A kind of wear-resistant ceramic clay and its preparation process

Abstract

The invention belongs to the field of ceramic technology, and specifically discloses a wear-resistant ceramic clay and a preparation process thereof. The ceramic clay comprises the following components by weight: 40-50 parts of kaolin, 10-15 parts of bentonite, 10-13 parts of ferric oxide, 6-9 parts of ferric oxide, 8-13 parts of talc, 5-10 parts of tetragonal zirconia polycrystals, 1-3 parts of composite additives and 2-4 parts of dispersant, wherein the grain size range of the tetragonal zirconia polycrystals is 0.5-1.3 μm, and the dispersant can be selected from ammonium polyacrylate or One of the polyvinyl pyrrolidones; tetragonal zirconia polycrystals modified by composite additives are added to ceramic clay to improve the wear resistance of the ceramic clay. CaO, MgO, and SiO2 in the composite additives are used to reduce the stress between the microscopic grains of tetragonal zirconia polycrystals and improve the bonding strength of the grain boundaries. Sm2O3 can relieve the stress concentration at the grain boundaries due to different thermal expansion coefficients, improve the bonding strength of the grain boundaries, ensure wear resistance, and improve the wear resistance and strength of the prepared ceramic products.

Description

Technical Field

[0001] The invention relates to the field of ceramic technology, in particular to wear-resistant ceramic clay and a preparation process thereof. Background Art

[0002] Vessels fired with pottery are called pottery, and vessels fired with porcelain clay are called porcelain. Ceramics is the general term for pottery, stoneware and porcelain. The ancients called ceramics "ou". Any vessel made of two different types of clay, pottery clay and porcelain clay, through the process of batching, molding, drying, and roasting can be called ceramics. There are many varieties of ceramic products, and their chemical composition, mineral composition, physical properties, and manufacturing methods are often close to each other and intertwined, with no obvious boundaries, but they are widely used.

[0003] At present, the research on ceramic materials has found that the addition of tetragonal zirconia polycrystals into ceramic materials can significantly improve the wear resistance of ceramic materials, and as the grain size of tetragonal zirconia polycrystals increases, the wear resistance of ceramic materials can be further improved. However, when the size of tetragonal zirconia polycrystals is higher than 0.9µm, the wear resistance of ceramic materials will drop significantly. Research has found that this is mainly due to changes in the wear mechanism inside the material, from the original intergranular fracture to severe wear caused by grain pullout. In order to improve the above situation, we provide a wear-resistant ceramic clay and its preparation process. Summary of the invention

[0004] The object of the present invention is to provide a wear-resistant ceramic clay and a preparation process thereof to solve the problems raised in the above background technology.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical scheme: a wear-resistant ceramic clay and a preparation process thereof, comprising the following components by weight: 40-50 parts of kaolin, 10-15 parts of bentonite, 10-13 parts of ferric oxide, 6-9 parts of ferrosoferric oxide, 8-13 parts of talc, 5-10 parts of tetragonal zirconia polycrystals, 1-3 parts of composite additives and 2-4 parts of dispersant, wherein the grain size range of the tetragonal zirconia polycrystals is 0.5-1.3µm, and the dispersant can be selected from one of ammonium polyacrylate or polyvinyl pyrrolidone.

[0006] Preferably, the hard kaolin can be selected as one of calcined kaolin or Longyan kaolin. The selection of hard kaolin with a harder texture can ensure the hardness of the ceramic product, and the hard kaolin still has plasticity after crushing and fine grinding; bentonite can be divided into sodium-based bentonite and calcium-based bentonite according to the difference in interlayer cations, and the physical properties of sodium-based bentonite are better than those of calcium-based bentonite. Therefore, sodium-based bentonite is used in the present invention; the dispersant can be selected as one of ammonium polyacrylate or polyvinyl pyrrolidone. The addition of the dispersant can make the tetragonal zirconia polycrystals more evenly distributed inside the ceramic soil, thereby improving the wear resistance of the ceramic soil.

[0007] Preferably, the grain size of tetragonal zirconia polycrystals is 1.1µm. The crystal structure of tetragonal zirconia polycrystals is very stable and has excellent thermal stability and chemical stability. It can form a good combination with ferric oxide and ferrosoferric oxide. When evenly dispersed in ceramic clay, it can improve the mechanical properties and wear resistance of ceramic clay.

[0008] Preferably, the composite additive includes CaO, MgO, SiO2 and Sm2O3; wherein the component ratio of CaO, MgO, SiO2 and Sm2O3 is (1.5-2.5):(1-2):(0.3-0.8):1; CaO, MgO and SiO2 can generate a second phase at the grain boundary, thereby reducing the microstress between grains, improving the bonding strength of the grain boundary, and reducing the probability of the grain being pulled out as a whole, while Sm2O3 can effectively promote the formation of the second phase calcium hexaaluminate in the grain boundary, reduce the content of the glass phase at the grain boundary, alleviate the stress concentration at the grain boundary caused by different thermal expansion coefficients, improve the grain boundary bonding strength, and ensure wear resistance.

[0009] A method for preparing wear-resistant ceramic clay comprises the following steps:

[0010] S1: sieving kaolin and bentonite through a 150-200 mesh sieve, respectively, then grinding and refining the kaolin and bentonite, washing the kaolin with water, and then separating the kaolin from the water through precipitation and filtration, and then drying the kaolin;

[0011] S2: The ground bentonite is placed in a drying box for drying, and then the ferric oxide, ferroferric oxide and talcum powder are respectively placed in a ball mill for ball milling. After the ball milling is completed, they are sieved in turn, and the mesh number of the sieve is controlled at 800-1000 meshes, so as to obtain a powdery material;

[0012] S3: After drying, the bentonite and kaolin are mixed, water is added and kneaded, and during this process, ferric oxide, ferric oxide and talcum powder are added in sequence, and the mixture is stirred evenly until the whole becomes a slurry to obtain a slurry;

[0013] S4: Prepare the solvent by removing water and glycerol, then put the solvent, tetragonal zirconia polycrystals and ammonium polyacrylate into a ball mill for 12 hours and stir evenly, then put the solvent, slurry, composite additives and polyvinyl pyrrolidone into a planetary ball mill for 12 hours to obtain ceramic clay.

[0014] Preferably, in the step S2, the drying temperature is controlled at 100-300°C, and the drying time is 6-8h.

[0015] Preferably, in the step S4, after being stirred evenly, the pH value of the solvent mixed with tetragonal zirconia polycrystals is adjusted to between 8 and 10.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The present invention adds tetragonal zirconia polycrystals modified by composite additives to ceramic clay to improve the wear resistance of the ceramic clay. CaO, MgO and SiO2 in the composite additives are used to reduce the stress between grains of tetragonal zirconia polycrystals at the microscopic level and improve the bonding strength of grain boundaries. Sm2O3 can alleviate the stress concentration at the grain boundaries caused by different thermal expansion coefficients and further improve the bonding strength of grain boundaries to ensure wear resistance.

[0018] The present invention studies the influence of tetragonal zirconia polycrystals with different grain sizes on the wear resistance of ceramic clay. When the grain size of the tetragonal zirconia polycrystals is less than 1.1µm, the wear resistance of the ceramic clay is improved as the grain size increases. When the grain size of the tetragonal zirconia polycrystals is greater than 1.1µm, the wear resistance of the ceramic clay decreases as the grain size increases. This improves the traditional tetragonal zirconia polycrystal size when it increases to 0.9µm, where the wear mechanism changes from intergranular fracture to severe wear caused by grain pullout. This further improves the wear resistance of the ceramic clay by the tetragonal zirconia polycrystals, and improves the wear resistance and strength of the prepared ceramic product. DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] The present invention provides a wear-resistant ceramic clay, which comprises the following components by weight: 40-50 parts of hard kaolin, 10-15 parts of sodium bentonite, 10-13 parts of ferric oxide, 6-9 parts of ferrosoferric oxide, 8-13 parts of talc, 5-10 parts of tetragonal zirconium oxide polycrystals, 1-3 parts of composite additives and 2-4 parts of dispersants;

[0021] Among them, the hard kaolin can be selected from calcined kaolin or Longyan kaolin. The hard kaolin with a harder texture can ensure the hardness of the ceramic product, and the hard kaolin has plasticity after crushing and fine grinding; bentonite can be divided into sodium bentonite and calcium bentonite according to the difference in interlayer cations, and the physical properties of sodium bentonite are better than those of calcium bentonite. Therefore, sodium bentonite is used in the present invention; the dispersant can be selected from ammonium polyacrylate or polyvinyl pyrrolidone. The addition of the dispersant can make the tetragonal zirconia polycrystals more evenly distributed inside the ceramic soil, thereby improving the wear resistance of the ceramic soil;

[0022] Among them, the grain size of tetragonal zirconia polycrystals ranges from 0.5 to 1.3 µm. The crystal structure of tetragonal zirconia polycrystals is very stable, and it has excellent thermal and chemical stability. It can form a good match with ferric oxide and ferrous oxide. When evenly dispersed in the ceramic clay, it can improve the mechanical properties and wear resistance of the ceramic clay.

[0023] The composite additives include CaO, MgO, SiO2 and Sm2O3; wherein the component ratios of CaO, MgO, SiO2 and Sm2O3 are (1.5-2.5): (1-2): (0.3-0.8): 1; CaO, MgO and SiO2 can generate a second phase at the grain boundary, thereby reducing the micro stress between grains, improving the bonding strength of the grain boundary, and reducing the probability of the grain being pulled out as a whole, while Sm2O3 can effectively promote the formation of the second phase calcium hexaaluminate in the grain boundary, reduce the content of the glass phase at the grain boundary, alleviate the stress concentration at the grain boundary caused by different thermal expansion coefficients, improve the bonding strength of the grain boundary, and ensure wear resistance.

[0024] A method for preparing wear-resistant ceramic clay comprises the following steps:

[0025] S1: sieving kaolin and bentonite through a 150-200 mesh sieve, respectively, then grinding and refining the kaolin and bentonite, washing the kaolin with water, and then separating the kaolin from the water through precipitation and filtration, and then drying the kaolin;

[0026] S2: The ground bentonite is placed in a drying box for drying, the drying temperature is controlled at 100-300°C, and the drying time is 6-8h; then, ferric oxide, ferroferric oxide, and talcum powder are respectively placed in a ball mill for ball milling, and after the ball milling is completed, they are sieved in turn, and the mesh number of the sieve is controlled at 800-1000 meshes, so as to obtain a powdery material;

[0027] S3: After drying, the bentonite and kaolin are mixed, water is added and kneaded, and during this process, ferric oxide, ferric oxide and talcum powder are added in sequence, and the mixture is stirred evenly until the whole becomes a slurry to obtain a slurry;

[0028] S4: Prepare the solvent by removing water and glycerol, then put the solvent, tetragonal zirconia polycrystals and ammonium polyacrylate into a ball mill for 12 hours. After stirring evenly, adjust the pH value of the solvent mixed with tetragonal zirconia polycrystals to between 8 and 10, then put the solvent, slurry, composite additives and polyvinyl pyrrolidone into a planetary ball mill for ball milling for 12 hours to obtain ceramic clay.

[0029] Embodiment 1:

[0030] A wear-resistant ceramic clay comprises the following components by weight: 50 parts of kaolin, 13 parts of bentonite, 11 parts of ferric oxide, 8 parts of ferrosoferric oxide, 12 parts of talc, 8 parts of tetragonal zirconia polycrystals, 2 parts of composite additives and 2 parts of dispersants, wherein the component ratio of CaO, MgO, SiO2 and Sm2O3 in the composite additives is 1.5:1:0.3:1. The ceramic clay obtained by the components in the above proportions is sintered into a ceramic product to obtain Example 1.

[0031] Embodiment 2:

[0032] A wear-resistant ceramic clay comprises the following components by weight: 50 parts of kaolin, 13 parts of bentonite, 11 parts of ferric oxide, 8 parts of ferrosoferric oxide, 12 parts of talc, 8 parts of tetragonal zirconia polycrystals, 2 parts of composite additives and 2 parts of dispersants, wherein the component ratio of CaO, MgO, SiO2 and Sm2O3 in the composite additives is 1.8:1.3:0.6:1. The ceramic clay obtained by sintering the components in the above proportions into a ceramic product obtains Example 2.

[0033] Embodiment 3:

[0034] A wear-resistant ceramic clay comprises the following components by weight: 50 parts of kaolin, 13 parts of bentonite, 11 parts of ferric oxide, 8 parts of ferrosoferric oxide, 12 parts of talc, 8 parts of tetragonal zirconia polycrystals, 2 parts of composite additives and 2 parts of dispersants, wherein the component ratio of CaO, MgO, SiO2 and Sm2O3 in the composite additives is 2.1:1.5:0.8:1. The ceramic clay obtained by the components in the above proportions is sintered into a ceramic product to obtain Example 3.

[0035] Embodiment 4:

[0036] A wear-resistant ceramic clay comprises the following components by weight: 50 parts of kaolin, 13 parts of bentonite, 11 parts of ferric oxide, 8 parts of ferrosoferric oxide, 12 parts of talc, 8 parts of tetragonal zirconia polycrystals, 2 parts of composite additives and 2 parts of dispersants, wherein the component ratio of CaO, MgO, SiO2 and Sm2O3 in the composite additives is 2.5:1.5:0.8:1. The ceramic clay obtained by the components in the above proportions is sintered into a ceramic product to obtain Example 4.

[0037] Embodiment 5:

[0038] A wear-resistant ceramic clay comprises the following components by weight: 50 parts of kaolin, 13 parts of bentonite, 11 parts of ferric oxide, 8 parts of ferrosoferric oxide, 12 parts of talc, 8 parts of tetragonal zirconia polycrystals, 2 parts of composite additives and 2 parts of dispersants, wherein the component ratio of CaO, MgO, SiO2 and Sm2O3 in the composite additives is 2.1:2:0.8:1. The ceramic clay obtained by sintering the components in the above proportions into a ceramic product yields Example 5.

[0039] Comparative Example 1:

[0040] Comparative Example 1 is also a ceramic product made by sintering ceramic clay with the same component content as above. The difference between Comparative Example 1 and Examples 1-5 is that no composite additive is added to the ceramic clay used in Comparative Example 1.

[0041] The wear resistance of the ceramic products of Examples 1-5 and Comparative Example 1 was tested using an MMD-1 multifunctional friction and wear tester. When the load was 15N and the rotation speed was 100r / min, the change in the wear amount of each sample at different sliding distances was studied. The calculation formula of the wear coefficient is λ=mV / MPL, where m is the wear amount, in g, M is the mass of the sample before wear, in g, P is the applied load, in N, and V is the sample volume, in m 3 , L is the relative wear distance, unit is m, the test results are shown in Table 1 below:

[0042] Table 1

[0043]

[0044] As can be seen from Table 1, the ceramic products prepared in Examples 1-5 all have good wear resistance. Compared with Examples 1-5, in Comparative Example 1, no composite additive is added, and the wear resistance of Comparative Example 1 begins to decrease significantly. This shows that composite additives are very important in the wear-resistant ceramic clay of the present invention.

[0045] It can be seen from Table 1 that among Examples 1-5, the 50m wear amount, 100m wear amount and 500m wear amount of Example 4 are all the lowest, which shows that the wear resistance of Example 4 is the best, indicating that in the composite additive, when the component ratio of CaO, MgO, SiO2 and Sm2O3 is 2.5:1.5:0.8:1, the obtained ceramic clay has the best wear resistance.

[0046] Embodiment 6:

[0047] A wear-resistant ceramic clay comprises the following components by weight: 50 parts of kaolin, 13 parts of bentonite, 11 parts of ferric oxide, 8 parts of ferrosoferric oxide, 12 parts of talc, 8 parts of tetragonal zirconia polycrystals, 2 parts of composite additives and 2 parts of dispersants, wherein the component ratio of CaO, MgO, SiO2 and Sm2O3 in the composite additive is 2.5:1.5:0.8:1, and the grain size of the tetragonal zirconia polycrystals is 0.5µm. The ceramic clay obtained by the components in the above proportions is sintered into a ceramic product to obtain Example 6.

[0048] Embodiment 7:

[0049] A wear-resistant ceramic clay comprises the following components by weight: 50 parts of kaolin, 13 parts of bentonite, 11 parts of ferric oxide, 8 parts of ferrosoferric oxide, 12 parts of talc, 8 parts of tetragonal zirconia polycrystals, 2 parts of composite additives and 2 parts of dispersants, wherein the component ratio of CaO, MgO, SiO2 and Sm2O3 in the composite additive is 2.5:1.5:0.8:1, and the grain size of the tetragonal zirconia polycrystals is 0.8µm. The ceramic clay obtained by the components in the above proportions is sintered into a ceramic product to obtain Example 7.

[0050] Embodiment 8:

[0051] A wear-resistant ceramic clay comprises the following components by weight: 50 parts of kaolin, 13 parts of bentonite, 11 parts of ferric oxide, 8 parts of ferrosoferric oxide, 12 parts of talc, 8 parts of tetragonal zirconia polycrystals, 2 parts of composite additives and 2 parts of dispersants, wherein the component ratio of CaO, MgO, SiO2 and Sm2O3 in the composite additive is 2.5:1.5:0.8:1, and the grain size of the tetragonal zirconia polycrystals is 1.1µm. The ceramic clay obtained by the components in the above proportions is sintered into a ceramic product to obtain Example 8.

[0052] Embodiment 9:

[0053] A wear-resistant ceramic clay comprises the following components by weight: 50 parts of kaolin, 13 parts of bentonite, 11 parts of ferric oxide, 8 parts of ferrosoferric oxide, 12 parts of talc, 8 parts of tetragonal zirconia polycrystals, 2 parts of composite additives and 2 parts of dispersants, wherein the component ratio of CaO, MgO, SiO2 and Sm2O3 in the composite additive is 2.5:1.5:0.8:1, and the grain size of the tetragonal zirconia polycrystals is 1.3µm. The ceramic clay obtained by the components in the above proportions is sintered into a ceramic product to obtain Example 9.

[0054] The above detection method was also used to detect Examples 6-9, and the detection results are shown in Table 2 below:

[0055] Table 2

[0056]

[0057] It can be seen from Table 2 that the ceramic products prepared in Examples 6-9 all have good wear resistance, and among them, the 50m wear, 100m wear and 500m wear of Example 8 are all the lowest, indicating that when the grain size of the tetragonal zirconia polycrystal is 1.1µm, the wear resistance of the obtained ceramic clay is the best.

[0058] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A wear-resistant ceramic clay, characterized in that: The composition comprises the following components by weight: 40-50 parts of kaolin, 10-15 parts of bentonite, 10-13 parts of ferric oxide, 6-9 parts of ferrosoferric oxide, 8-13 parts of talc, 5-10 parts of tetragonal zirconium oxide polycrystal, 1-3 parts of composite additives and 2-4 parts of dispersant, wherein the dispersant is selected from ammonium polyacrylate and polyvinyl pyrrolidone; The composite additive comprises CaO, MgO, SiO2 and Sm2O3; wherein the component ratio of CaO, MgO, SiO2 and Sm2O3 is (1.5-2.5): (1-2): (0.3-0.8): 1; The grain size of the tetragonal zirconia polycrystal is 1.1 μm.

2. The wear-resistant ceramic clay according to claim 1, characterized in that: The kaolin should be hard kaolin, and the bentonite should be sodium-based bentonite.

3. The wear-resistant ceramic clay according to claim 1, characterized in that: The composition includes the following components by weight: 50 parts of kaolin, 13 parts of bentonite, 11 parts of ferric oxide, 8 parts of ferrosoferric oxide, 12 parts of talc, 8 parts of tetragonal zirconia polycrystal, 2 parts of composite additives and 2 parts of dispersant.

4. A process for preparing wear-resistant ceramic clay according to any one of claims 1 to 3, characterized in that: The following steps are involved: S1: sieving kaolin and bentonite through a 150-200 mesh sieve, respectively, then grinding and refining the kaolin and bentonite, washing the kaolin with water, and then separating the kaolin from the water through precipitation and filtration, and then drying the kaolin; S2: The ground bentonite is placed in a drying box for drying, and then the ferric oxide, ferroferric oxide and talcum powder are respectively placed in a ball mill for ball milling. After the ball milling is completed, they are sieved in turn, and the mesh number of the sieve is controlled at 800-1000 meshes, so as to obtain a powdery material; S3: After drying, the bentonite and kaolin are mixed, water is added and kneaded, and during this process, ferric oxide, ferric oxide and talcum powder are added in sequence, and the mixture is stirred evenly until the whole becomes a slurry to obtain a slurry; S4: Prepare the solvent by removing water and glycerol, then put the solvent, tetragonal zirconia polycrystals and ammonium polyacrylate into a ball mill for 12 hours and stir evenly, then put the solvent, slurry, composite additives and polyvinyl pyrrolidone into a planetary ball mill for 12 hours to obtain ceramic clay.

5. The process for preparing a wear-resistant ceramic clay according to claim 4, characterized in that: In the step S2, the drying temperature is controlled at 100-300°C, and the drying time is 6-8h.

6. The process for preparing a wear-resistant ceramic clay according to claim 4, characterized in that: In the step S4, after being stirred evenly, the pH value of the solvent mixed with tetragonal zirconia polycrystals is adjusted to between 8 and 10.

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