Mottle crack glazed ceramic and preparation method thereof

Abstract

The invention relates to the technical field of ceramics, in particular to mottle crack glazed ceramic and a preparation method thereof.The ceramic comprises a green body, ground glaze and cover glaze, and the ground glaze is prepared from, by weight, 30-35 parts of kaolin, 25-30 parts of quartz, 20-25 parts of feldspar, 8-12 parts of ferric oxide, 5-8 parts of calcium carbonate and 3-5 parts of borax; the cover glaze is prepared from the following raw materials in parts by weight: 35 to 40 parts of feldspar, 25 to 30 parts of quartz, 6 to 10 parts of copper oxide, 5 to 8 parts of granular rock powder, 8 to 12 parts of borax and 5 to 8 parts of clay. Embedding porous particles into the green body to initiate explosion cracks, and fusing interlayer stress cracks and devitrification cracks to form a multi-stage composite crack network; iron ions in the ground glaze and copper ions in the cover glaze form ion gradient migration through the iron axe stone powder in the middle layer to generate red and green blended stripes; the microcapsule carbon powder regulates and controls the pores and texture of the glaze, and copper foil fragments are oxidized and reduced to form gilding-brown mottles.

Description

Technical Field

[0001] The present invention relates to the field of ceramic technology, and specifically to mottled crackle glaze ceramics and a preparation method thereof. Background Art

[0002] At present, the ceramic glaze effect is mainly achieved through a single glaze formula and conventional firing processes, and there are limitations in color blending, texture levels, and texture performance. In the prior art, although some ceramics use multiple metal oxides for coloring, colors such as red and green are mostly simple superpositions, lacking a mottled texture of natural blending. At the same time, the crackle effect is single, mostly generated by a single factor of the green body or glaze, lacking a three-dimensional and layered feeling. In addition, the combination of metallic luster and the overall glaze is not natural enough, and it is difficult to simulate the complex effects of natural weathering. Therefore, there is an urgent need for an innovative ceramic preparation technology to achieve a unique glaze effect and meet the requirements for artistry and craftsmanship of high-end ceramic products. Summary of the Invention

[0003] An object of the present invention is to solve at least the above problems through mottled crackle glaze ceramics and a preparation method thereof.

[0004] To solve the above technical problems, the technical solution adopted by the present invention is as follows: The mottled crackle glaze ceramic includes a green body, a base glaze, and a top glaze. The base glaze contains the following raw materials in parts by weight: 30-35 parts of kaolin, 25-30 parts of quartz, 20-25 parts of feldspar, 8-12 parts of iron oxide, 5-8 parts of calcium carbonate, and 3-5 parts of borax. The top glaze contains the following raw materials in parts by weight: 35-40 parts of feldspar, 25-30 parts of quartz, 6-10 parts of copper oxide, 5-8 parts of dolerite powder, 8-12 parts of borax, and 5-8 parts of clay.

[0005] Preferably, the top glaze further includes 4-5 parts of microcapsule carbon powder.

[0006] Preferably, the green body contains the following raw materials in parts by weight: 40-50 parts of clay, 10-12 parts of quartz, 20-25 parts of feldspar, and 7-8 parts of porous particles.

[0007] Preferably, the porous particles are expanded perlite particles or volcanic ash particles, and the particle size is 0.8-1.8 mm.

[0008] Preferably, a transition layer is further included between the base glaze and the top glaze. The transition layer contains the following raw materials in parts by weight: 90-95 parts of axinite powder, 5-10 parts of cordierite powder, 5-7 parts of carboxymethyl cellulose, and 4-5 parts of copper foil fragments.

[0009] The preparation method of the mottled crackle glaze ceramic includes the following steps:

[0010] Step a, forming the green body;

[0011] Step b: Apply the base glaze.

[0012] Step c: Apply the raw materials for the transition layer.

[0013] Step d: Apply the surface glaze.

[0014] Step e: Fire in a kiln for glaze firing.

[0015] Preferably, in step a, the green body is formed by slip casting or hand molding, dried to a moisture content of ≤10%, and porous particles are embedded in the green body. The embedding depth of the porous particles is 1 / 3 - 1 / 2 of their particle size, the particle spacing is 5 - 10 mm, and the coverage rate is 20 - 30%.

[0016] Preferably, in step c, when the base glaze is not dry, copper foil fragments are first sprinkled on a local area of the base glaze, then the base glaze is dried, and then a mixture is prepared according to the ratio of 90 - 95 parts of axinite powder, 5 - 10 parts of cordierite powder, and 5 - 7 parts of carboxymethyl cellulose, and is applied to the surface of the base glaze.

[0017] Preferably, in step d, the preparation process of the microcapsule carbon powder in the surface glaze raw materials is as follows: Take 10 parts of carbon powder and mix it with 90 parts of tetraethyl orthosilicate, add 2 parts of 37% hydrochloric acid to catalyze hydrolysis, stir at 40°C for 2 hours to form a sol, obtain carbon powder microcapsules coated with silica aerogel by spray drying, and sieve through an 80 - 120 mesh sieve for standby.

[0018] Preferably, the firing system in step e is as follows: It is fired in a natural gas shuttle kiln, specifically:

[0019] Preheating stage: Room temperature - 400°C, heating rate 5°C / min, time 1.5 h, oxidation atmosphere;

[0020] Heating stage 1: 400 - 900°C, heating rate 8°C / min, time 1.25 h, oxidation atmosphere;

[0021] Heating stage 2: 900 - 1280°C, heating rate 5°C / min, time 1.75 h, oxidation atmosphere;

[0022] Insulation stage: 1280°C, time 40 min, oxidation atmosphere;

[0023] Cooling stage 1: 1280 - 1000°C, cooling rate 10°C / min, time 28 min, neutral atmosphere;

[0024] Cooling stage 2: 1000 - 600°C, cooling rate 5°C / min, time 80 min, reduction atmosphere;

[0025] Natural cooling.

[0026] As described above, the mottled crack glaze ceramic provided by the present invention and its preparation method have the following beneficial effects: Porous particles are embedded in the green body to initiate crack marks, and the interlayer stress cracks and devitrification cracks are fused to form a multi-level composite crack network; Iron ions in the bottom glaze and copper ions in the top glaze form an ionic gradient migration through the axinite powder in the intermediate layer, generating red-green blended patterns; Microcapsule carbon powder regulates the pores and texture of the glaze, and copper foil fragments form gold-bronze mottles through redox reactions. Detailed implementation mode

[0027] The present invention will be further described below through specific implementation modes.

[0028] To make the technical means, creative features, achieved purposes and effects of the present invention easy to understand, the present invention will be further elaborated below in conjunction with specific implementation modes.

[0029] The mottled crack glaze ceramic of the present invention includes a green body, a bottom glaze and a top glaze. The bottom glaze contains the following raw materials in parts by weight: 30-35 parts of kaolin, 25-30 parts of quartz, 20-25 parts of feldspar, 8-12 parts of iron oxide, 5-8 parts of calcium carbonate, and 3-5 parts of borax. The top glaze contains the following raw materials in parts by weight: 35-40 parts of feldspar, 25-30 parts of quartz, 6-10 parts of copper oxide, 5-8 parts of dolerite powder, 8-12 parts of borax, and 5-8 parts of clay. Among the components of the bottom glaze, kaolin is the glaze skeleton to improve suspension, quartz increases the hardness and wear resistance of the glaze surface, feldspar is a flux to lower the melting point of the glaze, iron oxide is the main colorant of the bottom glaze to provide the base tone of rust red, calcium carbonate is used to adjust the viscosity and firing temperature of the glaze, and borax is used to assist in fluxing and promote the migration of iron ions; In the top glaze, copper oxide is the main colorant. In an oxidizing atmosphere, CuO dissociates into Cu 2+ , Cu 2+ tends to form coordination in the silicon-oxygen or boron-oxygen network, presenting a peacock green or blue-green tone. Dolerite powder contains magnesium-iron minerals to adjust the thermal expansion coefficient and increase the hardness of the glaze surface. Clay improves the suspension of the glaze and the adhesion to the green body; After firing, iron ions in the bottom glaze and copper ions in the top glaze migrate to generate the glaze surface effect of red-green blended patterns.

[0030] The top glaze also includes 4-5 parts of microcapsule carbon powder. The carbon powder is coated with silica, so its oxidation temperature is raised to above 1000 °C. The carbon powder oxidizes and volatilizes at high temperature, leaving micropores of silica aerogel, making the glaze surface form matte particles with a size of 0.1-0.5 mm, forming a gloss contrast with the gold-plated area of the copper foil.

[0031] The green body contains the following raw materials in parts by weight: 40-50 parts of clay, 10-12 parts of quartz, 20-25 parts of feldspar, and 7-8 parts of porous particles.

[0032] The porous particles are expanded perlite particles or volcanic ash particles, with a particle size of 0.8 - 1.8 mm.

[0033] There is also a transition layer between the bottom glaze and the top glaze. The transition layer contains the following raw materials in parts by weight: 90 - 95 parts of axinite powder, 5 - 10 parts of cordierite powder, 5 - 7 parts of carboxymethyl cellulose, and 4 - 5 parts of copper foil fragments. With the fluxing and ion conduction effects of axinite in the intermediate layer, the formation of Fe 2+ / Fe 3+ and Cu 2+ gradient migration, and the cordierite powder adjusts the thermal expansion coefficient to prevent the excessive melting of the transition layer at high temperatures from causing out - of - control ion migration.

[0034] Examples of the mottled crack glaze ceramic are as follows:

[0035] Example 1:

[0036] The mottled crack glaze ceramic of the present invention includes a body, a bottom glaze, and a top glaze. The bottom glaze contains the following raw materials in parts by weight: 30 parts of kaolin, 25 parts of quartz, 20 parts of feldspar, 8 parts of iron oxide, 5 parts of calcium carbonate, and 3 parts of borax. The top glaze contains the following raw materials in parts by weight: 35 parts of feldspar, 25 parts of quartz, 6 parts of copper oxide, 5 parts of dolerite powder, 8 parts of borax, 5 parts of clay, and 4 parts of micro - encapsulated carbon powder.

[0037] The body contains the following raw materials in parts by weight: 40 parts of clay, 10 parts of quartz, 20 parts of feldspar, and 7 parts of porous particles. The porous particles are expanded perlite particles or volcanic ash particles, with a particle size of 0.8 mm.

[0038] There is also a transition layer between the bottom glaze and the top glaze. The transition layer contains the following raw materials in parts by weight: 90 parts of axinite powder, 5 parts of cordierite powder, 5 parts of carboxymethyl cellulose, and 4 parts of copper foil fragments.

[0039] Example 2:

[0040] The mottled crack glaze ceramic of the present invention includes a body, a bottom glaze, and a top glaze. The bottom glaze contains the following raw materials in parts by weight: 35 parts of kaolin, 30 parts of quartz, 25 parts of feldspar, 12 parts of iron oxide, 8 parts of calcium carbonate, and 5 parts of borax. The top glaze contains the following raw materials in parts by weight: 40 parts of feldspar, 30 parts of quartz, 10 parts of copper oxide, 8 parts of dolerite powder, 12 parts of borax, 8 parts of clay, and 5 parts of micro - encapsulated carbon powder.

[0041] The body contains the following raw materials in parts by weight: 50 parts of clay, 12 parts of quartz, 25 parts of feldspar, and 8 parts of porous particles. The porous particles are expanded perlite particles or volcanic ash particles, with a particle size of 1.8 mm.

[0042] There is also a transition layer between the bottom glaze and the top glaze. The transition layer contains the following raw materials in parts by weight: 95 parts of axinite powder, 10 parts of cordierite powder, 7 parts of carboxymethyl cellulose, and 5 parts of copper foil fragments.

[0043] Example 3:

[0044] The mottled crack glaze ceramic of the present invention includes a body, a bottom glaze, and a top glaze. The bottom glaze contains the following raw materials in parts by weight: 32 parts of kaolin, 27 parts of quartz, 22 parts of feldspar, 10 parts of iron oxide, 7 parts of calcium carbonate, and 4 parts of borax. The top glaze contains the following raw materials in parts by weight: 38 parts of feldspar, 28 parts of quartz, 8 parts of copper oxide, 6 parts of dolerite powder, 10 parts of borax, 7 parts of clay, and 4.5 parts of microcapsule carbon powder.

[0045] The body contains the following raw materials in parts by weight: 45 parts of clay, 11 parts of quartz, 22 parts of feldspar, and 7.5 parts of porous particles. The porous particles are expanded perlite particles or volcanic ash particles, and the particle size is 1.2 mm.

[0046] There is also a transition layer between the bottom glaze and the top glaze. The transition layer contains the following raw materials in parts by weight: 92 parts of axinite powder, 7 parts of cordierite powder, 6 parts of carboxymethyl cellulose, and 4.5 parts of copper foil fragments.

[0047] The preparation method of the mottled crack glaze ceramic includes the following steps:

[0048] Step a, forming the body;

[0049] Step b, applying the bottom glaze;

[0050] Step c, applying the raw materials of the transition layer;

[0051] Step d, applying the top glaze;

[0052] Step e, firing the glaze in a kiln.

[0053] In step a, the body is formed by slip casting or hand forming, dried to a moisture content ≤ 10%, and the porous particles are embedded in the body. The embedding depth of the porous particles is 1 / 3 - 1 / 2 of their particle size, the particle spacing is 5 - 10 mm, and the coverage rate is 20 - 30%.

[0054] In step c, when the bottom glaze is not dry, copper foil fragments are first scattered in a local area of the bottom glaze, then the bottom glaze is dried, and then a mixture is prepared according to the ratio of 90 - 95 parts of axinite powder, 5 - 10 parts of cordierite powder, and 5 - 7 parts of carboxymethyl cellulose, and is applied to the surface of the bottom glaze.

[0055] In step d, the preparation process of the microcapsule carbon powder in the surface glaze raw material is as follows: Take 10 parts of carbon powder and mix it with 90 parts of tetraethyl orthosilicate, dropwise add 2 parts of 37% hydrochloric acid for catalytic hydrolysis, stir at 40 °C for 2 hours to form a sol, obtain carbon powder microcapsules coated with silica aerogel through spray drying, and sieve through an 80 - 120 mesh sieve for standby.

[0056] The firing system for step e is as follows: It is fired in a natural gas shuttle kiln, specifically:

[0057] Preheating stage: Room temperature - 400 °C, heating rate 5 °C / min, time 1.5 h, oxidation atmosphere; Remove the moisture and organic matter in the green body, and the porous particles expand preliminarily;

[0058] Heating stage 1: 400 - 900 °C, heating rate 8 °C / min, time 1.25 h, oxidation atmosphere;

[0059] Heating stage 2: 900 - 1280 °C, heating rate 5 °C / min, time 1.75 h, oxidation atmosphere; In this stage, axinite in the intermediate layer decomposes, iron ions are released, and the surface glaze melts; At high temperatures, the gas inside the porous particles expands and ruptures, driving the green body to generate radial cracks. After extending to the glaze surface, Cu in the surface glaze 2+ and Fe in the bottom glaze 3+ penetrate into the cracks, forming explosion cracks that are deep inside and shallow outside;

[0060] Insulation stage: 1280 °C, time 40 min, oxidation atmosphere; In this stage, B2O3 generated by the decomposition of axinite forms ion channels above 1200 °C, promoting the migration of Fe 3+ from the bottom glaze to the surface glaze and Cu 2+ from the surface glaze to the bottom glaze, generating Fe - Cu composite oxides at the interface, presenting an orange - red to brown - yellow transition zone; The copper foil generates brown copper oxides at high temperatures;

[0061] Cooling stage 1: 1280 - 1000 °C, cooling rate 10 °C / min, time 28 min, neutral atmosphere; In this stage, the crystal growth direction between the layers is fixed, inducing interlayer stress cracks;

[0062] Cooling stage 2: 1000 - 600 °C, cooling rate 5 °C / min, time 80 min, reduction atmosphere; In this stage, under the reduction atmosphere, the oxidized copper foil fragments are partially reduced to metallic copper gilding by the carbon particles remaining after the oxidation and volatilization of the microcapsule carbon powder and the introduced reducing gas. The partially unreduced local areas retain the dark brown formed by oxidation, so the effect of coexistence of gilding and dark brown copper oxides is presented, simulating the metal corrosion marks in natural weathering;

[0063] Natural cooling. In this stage, the glaze surface finally crystallizes and the cracks are stabilized.

[0064] The above are only several specific embodiments of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantive modification made to the present invention using this concept shall fall within the scope of infringement of the protection scope of the present invention.

Claims

1. Mottled crackle glaze ceramic, characterized in that: It includes a green body, a base glaze and a top glaze. The base glaze contains the following raw materials in parts by weight: 30 - 35 parts of kaolin, 25 - 30 parts of quartz, 20 - 25 parts of feldspar, 8 - 12 parts of iron oxide, 5 - 8 parts of calcium carbonate, and 3 - 5 parts of borax. The top glaze contains the following raw materials in parts by weight: 35 - 40 parts of feldspar, 25 - 30 parts of quartz, 6 - 10 parts of copper oxide, 5 - 8 parts of dolerite powder, 8 - 12 parts of borax, and 5 - 8 parts of clay.

2. The mottled crackled glaze ceramic according to claim 1, wherein: The top glaze also includes 4 - 5 parts of microcapsule carbon powder.

3. The mottled crackled glaze ceramic according to claim 1, wherein: The green body contains the following raw materials in parts by weight: 40 - 50 parts of clay, 10 - 12 parts of quartz, 20 - 25 parts of feldspar, and 7 - 8 parts of porous particles.

4. The mottled crackled glaze ceramic according to claim 3, wherein: The porous particles are expanded perlite particles or volcanic ash particles, with a particle size of 0.8 - 1.8 mm.

5. The mottled crackled glaze ceramic according to claim 1, wherein: There is also a transition layer between the base glaze and the top glaze. The transition layer contains the following raw materials in parts by weight: 90 - 95 parts of axinite powder, 5 - 10 parts of cordierite powder, 5 - 7 parts of carboxymethyl cellulose, and 4 - 5 parts of copper foil fragments.

6. The preparation method of the mottled crack glazed ceramic according to any one of claims 1-5, characterized in that It includes the following steps: Step a: Molding the green body; Step b: Applying the base glaze; Step c: Applying the raw materials of the transition layer; Step d: Applying the top glaze; Step e: Glaze firing in a kiln.

7. The preparation method of the mottled crack glazed ceramic according to claim 6, characterized in that: In step a, the green body is molded by slip casting or hand molding, dried to a moisture content ≤ 10%, and the porous particles are embedded in the green body. The embedding depth of the porous particles is 1 / 3 - 1 / 2 of their particle size, the particle spacing is 5 - 10 mm, and the coverage rate is 20 - 30%.

8. The preparation method of the mottled crack glazed ceramic according to claim 6, wherein: In step c, when the base glaze is not dry, first sprinkle copper foil fragments in a local area of the base glaze, then dry the base glaze, and then prepare a mixture according to the ratio of 90 - 95 parts of axinite powder, 5 - 10 parts of cordierite powder, and 5 - 7 parts of carboxymethyl cellulose, and brush it on the surface of the base glaze.

9. The preparation method of the mottled crack glaze ceramic according to claim 6, wherein: In step d, the preparation process of the microcapsule carbon powder in the top glaze raw materials is as follows: Take 10 parts of carbon powder and mix it with 90 parts of tetraethyl orthosilicate, dropwise add 2 parts of 37% hydrochloric acid to catalyze hydrolysis, stir at 40°C for 2 hours to form a sol, and obtain carbon powder microcapsules coated with silica aerogel through spray drying, and sieve them through an 80 - 120 mesh sieve for standby.

10. The preparation method of the mottled crack glaze ceramic according to claim 6, wherein: The firing system in step e is as follows: It is fired in a natural gas shuttle kiln, specifically: Preheating stage: Room temperature - 400°C, heating rate 5°C / min, time 1.5 h, oxidation atmosphere; Heating stage 1: 400 - 900°C, heating rate 8°C / min, time 1.25 h, oxidation atmosphere; Heating stage 2: 900 - 1280°C, heating rate 5°C / min, time 1.75 h, oxidation atmosphere; Insulation stage 1280°C, time 40 min, oxidation atmosphere; Cooling stage 1 1280 - 1000°C, cooling rate 10°C / min, time 28 min, neutral atmosphere; Cooling stage 2 1000 - 600°C, cooling rate 5°C / min, time 80 min, reducing atmosphere; Natural cooling.