A low-expansion impact-resistant ceramic plate and a method for manufacturing the same

Abstract

The present application belongs to the field of building ceramics, and relates to a low-expansion impact-resistant ceramic plate and a preparation method thereof. The low-expansion impact-resistant ceramic plate comprises a low-expansion ceramic body and a reinforced layer prepared by using a reinforced slurry on the bottom surface of the low-expansion ceramic body; and the mineral composition of the low-expansion ceramic body comprises, in percentage by mass, 8-12% of fused quartz, 20-35% of spodumene, 15-20% of cordierite, 10-15% of calcined kaolin, 12-20% of calcined talc and 15-22% of bauxite. The present application can greatly improve the low-expansion heat-shock resistance and mechanical impact resistance of traditional ceramic plates, overcome the problem of brittle fracture of traditional ceramic plates during use, and enhance the use safety of the ceramic plates.

Description

Technical Field

[0001] This invention belongs to the field of building ceramics, and specifically relates to a low-expansion, impact-resistant ceramic plate and its preparation method. Background Technology

[0002] In recent years, with the continuous improvement of living standards, ceramic slabs that combine decorative and functional effects have gradually become a new research and development direction. Ceramic dining tables, heating plates, and constant temperature plates with electromagnetic heating functions are very popular among consumers. However, traditional ceramic slabs have a large coefficient of expansion and high brittleness, resulting in poor resistance to thermal and mechanical shock, which cannot meet performance and usage requirements.

[0003] Currently, the main method for reducing the coefficient of thermal expansion in ceramics is to introduce low-expansion mineral raw materials. Patent CN202310613173.X uses a cordierite system formula to prepare low-expansion ceramic blanks and ceramic plates, reducing the coefficient of thermal expansion to 2.5 × 10⁻⁶. -6 / ℃~3.5×10 -6 / ℃ (20~600℃). Patent CN201810339192.7 introduces the preparation of low-expansion, high-thermal-conductivity ceramic plates using spodumene. Patent CN201810519000.0 uses spodumene, lepidolite, and cordierite as main raw materials to prepare low-expansion, heat-resistant ceramic products. Therefore, existing technologies mainly focus on improving thermal shock resistance, without improving mechanical shock resistance. Consequently, the incomplete performance limits the application of ceramic plates in functional fields.

[0004] While existing technologies have proposed using a backing mesh (glass fiber mesh + epoxy resin) to improve the mechanical impact resistance of ceramic plates, these methods are not heat-resistant and cannot be used in high-temperature environments. Conventional solutions, such as increasing the alumina content of the green body, introducing magnesium aluminum spinel, or introducing silicon carbide whiskers, offer very limited improvement in the mechanical impact resistance of the ceramic product after sintering, and cannot meet the requirements of this invention. Summary of the Invention

[0005] To enable the fabrication of safe and heat-resistant ceramic slabs, this invention aims to develop a ceramic slab that combines thermal shock resistance and mechanical shock resistance, along with its preparation method. This invention significantly improves the low-expansion thermal shock resistance and mechanical shock resistance of traditional ceramic slabs, overcoming the problem of easy cracking during use and enhancing the safety of ceramic slabs.

[0006] In a first aspect, the low-expansion impact-resistant ceramic plate of the present invention comprises a low-expansion ceramic green body and a reinforcing layer prepared by using a reinforcing slurry located on the bottom surface of the low-expansion ceramic green body; the mineral composition of the low-expansion ceramic green body comprises, by mass percentage: 8%~12% fused silica, 20%~35% spodumene, 15%~20% cordierite, 10%~15% calcined kaolin, 12%~20% calcined talc, and 15%~22% bauxite; the raw material composition of the reinforcing slurry comprises, by mass percentage: 25~32 parts aluminum phosphate solution, 20~25 parts alumina, 5~10 parts zirconium oxide, 3~5 parts boron nitride, 3~5 parts carbon fiber, 2~4 parts alumina fiber, 8~12 parts active magnesium oxide, 1~2 parts silane coupling agent, 0.5~1 parts hydrophobic fumed silica powder, and 10~15 parts water.

[0007] In an optional embodiment, the thickness of the low-expansion ceramic preform is 3-9 mm, and the thickness of the reinforcing layer is 0.5-3 mm (preferably 1-3 mm). Preferably, the thickness ratio of the low-expansion ceramic preform to the reinforcing layer is (2-4):1.

[0008] In an optional embodiment, the mass concentration of the aluminum phosphate solution is 40% to 80%.

[0009] In an optional embodiment, the low-expansion impact-resistant ceramic plate further includes a decorative glaze layer on the surface of the low-expansion ceramic body. The surface refers to the side facing away from the reinforcing layer.

[0010] Secondly, the present invention provides a method for preparing the aforementioned low-expansion impact-resistant ceramic plate. The preparation method includes the following steps: weighing raw materials according to the mineral composition of a low-expansion ceramic green body and forming it into a low-expansion ceramic green body; firing the low-expansion ceramic green body to obtain a low-expansion ceramic plate; applying a reinforcing slurry to the bottom surface of the low-expansion ceramic plate to form a reinforcing layer; and curing and solidifying the ceramic plate after applying the reinforcing slurry to obtain the low-expansion impact-resistant ceramic plate; wherein the mineral composition of the low-expansion ceramic green body includes, by mass percentage: 8%~12% fused silica, 20%~35% spodumene, and 15%~20% cordierite. The raw material composition of the reinforcing slurry includes, by mass, 10%~15% calcined kaolin, 12%~20% calcined talc, and 15%~22% bauxite; the raw material composition of the reinforcing slurry includes, by mass, 25~32 parts aluminum phosphate solution, 20~25 parts alumina, 5~10 parts zirconium oxide, 3~5 parts boron nitride, 3~5 parts carbon fiber, 2~4 parts alumina fiber, 8~12 parts active magnesium oxide, 1~2 parts silane coupling agent, 0.5~1 parts hydrophobic fumed silica, and 10~15 parts water.

[0011] In an optional embodiment, the firing temperature is 1100~1180℃ and the firing time is 40~60 min.

[0012] In an optional embodiment, the amount of reinforcing slurry applied is 150~500 g / m³. 2 .

[0013] In an optional embodiment, the curing is to let it stand for 2 to 5 hours at room temperature and humidity of 40% to 60%, and the solidification is to heat it to 140 to 160°C at a heating rate not exceeding 5°C / min and keep it at that temperature for 30 to 60 minutes, and then heat it to 450 to 500°C and keep it at that temperature for 2 to 3 hours.

[0014] In an optional embodiment, the preparation method further includes a step of applying a decorative glaze to the surface of a low-expansion ceramic body before firing.

[0015] In an optional embodiment, the chemical composition of the decorative glaze includes, by mass percentage: SiO2 60%~65%, Al2O3 12%~18%, CaO 4%~6%, MgO 4%~6%, Na2O 3%~5%, K2O 2%~3%, B2O3 3%~5%, ZrO2 1%~2%, Fe2O3+TiO2 <0.5%.

[0016] In optional embodiments, the decorative glaze is applied by spraying, dipping, or inkjet printing, preferably by inkjet printing; more preferably, the specific gravity of the decorative glaze is 1.05~1.20 g / cm³. 3 The glaze application rate is 50~100 g / m². 2 .

[0017] Compared with the prior art, the present invention has the following beneficial effects:

[0018] (1) The present invention designs a novel low-expansion ceramic body formula and uses a post-processing method to set a reinforcing layer on the bottom surface of the body to prepare a low-expansion ceramic plate that is resistant to thermal shock and mechanical shock, thus broadening the application field of ceramic plates.

[0019] (2) The novel ceramic reinforcing agent developed in this invention has a low coefficient of expansion, good heat resistance and impact resistance, which can greatly improve the mechanical impact resistance of traditional ceramic plates, overcome the problem of easy cracking during the use of traditional ceramic plates, and enhance the safety of ceramic plates.

[0020] (3) The novel ceramic reinforcing agent developed in this invention has strong adhesion and good durability. It has a strong bond with the ceramic substrate, a high degree of integration, can be cut arbitrarily with the ceramic substrate, and does not peel off or crack after long-term use.

[0021] (4) The low-expansion impact-resistant ceramic plate developed by this invention is compatible with existing ceramic production processes. The process is simple, and the color of both the ceramic body and the reinforcing layer can be changed according to requirements. Attached Figure Description

[0022] Figure 1 The images show the low-expansion ceramic plate 1A# (right, without reinforcement layer) and the low-expansion impact-resistant ceramic plate 1B# (left, with reinforcement layer) prepared in Example 1.

[0023] Figure 2 The graph shows the mechanical impact resistance test results of the low-expansion impact-resistant ceramic plate 2B# prepared in Example 2.

[0024] Figure 3 The results of the mechanical impact resistance test of the ordinary ceramic plate prepared in Comparative Example 1 are shown in the figure.

[0025] Figure 4 The image shows the cracking pattern of the low-expansion, impact-resistant ceramic plate 5B# prepared in Example 5 during a thermal cycling test. Detailed Implementation

[0026] The present invention is further illustrated by 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.

[0027] Raw materials are weighed according to the mineral composition of the low-expansion ceramic green body and formed into a low-expansion ceramic green body. The mineral composition of the low-expansion ceramic green body includes, by mass percentage: 8%~12% fused silica, 20%~35% spodumene, 15%~20% cordierite, 10%~15% calcined kaolin, 12%~20% calcined talc, and 15%~22% (raw) bauxite.

[0028] Fused silica has a low coefficient of thermal expansion (0.5 × 10⁻⁶). -6 (℃), exhibiting no crystal transformation during high-temperature firing, it demonstrates good thermal shock resistance and effectively improves the wear resistance of the green body. The coefficient of thermal expansion of spodumene is approximately 2.0 × 10⁻⁶. -6 At high temperatures (°C), lithium aluminum silicon low-expansion crystalline phases precipitate, and the sintering temperature of the green body is lowered, making it suitable for low-expansion ceramics fired at low temperatures. Cordierite has an extremely low coefficient of thermal expansion, approximately 0~1.0×10⁻⁶. -6 / ℃, is a core raw material for low-expansion ceramics and can be directly incorporated into the body. Cordierite can also be generated in situ using a raw material ratio of talc + kaolin + alumina. The expansion coefficient of calcined kaolin is approximately 2.0 × 10⁻⁶. -6 At a temperature of / ℃, it can simultaneously increase the density of the green body, indirectly help reduce expansion, and also improve molding performance. The coefficient of thermal expansion of calcined talc is approximately 1.0 × 10⁻⁶. -6At / ℃, calcination produces low-expansion crystalline phases such as enstatite and cordierite, which not only reduce expansion but also improve the heat resistance and stability of the green body. Bauxite promotes the formation of a large amount of mullite, stabilizes the expansion coefficient, and improves the strength and weather resistance of the green body.

[0029] In an optional embodiment, the particle size of fused silica, spodumene, and cordierite is all 325 mesh. Controlling the particle size of the raw materials aims to ensure their uniformity and avoid large deviations in local expansion coefficients.

[0030] Introducing organic reinforcing agents into the green body presents challenges due to the inherent limitations of organic systems, which typically have a temperature resistance not exceeding 300℃. Adding reinforcing components such as aluminum phosphate, alumina, zirconium oxide, boron nitride, carbon fiber, alumina fiber, or activated magnesium oxide to the green body for reinforcement, mixing them with the green body formulation, and then sintering them together, is practically difficult to implement. When ceramic green bodies are fired at 1100–1200℃, the carbon fibers directly burn away, creating pores. Furthermore, while the introduction of some components after high-temperature sintering can refine the grain size and increase the density of the green body to some extent, it does not alter the characteristic of full vitrification; the green body is hard but brittle, with poor mechanical properties.

[0031] In an optional embodiment, the raw materials are weighed according to the mineral composition of the low-expansion ceramic green body formula, and the raw materials are mixed evenly to obtain low-expansion ceramic green body powder. Then, the low-expansion ceramic green body powder is pressed into shape to obtain a low-expansion ceramic green body. The raw material mixing method can be wet ball milling. For example, the low-expansion ceramic green body raw materials, additives, and water are mixed. The additive can be sodium tripolyphosphate. For example, the mass ratio of sodium tripolyphosphate to the mineral composition of the green body can be 0.1%~0.3%, including but not limited to 0.1%, 0.2%, and 0.3%. The forming method includes but is not limited to pressing.

[0032] Then, the billet is dried to obtain a dried billet. The drying process can be carried out by placing the billet at 100~150℃ for 1~2 hours.

[0033] Next, as an optional step, the surface of the dried billet is pretreated. This pretreatment involves polishing the surface of the billet using a grinding disc to make it smoother and denser. The grinding disc is made of sponge or wool felt.

[0034] The dried green body is then fired to obtain low-expansion ceramic plates. These plates can then be fired in a roller kiln. The firing process is carried out at 1100~1180℃ for 40~60 minutes.

[0035] In an optional embodiment, a decorative glaze is applied to the surface of the dried body before firing. The composition of the decorative glaze is not limited and can be any decorative glaze in the art. In an optional embodiment, the decorative glaze is a digital glaze. As an example, but not limited to, the chemical composition of the decorative glaze includes, by mass percentage: SiO2 60%~65%, Al2O3 12%~18%, CaO 4%~6%, MgO 4%~6%, Na2O 3%~5%, K2O 2%~3%, B2O3 3%~5%, ZrO2 1%~2%, Fe2O3 + TiO2 <0.5%. The method of applying the decorative glaze is also not limited. It should be understood that common decorative glaze application methods in the art are applicable to this invention. The method of applying the decorative glaze includes, but is not limited to, spraying, dipping, or inkjet printing.

[0036] Finally, a reinforcing layer is prepared on the bottom surface of the low-expansion ceramic plate, followed by curing and hardening to obtain a low-expansion impact-resistant ceramic plate. For example, a reinforcing agent (reinforcing slurry) is applied to the bottom surface of the low-expansion ceramic plate to prepare the reinforcing layer.

[0037] The raw material composition of the reinforcing slurry includes, by a total mass of 100 parts, 25-32 parts by mass of aluminum phosphate solution (60% mass concentration), 20-25 parts by mass of alumina, 5-10 parts by mass of zirconium oxide, 3-5 parts by mass of boron nitride, 3-5 parts by mass of carbon fiber (0.2-1 mm in diameter), 2-4 parts by mass of alumina fiber (0.5-1 mm in diameter), 8-12 parts by mass of activated magnesium oxide, 1-2 parts by mass of silane coupling agent, 0.5-1 parts by mass of hydrophobic fumed silica powder, and 10-15 parts by mass of deionized water. The aluminum phosphate solution is commercially available. The main solvent of the aluminum phosphate solution is water. The silane coupling agent used in the various examples and comparative examples is silane coupling agent KH560.

[0038] In an optional embodiment, the reinforcing slurry comprises: 25-32 parts by mass of aluminum phosphate solution (60% by mass concentration), 20-25 parts by mass of alumina micro powder (1000-3000 mesh), 5-10 parts by mass of zirconia micro powder (1000-3000 mesh), 3-5 parts by mass of boron nitride micro powder (1000-3000 mesh), 3-5 parts by mass of carbon fiber (0.2-1 mm in diameter), 2-4 parts by mass of alumina fiber (0.5-1 mm in diameter), 8-12 parts by mass of activated magnesium oxide powder, 1-2 parts by mass of silane coupling agent KH560, 0.5-1 parts by mass of hydrophobic fumed silica powder (10-40 nm), and 10-15 parts by mass of deionized water.

[0039] The adhesive consists of: aluminum phosphate solution, which has good fluidity, high bonding strength, good temperature resistance, and low curing shrinkage, forming a magnesium aluminum phosphate complex framework structure after curing; alumina micropowder with good temperature resistance, which can improve the density of the bond; zirconia micropowder, which can improve the thermal shock resistance of the adhesive layer, ensuring that the adhesive layer does not crack due to internal stress during thermal cycling; boron nitride micropowder, which can reduce the expansion coefficient of the adhesive layer, further optimize the stability of thermal cycling, and improve the insulation of the adhesive layer; active magnesium oxide, which can trigger the curing reaction, has a mild reaction, avoids cracking due to excessive curing, and improves the density of the adhesive layer; carbon fiber with high tensile strength can disperse impact force and will not affect the temperature resistance of the adhesive layer after use; alumina fiber has good compatibility with the base material, and works with carbon fiber to improve the mechanical impact resistance and enhance temperature resistance. Silane coupling agent can improve the adhesion and bonding force between the adhesive layer and the ceramic, preventing the adhesive layer from falling off; hydrophobic fumed silica can prevent the sedimentation of fibers and fillers, ensuring uniform adhesive and consistent performance throughout the application.

[0040] Activated magnesium oxide is prepared at a relatively low temperature (around 500°C), resulting in small particle size, a loose and porous structure, numerous surface defects, high reactivity, and strong interfacial bonding. In this invention, the high reactivity of activated magnesium oxide allows for rapid reaction with aluminum phosphate and other materials, significantly shortening the reaction time, achieving room temperature curing, and improving the strength and density of the adhesive layer. Ordinary alumina is prepared at a higher temperature (around 950°C), resulting in larger particle size, a dense crystal structure, fewer surface defects, and strong inertness, making it unsuitable for the formulation system of this invention.

[0041] The reinforcing slurry is applied by roller coating or brushing. In an optional embodiment, the application rate of the reinforcing slurry is 150~500 g / m². 2 .

[0042] The curing process involves allowing the surface to stand for 2-5 hours at room temperature and 40%-60% humidity to dry. The solidification process involves raising the temperature to 140-160℃ (e.g., 150℃) and holding it for 30-60 minutes, while maintaining a heating rate not exceeding 5℃ / min, and then raising the temperature to 450-500℃ (e.g., 500℃) and holding it for 2-3 hours.

[0043] The thickness of the reinforcing layer is 0.5~3 mm (preferably 1~3 mm). If the reinforcing layer is too thin, it cannot effectively absorb and disperse impact energy, resulting in insufficient resistance to mechanical impact. If the reinforcing layer is too thick, the heat dissipation inside the reinforcing layer is not synchronized with the surface, increasing internal stress. During thermal cycling, the adhesive layer itself is prone to cracking or delamination, resulting in insufficient thermal shock resistance.

[0044] The thickness ratio of the low-expansion ceramic body layer to the reinforcing layer is (2~4):1. An unsuitable thickness ratio between the low-expansion ceramic body layer and the reinforcing layer results in two problems: firstly, it cannot effectively disperse mechanical impact energy, leading to poor mechanical impact resistance; secondly, the difference in heat dissipation rates between the inside and outside of the reinforcing layer leads to insufficient thermal shock resistance.

[0045] The thickness of the low-expansion impact-resistant ceramic plate is 4~12 mm.

[0046] The coefficient of thermal expansion (0~500℃) of the low-expansion heat-resistant ceramic plate described in this invention is 2×10⁻⁶. -6 / K~3×10 -6 / K, mechanical impact resistance height 100~120mm (50g steel ball, 2cm diameter).

[0047] In summary, the low-expansion impact-resistant ceramic plate of the present invention has both thermal shock resistance and mechanical shock resistance, achieving no cracks or fissures after 5 or more thermal cycles at 0~500℃, and has mechanical shock resistance ≥5J (a 50g, 20mm diameter steel ball dropped from a height of 1 meter or more onto the ceramic plate without cracks or fissures).

[0048] The following examples further illustrate the present invention in detail. It should also be understood that the following examples are only for further explanation of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made by those skilled in the art based on the above description of the present invention are within the scope of protection of the present invention. The specific process parameters, etc., in the following examples are merely examples within a suitable range; that is, those skilled in the art can make appropriate selections within the appropriate range based on the description herein, and are not intended to be limited to the specific values ​​in the examples below.

[0049] Example 1

[0050] The preparation method of low-expansion impact-resistant ceramic plate includes the following steps:

[0051] Step 1. Weigh the raw materials according to the low-expansion ceramic green body formula, mix them evenly, press them into ceramic green bodies (thickness 3mm), and then dry the pressed ceramic green bodies in an oven at 100℃ for 2 hours to obtain dried green bodies.

[0052] Step 2. Use a wool floppy disk to polish the surface of the dried blank to make the surface of the blank smooth and flat.

[0053] Step 3. Use a high-precision inkjet printer to inkjet print digital glaze onto the polished surface of the blank. The chemical composition of the digital glaze includes, by mass percentage: SiO2 60%, Al2O3 17.6%, CaO 4%, MgO 4%, Na2O 5%, K2O 3%, B2O 35%, ZrO2 1%, Fe2O3 0.2%, TiO2 0.2%. The specific gravity of the digital glaze is 1.05 g / cm³. 3 Glazing amount is 100 g / m 2 .

[0054] Step 4. The blank after inkjet printing digital glaze is fired in a kiln, and after cooling after removal from the kiln, low-expansion ceramic plate 1A# is obtained. The firing temperature is 1100℃ and the firing time is 60 min.

[0055] Step 5. Weigh the raw materials according to the reinforcing slurry formula, mix them evenly, and then apply the reinforcing slurry evenly to the bottom surface of the low-expansion ceramic plate by brushing. The application rate of the reinforcing slurry is 150 g / m². 2 .

[0056] Step 6. After the ceramic plate with the reinforcing slurry is brushed on, it is left to stand for 2 hours under normal temperature and humidity of 40%. Then it is transferred to an oven and heated to 150°C at a heating rate of 5°C / min and held for 30 minutes. The temperature is then increased to 500°C and held for 3 hours. After cooling to room temperature, a low-expansion impact-resistant ceramic plate 1B# with a reinforcing layer (1 mm thick) is obtained.

[0057] Example 2

[0058] The preparation method of low-expansion impact-resistant ceramic plate includes the following steps:

[0059] Step 1. Weigh the raw materials according to the low-expansion ceramic green body formula, mix them evenly, press them into ceramic green bodies (9mm thick), and then dry the pressed ceramic green bodies in an oven at 150℃ for 1 hour to obtain dried green bodies.

[0060] Step 2. Use a sponge-material floppy disk to polish the surface of the dried blank, making the surface of the blank smooth and flat.

[0061] Step 3. Use a high-precision inkjet printer to inkjet print digital glaze onto the polished surface of the blank. The chemical composition of the digital glaze includes, by mass percentage: SiO2 65%, Al2O3 14%, CaO 5.6%, MgO 6%, Na2O 3%, K2O 2%, B2O3 3%, ZrO2 1%, Fe2O3 0.2%, TiO2 0.2%. The specific gravity of the digital glaze is 1.20 g / cm³. 3 Glazing amount is 50 g / m 2 .

[0062] Step 4. The blank after inkjet printing digital glaze is fired in a kiln, and after cooling after removal from the kiln, low-expansion ceramic plate 2A# is obtained. The firing temperature is 1180℃ and the firing time is 40min.

[0063] Step 5. Weigh the raw materials according to the reinforcing slurry formula, mix them evenly, and then apply the reinforcing slurry evenly to the bottom surface of the low-expansion ceramic plate by brushing. The application rate of the reinforcing slurry is 500 g / m². 2 .

[0064] Step 6. After the ceramic plate with the reinforcing slurry is brushed on, it is left to stand for 5 hours at room temperature and 60% humidity. Then, it is transferred to an oven and heated to 150℃ at a rate of 5℃ / min and held for 60 minutes. The temperature is then increased to 500℃ and held for 2 hours. After cooling to room temperature, a low-expansion impact-resistant ceramic plate 2B# with a reinforcing layer (thickness 3 mm) is obtained.

[0065] Example 3

[0066] The preparation method of low-expansion impact-resistant ceramic plate includes the following steps:

[0067] Step 1. Weigh the raw materials according to the low-expansion ceramic green body formula, mix them evenly, press them into ceramic green bodies (4mm thick), and then dry the pressed ceramic green bodies in an oven at 100℃ for 2 hours to obtain dried green bodies.

[0068] Step 2. Use a wool floppy disk to polish the surface of the dried blank to make the surface of the blank smooth and flat.

[0069] Step 3. Use a high-precision inkjet printer to inkjet print digital glaze onto the polished surface of the blank. The chemical composition of the digital glaze includes, by mass percentage: SiO2 60%, Al2O3 17.6%, CaO 4%, MgO 4%, Na2O 5%, K2O 3%, B2O 35%, ZrO2 1%, Fe2O3 0.2%, TiO2 0.2%. The specific gravity of the digital glaze is 1.05 g / cm³. 3 Glazing amount is 100 g / m 2 .

[0070] Step 4. The blank after inkjet printing digital glaze is fired in a kiln, and after cooling after removal from the kiln, low-expansion ceramic plate 3A# is obtained. The firing temperature is 1100℃ and the firing time is 60 min.

[0071] Step 5. Weigh the raw materials according to the reinforcing slurry formula, mix them evenly, and then apply the reinforcing slurry evenly to the bottom surface of the low-expansion ceramic plate by brushing. The application rate of the reinforcing slurry is 325 g / m². 2 .

[0072] Step 6. After the ceramic plate with the reinforcing slurry is brushed on, it is left to stand for 2 hours under normal temperature and humidity of 40%. Then it is transferred to an oven and heated to 150°C at a heating rate of 5°C / min and held for 30 minutes. The temperature is then increased to 500°C and held for 3 hours. After cooling to room temperature, a low-expansion impact-resistant ceramic plate 3B# with a reinforcing layer (2 mm thick) is obtained.

[0073] Table 1. Composition of the green body formula

[0074] .

[0075] Table 2 Composition of reinforced slurry formulation

[0076] .

[0077] Example 4

[0078] The process is essentially the same as in Example 1, except that the blank thickness is 3 mm and the reinforcing layer thickness is 0.5 mm. This yields a low-expansion, impact-resistant ceramic plate 4B#.

[0079] Example 5

[0080] The process is essentially the same as in Example 2, except that the blank thickness is 9 mm and the reinforcing layer thickness is 4 mm. This yields a low-expansion, impact-resistant ceramic plate 5B#.

[0081] Example 6

[0082] The process is basically the same as in Example 1, except that spodumene in the low-expansion green body formulation of Example 1 is replaced with cordierite. Steps (4) and (6) respectively prepare low-expansion ceramic plate 6A# and low-expansion impact-resistant ceramic plate 6B#.

[0083] Comparative Example 1

[0084] The preparation method of ordinary ceramic plates includes the following steps:

[0085] Step 1. Weigh the raw materials according to the ordinary ceramic body formula, mix them evenly, and press them into ceramic bodies (thickness 4mm, 12mm). Then, dry the pressed ceramic bodies in an oven at 150℃ for 1 hour to obtain dried bodies. The chemical composition of the ordinary ceramic body includes, by mass percentage: SiO2 61.7%, Al2O3 22.3%, Fe2O3 0.9%, TiO2 0.2%, CaO 3.55%, MgO 0.6%, K2O 3.1%, Na2O 1.35%, IL 6.3%. The mineral composition of the ordinary ceramic body includes, by mass percentage: sodium feldspar 21%, potassium feldspar 6%, Hesheng white sand 12%, washed clay 18.5%, Jingkaolin 4%, Zhongshan black mud 2%, high-white fine clay 30%, calcined alumina 2%, calcined talc 2.2%, and high-white bentonite 2.3%.

[0086] Table 3 Mineral Chemical Composition

[0087]

[0088] Step 2. Use a sponge-material floppy disk to polish the surface of the dried blank, making the surface of the blank smooth and flat.

[0089] Step 3. Use a high-precision inkjet printer to inkjet print digital glaze onto the polished surface of the blank. The chemical composition of the digital glaze includes, by mass percentage: SiO2 65%, Al2O3 12%, CaO 6%, MgO 5.8%, Na2O 3.8%, K2O 2%, B2O3 4%, ZrO2 1%, Fe2O3 0.2%, TiO2 0.2%. The specific gravity of the digital glaze is 1.15 g / cm³. 3 Glazing amount is 70 g / m 2 .

[0090] Step 4. The blank after inkjet printing digital glaze is fired in a kiln, and after cooling, ordinary ceramic slabs are obtained. The firing temperature is 1180℃ and the firing time is 40 minutes.

[0091] Comparative Example 2

[0092] The process is essentially the same as in Example 1, except that the raw material composition of the reinforcing slurry includes, by weight, 19.5 parts aluminum phosphate solution (60%), 33 parts 1000-mesh alumina, 10 parts 1000-mesh zirconium oxide, 5 parts 1000-mesh boron nitride, 3 parts carbon fiber (1 mm in diameter), 4 parts alumina fiber (0.5 mm in diameter), 12 parts activated magnesium oxide, 1 part silane coupling agent, 0.5 parts hydrophobic fumed silica, and 12 parts deionized water. Low-expansion, impact-resistant ceramic plate 7B# was prepared.

[0093] Comparative Example 3

[0094] The process is essentially the same as in Example 1, except that the raw material composition of the reinforcing slurry includes, by weight, 39.5 parts aluminum phosphate solution (60%), 13 parts 1000-mesh alumina, 10 parts 1000-mesh zirconium oxide, 5 parts 1000-mesh boron nitride, 3 parts carbon fiber (1 mm in diameter), 4 parts alumina fiber (0.5 mm in diameter), 12 parts activated magnesium oxide, 1 part silane coupling agent, 0.5 parts hydrophobic fumed silica, and 12 parts deionized water. Low-expansion, impact-resistant ceramic plate 8B# was prepared.

[0095] Comparative Example 4

[0096] The process is basically the same as in Example 1, except that zirconium oxide is replaced with cordierite powder and boron nitride is replaced with mica powder in the reinforcing slurry formulation, resulting in low-expansion impact-resistant ceramic plate 9B#.

[0097] Comparative Example 5

[0098] The process is basically the same as in Example 1, except that the short-cut carbon fibers in the reinforcing slurry formulation are replaced with alumina fibers to obtain low-expansion impact-resistant ceramic plate 10B#.

[0099] Performance testing

[0100] The thermal cycling test method involves placing a 300 mm × 300 mm ceramic plate in a muffle furnace and heating it to the set temperature. After holding it at that temperature for 30 minutes, the plate is immediately removed and placed in 0°C ice water. The ceramic plate is then observed for cracking or the appearance of fissures. This heating-holding-rapid cooling process is repeated multiple times. The number of cycles is recorded when cracks or fissures appear. The mechanical impact resistance test method involves placing a 300 mm × 300 mm ceramic plate on a wooden block. A 50 g steel ball with a diameter of 2 cm is used. The test begins at a height of 30 cm, with increments of 10 cm. A steel ball is dropped freely onto the center of the ceramic plate, and the impact height is recorded as the number of times the plate shatters or cracks. The results are shown in Table 4.

[0101] Table 4 Performance Test Results

[0102]

[0103] The data in Table 4 show that the ordinary ceramic plates exhibit poor thermal cycling resistance and mechanical impact resistance. Ordinary ceramic plates with thicknesses of 4mm and 12mm cracked after just one thermal cycling test, and the 12mm thick ordinary ceramic plate only achieved a mechanical impact resistance height of 50cm. Low-expansion ceramic plates 1A#, 2A#, and 3A# showed significantly improved thermal cycling resistance, with no cracks appearing after 20 thermal cycling tests, but their impact resistance was poor. Low-expansion impact-resistant ceramic plates 1B#, 2B#, and 3B# showed significantly improved thermal cycling resistance and mechanical impact resistance, with the latter reaching a mechanical impact resistance height of 130cm. Low-expansion impact-resistant ceramic plates 4B# and 5B# failed to meet the requirements of this invention in terms of thermal cycling resistance and mechanical impact resistance due to a mismatch between the thickness of the green body and the reinforcing layer. The green bodies of the low-expansion ceramic plate 6A# and the low-expansion impact-resistant ceramic plate 6B# adopt a cordierite formulation system and do not contain spodumene components. Their thermal cycling performance does not meet the requirements set by this invention.

[0104] As can be seen from Comparative Example 2, due to the low aluminum phosphate content, there is too much filler and too little adhesive, resulting in insufficient bonding strength to other components. This leads to an insufficient number of aluminum magnesium phosphate skeleton structures formed in the reinforcing layer, resulting in a loose structure at high temperatures. Consequently, the impact resistance of the final reinforcing layer is significantly reduced.

[0105] As can be seen from Comparative Example 3, the high aluminum phosphate content leads to greater shrinkage during curing of the adhesive layer, reduced thermal cycling performance, slower initial curing speed, and poorer water resistance. In humid environments, it is prone to detachment from the ceramic substrate.

[0106] As can be seen from Comparative Example 4, the increased internal stress of the adhesive layer in the thermal cycling experiment, coupled with its mismatch with the coefficient of thermal expansion of the substrate, led to a significant decrease in thermal shock resistance. This is because zirconium oxide can significantly improve thermal shock resistance, preventing the adhesive layer from generating internal stress during thermal cycling. Boron nitride can reduce the coefficient of thermal expansion of the adhesive layer, matching it with the ceramic substrate and further optimizing thermal cycling stability. After changing the material composition, the increased internal stress of the adhesive layer in the thermal cycling experiment, coupled with its mismatch with the coefficient of thermal expansion of the substrate, resulted in a significant decrease in thermal shock resistance and also had a certain negative impact on mechanical shock resistance.

[0107] As can be seen from Comparative Example 5, replacing chopped carbon fibers with alumina fibers makes the adhesive layer prone to cracking under mechanical impact. The main reason is that carbon fibers have high strength and can form a three-dimensional mesh-like reinforcement within the adhesive layer, effectively absorbing the energy of mechanical impact. The main function of alumina fibers is to improve the temperature resistance of the adhesive layer, reduce thermal stress, and prevent thermal shock cracking. Only by using carbon fibers and alumina fibers in synergy can the thermal shock resistance and mechanical impact resistance requirements of this invention be simultaneously met.

Claims

1. A low-expansion, impact-resistant ceramic plate, characterized in that, The low-expansion impact-resistant ceramic plate comprises a low-expansion ceramic green body and a reinforcing layer prepared by a reinforcing slurry on the bottom surface of the low-expansion ceramic green body. The preparation method of the low-expansion impact-resistant ceramic plate includes the following steps: weighing raw materials according to the mineral composition of the low-expansion ceramic green body and forming it into a low-expansion ceramic green body; firing the low-expansion ceramic green body to obtain a low-expansion ceramic plate; applying a reinforcing slurry to the bottom surface of the low-expansion ceramic plate to form the reinforcing layer; and curing and solidifying the ceramic plate after applying the reinforcing slurry to obtain the low-expansion impact-resistant ceramic plate. The mineral composition of the low-expansion ceramic green body includes, by mass percentage: 8%~12% fused silica, spodumene... The raw material composition of the reinforcing slurry includes: 20%~35% aluminum phosphate solution, 15%~20% cordierite, 10%~15% calcined kaolin, 12%~20% calcined talc, and 15%~22% bauxite; the raw material composition of the reinforcing slurry includes: 25~32 parts by weight of aluminum phosphate solution, 20~25 parts by weight of alumina, 5~10 parts by weight of zirconium oxide, 3~5 parts by weight of boron nitride, 3~5 parts by weight of carbon fiber, 2~4 parts by weight of alumina fiber, 8~12 parts by weight of activated magnesium oxide, 1~2 parts by weight of silane coupling agent, 0.5~1 parts by weight of hydrophobic fumed silica, and 10~15 parts by weight of water; the thickness of the low-expansion ceramic green body is 3~9 mm. The thickness of the reinforcing layer is 0.5~3 mm; the thickness ratio of the low-expansion ceramic body to the reinforcing layer is (2~4):1; the curing is to stand for 2~5 h at room temperature and humidity of 40%~60%; the solidification is to heat to 140~160℃ and hold for 30~60 min at a heating rate not higher than 5℃ / min, and then heat to 450~500℃ and hold for 2~3 h.

2. The low-expansion impact-resistant ceramic plate according to claim 1, characterized in that, The mass concentration of the aluminum phosphate solution is 40%~80%.

3. The low-expansion impact-resistant ceramic plate according to claim 1, characterized in that, The low-expansion impact-resistant ceramic plate also includes a decorative glaze layer on the surface of the low-expansion ceramic body.

4. The method for preparing the low-expansion impact-resistant ceramic plate according to any one of claims 1 to 3, characterized in that, The preparation method includes the following steps: weighing raw materials according to the mineral composition of the low-expansion ceramic green body and forming it into a low-expansion ceramic green body; firing the low-expansion ceramic green body to obtain a low-expansion ceramic plate; applying a reinforcing slurry to the bottom surface of the low-expansion ceramic plate to form a reinforcing layer; curing and solidifying the ceramic plate after applying the reinforcing slurry to obtain a low-expansion impact-resistant ceramic plate; wherein, the mineral composition of the low-expansion ceramic green body includes, by mass percentage: 8%~12% fused silica, 20%~35% spodumene, 15%~20% cordierite, 10%~15% calcined kaolin, and calcined slip. The raw materials of the reinforcing slurry are: 12%~20% stone and 15%~22% bauxite; the raw material composition of the reinforcing slurry includes: 25~32 parts by mass of aluminum phosphate solution, 20~25 parts by mass of alumina, 5~10 parts by mass of zirconium oxide, 3~5 parts by mass of boron nitride, 3~5 parts by mass of carbon fiber, 2~4 parts by mass of alumina fiber, 8~12 parts by mass of active magnesium oxide, 1~2 parts by mass of silane coupling agent, 0.5~1 parts by mass of hydrophobic fumed silica, and 10~15 parts by mass of water; the curing is to stand for 2~5 hours at room temperature and 40%~60% humidity; the solidification is to heat to 140~160℃ and hold for 30~60 minutes at a heating rate not exceeding 5℃ / min, and then heat to 450~500℃ and hold for 2~3 hours.

5. The preparation method according to claim 4, characterized in that, The firing temperature is 1100~1180℃, and the firing time is 40~60 min.

6. The preparation method according to claim 4, characterized in that, The application rate of the reinforcing slurry is 150~500 g / m³. 2 .

7. The preparation method according to claim 4, characterized in that, The preparation method also includes the step of applying a decorative glaze to the surface of a low-expansion ceramic body before firing.

8. The preparation method according to claim 7, characterized in that, The decorative glaze can be applied by spraying, dipping, or inkjet printing; the specific gravity of the decorative glaze is 1.05~1.20 g / cm³. 3 The glaze application rate is 50~100 g / m². 2 .

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