopped firing, taken out after cooling to room temperature to obtain the clinker;

[0076] (2) Preparation of additive: A) Decanediamine is mixed with sodium methoxide catalyst, then heated to 80 °C, and dimethyl maleate is added dropwise under nitrogen protection, and the reaction is carried out at a constant temperature for 18 h to obtain aspartic acid ester; the molar ratio of decanediamine to dimethyl maleate is 1:2.2, and the addition amount of sodium methoxide catalyst is 0.5% of the total mass of decanediamine and dimethyl maleate; B) The obtained aspartic acid ester and polyethylene glycol monomethyl ether (average molecular weight 500) are mixed, sodium methoxide catalyst is added, and the reaction is carried out at 140 °C for 6 h to obtain the additive; the mass ratio of aspartic acid ester to polyethylene glycol monomethyl ether is 1:5, and the addition amount of sodium methoxide catalyst is 0.5% of the total mass of aspartic acid ester and polyethylene glycol monomethyl ether;

[0077] (3) Preparation of clay powder: By weight, 65 parts of Baoxi purple gold clay, 35 parts of Longquan kaolin, 5 parts of iron oxide and 8 parts of clinker are mixed to obtain a mixture. After adding an additive accounting for 5% of the mass of the mixture and water to the mixture, ball milling is carried out. The mass ratio of ball stones: mixture: water is 2:1:0.8, and the ball milling time is 12 h; after the ball milling is completed, the mixture is subjected to pressure filtration, vacuum clay refining, and aging to obtain clay material; the clay material is dried to obtain clay powder;

[0078] (4) Preparation of 3D printing slurry: Clay powder and pulp (with a moisture content of 50 wt%) with a mass ratio of 100:15 are mixed, and after stirring evenly, water is added and stirred until the moisture content of the slurry is 30 wt% to obtain 3D printing slurry;

[0079] (5) Preparation of calcined kaolin: Place Longquan kaolin in an electric kiln, heat it to 300 °C within 60 min, then heat it to 600 °C within 120 min and stop firing, and take it out after cooling to room temperature to obtain the calcined kaolin;

[0080] (6) Preparation of glazing slurry: The glaze components are added with water and ball milled, and then passed through a 150-mesh sieve to obtain glazing slurry; by weight, the glaze components include: 60 parts of Huangtang stone, 15 parts of quartz, 15 parts of calcined kaolin, 15 parts of calcite, 20 parts of talc, and 1 part of iron oxide; during ball milling, the mass ratio of ball stones: glaze components: water is 1.5:1:0.8, and the ball milling time is 12 h;

[0081] (7) 3D printing of green body forming: The prepared 3D printing slurry is printed and formed with an LDM method 3D printer to obtain a green body; the nozzle diameter during 3D printing is 0.5 mm, the layer height is set to 0.4 mm, and the air pump air pressure is 5 MPa;

[0082] (8) Biscuit firing of green body: The green body is biscuit fired at 860 °C for 5 h to obtain a biscuit body;

[0083] (9) Glazing dipping: The biscuit body is dipped into the glazing slurry twice;

[0084] (10) Firing: The glazed green body is fired to obtain the 3D printed semi-opalescent crackled celadon ceramic product; the firing method is: first heat it to 980 °C in 5 h; then heat it to 1080 °C and hold for 1.5 h; continue to heat it to 1290 °C in 4 h; finally heat it to 1300 °C and hold for 40 min, and then cool naturally and take it out of the kiln.

[0085] Comparative example 1:

[0086] The difference between Comparative example 1 and Example 1 is that calcined kaolin is used to replace the clinker in Example 1 when preparing the clay powder, and the rest are the same as in Example 1.

[0087] Comparative example 2:

[0088] The difference between Comparative Example 2 and Example 1 lies in that the preparation method of the clinker is as follows: Kaolin, MgO, and ZrO2 are mixed in a mass ratio of 12:6:4 and placed in an electric kiln. The temperature is raised to 300 °C within 60 min, then raised to 600 °C within 120 min and the fire is stopped. After cooling to room temperature, it is taken out to obtain the clinker; the rest are the same as in Example 1.

[0089] Comparative Example 3:

[0090] The difference between Comparative Example 3 and Example 1 lies in that the preparation method of the clinker is as follows: Kaolin, MgO, and Nd2O3 are mixed in a mass ratio of 12:6:1 and placed in an electric kiln. The temperature is raised to 300 °C within 60 min, then raised to 600 °C within 120 min and the fire is stopped. After cooling to room temperature, it is taken out to obtain the clinker; the rest are the same as in Example 1.

[0091] Comparative Example 4:

[0092] The difference between Comparative Example 4 and Example 1 lies in that the preparation method of the clinker is as follows: Kaolin, ZrO2, and Nd2O3 are mixed in a mass ratio of 12:4:1 and placed in an electric kiln. The temperature is raised to 300 °C within 60 min, then raised to 600 °C within 120 min and the fire is stopped. After cooling to room temperature, it is taken out to obtain the clinker; the rest are the same as in Example 1.

[0093] Comparative Example 5:

[0094] The difference between Comparative Example 5 and Example 1 lies in that when preparing the mud powder in step (3), no additive is added during ball milling, and the rest are the same as in Example 1.

[0095] Comparative Example 6:

[0096] The difference between Comparative Example 6 and Example 1 lies in that when preparing the mud powder in step (3), methoxypolyethylene glycol is used as an additive during ball milling, and the rest are the same as in Example 1.

[0097] The properties of the 3D printed semi-opaque crackled celadon ceramics prepared in the above examples and comparative examples were tested, and the results are shown in Table 1;

[0098] Among them, the flexural strength was detected by an electronic universal strength tester;

[0099] The anti-freezing test method is as follows: The ceramic product sample is immersed in water at 20 °C, taken out after 24 h, and placed in a freezer at -15 °C ± 3 °C. When the sample temperature drops to -15 °C ± 3 °C, timing starts, and it is maintained at this temperature for 3 h. This is one freeze-thaw cycle; after 15 freeze-thaw cycles, check and record the damage conditions that occur during the freeze-thaw process of the sample;

[0100] The method for testing the resistance to thermal shock is as follows: Put the ceramic product specimen into an oven preheated to a temperature 130°C ± 2°C higher than the cold water temperature. Let the specimen reach the preheated temperature within 5 minutes and start timing. Keep the specimen at this temperature for 45 minutes. Take out the specimen and immediately immerse it in a water tank filled with flowing cold water for rapid cooling for 5 minutes. This is one cycle of rapid heating and rapid cooling. After 3 cycles, check and record the damage conditions that occur during the rapid heating and rapid cooling process of each specimen.

[0101] The method for testing the bonding performance of the body-glaze interface is as follows: Let a steel ball with a diameter of 15 mm and a weight of 20 g freely fall from a height of 3 m and hit the glaze surface of the ceramic product. Observe the glaze surface after repeated falling.

[0102] Table 1: Test results of the performance of ceramic products.

[0103]

[0104]

[0105] As can be seen from Table 1, for the semi-opalescent crackled celadon glaze ceramic products prepared by the method of the present invention in Examples 1 to 3, the body has a high density, good bonding property at the body-glaze interface, high flexural strength, good frost resistance and resistance to thermal shock.

[0106] In Comparative Example 1, calcined kaolin is used as the grog in the clay powder, lacking the doping of MgO, ZrO2 and Nd2O3. The plasticity of the blank decreases, and the formation of the intermediate layer between the body and the glaze is also affected. All the properties of the ceramic products are lower than those in Example 1. In Comparative Examples 2 to 4, not adding Nd2O3, ZrO2 or MgO to the grog will affect the mutual diffusion and penetration of the body and the glaze during the firing process, affecting the properties of the formed intermediate layer between the body and the glaze, resulting in a decrease in the body-glaze bonding property compared with the examples.

[0107] In Comparative Example 5, during the process of preparing the clay powder for the blank, no additive of the present invention is added during ball milling. The density of the body decreases, and the bonding property between the body and the glaze, as well as the flexural strength, frost resistance and resistance to thermal shock of the product, also decrease. This shows that the additive of the present invention can effectively improve the ball milling efficiency, and improve the plasticity of the blank, the density and strength of the body. In Comparative Example 6, polyethylene glycol monomethyl ether is directly used as an additive without reacting it with aspartic acid ester. The properties of the product are also significantly lower than those in Example 1, indicating that the type of additive has a significant impact on the properties of the blank after ball milling. Selecting an additive that matches the properties of the blank can effectively improve the quality of ceramic products.

Claims

1. A preparation method of a 3D printed opacified crackled celadon ceramic product, characterized in that the steps Including: (1) Mix clay powder and pulp with a mass ratio of 100:10 - 15, stir evenly, then add water and stir until the water content of the slurry is 25 - 30 wt% to obtain 3D printing slurry; the preparation method of the clay powder is as follows: by weight, mix 60 - 65 parts of purple gold clay, 25 - 35 parts of kaolin, 3 - 5 parts of iron oxide and 5 - 8 parts of clinker to obtain a mixture, add an additive and water to the mixture and then perform ball milling, and then obtain the clay material after pressure filtration, vacuum clay kneading and aging; obtain the clay powder after drying; The clinker is sintered from kaolin, MgO, ZrO2 and Nd2O3 with a mass ratio of 10 - 15:5 - 8:3 - 5:1; The preparation method of the additive is as follows: mix decanediamine and sodium methoxide, heat up to 70 - 90 °C, dropwise add dimethyl maleate under N2 protection, keep the temperature for reaction for 12 - 24 h to obtain aspartic acid ester; mix the aspartic acid ester and polyethylene glycol monomethyl ether with a molecular weight of 300 - 500, add sodium methoxide, and react at 130 - 150 °C for 5 - 8 h to obtain the additive; the molar ratio of decanediamine to dimethyl maleate is 1:2 - 2.2, and the mass ratio of aspartic acid ester to polyethylene glycol monomethyl ether is 1:3 - 5; (2) Grind the glaze components with water to obtain glazing slurry; By weight, the glaze components include: 40 - 60 parts of Huangtang stone, 10 - 15 parts of quartz, 10 - 15 parts of calcined kaolin, 10 - 15 parts of calcite, 15 - 20 parts of talc, 0.5 - 1 part of iron oxide; (3) Print and form the prepared 3D printing slurry with an LDM method 3D printer to obtain a green body; (4) Bisque-fire the green body at 800 - 900 °C to obtain a bisque body; (⑤) Immerse the bisque body in the glazing slurry; (⑥) Fire the immersed green body.

2. The preparation method of the 3D printed opalescent crackled celadon ceramic product according to claim 1, characterized in that, The sintering method of the clinker in step (1) is as follows: mix kaolin, MgO, ZrO2 and Nd2O3 in proportion and place them in an electric kiln, heat up to 300 °C within 50 - 70 min, then heat up to 600 °C within 100 - 130 min and stop firing, and take it out after cooling to room temperature to obtain the clinker.

3. The preparation method of the 3D printed opacified crackled celadon ceramic article according to claim 1, characterized in that, In step (1), the mass ratio of ball stones: mixture: water during ball milling is 2 - 3:1:0.5 - 1, and the ball milling time is 10 - 15 h.

4. The preparation method of the 3D printed opalescent crackled celadon ceramic product according to claim 1, characterized in that, The water content of the pulp in step (1) is 40 - 60 wt%.

5. The preparation method of the 3D printed opalescent cracked celadon ceramic product according to claim 1, characterized in that, The preparation method of the calcined kaolin in step (2) is as follows: place kaolin in an electric kiln, heat up to 300 °C within 50 - 70 min, then heat up to 600 °C within 100 - 130 min and stop firing, and take it out after cooling to room temperature to obtain the calcined kaolin.

6. The preparation method of the 3D printed opacified cracked celadon ceramic product according to claim 1 or 5, characterized in that, In step (2) during ball milling, the mass ratio of ball stones: glaze components: water is 1 - 2:1:0.5 - 1, and the ball milling time is 10 - 15 h; after ball milling, sieve through a 100 - 200 mesh sieve to obtain the glazing slurry.

7. The preparation method of the 3D printed opacified cracked celadon ceramic product according to claim 1, characterized in that, In step (3) during 3D printing, the nozzle diameter is 0.4 - 0.6 mm, the layer height is set to 0.3 - 0.5 mm, and the air pump air pressure is 5 - 6 MPa.

8. The preparation method of the 3D printed opalescent crackled celadon ceramic product according to claim 1, characterized in that, In step (4), the bisque-firing time is 4 - 6 h.

9. The preparation method of the 3D printed opacified cracked celadon ceramic product according to claim 1, characterized in that, The firing method in step (6) is as follows: First, heat up to 950 - 1000 °C within 4 - 6 hours; then heat up to 1050 - 1100 °C and keep warm for 1 - 2 hours; continue to heat up to 1280 - 1300 °C within 3 - 5 hours; finally, heat up to 1300 - 1310 °C, keep warm for 40 - 50 minutes, and then cool down naturally and take out of the kiln.

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