CN110818264A - High-temperature all-ceramic crack glaze and preparation method thereof - Google Patents

Abstract

The invention belongs to the technical field of ceramic glaze, and particularly relates to a high-temperature all-ceramic crackle glaze and a preparation method thereof, wherein the high-temperature all-ceramic crackle glaze comprises the following components in percentage by weight: 27-33% of transparent frit, 15-23% of high-expansion frit, 8-15% of glass powder, 4-10% of albite powder, 5-10% of kaolin, 5-10% of barium carbonate, 5-10% of strontium carbonate, 3-5% of quartz powder and 1-5% of colorant.

Description

High-temperature all-ceramic crack glaze and preparation method thereof

Technical Field

The invention belongs to the technical field of ceramic glaze materials, and particularly relates to a high-temperature all-ceramic crackle glaze and a preparation method thereof.

Background

At present, the domestic crackle glaze is basically based on single-side crackle glaze, and all-ceramic crackle glaze products with front and back sides of the crackle glaze are rare and expensive. The crack glaze is characterized in that the expansion coefficient of the glaze is far larger than that of a blank body to generate larger stress, so that fine cracks are formed, and the crack glaze is special and has extremely good decorative aesthetic feeling. At present, the crack glaze is mainly used for the inner glaze of a product or a certain part of the product, and the outer glaze or other parts of the product are glazed glaze and matte glaze so as to reduce the generated stress and reduce the problems of porcelain explosion and the like.

Crack glaze and application, Cao Wen Biao, Zhang Ling, the seventh Asian ceramic technology seminar treatise paper abstract set, which explains the factors affecting crack glaze, including: oxide, silicon-aluminum ratio, blank, crack glaze formula and the like.

The basic formula (mass%) of the high-temperature ice crack glaze, Baozifu and the like, ceramics, 2015.05.15, is as follows: 73 parts of albite, 3-7 parts of wollastonite, 4-7 parts of kaolin, 13-16 parts of quartz and 3 parts of dolomite. When the content of the wollastonite in the formula is 3-4%, the mass ratio of the kaolin to the quartz is 6: 14, and the glaze dipping time is 12s, the ice crack effect that the glaze surface is smooth and the cracks are large can be obtained. The reason for this is that the glaze surface has larger stress due to different thermal expansion coefficients between the glaze blanks, so that the poor intermediate layer of the blank glaze effectively transfers the stress between the blank glazes to cause cracking in the glaze layer, and the crack is deflected in the direction when meeting the bubbles in the glaze layer in the process of expansion, thereby forming the appearance of 'ice crack' similar to the crystal flower state. With the increase of the content of the silicon dioxide and the decrease of the content of the kaolin, the thermal expansion coefficient of the glaze is also reduced with the increase of the content of the glassy silicon dioxide, and at the moment, the difference with the thermal expansion of the blank is smaller, so that the generated tensile stress is gradually reduced, and the cracking condition of the glaze surface is correspondingly weakened. The glaze of the sample fired in the reducing atmosphere is cyan, the cracking effect is clear and visible, while the glaze fired in the oxidizing atmosphere is milky, and the cracks are clear and visible and have stereoscopic impression. The difference of the expansion coefficients of the blank and the glaze is large, and the difference is an important influence factor of the cracking of the glaze. In this experiment, when the expansion coefficient of the blank is 2.6X 10^-6The expansion coefficient of the glaze is 5.4 multiplied by 10 DEG C^-6When the temperature is lower than the temperature of the glaze layer, the blank glaze is subjected to higher stress, and the direction of the crack is deflected when the crack meets the bubble in the glaze layer in the expanding process, so that the ice crack is better formed.

The influence of the shallow analysis formula composition on the ice crack glaze effect, Wuzechangchang and the like, Foshan ceramics, in 2017, at the 06 th stage, explains that the cracking reasons of the glaze of the porcelain are two: firstly, the blank mud extends along certain direction during the shaping, has influenced the arrangement of molecule. Secondly, the expansion coefficients of the blank and the glaze are different, and the shrinkage rate of the glaze layer is large when the glaze layer is cooled after roasting. The optimal formula is as follows: potassium feldspar: 35%, albite: 40%, calcite: 4%, kaolin: 6%, quartz: 7%, glass powder: 6% of BaCO₃: 1%, ZnO: 1 percent. When the expansion coefficient of the glaze is obviously larger than that of the blank body, the generated cracks have good effect of coarse and fine interweaving.

When the formula is used for preparing the all-ceramic crackle glaze, as the daily porcelain product is mainly in a vertical surface and a special shape, the glaze layer cannot be too thick (the thicker the glaze layer is, the larger the stress is), the sintering time is long, the cooling is slow, and the expansion coefficient of the glaze on a common daily porcelain clay blank is not enough to generate a better crackle effect, high-expansion frits with the expansion coefficient larger than that of potassium feldspar and sodium feldspar are required to be used in the all-ceramic crackle glaze of the daily porcelain. And the high expansion frit is used in a large proportion, so that the product is easy to fry porcelain, has poor thermal stability, is easy to cause the problems of brewing and bottom sticking caused by flowing glaze, and is not easy to accept by common consumers due to higher production cost.

Disclosure of Invention

The invention aims to provide a high-temperature all-ceramic crackle glaze and a preparation method thereof, and solves the problems of brewing of all-ceramic crackle glaze products, easiness in ceramic frying, poor thermal stability and the like.

The invention comprises the following components and raw materials in percentage by weight: 27-33% of transparent frit, 15-23% of high-expansion frit, 8-15% of glass powder, 4-10% of albite powder, 5-10% of kaolin, 5-10% of barium carbonate, 5-10% of strontium carbonate, 3-5% of quartz powder and 1-5% of toner.

Preferably, the composition comprises the following components in percentage by weight: 30% of transparent frit, 21% of high-expansion frit, 10% of glass powder, 9% of albite powder, 7% of kaolin, 7% of barium carbonate, 9% of strontium carbonate, 4% of quartz powder and 3% of colorant.

Preferably, the colorant is one or more of silver ash, cobalt blue and malachite green.

The invention provides a preparation method of high-temperature all-ceramic crackle glaze, which comprises the following steps:

1) preparing materials according to all components, mixing the raw materials, high alumina ball stone and water, and performing wet ball milling, wherein the fineness of the glaze after ball milling is preferably controlled to be 0.2-0.3% of the rest of 325 meshes, so as to obtain the glaze;

2) sieving the glaze material with a 100-mesh sieve after the glaze material is discharged from a ball mill to obtain glaze slip, adding water to adjust the concentration of the glaze slip, wherein the concentration of the glaze slip is preferably 60-70 baume degrees;

3) the glaze slurry is evenly sprayed on a glaze blank by a spray gun, the glaze blank can be a high-temperature glaze blank commonly used by common daily porcelain, after glaze spraying, the glaze blank is dried and then is placed into a roller kiln for sintering, the sintering atmosphere is preferably an oxidizing atmosphere, the sintering curve is a commonly used high-temperature white porcelain sintering curve, the highest temperature is 1280-1320 ℃, the sintering period is 7-7.5 hours, the high-temperature full-porcelain crack glaze is obtained, and the thickness of a glaze layer of the finally obtained glaze blank is 0.3-0.6 mm.

Preferably, the raw materials: high alumina ball stone: the mass ratio of water is 1: 2: 0.5. the mass ratio of the large spherulites to the medium spherulites to the small spherulites is 2: 5: 3.

the main components of each raw material of the present invention are shown in table 1.

TABLE 1 chemical component content of each component in raw materials

The albite powder is produced in Hengshan county of Hunan province, is off-white and powdery; the quartz powder is produced in the city of carignane in Hunan province and is in a fine sand shape; the high expansion frit, produced in Guangdong province; the glass powder is produced in Guangdong province; the barium carbonate is produced in Hebei; the strontium carbonate is produced in Hebei province; the kaolin is produced from Longyan city in Fujian province; the toner is produced in Foshan City of Guangdong province.

The invention has the beneficial effects that the crack effect is formed by using the raw materials, wherein the larger thermal expansion coefficient is far larger than that of the blank body, and larger stress is generated in the cooling stage. The quartz powder and the kaolin can improve the melting temperature of the glaze and the high-temperature viscosity of the glaze, so that the product is not easy to generate flowing glaze and bottom sticking. The firing system of the product of the invention has no special requirements like the common high-temperature porcelain products, has no high requirements on pug, has low production cost, is suitable for large-scale production, and simultaneously has the physicochemical properties of thermal stability, lead and cadmium dissolution and the like which reach the national relevant standards of daily porcelain.

Common transparent frit: the common transparent frit mainly comprises sodium oxide, calcium oxide, silicon dioxide, boron oxide, potassium oxide and the like, wherein sodium oxide and potassium oxide alkali metal are strong fluxing agents, so that the melting temperature and viscosity of the glaze can be reduced, and the refractive index of the glaze can be increased, so that the glossiness is improved. The expansion coefficient of sodium oxide is the largest among alkali metals. The general transparent frit contains substantially no or little alumina, and the use of the transparent frit can reduce impurities caused by the use of raw ore and has a large expansion coefficient.

Albite powder: albite is a commonly used raw material for glaze and can be used as a flux for a plurality of glazes, and the commonly used albite powder is potassium-sodium feldspar powder with high albite content, can be simultaneously introduced with silicon dioxide, aluminum oxide, sodium oxide and potassium oxide, and is a suitable raw material for introducing metal oxides into the glaze.

Quartz powder: the silica in the glaze is the main component for generating a glass phase, and the melting temperature and viscosity of the glaze can be improved and the expansion coefficient of the glaze can be reduced by increasing the quartz content in the glaze. At the same time it is the main reason for imparting high strength, hardness, abrasion resistance and chemical stability to the glaze.

High expansion frit: the high-expansion frit mainly comprises sodium oxide, calcium oxide, silicon dioxide, potassium oxide and the like, the content of the sodium oxide is high, and the thermal expansion coefficient of the glaze is improved.

Glass powder: the glass powder mainly comprises sodium oxide, calcium oxide, silicon dioxide, boron oxide and the like, namely common soda-lime-silica glass is common flat glass powder, mainly is flat glass leftover, waste material and the like, and has the advantages of wide source, low cost and the like.

Kaolin: the introduction of alumina, silica and the like leads the glaze to have better suspension property and stability.

Color agent: the color of the glaze is adjusted, and as the crack glaze has certain decomposition destructiveness to general compound pigments, the crack glaze color agent generally uses metal oxides with better stability or other color agents with better stability, such as silver ash, cobalt blue, malachite green and the like.

Usually, the crack glaze is prepared by enlarging the difference between the expansion coefficients of the glaze and the mud blank, and the crack effect can be improved by the following four methods: firstly, the thermal expansion coefficient of the glaze is increased, secondly, the thickness of the glaze layer is increased, the thickness of the glaze layer is 1-3mm thicker than that of the common glaze, the thicker the glaze layer is, the larger the generated stress is, thirdly, the expansion coefficient of the clay blank is reduced, fourthly, the rapid cooling is carried out in the cooling stage, and the stress is not reduced along with the slow cooling. In actual production, the first three methods are used more, the general ceramic factories produce cracked glaze products by combining the first three methods, and the ceramic factories which individually and specially produce or produce the cracked glaze products in large quantities adopt a special firing system for accelerating cooling in a cooling stage.

As mentioned above, in general ceramic factories, crack glaze products are produced by using glaze with high expansion clinker as main material (usually, the weight value of the high expansion clinker is 60-90%), and using mud blank with lower expansion coefficient. The price of high expansion frits is usually 6000-. Thus, the cost of the crack glaze is quite high.

Because the all-ceramic crackle glaze needs to have a higher expansion coefficient, the content of high-expansion frits with high expansion coefficients is usually larger and accounts for more than 60 percent of the total amount, if a part of the high-expansion frits is replaced by common frits or other substances with higher expansion coefficients for use, the all-ceramic crackle glaze is difficult to obtain due to insufficient expansion coefficients, and the porcelain explosion phenomenon is often caused by insufficient heat stability due to the use of a formula of high-expansion frits with large proportion (more than 60 percent) if other conditions are not controlled.

The invention adds barium carbonate and strontium carbonate, on one hand, the melting range of the glaze is enlarged, on the other hand, the melting temperature and the viscosity of the glaze are reduced, so that the glaze surface can be mixed with other materials by using high-expansion frit with lower weight, the effect which can be achieved only by using the high-expansion frit in the past is achieved, meanwhile, the problem that the thermal stability is poor due to using the high-expansion frit in large proportion is solved, the product quality is improved, the product cost is reduced, and meanwhile, the purpose that the physical and chemical properties of the product reach the national standard is achieved.

The crack glaze product obtained by the method is fired at a high temperature of 1280-1320 ℃, and has the advantages of good crack effect, high glaze glossiness, good brightness and fine and dense cracks.

Drawings

FIG. 1 is a diagram of the external glaze effect of the full-ceramic crackle glaze of the present invention.

FIG. 2 is a diagram of the inner surface glaze effect of the full-ceramic crackle glaze of the present invention.

Detailed Description

Example 1

Weighing 30 parts of transparent frit, 21 parts of high-expansion frit, 10 parts of glass powder, 9 parts of albite powder, 7 parts of kaolin, 7 parts of barium carbonate, 9 parts of strontium carbonate, 4 parts of quartz powder and 3 parts of silver ash in parts by weight, adding the materials into a ball milling tank, and then adding the materials in parts by weight: ball stones: the mass ratio of water is 1: 2: 0.5, adding water, wherein the mass ratio of the large spherulites to the medium spherulites to the small spherulites is 2: 5: 3, the ball milling time is 24 hours, and the fineness of the glaze after ball milling is controlled to be 0.2-0.3 percent of the rest of 325 meshes. Sieving the glaze material after the glaze material is discharged through a 100-mesh sieve to obtain glaze slurry, measuring the concentration of the glaze slurry, adding water to adjust the concentration of the glaze slurry to 65 baume degrees, beating 5mm of latex on a footing of a mud blank, uniformly spraying the glaze, tearing off the latex, drying at 50 ℃ for 2 hours, placing the dried glaze blank into a roller kiln for firing, wherein the maximum temperature is 1310 ℃, the firing period is 7.5 hours, the firing curve is a firing curve of the high-temperature white porcelain commonly used in the nonlyming, the atmosphere is an oxidizing atmosphere, and the thickness of a finally obtained glaze layer of the glaze blank is 0.32-0.35 mm.

Example 2

Weighing 31 parts of transparent frit, 18 parts of high-expansion frit, 13 parts of glass powder, 4 parts of albite powder, 7 parts of kaolin, 9 parts of barium carbonate, 9 parts of strontium carbonate, 7 parts of quartz powder and 2 parts of cobalt blue in parts by weight, adding the materials into a ball milling tank, and then adding the materials in parts by weight: ball stones: the mass ratio of water is 1: 2: 0.5, adding water, wherein the mass ratio of the large spherulites to the medium spherulites to the small spherulites is 2: 5: 3, the ball milling time is 24 hours, and the fineness of the glaze after ball milling is controlled to be 0.2-0.3 percent of the rest of 325 meshes. Sieving a glaze material with a 100-mesh sieve after the glaze material is discharged from a ball to obtain a glaze slurry, measuring the concentration of the glaze slurry, adding water to adjust the concentration of the glaze slurry to 65 baume degrees, beating 5mm of latex on a footing of a mud blank, uniformly spraying all glaze, tearing off the latex, drying at 50 ℃ for 2 hours, putting the dried glaze blank into a roller kiln to be fired, wherein the highest temperature is 1300 ℃, the firing period is 7 hours, the firing curve is a firing curve of high-temperature white porcelain commonly used in carinline, the atmosphere is an oxidizing atmosphere, and the thickness of a finally obtained glaze layer of the glaze blank is 0.35-0.4 mm. The glaze effect graph obtained by the method is shown in figures 1-2.

Comparative example 1

Weighing 10 parts of transparent frit, 5 parts of albite powder, 71 parts of high-expansion frit, 5 parts of glass powder, 5 parts of kaolin and 4 parts of silver ash in parts by weight, adding the materials into a ball milling tank, and then adding the materials in parts by weight: ball stones: the mass ratio of water is 1: 2: 0.5, adding water, wherein the mass ratio of the large spherulites to the medium spherulites to the small spherulites is 2: 5: 3, the ball milling time is 24 hours, and the fineness of the glaze after ball milling is controlled to be 0.2-0.3 percent of the rest of 325 meshes. Sieving the glaze material after the glaze material is discharged through a 100-mesh sieve to obtain glaze slurry, measuring the concentration of the glaze slurry, adding water to adjust the concentration of the glaze slurry to 65 baume degrees, beating 10mm of latex on a footing of a mud blank, uniformly spraying the glaze, tearing off the latex, drying at 50 ℃ for 2 hours, putting the dried glaze blank into a roller kiln to be fired, wherein the highest temperature is 1310 ℃, the firing period is 7 hours, the firing curve is a firing curve of high-temperature white porcelain commonly used in carinline, the atmosphere is an oxidizing atmosphere, and the thickness of a finally obtained glaze layer of the glaze blank is 0.3-0.32 mm.

The effects and properties of the crack glazes obtained in examples 1 and 2 and comparative example 1 were compared, and the results are shown in table 2.

TABLE 2 Effect data for different crackle glazes

Examples	Crack effect	Degree of glaze flow	Thermal stability
				Example 1	Good taste	1-3mm	Does not crack
Example 2	Good taste	1-2mm	Does not crack
				Comparative example 1	Good taste	4-8mm	Cracking of

The crack effect is a comprehensive evaluation of the fineness of the cracks and the aesthetic feeling of the cracks by visual inspection.

The thermal stability is detected by a heating and quenching method, the crack glaze product is placed in an electric furnace heated to 160 ℃, the temperature is kept for 30 minutes, the crack glaze product is rapidly placed in water at 20 ℃ for 10 minutes, the product is taken out and wiped dry, and whether the product cracks or explodes or not is checked.

As can be seen from the table above, the crack glaze obtained in the embodiment has good crack effect, more common cheap raw materials are added, and part of quartz powder, barium carbonate and strontium carbonate are added, so that the degree of the flowing glaze is reduced, the problem of product brewing is solved, the thermal stability of the product is improved, the product quality is improved, and the product cost is reduced.

Claims (8)

1. The high-temperature all-ceramic crackle glaze is characterized by comprising the following components in percentage by weight: 27-33% of transparent frit, 15-23% of high-expansion frit, 8-15% of glass powder, 4-10% of albite powder, 5-10% of kaolin, 5-10% of barium carbonate, 5-10% of strontium carbonate, 3-5% of quartz powder and 1-5% of toner.

2. The high-temperature all-ceramic crack glaze of claim 1, which is characterized by comprising the following components in percentage by weight: 30% of transparent frit, 21% of high-expansion frit, 10% of glass powder, 9% of albite powder, 7% of kaolin, 7% of barium carbonate, 9% of strontium carbonate, 4% of quartz powder and 3% of colorant.

3. The high-temperature all-ceramic crack glaze according to claim 1 or 2, wherein the colorant is one or more of silver ash, cobalt blue and malachite green.

4. A method for preparing a high-temperature all-ceramic crackle glaze according to any of claims 1-3, characterized by comprising the steps of:

1) preparing materials according to all components, mixing the raw materials, high alumina ball stone and water, and performing wet ball milling to obtain glaze;

2) sieving the glaze material with a 100-mesh sieve to obtain glaze slip, and adding water to adjust the concentration of the glaze slip;

3) and (3) uniformly spraying the glaze slurry on the glaze blank, drying after spraying the glaze, and sintering at the maximum temperature of 1280-1320 ℃ for 7-7.5 hours to obtain the high-temperature all-ceramic crackle glaze.

5. The method of claim 4, wherein the starting material: high alumina ball stone: the mass ratio of water is 1: 2: 0.5.

6. the preparation method according to claim 4 or 5, wherein the fineness of the ball-milled glaze in step 1) is controlled to 0.2-0.3% of 325 mesh.

7. The method according to claim 4 or 5, wherein the glaze slurry has a concentration of 60 to 70 baume degrees.

8. The production method according to claim 4 or 5, wherein the firing atmosphere is an oxidizing atmosphere.