Glass ceramic, glass ceramic manufacturing method and household appliance

Abstract

The invention discloses microcrystalline glass, a microcrystalline glass manufacturing method and a household appliance, and relates to the technical field of microcrystalline glass manufacturing, the surface roughness of the microcrystalline glass is greater than or equal to 0.8 [mu] m and less than or equal to 2.0 [mu] m, and the Mohs hardness of the microcrystalline glass is greater than or equal to 6.5 and less than or equal to 8.0. The microcrystalline glass provided by the invention can have better usability.

Description

Technical Field

[0001] The present invention relates to the technical field of glass-ceramics manufacturing, and particularly to a glass-ceramic, a method for manufacturing the glass-ceramic, and a household appliance. Background Art

[0002] Due to the characteristics of low coefficient of thermal expansion and resistance to thermal shock of glass-ceramics, they are often used in household appliances and used as the panels of household appliances; for example, glass-ceramics can be used as the panels of induction cookers, radiant cookers, gas stoves, and ovens. Among the above household appliances, especially in Europe, induction cookers and radiant cookers are widely used in the decoration of open kitchens.

[0003] When a user uses an induction cooker or a radiant cooker, different cooking utensils, such as baking trays, cookware, and ceramic pots, may be dragged and rubbed on the panel of the induction cooker or the radiant cooker, causing scratches on the surface of the glass-ceramic serving as the panel; the user may even directly cut food on the surface of the glass-ceramic, and in this way, the glass-ceramic will also rub against the knife, resulting in more serious scratches.

[0004] On the other hand, during the food heating process, water, oil, and food may overflow from the cooking utensils placed on the panel and spill onto the glass-ceramic panel. It may be difficult to clean the glass-ceramic after being contaminated.

[0005] To make the panel more scratch-resistant, it is necessary to increase the hardness of the panel; to improve the cleanability of the panel, it is necessary to reduce the roughness of the panel. However, the glass-ceramic serving as the panel often cannot have high hardness while having low roughness. Therefore, a glass-ceramic that takes into account both hardness and roughness is needed to improve the usability of the glass-ceramic. Summary of the Invention

[0006] The main object of the present invention is to propose a glass-ceramic, a method for manufacturing the glass-ceramic, and a household appliance, aiming to improve the usability of the glass-ceramic.

[0007] To achieve the above object, the glass-ceramic proposed by the present invention has a surface roughness greater than or equal to 0.8 μm and less than or equal to 2.0 μm, and a Mohs hardness greater than or equal to 6.5 and less than or equal to 8.0.

[0008] The present invention also proposes a method for manufacturing a glass-ceramic, including:

[0009] Performing gradient sandblasting on the surface of the semi-finished glass-ceramic to form a first work-in-progress with a surface roughness greater than or equal to 2.5 μm and less than or equal to 3.0 μm;

[0010] Etching the first work-in-progress with an etching solution to form a second work-in-progress having strengthened micropores with pore diameters greater than or equal to 10 μm and less than or equal to 30 μm on the surface;

[0011] Polish the surface of the second work-in-progress with a composite polishing liquid to form the finished product of the microcrystalline glass; the surface roughness of the finished product is greater than or equal to 0.8 μm and less than or equal to 2.0 μm, and the Mohs hardness is greater than or equal to 6.5 and less than or equal to 8.0.

[0012] In some embodiments, the abrasive materials for the gradient sandblasting include a first abrasive material, a second abrasive material, and a third abrasive material; wherein, the mesh number of the first abrasive material is greater than or equal to 45 mesh and less than or equal to 55 mesh, the mesh number of the second abrasive material is greater than or equal to 75 mesh and less than or equal to 85 mesh, and the mesh number of the third abrasive material is greater than or equal to 115 mesh and less than or equal to 125 mesh.

[0013] In some embodiments, the raw material of the first abrasive material is Al2O3, the raw material of the second abrasive material is SiC, and the raw material of the third abrasive material is ZrO2; and / or

[0014] The molar fraction of the first abrasive material is greater than or equal to 55% and less than or equal to 65%, the molar fraction of the second abrasive material is greater than or equal to 20% and less than or equal to 30%, and the molar fraction of the third abrasive material is greater than or equal to 5% and less than or equal to 20%.

[0015] In some embodiments, the linear velocity of the abrasive materials for the gradient sandblasting relative to the surface of the semi-finished product is greater than or equal to 10 m / s and less than or equal to 20 m / s.

[0016] In some embodiments, the etching solution includes hydrofluoric acid with a molar fraction greater than or equal to 5% and less than or equal to 7%, nitric acid with a molar fraction greater than or equal to 11% and less than or equal to 13%, and sodium fluorosilicate with a molar fraction greater than or equal to 3% and less than or equal to 4%.

[0017] In some embodiments, the method of using the etching solution to etch the first work-in-progress to form a second work-in-progress with strengthened micropores having a pore diameter greater than or equal to 10 μm and less than or equal to 30 μm on the surface includes:

[0018] Place the first work-in-progress in the etching solution for greater than or equal to 8 minutes and less than or equal to 12 minutes, and keep the temperature of the etching solution greater than or equal to 50 °C and less than or equal to 53 °C, and simultaneously perform ultrasonic treatment to etch the first work-in-progress to form a second work-in-progress with strengthened micropores having a pore diameter greater than or equal to 10 μm and less than or equal to 30 μm on the surface.

[0019] In some embodiments, the composite polishing liquid comprises cerium oxide with a molar fraction greater than or equal to 13% and less than or equal to 15% and diamond with a molar fraction greater than or equal to 1% and less than or equal to 3%; wherein, the particle size of the cerium oxide is greater than or equal to 0.1 μm and less than or equal to 0.2 μm, and the particle size of the diamond is 50 nm.

[0020] In some embodiments, the step of polishing the surface of the second workpiece with the composite polishing liquid to form the finished product of the glass-ceramics comprises:

[0021] Under a pressure of 0.7 MPa and at a polishing speed of 25 - 35 m / s, the surface of the second workpiece is polished with the composite polishing liquid for a duration greater than or equal to 10 minutes and less than or equal to 15 minutes to form the finished product.

[0022] The present invention also provides a household appliance, which comprises the above-mentioned glass-ceramics, or comprises glass-ceramics manufactured by the above-mentioned glass-ceramics manufacturing method.

[0023] The technical solution of the present invention provides glass-ceramics with a smaller surface roughness (greater than or equal to 0.8 μm and less than or equal to 2.0 μm) and a greater hardness (greater than or equal to 6.5 and less than or equal to 8.0). The smoother glass-ceramics can make it easier to clean the glass-ceramics; the greater hardness of the glass-ceramics can ensure that the glass-ceramics are not scratched or damaged under the impact of the cookware. For the existing glass-ceramics, when the surface roughness is less than or equal to 2.0 μm, the Mohs hardness is often less than 6.5; when the Mohs hardness is greater than or equal to 6.5, the surface roughness is greater than 2.0 μm. Therefore, the glass-ceramics provided by the present invention take into account the easy cleanability and scratch resistance of the glass-ceramics, thereby improving the usability of the glass-ceramics. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on the structures shown in these drawings.

[0025] Figure 1 It is a flowchart of the first embodiment of the glass-ceramics manufacturing method provided by the present invention;

[0026] Figure 2 It is a flowchart of the second embodiment of the glass-ceramics manufacturing method provided by the present invention.

[0027] The realization, functional features and advantages of the object of the present invention will be further described with reference to the embodiments and the drawings. Specific Embodiments

[0028] The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts fall within the scope of protection of the present invention.

[0029] If there are descriptions involving "first", "second", etc. in the embodiments of the present invention, such descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one such feature. Additionally, if "and / or" or "and / or" appears throughout the text, its meaning includes three parallel scenarios. Taking "A and / or B" as an example, it includes Scenario A, or Scenario B, or the scenario where both A and B are satisfied simultaneously. Furthermore, the technical solutions between various embodiments can be combined with each other, but it must be based on the ability of those of ordinary skill in the art to implement. When the combination of technical solutions results in contradictions or inability to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0030] The present invention provides a glass-ceramic with a surface roughness greater than or equal to 0.8 μm and less than or equal to 2.0 μm, and a Mohs hardness greater than or equal to 6.5 and less than or equal to 8.0. Among them, the surface roughness can be the arithmetic mean deviation of the profile (Roughness Average Arithmetic, Ra).

[0031] The glass-ceramic has grains. When the hardness of the glass-ceramic is high, the brittleness of the glass-ceramic is also high. When performing sandblasting process on the surface of the glass-ceramic, it is easy to cause the whole grain to fall off, or the brittle crack to spread, resulting in an increase in the surface roughness or a decrease in the hardness of the glass-ceramic. In the glass-ceramic industry, it is difficult to simultaneously meet the requirements of a small surface roughness and a high hardness.

[0032] For example, the mainstream products of glass-ceramics (such as Corning Glass and Schott ) to achieve a Mohs hardness greater than or equal to 7.0, the surface roughness is forced to be maintained at Ra greater than or equal to 2.5 μm (data source: Journal of Non-Crystalline Solids, 2023, Vol. 601).

[0033] Some chemical strengthening processes can make Ra ≤ 1.0 μm, but the Mohs hardness is only between 6.0 and 6.5.

[0034] Some sandblasting strengthening processes can make the Mohs hardness of the glass-ceramics reach 7.5, but Ra ≥ 3.0 μm.

[0035] It can be seen that it is difficult to make the surface roughness of the glass-ceramics less than or equal to 2.0 μm while also making the Mohs hardness greater than or equal to 6.5.

[0036] The glass-ceramics surface with large roughness has more microcracks, grain boundary gaps, and unclosed pores, allowing oil stains to penetrate through capillary action, resulting in the penetration of oil stains into the glass-ceramics and making it difficult to clean.

[0037] The glass-ceramics with lower hardness are difficult to resist scratches from hard objects such as cookware, wire brushes, tableware, or knives.

[0038] It can be seen that when the surface roughness of the glass-ceramics is less than or equal to 2.0 μm and the Mohs hardness is greater than or equal to 6.5, it can have high scratch resistance and be easy to clean, improving the usability of the glass-ceramics.

[0039] Please refer to Figure 1 , the present invention also provides a method for manufacturing glass-ceramics, including:

[0040] S10 Perform gradient sandblasting on the surface of the semi-finished glass-ceramics to form a first in-process product with a surface roughness greater than or equal to 2.5 μm and less than or equal to 3.0 μm;

[0041] S20 Etch the first in-process product with an etching solution to form a second in-process product with strengthened micropores having pore diameters greater than or equal to 10 μm and less than or equal to 30 μm on the surface;

[0042] S30 Polish the surface of the second in-process product with a composite polishing solution to form the finished glass-ceramics.

[0043] The surface roughness of the above-mentioned finished product is greater than or equal to 0.8 μm and less than or equal to 2.0 μm, and the Mohs hardness is greater than or equal to 6.5 and less than or equal to 8.0.

[0044] The semi-finished product of the glass-ceramics is the glass-ceramics that have not been processed through the above steps. At this time, the hardness of the glass-ceramics is still relatively low. The semi-finished product can also be pre-treated. For example, surface cleaning and rough polishing can be carried out: use a surface polishing device to perform rough surface polishing on the blank plate of the glass-ceramics, then spray clean water on the blank plate for cleaning, or brush cleaning can also be used. Finally, the cleaned blank plate can be dried to form the above semi-finished product. During the process of forming the semi-finished product, pre-treatment such as cutting or edge grinding of the blank plate can be not carried out, so as to reduce the probability of the plate being scrapped due to abnormalities during the production process.

[0045] Gradient sandblasting can make the surface roughness of the glass-ceramics greater than or equal to 2.5 μm and less than or equal to 3.0 μm to form a pre-roughened layer, which is convenient for subsequent processing. The first work-in-progress is the glass-ceramics with the above pre-roughened layer formed on the surface. Gradient sandblasting refers to a sandblasting process including at least two kinds of abrasives. Different kinds of abrasives can have different grinding capabilities (such as various abrasives with different mesh numbers, various abrasives with different hardnesses, etc.), and can take into account both grinding efficiency and precision.

[0046] Etching the first work-in-progress with an etching solution, the formed strengthening micropores can reduce the sharp microcracks on the surface of the glass-ceramics, thereby avoiding stress concentration and improving the strength of the glass. The strengthening micropores may even be arranged in a honeycomb or reticular micropore structure, thereby improving the surface strength of the glass-ceramics structurally. However, it should be noted that different etching solutions can also produce corresponding different effects, and specific details can refer to other embodiments in the following text.

[0047] After being processed through the foregoing steps, the glass-ceramics already have a relatively high hardness. Then, the glass-ceramics are polished with a composite polishing solution, so that the surface roughness of the glass also drops to 2.0 micrometers or less than 2.0 micrometers. In this way, the glass-ceramics with a Mohs hardness greater than or equal to 6.5 and less than or equal to 8.0, and a surface roughness greater than or equal to 0.8 μm and less than or equal to 2.0 μm are obtained, that is, the finished product.

[0048] The composite polishing solution is a polishing solution including at least two kinds of polishing abrasives. Since different abrasives have different grinding performances, the composite polishing solution can reduce the required polishing processes. In Figure 2 the shown embodiment, even single-step polishing can be achieved, thereby improving the production efficiency of the glass-ceramics.

[0049] Please refer to Figure 2 , in some embodiments, the abrasives for gradient sandblasting include a first abrasive, a second abrasive, and a third abrasive. Among them, the mesh number of the first abrasive is greater than or equal to 45 mesh and less than or equal to 55 mesh, the mesh number of the second abrasive is greater than or equal to 75 mesh and less than or equal to 85 mesh, and the mesh number of the third abrasive is greater than or equal to 115 and less than or equal to 125.

[0050] In step S11, gradient sandblasting is performed using abrasive materials of multiple mesh sizes. The abrasive material with a small mesh size has a high polishing efficiency, which can improve the sandblasting efficiency. The abrasive material with a large mesh size can make the surface roughness of the microcrystalline glass lower, which is beneficial to improving the subsequent grinding efficiency. The abrasive material with a medium mesh size can balance the effect of the abrasive material with a small mesh size, making the polishing effect more controllable and not easily over-polished. The mixing of the above three mesh sizes of abrasive materials forms a three-stage impact on the surface of the microcrystalline glass, making the sandblasting efficient and controllable and beneficial to improving the grinding efficiency.

[0051] Please refer to Figure 2 , in some embodiments, the raw material of the first abrasive material is Al2O3, the raw material of the second abrasive material is SiC, and the raw material of the third abrasive material is ZrO2.

[0052] Al2O3 has medium hardness, which can cause plastic deformation on the surface of the microcrystalline glass to form a stress layer. SiC has a high hardness, which can improve the grinding efficiency. ZrO2 has a low hardness, which can balance the polishing efficiency of SiC, making the polishing process more controllable, thereby increasing the surface hardness of the microcrystalline glass.

[0053] In some embodiments, the molar fraction of the first abrasive material is greater than or equal to 55% and less than or equal to 65%, the molar fraction of the second abrasive material is greater than or equal to 20% and less than or equal to 30%, and the molar fraction of the third abrasive material is greater than or equal to 5% and less than or equal to 20%.

[0054] In this way, abrasive materials of different mesh sizes form the total abrasive material in different proportions, which can take into account the grinding efficiency and the roughness of the finished product, facilitating manufacturing.

[0055] In particular, please refer to Figure 2 the embodiment in which step S11 uses Al2O3 sand with a molar fraction of 60% and a mesh size of 50, SiC sand with a molar fraction of 25% and a mesh size of 80, and ZrO2 sand with a molar fraction of 15% and a mesh size of 120 mixed as the abrasive material. Such an abrasive material for three-stage impact can make Al2O3 with a large momentum play a leading role, mainly forming a stress layer on the surface of the microcrystalline glass, using SiC sand to improve the grinding efficiency, and using ZrO2 sand to reduce the roughness of the first workpiece in process for subsequent treatment. In this way, the sandblasting step can be reduced, and the surface stress and pre-roughening layer of the microcrystalline glass can be formed by three-stage impact, improving the production efficiency.

[0056] Please refer to Figure 2 , in some embodiments, the linear velocity of the abrasive material for gradient sandblasting relative to the surface of the semi-finished product is greater than or equal to 10 m / s and less than or equal to 20 m / s.

[0057] If the linear velocity is too high, the momentum carried by the abrasive will be too large, which may damage the microcrystalline glass. If the linear velocity is too low, the momentum of the abrasive will be too small and the grinding efficiency will be too low. When the linear velocity is greater than or equal to 10 m / s and less than or equal to 20 m / s, the microcrystalline glass will not be damaged and the grinding effect can be achieved.

[0058] Specifically, the semi-finished product can be subjected to gradient grinding using the examples shown in the following table:

[0059]

[0060]

[0061] The ratios in the table refer to mole fractions. In Figure 2 the embodiment shown, the specific parameters in step S11, that is, the ratios and mesh numbers of Al2O3 sand, SiC sand and ZrO2 sand, and the linear velocity of the abrasive, can all be replaced by the examples in the above table. After replacement, the semi-finished product can be processed into a first in-process product with a surface roughness greater than or equal to 2.5 μm and less than or equal to 3.0 μm.

[0062] Please refer to Figure 2 , in some embodiments, the etching solution includes hydrofluoric acid with a mole fraction greater than or equal to 5% and less than or equal to 7%, nitric acid with a mole fraction greater than or equal to 11% and less than or equal to 13%, and sodium fluorosilicate with a mole fraction greater than or equal to 3% and less than or equal to 4%.

[0063] In step S21, that is, the microcrystalline glass is etched using the etching solution of a specific embodiment within the above configuration range. The etched solution configured in this way can not only form strengthened micropores (that is, form a strengthened framework), but also form a covalent bond between the perfluoropolyether and the fluorosilicate network. This bonding method can increase the binding energy on the surface of the microcrystalline glass by several times. For example, in Figure 2 the microcrystalline glass produced in the embodiment shown, at 650 °C, the surface energy is less than or equal to 22 mN / m. The smaller the surface energy, the more likely the liquid adsorbed on the surface of the microcrystalline glass is to gather into droplets under the action of its own surface tension rather than wet the surface of the microcrystalline glass. The liquid forming droplets is not easy to enter the microcracks on the surface of the microcrystalline glass and is not easy to bond with the atoms in the microcrystalline glass. Therefore, it is possible to prevent dirt such as oil droplets from binding to the surface of the microcrystalline glass, making the microcrystalline glass easy to clean.

[0064] For household appliances such as induction cooktops that have a relatively high panel temperature during operation, maintaining a low surface energy at high temperatures is particularly important. Because when the panel glass of the induction cooktop rises to a relatively high temperature, it is also possible that oil droplets or water droplets containing organic substances such as proteins will splash onto the panel, resulting in molecular bonding with the panel at high temperatures. In this case, even if the temperature decreases, it is difficult to clean.

[0065] When the glass temperature rises, due to the more intense thermal motion of the atoms in the glass, the interatomic gaps become larger, and the connections between various atoms or groups tend to become loose. Therefore, it is more inclined to bond with free atoms or groups in the outside world. Thus, the higher the glass temperature, the higher the general surface energy, and the easier it is to combine with external substances. However, precisely due to the formation of the covalent bonding between the perfluoropolyether and the fluorosilicate network, the surface energy of the glass-ceramics produced by the implementation method of the present application can be maintained at a relatively low level at high temperatures, improving the cleanability of the glass-ceramics.

[0066] Please refer to Figure 1 and Figure 2 , in some implementation manners, S20 uses an etching solution to etch the first work-in-progress to form a second work-in-progress with strengthened micropores having a pore diameter greater than or equal to 10 μm and less than or equal to 30 μm on the surface, including:

[0067] Place the first work-in-progress in the etching solution for greater than or equal to 8 minutes and less than or equal to 12 minutes, and keep the temperature of the etching solution greater than or equal to 50 °C and less than or equal to 53 °C, and simultaneously perform ultrasonic treatment to etch the first work-in-progress to form a second work-in-progress with strengthened micropores having a pore diameter greater than or equal to 10 μm and less than or equal to 30 μm on the surface.

[0068] The reaction time between the etching solution and the glass-ceramics will affect the degree of etching of the glass-ceramics. When the reaction time is too short, it may not be sufficient to etch out large enough strengthened micropores, nor is it sufficient to form enough covalent bonding between the perfluoropolyether and the fluorosilicate network; while when the reaction time is too long, it may over-corrode the surface of the glass-ceramics, causing the glass-ceramics to become thinner, or the pore diameter of the micropores formed on the surface by etching to be too large. And when the first product is placed in the etching solution for greater than or equal to 8 minutes and less than or equal to 12 minutes, and the temperature of the etching solution is kept greater than or equal to 50 °C and less than or equal to 53 °C, and ultrasonic treatment is performed simultaneously, strengthened micropores of the target size can be formed, and it is ensured that enough covalent bonding between the perfluoropolyether and the fluorosilicate network is formed, ensuring the cleanability of the glass-ceramics.

[0069] The temperature of the etching solution will also affect the reaction rate. If the temperature is too high, the reaction may be too fast to control; if the temperature is too low, the reaction may be too slow, and even some reactions that require high-energy excitation cannot proceed. And controlling the temperature of the etching solution to be greater than or equal to 50 °C and less than or equal to 53 °C can just overcome the above problems.

[0070] On the one hand, ultrasonic treatment can provide physical catalysis for some reactions. On the other hand, it is conducive to the etching solution entering the micro-gaps on the surface of the glass-ceramics, playing a role in corroding the micro-gaps, passivating the micro-gaps, avoiding sharp cracks, and reducing the position of stress concentration on the surface of the glass-ceramics, thereby improving the strength of the glass-ceramics.

[0071] If the pore diameter of the strengthened micropores on the surface of the glass-ceramics is too large, the structural strength of the micropores themselves may be reduced, and in this way, the strengthening effect of the strengthened micropores on the glass is weak; while if the pore diameter of the micropores is too small, the proportion of the surface area of the glass-ceramics occupied by the micropores is relatively low, and it cannot play an obvious strengthening role either. When the pore diameter of the micropores of the glass-ceramics is greater than or equal to 10 μm and less than or equal to 30 μm, it can play an obvious strengthening role on the glass-ceramics.

[0072] Specifically, the following examples shown in the table can be used to etch the first work-in-progress:

[0073]

[0074] (%) in the table refers to the molar fraction. In Figure 2 In the shown embodiment, the specific parameters in step S21, that is, the ratio of hydrofluoric acid, nitric acid and sodium fluorosilicate, as well as the temperature and etching time of the etching solution, can all be replaced by the examples in the above table. After replacement, it can all realize processing the first work-in-progress into a second work-in-progress with strengthened micropores having a pore diameter greater than or equal to 10 μm and less than or equal to 30 μm on the surface.

[0075] When etching the first work-in-progress, a tunnel-type planar spraying device developed by the inventor of the present application can be used for etching, that is, the etching solution in the embodiment of the present application can be added to the tunnel-type planar spraying device, and the spraying etching method is used instead of the immersion etching method. In this way, the environmental protection problems during the use of hydrofluoric acid can be reduced, and the risk of operators contacting hydrofluoric acid corrosion of the skin caused by the volatilization of hydrofluoric acid can be reduced. Tunnel planar spraying etching also simplifies the operation of the etching process. Compared with the 40% defective product ratio of the immersion method etching, the defective product ratio can be reduced to 10% by using the spraying etching method, thereby improving the overall product yield.

[0076] The above-mentioned etching solution formula can also simplify the components of the etching solution, reduce the ratio of hydrofluoric acid, and thus reduce the environmental pollution problems and safety risks of hydrofluoric acid.

[0077] Sometimes, it is only necessary to process one side of the first work-in-progress, that is, it is only necessary to make the surface roughness of one side of the finished microcrystalline glass greater than or equal to 0.8 μm and less than or equal to 2.0 μm, and the Mohs hardness greater than or equal to 6.5 and less than or equal to 8.0. For such an embodiment, the following treatment can be carried out before etching:

[0078] Place the first work-in-progress on a glass washing and scrubbing device. After the first work-in-progress is treated with an oxalic acid cleaning solution, brush cleaning, and drying and heating, an acid-resistant film is used to coat one side of the first work-in-progress, so that the coated side will not be etched by the etching solution. This can reduce the amount of etching solution used and save costs.

[0079] Please refer to Figure 2 , in some embodiments, the composite polishing liquid includes cerium oxide with a molar fraction greater than or equal to 13% and less than or equal to 15% and diamond with a molar fraction greater than or equal to 1% and less than or equal to 3%. Among them, the particle size of cerium oxide is greater than or equal to 0.1 μm and less than or equal to 0.2 μm, and the particle size of diamond is 50 nm.

[0080] In step S31, that is, polishing is carried out using the polishing liquid of a specific embodiment within the above configuration range. Among them, cerium oxide can soften the surface of the microcrystalline glass and disperse the high-hardness diamond abrasive. Softening the surface of the microcrystalline glass can improve the grinding efficiency, and dispersing the diamond can improve the grinding uniformity. Cerium oxide itself can also play a polishing role. The high hardness of the diamond abrasive can also accelerate the grinding efficiency.

[0081] In addition, the diamond used is a nano-level abrasive, which can improve the smoothness of the final grinding and make the surface roughness of the finished microcrystalline glass less than 2.0 μm.

[0082] Due to the cooperation of the above composite polishing liquid, in Figure 2 the shown embodiment, polishing can be completed in a single step without multi-step polishing, improving the production efficiency of microcrystalline glass.

[0083] Please refer to Figure 2 , in some embodiments, using a composite polishing liquid to polish the surface of the second work-in-progress to form a finished microcrystalline glass includes:

[0084] Under a pressure of 0.7 MPa, and the polishing speed is greater than or equal to 25 m / s and less than or equal to 35 m / s, use the composite polishing liquid to polish the surface of the second work-in-progress for a duration greater than or equal to 10 minutes and less than or equal to 15 minutes to form a finished product.

[0085] Step S31 is to polish the surface of the glass-ceramic by using an implementation method within the above physical conditions. When the pressure is too high, the abrasive in the polishing liquid is difficult to disperse evenly, and uniform polishing may not be possible. When the pressure is too low, the polishing speed may be too slow due to the small force between the abrasive and the glass-ceramic. When a pressure of 0.7 MPa is applied to the glass-ceramic to polish the glass-ceramic, the above problems can be overcome.

[0086] If the polishing liquid acts on the surface of the microcrystalline glass for too long, it may cause the polishing liquid to over-react and reduce the hardness of the glass surface. If the polishing liquid acts on the surface of the microcrystalline glass for too short a time, on the one hand, the polishing efficiency may not enable the microcrystalline glass to achieve the expected polishing effect, and on the other hand, it may not have enough reaction time with the glass, making it difficult for some components in the polishing liquid to work. The above problems can be overcome when the polishing time is greater than or equal to 10 minutes and less than or equal to 15 minutes.

[0087] The polishing speed is the movement speed of the polishing brush head relative to the second work-in-progress. When the relative speeds of the various parts of the brush head and the second work-in-progress are not uniform, the average speed of each part of the brush head can be used as the above movement speed, or the translation speed of the brush head (without considering rotation) can be used as the above movement speed. The lower the polishing speed, the lower the polishing efficiency and the longer the polishing time required; the higher the polishing speed, the more likely it is to cause uneven polishing. When the polishing speed is within the above range, it can have higher polishing efficiency and polishing uniformity, thereby overcoming the above problems.

[0088] In particular, when the microcrystalline glass is manufactured by the embodiment of the microcrystalline glass manufacturing method of the present application, the obtained microcrystalline glass has good acid resistance. The experimental measurement shows that the weight loss after immersion in 5% hydrochloric acid for 48 hours is ≤0.01mg / cm2. Similarly, the high-temperature light transmittance of this type of microcrystalline glass is also strong. The experimental measurement shows that the light transmittance is ≥92% at 650°C. Under high temperature conditions, the surface energy of some finished products is ≤20mN / m.

[0089] This makes the glass-ceramic manufactured by the embodiment of the glass-ceramic manufacturing method of the present application suitable for the panel of the electric ceramic stove. The panel of the electric ceramic stove may be corroded by acidic food materials, and it is also necessary to transmit the heat radiation emitted by the heating element to the outside world, so it needs better high-temperature light transmittance. At the same time, the panel of the electric ceramic stove may also be contaminated by food at high temperatures, and requires lower surface energy to avoid reacting with food and combining. Coincidentally, through the above experiments, it can be seen that the glass-ceramic has good acid resistance, strong high-temperature light transmittance, and low high-temperature surface energy.

[0090] Specifically, the second work-in-progress may be polished using the embodiments shown in the following table:

[0091] Polishing Example Cerium Oxide Water Diamond Speed Time Roughness Mohs Hardness Example 1 13％ 84％ 3％ 35 15 0.8 6.5 Example 2 14％ 84％ 2％ 30 13 1.5 7 Example 3 15％ 84％ 1％ 25 10 2.0 8 Example 4 13％ 85％ 2％ 35 15 0.8 6.5 Example 5 14％ 85％ 1％ 30 13 1.5 7 Example 6 15％ 83％ 2％ 25 10 2.0 8

[0092] The (%) in the table refers to the amount fraction of the substance, the speed refers to the polishing speed, and the time refers to the polishing time. The particle size of the cerium oxide in the table is greater than or equal to 0.1 μm and less than or equal to 0.2 μm, that is, for example, it can be 0.1 μm or 0.2 μm, and the finished product with the above roughness and Mohs hardness can be obtained.

[0093] exist Figure 2 In the embodiment shown, the specific parameters in step S31, i.e., the ratio of cerium oxide to diamond, and the polishing speed and polishing time can be replaced by the embodiments in the above table. After the replacement, the second work-in-progress can be processed into a finished product of microcrystalline glass. The surface roughness of the finished product is greater than or equal to 0.8 μm and less than or equal to 2.0 μm, and the Mohs hardness is greater than or equal to 6.5 and less than or equal to 8.0. For specific surface roughness and Mohs hardness, please refer to the above table (and attached Figure 2 Surface roughness and Mohs hardness as specified in the embodiment shown).

[0094] Before polishing the second work-in-progress, acid-base neutralization cleaning, high-pressure cleaning, brush grinding, drying cleaning and other operations may be performed, so that the second work-in-progress may be better polished.

[0095] For some existing low-roughness glasses (Ra≤2.0μm), when working at above 600°C, the surface energy rises to a level of ≥35mN / m, which means that they basically lose their self-cleaning function, that is, they are difficult to clean.

[0096] Generally, when the temperature of glass-ceramics rises, the lattice structure undergoes dynamic distortion, which destroys the uniformity of the glass, causing Rayleigh scattering or Mie scattering of light during propagation. The scattering loss of light during propagation in the glass increases, and thus the light transmittance of the glass decreases. Please refer to the table below for details.

[0097] Test Item Comparative Example 1 Comparative Example 2 This Application Scratch Depth of Steel Wool 8.2μm 15.5μm 2.1μm Transmittance at 650℃ 87.3％ 92.1％ 92.7％ Surface Energy at 650℃ 38mN / m 28mN / m 19mN / m

[0098] Comparative Example 1 in the table is a commercially available scratch-resistant microcrystalline glass (Ra=2.8 μm, Mohs hardness 7.1);

[0099] Comparative Example 2 is a low-roughness soda-lime glass (Ra=1.2 μm, Mohs hardness 6.3);

[0100] This application refers to the use of Figure 2 A sample (Ra=1.28 μm, Mohs hardness 7.3) produced by the embodiment shown.

[0101] It can be seen that the light transmittance of the present application is the highest at 650 °C. Although the light transmittance of Comparative Example 2 is close to that of the present application, its hardness is much smaller than that of the present application. Therefore, in the steel wool scratch test, the scratched depth is the largest. The scratch resistance (the smaller the scratch depth, the more scratch-resistant) and high-temperature light transmittance of the samples of the present application are both higher than those of the microcrystalline glass in Comparative Example 1. At the same time, the high-temperature surface energy of the samples of the present application is also the lowest. It can be seen that the present application has high hardness, high light transmittance and low surface energy, and has excellent usability.

[0102] In addition, it is worth noting that since Comparative Example 2 is soda-lime glass, although it has high high-temperature light transmittance, it has softened and deformed at 650 °C and is not applicable to application scenarios such as the panel of an electric ceramic stove.

[0103] For the performance of the microcrystalline glass produced by the embodiment of the method for manufacturing microcrystalline glass proposed in the present application, reference can also be made to the following table

[0104]

[0105]

[0106] In the table, Comparative Example 3 is another microcrystalline glass, and the present application refers to a certain microcrystalline glass sample produced by the Figure 2 shown implementation method.

[0107] It can be seen that Comparative Example 3 basically reaches the hardness of the microcrystalline glass proposed in the present application, but the surface roughness is significantly higher than that of the microcrystalline glass proposed in the present application. The light transmittance of Comparative Example 3 at high temperature is also lower than that of the samples of the present application at high temperature. At the same time, due to the large surface roughness of Comparative Example 3, after being contaminated with vinegar stains under the same conditions, the samples of the present application can be cleaned within less than 6 seconds, and 60% of the vinegar stains still remain on the surface of Comparative Example 3 after 15 s under the same cleaning conditions.

[0108] Similarly, due to Figure 2 in the shown implementation method, regarding the proportion of abrasive materials and the setting of polishing liquid, the light transmittance fluctuation of the microcrystalline glass produced by the manufacturing method of the Figure 2 implementation method can be less than or equal to 1%, and the product consistency is high. At the same time, compared with the traditional production method of scratch-resistant glass, the single-piece production cost is reduced by 40%, and the good product rate is increased from the industry average of 82% to 98.6%.

[0109] The present invention also proposes a household appliance, including the above-mentioned microcrystalline glass, or including the microcrystalline glass manufactured by the above-mentioned method for manufacturing microcrystalline glass. Among them, the specific features or processes of the microcrystalline glass and the method for manufacturing microcrystalline glass refer to the above implementation methods. Since this household appliance adopts all the technical solutions of the above-mentioned all implementation methods, it has at least all the beneficial effects brought by the technical solutions of the above implementation methods, which will not be elaborated here one by one.

[0110] The household appliance can be an induction cooker, a halogen cooker, a gas stove, an oven, etc. The glass-ceramics can be used to manufacture the panel of the household appliance.

[0111] The above are only exemplary embodiments of the present invention, and do not limit the patent scope of the present invention accordingly. Any equivalent structural transformation made under the technical concept of the present invention by using the content of the specification and drawings of the present invention, or any direct / indirect application in other related technical fields is included in the patent protection scope of the present invention.

Claims

1. A glass-ceramic, characterized in that, The surface roughness of the glass-ceramics is greater than or equal to 0.8 μm and less than or equal to 2.0 μm, and the Mohs hardness is greater than or equal to 6.5 and less than or equal to 8.

0.

2. A method for manufacturing glass-ceramics, characterized in that, Including: Performing gradient sandblasting on the surface of the semi-finished glass-ceramics to form a first work-in-progress with a surface roughness greater than or equal to 2.5 μm and less than or equal to 3.0 μm; Etching the first work-in-progress with an etching solution to form a second work-in-progress with strengthened micropores having a pore diameter greater than or equal to 10 μm and less than or equal to 30 μm on the surface; Polishing the surface of the second work-in-progress with a composite polishing solution to form the finished glass-ceramics; the surface roughness of the finished product is greater than or equal to 0.8 μm and less than or equal to 2.0 μm, and the Mohs hardness is greater than or equal to 6.5 and less than or equal to 8.

0.

3. The method for manufacturing the glass-ceramics according to claim 2, wherein, The abrasive materials for the gradient sandblasting include a first abrasive material, a second abrasive material, and a third abrasive material; wherein, the mesh number of the first abrasive material is greater than or equal to 45 mesh and less than or equal to 55 mesh, the mesh number of the second abrasive material is greater than or equal to 75 mesh and less than or equal to 85 mesh, and the mesh number of the third abrasive material is greater than or equal to 115 mesh and less than or equal to 125 mesh.

4. The method for manufacturing the glass-ceramics according to claim 3, wherein The raw material of the first abrasive material is Al2O3, the raw material of the second abrasive material is SiC, and the raw material of the third abrasive material is ZrO2; and / or The molar fraction of the first abrasive material is greater than or equal to 55% and less than or equal to 65%, the molar fraction of the second abrasive material is greater than or equal to 20% and less than or equal to 30%, and the molar fraction of the third abrasive material is greater than or equal to 5% and less than or equal to 20%.

5. The method for manufacturing glass-ceramics according to any one of claims 2 to 4, characterized in that, The linear velocity of the abrasive materials for the gradient sandblasting relative to the surface of the semi-finished product is greater than or equal to 10 m / s and less than or equal to 20 m / s.

6. The method for manufacturing the glass-ceramics according to claim 2, wherein, The etching solution includes hydrofluoric acid with a molar fraction greater than or equal to 5% and less than or equal to 7%, nitric acid with a molar fraction greater than or equal to 11% and less than or equal to 13%, and sodium fluorosilicate with a molar fraction greater than or equal to 3% and less than or equal to 4%.

7. The method for manufacturing the glass-ceramics according to claim 2 or 6, characterized in that, The step of etching the first work-in-progress with the etching solution to form a second work-in-progress with strengthened micropores having a pore diameter greater than or equal to 10 μm and less than or equal to 30 μm on the surface includes: Placing the first work-in-progress in the etching solution for greater than or equal to 8 minutes and less than or equal to 12 minutes, and maintaining the temperature of the etching solution greater than or equal to 50 °C and less than or equal to 53 °C, and simultaneously performing ultrasonic treatment to etch the first work-in-progress to form a second work-in-progress with strengthened micropores having a pore diameter greater than or equal to 10 μm and less than or equal to 30 μm on the surface.

8. The method for manufacturing the glass-ceramics according to claim 2, characterized in that, The composite polishing solution includes cerium oxide with a molar fraction greater than or equal to 13% and less than or equal to 15% and diamond with a molar fraction greater than or equal to 1% and less than or equal to 3%; wherein, the particle size of the cerium oxide is greater than or equal to 0.1 μm and less than or equal to 0.2 μm, and the particle size of the diamond is 50 nm.

9. The method for manufacturing glass-ceramics according to claim 2 or 8, characterized in that, The step of polishing the surface of the second work-in-progress with the composite polishing solution to form the finished glass-ceramics includes: Under a pressure of 0.7 MPa, and when the polishing speed is greater than or equal to 25 m / s and less than or equal to 35 m / s, the surface of the second work-in-progress is polished with a composite polishing liquid for a duration greater than or equal to 10 minutes and less than or equal to 15 minutes to form the finished product.

10. A household appliance, characterized in that, It includes the glass-ceramics described in claim 1, or glass-ceramics manufactured by the glass-ceramics manufacturing method described in any one of claims 2-9.

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