Tempered high-strength impact-resistant ceramic sheet and method for manufacturing the same

Abstract

The application belongs to the technical field of building ceramics, and particularly relates to a tempered high-strength impact-resistant ceramic sheet and a preparation method thereof. The tempered high-strength impact-resistant ceramic sheet comprises a ceramic sheet blank and a tempered coating layer obtained by firing a tempered coating slurry on the surface of the ceramic sheet blank. The ceramic sheet strengthening process is developed by referring to the stress structure of tempered glass. By establishing a compressive stress layer on the bottom surface of the blank, the compressive stress layer of the glaze layer is coordinated, the impact resistance and the bending strength of the material are significantly improved, and the application field of the ceramic sheet is widened.

Description

Technical Field

[0001] This invention belongs to the field of building ceramics technology, and particularly relates to a tempered high-strength impact-resistant ceramic thin plate and its preparation method. Background Technology

[0002] As an innovative building material, ceramic thin slabs have gained widespread application in recent years in architectural decoration, appliance exterior panels, and high-end countertop surfaces due to their lightweight, energy-saving, environmentally friendly, and highly customizable design characteristics. Compared to traditional ceramic materials, ceramic thin slabs significantly reduce raw material consumption and energy requirements during production, aligning with the low-carbon and environmentally friendly principles promoted by the ceramic industry. With technological advancements and consumption upgrades, ceramic thin slabs have gradually expanded from traditional architectural decoration to emerging markets such as integrated home appliances.

[0003] However, despite the continued growth in high-end market demand, ceramic thin slabs face a key technological bottleneck: as a brittle material, its inherent mechanical property defects severely limit its application range, especially as the thickness is reduced, its destructive load (the force that causes the sample to break) is greatly reduced. Studies have shown that ceramic materials exhibit typical brittle fracture characteristics under impact loads, in stark contrast to the plastic deformation capabilities of metallic materials. In impact tests, the damage development delay time of ceramic materials is extremely short; cracks rapidly form and propagate upon impact, leading to material fracture. This characteristic makes ceramic thin slabs highly susceptible to damage during processing, transportation, and use, especially during on-site processing such as cutting and drilling, where microcracks easily form in the edge areas. These cracks propagate rapidly under stress, causing the entire slab to break. The insufficient impact resistance of ceramic thin slabs is particularly prominent when applied to building curtain walls and appliance panels. Taking building curtain walls as an example, ceramic thin slabs need to withstand wind loads, temperature changes, and even accidental impacts. While traditional thick slabs are heavier, they have higher bending strength, while thin slabs are more prone to fracture under the same conditions. In the field of home appliance applications, such as refrigerator doors and countertops, bumps and impacts are unavoidable in daily use. Existing thin ceramic plates often suffer from high breakage rates due to insufficient destructive load.

[0004] Glass, which also belongs to the inorganic materials branch, cleverly redistributes the stress structure on its surface and inside through physical "tempering" treatment. Ultimately, the glass material establishes a stable stress system of "surface compressive stress + central tensile stress", thereby significantly improving its performance without changing the chemical composition of the glass.

[0005] Ceramic thin slab products consist of a body layer and a decorative glaze layer. The body layer is a homogeneous material, much thicker than the glaze layer, and its coefficient of thermal expansion is also greater. Therefore, during the cooling process after firing, the body shrinks more while the glaze layer shrinks less. The glaze layer experiences compressive stress, while the body experiences tensile stress. Consequently, when the front side (glaze layer) of the ceramic thin slab is subjected to external force, the body is further subjected to tensile stress, leading to fracture. Therefore, the key is to ensure that the bottom of the body also experiences compressive stress, thus forming a stable stress system similar to tempered glass—a combination of surface compressive stress and central tensile stress—thereby improving the strength and impact resistance of the ceramic thin slab.

[0006] Unlike glass tempering, which utilizes a homogeneous isotropic material with a much lower softening temperature than ceramic slabs, glass exhibits a very wide softening temperature range. Given a fixed chemical composition, its high-temperature viscosity is controllable under temperature variations, making tempering a straightforward process. Ceramic slabs, however, consist of a body layer and a decorative glaze layer, which differ in composition and properties. The body layer is a multiphase material composed of various crystalline phases, glassy phases, and bubbles, resulting in a higher softening temperature during firing and a phase transition process. This leads to a very narrow softening temperature range, high viscosity, and a low concentration of high-temperature liquid phase, making it difficult to introduce surface compressive stress through the viscosity difference between the surface and interior using a tempering process similar to glass. Furthermore, the bottom of the ceramic slab is in constant contact with the ceramic rollers during high-temperature firing. Introducing a glaze-like material structure at the bottom would create numerous problems, such as roller adhesion and difficulty in bonding during later application. Therefore, without changing the original system and properties of the "tempered" compressive stress layer and the ceramic slab blank, a compressive stress layer is introduced at the bottom of the ceramic slab by adjusting the thermal expansion coefficient of the surface tempered coating, thereby achieving a reinforced stress structure similar to tempered glass. Summary of the Invention

[0007] To significantly improve the breaking strength and impact resistance of ceramic thin plates, this invention provides a tempered high-strength impact-resistant ceramic thin plate and its preparation method. Drawing inspiration from the stress structure of tempered glass, a ceramic thin plate reinforcement process is developed. By establishing a compressive stress layer on the bottom surface of the green body, which works in conjunction with the compressive stress layer of the glaze, the impact resistance and flexural strength of the material are significantly improved, broadening the application areas of ceramic thin plates.

[0008] In a first aspect, the present invention provides a tempered high-strength and impact-resistant ceramic sheet. The tempered high-strength and impact-resistant ceramic sheet includes a ceramic sheet blank and a tempered coating disposed on the surface of the ceramic sheet blank, which is obtained by firing a tempered coating slurry;

[0009] The mineral composition of the ceramic thin slab body includes, by mass percentage: 14%~16% potassium feldspar, 24%~28% clay, 11%~13% potassium sodium sand, 10%~12% kaolin, 1%~2% black talc, 3%~5% bentonite, 14%~16% sodium feldspar, 9%~11% wollastonite, and 5%~6% brick powder;

[0010] The mineral composition of the tempered coating includes, by mass percentage: 16%~20% potassium feldspar, 8%~12% water-milled potassium feldspar, 22%~30% clay, 8%~12% bentonite, 14%~18% kaolinite, 6%~10% wollastonite, 2%~4% calcined talc, and 10%~14% sodium feldspar.

[0011] Preferably, the coefficient of thermal expansion of the ceramic slab is higher than that of the tempered coating, and the difference between the coefficients of thermal expansion of the ceramic slab and the tempered coating is not higher than 1.2 × 10⁻⁶. -6 / ℃. Preferably, the difference in the coefficients of thermal expansion between the ceramic slab and the tempered coating is not higher than 1.1×10⁻⁶. -6 / ℃.

[0012] Preferably, the chemical composition of the ceramic thin slab includes, by mass percentage: SiO2 65%~67%; Al2O3 18%~20%; Fe2O3 0.7%~0.8%; TiO2 0.2%~0.3%; CaO 3.5%~4.0%; MgO 0.6%~0.8%; K2O 2.0%~2.2%; Na2O 1.8%~2.0%; and loss on ignition 4.5%~5.5%.

[0013] Preferably, the coefficient of thermal expansion of the ceramic thin slab is 8.15 × 10⁻⁶ over a temperature range from room temperature to 600°C. -6 / ℃~8.25×10 -6 / ℃.

[0014] Preferably, the chemical composition of the tempered coating includes, by mass percentage: SiO2 55%~60%, Al2O3 20%~25%, Fe2O3 0.5%~1.0%, TiO2 0.1%~0.3%, CaO 3%~5%, MgO 1%~3%, K2O 4%~5%, Na2O 2%~4%, and loss on ignition 5%~7%.

[0015] Preferably, the coefficient of thermal expansion of the tempered coating is 7.12 × 10⁻⁶ over a temperature range from room temperature to 600°C. -6 / ℃~7.25×10 -6 / ℃.

[0016] Preferably, the thickness of the tempered coating is 0.08~0.4mm.

[0017] Preferably, the firing temperature is 1180~1220℃ and the firing cycle is 40~60min.

[0018] Preferably, the specific gravity of the tempered coating slurry is 1.6~1.7 g / cm³. 3 The application rate is 300~400 g / m 2 .

[0019] Secondly, the present invention provides a method for preparing the aforementioned tempered high-strength impact-resistant ceramic thin plate. The preparation method includes the following steps:

[0020] Dry the ceramic slab blank;

[0021] A tempered coating slurry is applied to the surface of the dried ceramic slab away from the decorative glaze layer.

[0022] The ceramic sheet blank with the applied tempering coating slurry is fired to obtain a tempered high-strength and impact-resistant ceramic sheet.

[0023] Preferably, the tempered coating slurry is applied by roller coating.

[0024] Preferably, the preparation method further includes the following steps: before firing, sequentially applying a base glaze, inkjet printing ink decorative pattern, and applying a protective glaze to the surface of the ceramic slab blank after applying a tempered coating slurry.

[0025] The present invention, by applying a special tempered coating to the bottom of the ceramic thin slab blank, has the following beneficial effects:

[0026] (1) Significantly improve mechanical properties. By applying a special tempered coating to the bottom of the ceramic thin plate blank, a stable stress structure of "surface compressive stress + central tensile stress" is formed in synergy with the glaze layer on the surface, which significantly improves the impact resistance and bending strength of the ceramic thin plate and effectively overcomes the defects of traditional ceramic thin plates that are brittle and easy to break.

[0027] (2) Structural biomimicry and synergistic enhancement. Drawing on the stress enhancement principle of tempered glass, the thermal expansion coefficients of the preform and the tempered coating are matched to form a synergistic compressive stress layer during the firing and cooling process, which enhances the overall toughness and impact resistance of the material.

[0028] (3) Material matching and performance stability. The chemical composition of the ceramic slab blank and the tempered coating belong to the same blank formulation system as the raw material composition. Through the precise design of the thermal expansion coefficient, it is ensured that the two are matched and coordinated during the firing process, and have good bonding.

[0029] (4) Process optimization and reliability improvement. The coating is applied by roller coating, the process parameters are clear and controllable, it is suitable for industrial production, and the finished product has good consistency.

[0030] (5) Application expansion and economic benefits. The ceramic thin plate of the present invention is not only suitable for the field of building decoration, but can also be widely used in scenarios with high requirements for strength and impact resistance, such as home appliance panels and counter surfaces, thus broadening the market application scope of ceramic thin plates and increasing product added value. Attached Figure Description

[0031] Figure 1 This is an optical microscope image of the cross-section of the tempered high-strength impact-resistant ceramic thin plate of Example 1;

[0032] Figure 2 The XRD phase analysis spectra of the bottom surfaces of the tempered high-strength and impact-resistant ceramic sheet of Example 2 and the untempered ceramic sheet of the same green body formulation are shown. Detailed Implementation

[0033] The present invention will be further described below with reference to the following embodiments. It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the present invention. The following exemplarily illustrates tempered high-strength impact-resistant ceramic thin plates and their preparation methods.

[0034] Ceramic thin slab blanks are obtained by dry pressing of ceramic thin slab blank powder. The mineral composition of the ceramic thin slab blanks includes, by mass percentage: 14%~16% potassium feldspar, 24%~28% clay, 11%~13% potassium sodium sand, 10%~12% kaolin, 1%~2% black talc, 3%~5% bentonite, 14%~16% sodium feldspar, 9%~11% wollastonite, and 5%~6% brick powder.

[0035] The brick powder is derived from crushed waste bricks, and its chemical composition includes, by mass percentage: SiO2 72%~74%; Al2O3 17%~19%; Fe2O3 0.8%~1.5%; TiO2 0.1%~0.5%; CaO 0.4%~0.8%; MgO 0.8%~1.2%; K2O 2.4%~2.8%; Na2O 2.6%~3.0%.

[0036] For example, the specific chemical composition of the brick powder used in the embodiment includes, by mass percentage: SiO2 73.3%, Al2O3 18.2%, Fe2O3 1.2%, TiO2 0.3%, CaO 0.6%, MgO 1.0%, K2O 2.6%, Na2O 2.8%.

[0037] In an optional embodiment, the chemical composition of the ceramic thin slab includes, by mass percentage: SiO2 65%~67%; Al2O3 18%~20%; Fe2O3 0.7%~0.8%; TiO2 0.2%~0.3%; CaO 3.5%~4.0%; MgO 0.6%~0.8%; K2O 2.0%~2.2%; Na2O 1.8%~2.0%; and loss on ignition 4.5%~5.5%.

[0038] For example, the chemical composition of the ceramic thin slab includes, by mass percentage: SiO2 65.5%; Al2O3 19.2%; Fe2O3 0.75%; TiO2 0.25%; CaO 3.8%; MgO 0.7%; K2O 2.0%; Na2O 1.8%; and loss on ignition 6.0%.

[0039] The coefficient of thermal expansion of the ceramic slab blank is 8.15 × 10⁻⁶ over a temperature range from room temperature to 600°C. -6 / ℃~8.25×10 -6 / ℃.

[0040] The ceramic slab blank is dried. Drying can be carried out in a drying kiln. The drying temperature and drying time can be set as needed.

[0041] A tempered coating slurry is applied to the bottom surface of the dried body. The bottom refers to the surface away from the decorative glaze. The mineral composition of the tempered coating slurry includes, by mass percentage: 16%–20% potassium feldspar, 8%–12% water-polished potassium feldspar, 22%–30% clay, 8%–12% bentonite, 14%–18% kaolinite, 6%–10% wollastonite, 2%–4% calcined talc, and 10%–14% sodium feldspar.

[0042] In an optional embodiment, the chemical composition of the tempered coating slurry includes, by mass percentage: SiO2 55%~60%, Al2O3 20%~25%, Fe2O3 0.5%~1.0%, TiO2 0.1%~0.3%, CaO 3%~5%, MgO 1%~3%, K2O 4%~5%, Na2O 2%~4%, and loss on ignition 5%~7%.

[0043] In an optional embodiment, the coefficient of thermal expansion of the tempered coating is 7.12 × 10⁻⁶ over a temperature range from room temperature to 600°C. -6 / ℃~7.25×10 -6 / ℃.

[0044] Preferably, the coefficient of thermal expansion of the ceramic slab is higher than that of the tempered coating, and the difference between the coefficients of thermal expansion of the ceramic slab and the tempered coating is not higher than 1.2 × 10⁻⁶. -6 / ℃.

[0045] Preparation of tempered coating slurry. The mineral raw materials, additives, and water of the tempered coating slurry are ball-milled to form a homogeneous slurry. Additives can be one or more of sodium tripolyphosphate, sodium carboxymethyl cellulose, sodium polyacrylate, and sodium citrate. In practical use, water can be added to the slurry to adjust the final slurry specific gravity to the desired level. For example, the additives may account for 0.1% to 0.5% of the mass of the mineral raw materials in the tempered coating slurry.

[0046] In an optional embodiment, the specific gravity of the tempered coating slurry is controlled to be 1.6~1.7 g / cm³. 3 The glaze application rate is 300~400 g / m². 2 The thickness of the tempered coating obtained after firing the tempered coating slurry ranges from 0.08 to 0.4 mm. A coating thickness that is too low will result in insufficient compressive stress applied to the coating, leading to little improvement in the strength and impact resistance of the ceramic slab. Conversely, a coating thickness that is too high will cause the compressive stress to gradually decrease along the coating thickness direction from the interface between the ceramic slab and the tempered coating, resulting in insufficient compressive stress reaching the coating surface to significantly improve the strength of the ceramic slab. As an example, but not limited to this, the tempered coating slurry is applied by roller coating.

[0047] The firing method is a common method used in building ceramics. In an optional embodiment, the firing temperature is 1180~1220℃, and the firing cycle is 40~60min.

[0048] In an optional embodiment, before firing, a base glaze is applied to the surface of the ceramic slab blank, an inkjet-printed decorative pattern is created, a protective glaze is applied, and the surface is dried. The surface refers to the side opposite the bottom surface to which the tempered coating slurry is applied. The glazing and decoration processes are adjusted according to industry-standard process parameters and glaze formulations. Then, the dried blank is fired in a roller kiln and, after edge grinding, is produced as a tempered, high-strength, impact-resistant ceramic slab.

[0049] As an example, the base glaze is a conventional base glaze or slip, with no special requirements. The base glaze mainly serves to cover the body of the brick, enhance the whiteness of the brick, and provide an exhaust channel during the high-temperature firing process, thus preventing glaze defects. In some embodiments, the chemical composition of the base glaze includes, by mass percentage: SiO2 53%~60%; Al2O3 25%~30%; Fe2O3 0.2%~0.5%; TiO2 0.1%~0.2%; CaO 0.3%~0.8%; MgO 0.1%~0.5%; K2O 2%~6%; Na2O 2%~3.5%; ZrO2 4%~8%; loss on ignition 2%~5%. Any base glaze mineral composition formulation that brings the chemical composition of the base glaze into the above range is applicable to this invention. The base glaze is prepared into a glaze slurry. For example, the base glaze mineral composition, glaze slurry dispersant, and water are ball-milled uniformly to prepare a base glaze slurry. The dispersant can be any one or more of sodium tripolyphosphate, sodium carboxymethyl cellulose, sodium polyacrylate, and sodium citrate. In actual use, water can be added to the base glaze slurry to adjust the final desired glaze specific gravity. The base glaze can be applied by pouring or spraying. Preferably, the specific gravity of the base glaze is 1.40~1.45 g / cm³. 3 The glaze application rate is 500~650g / m². 2 .

[0050] In a specific embodiment, a base glaze is applied to the surface of the dried brick blank using a spray glazing method and then dried. The chemical composition of the base glaze includes, by mass percentage: SiO2 54.5%; Al2O3 29.1%; Fe2O3 0.4%; TiO2 0.1%; CaO 0.7%; MgO 0.2%; K2O 2.4%; Na2O 3.4%; ZrO2 5.8%; and a loss on ignition of 3.4%. The specific gravity of the base glaze is controlled at 1.42 g / cm³. 3 Glazing amount is 600 g / m 2 .

[0051] As an example, the chemical composition of the protective glaze includes, by mass percentage: 1L 7%~10%, SiO2 45%~60%, Al2O3 16%~21%, Fe2O3 0.1%~0.4%; TiO2 0.1%~0.3%, CaO 4.5%~7%, MgO 1.5%~3.5%, K2O 4.5%~6%, Na2O 1%~2%, ZnO 4%~8%, SrO 1%~3%, BaO 3%~5%. The protective glaze can be applied by spraying or dipping. In an optional embodiment, the specific gravity of the protective glaze is 1.3~1.4 g / cm³. 3 The glaze application rate is 170~250 g / m². 2 .

[0052] In a specific embodiment, the chemical composition of the protective glaze includes, by mass percentage: 8.4% L, 46.1% SiO2, 16.5% Al2O3, 0.25% Fe2O3, 0.25% TiO2, 6.3% CaO, 2.8% MgO, 5.5% K2O, 1.5% Na2O, 4.8% ZnO, 2.8% SrO, and 4.8% BaO. The protective glaze is applied by spraying. The specific gravity of the protective glaze is 1.35 g / cm³. 3 The glaze application rate is 190 g / m². 2 .

[0053] Example 1

[0054] The specific steps for preparing tempered high-strength impact-resistant ceramic thin plates are as follows:

[0055] (1) Preparation of thin ceramic slab body powder: Weigh out the following by mass percentage: 15% potassium feldspar, 26% clay, 12% potassium sodium sand, 11% kaolin, 1.5% black talc, 4% bentonite, 15% sodium feldspar, 10% wollastonite, and 5.5% brick powder. Mix the above raw materials evenly, dry press into shape, and dry to obtain the slab body. The coefficient of thermal expansion of the slab body in the temperature range of room temperature to 600℃ is 8.22×10⁻⁶. -6 Around / ℃.

[0056] (2) Preparation of tempered coating slurry: 16% potassium feldspar, 10% water-milled potassium feldspar, 25% ball clay, 10% bentonite, 16% kaolin, 8% wollastonite, 3% calcined talc, and 12% sodium feldspar were weighed by mass percentage. Sodium tripolyphosphate and deionized water were added as additives, and the mixture was ball-milled uniformly to obtain the tempered coating slurry. The specific gravity of the tempered coating slurry was 1.65 g / cm³. 3 The coefficient of thermal expansion of the tempered coating is 7.15 × 10⁻⁶ over a temperature range from room temperature to 600°C. -6 Around / ℃.

[0057] (3) Apply the above-mentioned tempered coating slurry to the bottom of the dried blank by roller coating, and control the glaze application amount to about 320 g / m. 2 .

[0058] (4) Apply base glaze, inkjet print decorative pattern, apply protective glaze, and dry on the surface of the blank after applying the above-mentioned tempered coating slurry.

[0059] (5) The processed billet is sent into the roller kiln for firing. The firing temperature is 1200℃ and the firing cycle is 50 minutes.

[0060] (6) After firing, the ceramic sheet is edge-ground to obtain a tempered high-strength impact-resistant ceramic sheet.

[0061] The bending strength test adopted the three-point bending method commonly used in the ceramic industry. The sample span was 80mm, the sample size was 100mm x 20mm (length x width), and the loading rate was 0.1mm / min.

[0062] Impact resistance testing was conducted in accordance with GB / T 14389-1993, "Test Method for Impact Toughness of Engineering Ceramics".

[0063] Figure 1 The image shows an optical microscope image of the cross-section of the tempered ceramic thin plate prepared in Example 1. As can be seen from the image, the thickness of the tempered coating is about 270 μm, and the tempered coating is tightly bonded to the ceramic thin plate blank, indicating that it is fused together as one piece during the firing process and has good compatibility.

[0064] In other words, the cross-sectional optical microscope images of the prepared tempered ceramic thin plate show that the thickness of the tempered coating at the bottom of the plate is approximately 0.27 mm, exhibiting a morphology where the tempered coating is tightly bonded to the green body. Tests revealed that the flexural strength of the tempered ceramic thin plate is 88.68 MPa, a 39% increase compared to the 63.65 MPa of the untempered plate, and its impact resistance is also significantly improved.

[0065] The coating thickness was further adjusted, and its bending strength and impact resistance were tested. The results are shown in Table 1.

[0066] Table 1 shows the experimental results of Example 1, which investigated the effect of different coating thicknesses on the bending strength and impact resistance of the prepared tempered ceramic thin plates. The results show that coatings with a thickness range of 0.08~0.4 mm can significantly improve the bending strength and impact resistance of the ceramic thin plates.

[0067] Table 1

[0068] .

[0069] Example 2

[0070] The main difference between this embodiment and Example 1 lies in the adjustments made to the ceramic thin slab preform formula and the tempered coating formula. The specific preparation process is as follows:

[0071] (1) The raw material composition (by mass percentage) of the ceramic thin slab body powder is as follows: potassium feldspar 15%, clay 26%, potassium sodium sand 12%, kaolin 12%, black talc 1.5%, bentonite 5%, sodium feldspar 14%, wollastonite 9%, and brick powder 5.5%. The coefficient of thermal expansion of the ceramic thin slab body in the temperature range of room temperature to 600℃ is approximately 8.15×10⁻⁶. -6 Around / ℃.

[0072] (2) The raw material composition (by mass percentage) of the tempered coating slurry is as follows: 18% potassium feldspar, 9% water-milled potassium feldspar, 24% ball clay, 11% bentonite, 15% kaolin, 9% wollastonite, 2% calcined talc, and 12% sodium feldspar are weighed, sodium tripolyphosphate and deionized water are added, and the mixture is ball-milled uniformly to obtain the tempered coating slurry. The specific gravity of the tempered coating slurry is 1.7 g / cm³. 3 The coefficient of thermal expansion of the tempered coating is 7.22 × 10⁻⁶ over a temperature range from room temperature to 600°C. -6 Around / ℃.

[0073] (3) Apply the above-mentioned tempered coating slurry to the bottom of the dried blank by roller coating, and control the glaze application amount to about 400 g / m². 2 .

[0074] (4) Apply base glaze, inkjet print decorative pattern, apply protective glaze, and dry on the surface of the blank in sequence.

[0075] (5) The processed billet is sent into the roller kiln for firing. The firing temperature is 1220℃ and the firing cycle is 55 minutes.

[0076] (6) After firing, the ceramic sheet is edge-ground to obtain a tempered high-strength impact-resistant ceramic sheet.

[0077] Figure 2 The XRD phase analysis spectra of the bottom surfaces of the tempered ceramic thin plate prepared in Example 2 and the untempered ceramic thin plate with the same green body formulation are shown in the figure. It can be seen from the figure that the phase composition before and after tempering is basically the same, indicating that the tempered coating and the ceramic thin plate belong to the same formulation system, and therefore have excellent matching and bonding, similar to the stress redistribution achieved in tempered glass without changing the composition.

[0078] Performance test results: The tempered coating thickness of the obtained ceramic sheet was approximately 0.4 mm, and its flexural strength was 79.32 MPa, while the strength of the untempered ceramic sheet was 59.93 MPa. These results demonstrate that, while maintaining the stability of the key performance parameters (coefficient of thermal expansion) of the green body, reasonable adjustments to the raw material ratio can also achieve excellent reinforcing effects.

[0079] Comparative Example 1

[0080] (1) The formulation and preparation of the ceramic thin slab blank powder are exactly the same as in Example 2 (thermal expansion coefficient 8.15×10). -6 (around / ℃).

[0081] (2) Prepare a coating slurry with a thermal expansion coefficient similar to that of the blank. The raw material composition (mass percentage) is: 7% kaolin, 25% clay, 25% sodium feldspar, 10% potassium feldspar, 15% potassium-sodium sand, 5% bentonite, 3% wollastonite, and 10% brick powder. The thermal expansion coefficient of the coating in the temperature range of room temperature to 600℃ is 8.08 × 10⁻⁶. -6 Around / ℃.

[0082] (3) Using the same process as in Example 1, this slurry was applied to the bottom of the blank by roller coating, and the coating thickness after firing was controlled to be about 0.27 mm.

[0083] Performance test results: The bending strength of the prepared ceramic thin plate is 61.75 MPa, the strength of the untempered ceramic thin plate is 59.93 MPa, and the impact resistance is 2.56 kJ / m. 2 The improvement in strength and impact resistance is not significant. This indicates that if the thermal expansion coefficients of the tempered coating and the blank are similar, an effective "surface compressive stress + central tensile stress" structure cannot be formed, and the reinforcing effect is significantly weakened.

[0084] Comparative Example 2

[0085] (1) The formulation and preparation of the ceramic thin slab blank powder are exactly the same as in Example 2 (thermal expansion coefficient 8.15×10). -6 (around / ℃).

[0086] (2) Prepare a coating slurry with a thermal expansion coefficient greater than that of the blank. Its raw material composition (mass percentage) is: 7% kaolin, 18% clay, 28% sodium feldspar, 15% potassium feldspar powder, 15% potassium-sodium sand, 5% bentonite, 2% wollastonite, and 10% brick powder. The thermal expansion coefficient of the coating in the temperature range of room temperature to 600℃ is 8.34 × 10⁻⁶. -6 Around / ℃.

[0087] (3) Using the same process as in Example 1, the slurry was rolled onto the bottom of the blank, and the coating thickness after firing was controlled to be about 0.28 mm.

[0088] Performance test results: The bending strength of the obtained ceramic sheet was 52.85 MPa, which is lower than that of the untempered ceramic sheet. This is because the coefficient of thermal expansion of the coating is greater than that of the sheet blank, creating pre-tension stress on the surface, making it more prone to fracture and reducing strength when subjected to external force.

[0089] Comparative Example 3

[0090] (1) The formulation and preparation of the ceramic thin slab blank powder are exactly the same as in Example 1 (thermal expansion coefficient 8.22×10). -6 (around / ℃).

[0091] (2) A coating slurry with a coefficient of thermal expansion lower than that of the ceramic slab body, but with a large difference in the coefficients of thermal expansion, is prepared. Its raw material composition (mass percentage) is: 9% kaolin, 28% clay, 24% sodium feldspar, 15% potassium feldspar, 10% potassium-sodium sand, 7% bentonite, 2% wollastonite, and 5% brick powder. The coefficient of thermal expansion of this coating in the temperature range of room temperature to 600℃ is 7.01 × 10⁻⁶. -6 At approximately ℃, the difference in thermal expansion coefficient between the solid and the billet reaches 1.21 × 10⁻⁶. -6 / ℃.

[0092] (3) Using the same process as in Example 1, the slurry was rolled onto the bottom of the blank, and the coating thickness after firing was controlled to be about 0.28 mm.

[0093] Results: The obtained ceramic sheet has a flexural strength of 103.25 MPa, showing a significant increase in strength. However, due to the large compressive stress applied by the coating, the ceramic sheet underwent significant bulging deformation after firing, resulting in poor flatness.

Claims

1. A tempered, high-strength, impact-resistant ceramic sheet, characterized in that: The tempered high-strength and impact-resistant ceramic sheet includes a ceramic sheet blank and a tempered coating obtained by firing a tempered coating slurry on the surface of the ceramic sheet blank away from the decorative glaze layer. The mineral composition of the ceramic thin slab body includes, by mass percentage: potassium feldspar 14%~16%, clay 24%~28%, potassium sodium sand 11%~13%, kaolin 10%~12%, black talc 1%~2%, bentonite 3%~5%, sodium feldspar 14%~16%, wollastonite 9%~11%, and brick powder 5%~6%; the chemical composition of the brick powder includes, by mass percentage: SiO2 72%~74%, Al2O3 17%~19%, Fe2O3 0.8%~1.5%, TiO2 0.1%~0.5%, CaO 0.4%~0.8%, MgO 0.8%~1.2%, K2O 2.4%~2.8%, and Na2O 2.6%~3.0%; the coefficient of thermal expansion of the ceramic thin slab body in the temperature range from room temperature to 600℃ is 8.15×10⁻⁶. -6 / ℃~8.25×10 -6 / ℃; The mineral composition of the tempered coating includes, by mass percentage: 16%~20% potassium feldspar, 8%~12% water-milled potassium feldspar, 22%~30% clay, 8%~12% bentonite, 14%~18% kaolinite, 6%~10% wollastonite, 2%~4% calcined talc, and 10%~14% sodium feldspar; The coefficient of thermal expansion of the tempered coating in the temperature range of room temperature to 600℃ is 7.12×10⁻⁶. -6 / ℃~7.25×10 -6 / ℃, and the difference in the coefficient of thermal expansion between the ceramic slab and the tempered coating is no higher than 1.2×10. -6 / ℃; the specific gravity of the tempered coating slurry is 1.6~1.7 g / cm³. 3 The application rate is 300~400 g / m 2 The thickness of the tempered coating ranges from 0.08 to 0.4 mm.

2. The tempered high-strength impact-resistant ceramic thin plate according to claim 1, characterized in that, The chemical composition of the ceramic thin slab blank includes, by mass percentage: SiO2 65%~67%, Al2O3 18%~20%, Fe2O3 0.7%~0.8%, TiO2 0.2%~0.3%, CaO 3.5%~4.0%, MgO 0.6%~0.8%, K2O 2.0%~2.2%, Na2O 1.8%~2.0%, and loss on ignition 4.5%~5.5%.

3. The tempered high-strength impact-resistant ceramic thin plate according to claim 1, characterized in that, The chemical composition of the tempered coating includes, by mass percentage: SiO2 55%~60%, Al2O3 20%~25%, Fe2O3 0.5%~1.0%, TiO2 0.1%~0.3%, CaO 3%~5%, MgO 1%~3%, K2O 4%~5%, Na2O 2%~4%, and loss on ignition 5%~7%.

4. The tempered high-strength impact-resistant ceramic thin plate according to claim 1, characterized in that, The firing temperature is 1180~1220℃, and the firing cycle is 40~60min.

5. The method for preparing a tempered high-strength impact-resistant ceramic thin plate according to any one of claims 1 to 4, characterized in that, The preparation method includes the following steps: The ceramic slab is dried. The mineral composition of the ceramic slab includes, by mass percentage: potassium feldspar 14%–16%, clay 24%–28%, potassium sodium sand 11%–13%, kaolin 10%–12%, black talc 1%–2%, bentonite 3%–5%, sodium feldspar 14%–16%, wollastonite 9%–11%, and brick powder 5%–6%. The chemical composition of the brick powder includes, by mass percentage: SiO2 72%–74%, Al2O3 17%–19%, Fe2O3 0.8%–1.5%, TiO2 0.1%–0.5%, CaO 0.4%–0.8%, MgO 0.8%–1.2%, K2O 2.4%–2.8%, and Na2O 2.6%–3.0%. The coefficient of thermal expansion of the ceramic slab in the temperature range of room temperature to 600℃ is 8.15 × 10⁻⁶. -6 / ℃~8.25×10 -6 / ℃; A tempered coating slurry is applied to the surface of the dried ceramic slab away from the decorative glaze layer. The mineral composition of the tempered coating obtained by firing the slurry includes, by mass percentage: 16%–20% potassium feldspar, 8%–12% water-milled potassium feldspar, 22%–30% clay, 8%–12% bentonite, 14%–18% kaolinite, 6%–10% wollastonite, 2%–4% calcined talc, and 10%–14% sodium feldspar. The coefficient of thermal expansion of the tempered coating is 7.12 × 10⁻⁶ in the temperature range of room temperature to 600°C. -6 / ℃~7.25×10 -6 / ℃, and the difference in the coefficient of thermal expansion between the ceramic slab and the tempered coating is no higher than 1.2×10. -6 / ℃; the specific gravity of the tempered coating slurry is 1.6~1.7 g / cm³. 3 The application rate is 300~400 g / m 2 ; The ceramic sheet blank after applying the tempering coating slurry is fired to obtain a tempered high-strength and impact-resistant ceramic sheet.

6. The preparation method according to claim 5, characterized in that, The tempered coating slurry is applied by roller coating.

7. The preparation method according to claim 5, characterized in that, The preparation method further includes the following steps: before firing, sequentially applying a base glaze, inkjet printing ink decorative patterns, and applying a protective glaze to the surface of the ceramic slab blank after applying a tempered coating slurry.

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