Arc-shaped microcrystalline glass plate, and preparation method therefor and use thereof

Abstract

The present disclosure relates to the technical field of arc-shaped microcrystalline panels, and particularly relates to an arc-shaped microcrystalline glass plate, and a preparation method therefor and the use thereof. The roughness of the inner and outer surfaces of the arc-shaped microcrystalline glass plate is less than or equal to 0.06 μm; the radial unevenness A of the arc-shaped microcrystalline glass plate is less than or equal to 0.4%, and A=h / L×100%; and the axial unevenness B of the arc-shaped microcrystalline glass plate is less than or equal to 0.4%, and B=d / L×100%. The arc-shaped microcrystalline glass plate provided in the present disclosure has a flat and smooth surface, can avoid optical scattering, satisfies the visibility requirement, has good flatness, low radial unevenness and axial unevenness, and has no "warping angle" phenomenon or obvious visual distortion.

Description

Arc-shaped microcrystalline glass plate and preparation method and application thereof

[0001] Cross-reference to related disclosures

[0002] The present disclosure claims priority to the Chinese patent application No. 2025103396761, filed on March 21, 2025, and entitled "Arc-shaped microcrystalline glass plate and preparation method and application thereof", the entire content of which is incorporated herein by reference. TECHNICAL FIELD

[0003] The present disclosure relates to the technical field of arc-shaped microcrystalline panels, in particular, to an arc-shaped microcrystalline glass plate and a preparation method and application thereof. BACKGROUND

[0004] The main crystal phase composition of LAS microcrystalline glass (hereinafter referred to as microcrystalline glass) is Li2O-Al2O3-SiO2 system. With its low expansion, high strength, light transmission adjustment and other characteristics, it is widely used in various heating fields, especially in cooktops, kitchen appliance cover plates and other scenes, which is the main application field of microcrystalline glass. The mainstream microcrystalline glass preparation technology is to prepare flat microcrystalline glass by melt glass calendering forming method. Microcrystalline glass can be divided into colored microcrystalline glass, transparent microcrystalline glass and white microcrystalline glass according to its body color attribute. Among them, the visible light transmittance of the 4mm thick microcrystalline panel prepared by transparent microcrystalline glass can reach more than 70%, and it has the characteristics of low expansion, high strength, good chemical stability, etc., which is an ideal material for high temperature observation window, fireplace and other applications. Limited by the production process of calendering forming, in order to adapt to flat microcrystalline panel, the early fireplace design is mainly square. With the birth of cylindrical fireplace design, its appearance is novel and unique, and the manufacturing of arc-shaped microcrystalline glass panel matched with it is particularly critical. In order to enhance the visibility, the arc-shaped microcrystalline panel is often required to be smooth and flat on both sides, that is, the roughness Ra≤0.06μm, so as to avoid optical scattering. In addition, the arc-shaped microcrystalline panel is generally loaded in a specific metal frame in actual application, and the size tolerance and flatness are required to be relatively strict.

[0005] The existing arc-shaped microcrystalline panel production process is generally gravity forming. That is, a concave mold is first prepared, and the flat base glass (the base glass refers to the uncrystallized microcrystalline panel) panel is placed horizontally in the concave mold and heated to the softening temperature for heat preservation. Under the action of gravity, the base glass plate deforms until it fits the mold, achieving the effect of arc forming. Then the temperature is continuously increased to crystallize in the arc-shaped plate, and the arc-shaped microcrystalline glass is obtained. This method is particularly suitable for small arc-shaped microcrystalline panels with small central angles. Among them, the mold is the key equipment of the gravity forming method. The size of the arc-shaped microcrystalline glass, such as the inner radius, tolerance, etc., is directly determined by the mold.

[0006] In actual production, the mold is mainly made of heat-resistant iron-based alloy. However, the inherent property of the metal material that the thermal expansion coefficient is large is prone to torsional deformation after repeated thermal cycles, which causes the arc-shaped microcrystalline plate attached to the inner wall to have the same torsional deformation, and when it is inverted, the "corner lifting" phenomenon is obvious. For example, when an iron-based mold is used to prepare an arc-shaped microcrystalline plate with an inner diameter R (the shape of the iron-based mold is arc-shaped, and R refers to the inner diameter of the arc) of 260 mm, a central angle of 60°, and a length of 300 mm, the radial unevenness is as high as 1.67%. Among them, the radial unevenness A = h / L x 100%; when the opening of the arc-shaped microcrystalline plate is placed downward on the horizontal plane, three vertices of the arc-shaped microcrystalline plate are in contact with the horizontal plane, and the distance between the other vertex and the horizontal plane is h; L is the length of the arc-shaped microcrystalline plate in the axial direction. That is, the remaining vertex of the 300 mm long arc-shaped microcrystalline plate is as high as 5 mm from the horizontal plane when it is inverted, which completely fails to meet the assembly requirements of the fireplace observation window.

[0007] In addition, for arc-shaped microcrystalline plates with a central angle greater than 114°, when the length of the microcrystalline plate exceeds 2R (R is the inner diameter of the concave mold), it cannot be simply prepared by the concave mold.

[0008] In related technologies, the forming device is used for the case where the length of the microcrystalline plate exceeds the concave mold. A cylindrical rotating roller is arranged at the top of the left and right sides of the concave mold to help the flat microcrystalline plate continuously descend under the action of gravity. In the softening stage, the center of the basic glass softens and descends, continuously driving the basic glass on the support strips on both sides of the concave mold to move towards the concave mold, and finally forming an arc-shaped shape that falls into the concave mold. However, the structure of this device is obviously more complex, and it is obviously difficult to easily solve the problems such as the fixation and rotation of the rotating roller always maintaining horizontal at a high temperature of 800-900°C. Moreover, the microcrystalline plate is always in contact with the support strips and the rotating roller during the softening process, and there is relative movement, which is easy to form scratches on the surface of the microcrystalline plate. These scratches need to be removed by adding a polishing process, but the polishing of arc-shaped glass is much more complex than that of flat glass. Moreover, the inherent characteristics of small batch and multiple specifications of arc-shaped glass products make the process path of forming first and then polishing extremely uneconomical. In addition, this scheme cannot overcome the problem of torsion of the microcrystalline plate during the softening process. Various disturbances in the production process can easily cause the microcrystalline plate to rotate at a small angle when it descends, resulting in high radial unevenness. Therefore, a cutting process needs to be added to cut the arc-shaped glass prepared by the above method to the four vertices on the same horizontal plane.

[0009] Furthermore, the axial flatness B, wherein B = d / L x 100%, L is the length of the arc-shaped microcrystalline plate along the axial direction, and the maximum distance between the curved arc formed by the top end of the arc-shaped microcrystalline plate bending downward when the arc-shaped microcrystalline plate is placed on a horizontal surface with the opening downward and the line connecting the midpoints of the two arc-shaped edges of the arc-shaped microcrystalline plate, is not mentioned in the related art and existing applications. In fact, during the crystallization process of the microcrystalline raw plate, it is extremely easy to form an inward arch in the axial direction. Although this deformation does not affect the assembly of the arc-shaped microcrystalline glass panel in applications such as fireplaces, there is a visually obvious visual distortion near the arc-shaped edge, so the axial flatness B also needs to be controlled at a low level.

[0010] In order to achieve a smooth and non-distorted surface of the arc-shaped microcrystalline panel, the flatness can be adapted to the tooling, and the conventional preparation method often also needs complicated subsequent processing procedures to further polish or cut the formed arc-shaped microcrystalline glass to the designed size.

[0011] In view of this, the present disclosure is proposed.

[0012] Disclosed content

[0013] The first object of the present disclosure is to provide an arc-shaped microcrystalline glass plate with a smooth and flat surface, an inner surface roughness Ra of ≤0.06 μm, and an outer surface roughness Ra of ≤0.06 μm, which can avoid optical scattering, meet the visibility requirements, and has good flatness, low radial and axial flatness, no "corner lifting" phenomenon, and no obvious visual distortion of the arc edge. The problem of the arc-shaped microcrystalline panel in the prior art that it is difficult to meet the requirements of a double-sided roughness of ≤0.06 μm and poor radial and axial flatness is solved.

[0014] The second object of the present disclosure is to provide a preparation method of an arc-shaped microcrystalline glass plate, which adopts the steps of polishing first and forming and crystallizing later, can be formed at one time, and directly obtains the required arc-shaped microcrystalline panel with a smooth and flat surface and good flatness, without subsequent mechanical processing such as arc-shaped panel polishing, edge cutting, and chamfering.

[0015] The third object of the present disclosure is to provide the application of the arc-shaped microcrystalline glass plate in the fields of building and decoration.

[0016] In order to achieve the above objects of the present disclosure, the following technical solutions are adopted:

[0017] The present disclosure first provides an arc-shaped microcrystalline glass plate, wherein the inner surface roughness of the arc-shaped microcrystalline glass plate is ≤0.06 μm, and the outer surface roughness of the arc-shaped microcrystalline glass plate is ≤0.06μm;

[0018] The shape of the arc-shaped microcrystalline glass plate is arc-shaped;

[0019] The radial unevenness A of the arc-shaped glass-ceramic plate is ≤0.4%, wherein A = h / L*100%; when the arc-shaped glass-ceramic plate is placed with the opening downward on a horizontal plane, three vertices of the arc-shaped glass-ceramic plate are in contact with the horizontal plane, and the distance between the other vertex and the horizontal plane is h; L is the length of the arc-shaped glass-ceramic plate in the axial direction; h and L have the same unit.

[0020] The axial unevenness B of the arc-shaped glass-ceramic plate is ≤0.4%, wherein B = d / L*100%; when the arc-shaped glass-ceramic plate is placed with the opening downward on a horizontal plane, the top end of the arc-shaped glass-ceramic plate is bent downward to form a bending arc in the axial direction of the arc-shaped glass-ceramic plate, and the maximum distance between the bending arc and the line connecting the midpoints of the two arc-shaped edges of the arc-shaped glass-ceramic plate is d; L is the length of the arc-shaped glass-ceramic plate in the axial direction; d and L have the same unit.

[0021] Further, the thermal expansion coefficient of the arc-shaped glass-ceramic plate at a temperature of 40-700°C is <0.5ppm / ℃.

[0022] The present disclosure further provides a preparation method of the arc-shaped glass-ceramic plate, comprising the following steps:

[0023] obtaining a double-side polished flat plate type glass-ceramic original plate;

[0024] placing the double-side polished flat plate type glass-ceramic original plate on a refractory material mold, and then performing heat treatment to perform shaping and crystallization, so as to obtain the arc-shaped glass-ceramic plate.

[0025] Further, the vertices of the double-side polished flat plate type glass-ceramic original plate are chamfered and / or rounded, and the four edges of the double-side polished flat plate type glass-ceramic original plate are chamfered and / or rounded.

[0026] Further, the material of the flat plate type glass-ceramic original plate comprises LAS glass-ceramic.

[0027] Further, the refractory material in the refractory material mold comprises at least one of zirconia refractory material, corundum refractory material, magnesia refractory material, calcium-magnesia refractory material and silica refractory material.

[0028] Further, the thickness of the refractory material mold is ≤15mm.

[0029] Further, the roughness of the inner surface of the refractory material mold is 0.05-4.00μm.

[0030] Further, the central angle of the arc-shaped glass-ceramic plate is >114°.

[0031] Further, the shape of the refractory material mold is arc-shaped; the refractory material mold is connected with auxiliary side edges on two edges in the axial direction of the refractory material mold, respectively; the auxiliary side edges are in the shape of a flat plate; the refractory material mold is fixedly connected or detachably connected with the two auxiliary side edges; and when the refractory material mold is placed with the opening upward, the included angle a between the auxiliary side edge and the horizontal plane satisfies: a > (21750-2490000 / θ) 1 / 2 wherein θ is the central angle of the arc-shaped glass-ceramic plate, in degrees.

[0032] The present disclosure also provides an application of the arc-shaped glass-ceramic plate in the fields of building and decoration.

[0033] Compared with the prior art, the present disclosure has the following beneficial effects:

[0034] (1) The arc-shaped glass-ceramic plate provided by the present disclosure has a smooth surface and good flatness.

[0035] (2) The arc-shaped glass-ceramic plate provided by the present disclosure has no scratches on the surface.

[0036] (3) The arc-shaped glass-ceramic plate provided by the present disclosure has a central angle > 114° and a low thermal expansion coefficient.

[0037] (4) The preparation method of the arc-shaped glass-ceramic plate provided by the present disclosure can produce a low-expansion arc-shaped glass-ceramic plate with a smooth surface and good flatness by polishing first and then forming and crystallizing.

[0038] (5) The preparation method of the arc-shaped glass-ceramic plate provided by the present disclosure has high production efficiency and high yield, and uses the polishing method to polish the flat plate, which has high polishing quality and efficiency, and the plate surface is basically not broken during the polishing process, and the plate loss is small.

[0039] (6) The preparation method of the arc-shaped glass-ceramic plate provided by the present disclosure uses refractory material to replace traditional metal alloy material to manufacture the mold, and the refractory material mold can be used for a long time without deformation and can be used repeatedly.

[0040] (7) The preparation method of the arc-shaped glass-ceramic plate provided by the present disclosure can prepare an arc-shaped glass-ceramic plate with a central angle > 114° by arranging auxiliary side edges on both sides of the mold.

[0041] (8) The preparation method of the arc-shaped glass-ceramic plate provided by the present disclosure can improve the axial flatness of the arc-shaped glass-ceramic plate by controlling the thickness of the refractory material mold.

[0042] (9) The preparation method of the arc-shaped microcrystalline glass plate provided by the present disclosure can ensure that no scratches are generated on the surface of the microcrystalline original plate during the falling process by controlling the included angle a between the auxiliary side edge and the horizontal plane, so that the arc-shaped microcrystalline glass plate prepared has no scratches on the surface. BRIEF DESCRIPTION OF DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the specific embodiments of the present disclosure or the prior art, the drawings needed in the specific embodiment or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are some embodiments of the present disclosure, and those skilled in the art can also obtain other drawings according to these drawings without creative labor.

[0044] Fig. 1 is a structural schematic diagram of the arc-shaped microcrystalline glass plate provided by the present disclosure;

[0045] Fig. 2 is a structural schematic diagram of the arc-shaped microcrystalline glass plate provided by the present disclosure when placed with the opening downward;

[0046] Fig. 3 is another structural schematic diagram of the arc-shaped microcrystalline glass plate provided by the present disclosure when placed with the opening downward;

[0047] Fig. 4 is a structural schematic diagram of the refractory material mold provided by the present disclosure with an auxiliary side edge;

[0048] Fig. 5 is a structural schematic diagram of the double-sided polished flat plate type microcrystalline original plate horizontally placed on the refractory material mold in Example 1 provided by the present disclosure;

[0049] Fig. 6 is a linear expansion coefficient curve diagram of the arc-shaped microcrystalline panel prepared in Example 1 provided by the present disclosure;

[0050] Fig. 7 is a visible light transmittance curve diagram of the arc-shaped microcrystalline panel prepared in Example 1 provided by the present disclosure. DETAILED DESCRIPTION

[0051] The technical solutions of the present disclosure will be described clearly and completely in combination with the drawings and specific embodiments, but those skilled in the art will understand that the following described embodiments are part of the embodiments of the present disclosure, not all the embodiments, and are only used to illustrate the present disclosure, and should not be regarded as limiting the scope of the present disclosure. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present disclosure. The specific conditions are not specified in the embodiments, and the conventional conditions or the conditions recommended by the manufacturer are used. The reagents or instruments used are not specified by the manufacturer, and are conventional products that can be purchased on the market.

[0052] Unless otherwise specified, in this disclosure, terms such as "first aspect," "second aspect," "third aspect," and "fourth aspect" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or quantity, nor should they be construed as implicitly indicating the importance or quantity of the indicated technical features. Moreover, terms such as "first," "second," "third," and "fourth" serve only as a non-exhaustive enumeration and should be understood not to constitute a closed limitation on quantity.

[0053] Unless otherwise specified, the terms "comprising" and "including" as used in this disclosure can be open-ended or closed-ended. For example, "comprising" and "including" can mean that other components not listed may also be included, or that only the listed components may be included.

[0054] Unless otherwise specified, in this disclosure, "one or more" or "at least one" refers to any one, two, or more of the listed items. "Several" refers to any two or more.

[0055] In a first aspect, referring to Figure 1, this disclosure provides an arc-shaped microcrystalline glass plate, wherein the roughness of the inner surface of the arc-shaped microcrystalline glass plate is ≤0.06μm and the roughness of the outer surface of the arc-shaped microcrystalline glass plate is ≤0.06μm;

[0056] The arc-shaped microcrystalline glass plate is arc-shaped;

[0057] The radial unevenness A of the arc-shaped microcrystalline glass plate is ≤0.4%, where A = h / L × 100%; when the arc-shaped microcrystalline glass plate is placed on a horizontal surface with its opening facing down, three vertices of the arc-shaped microcrystalline glass plate are in contact with the horizontal surface, and the distance h from the other vertex to the horizontal surface is; L is the length of the arc-shaped microcrystalline glass plate along the axial direction; h and L have the same unit;

[0058] The axial unevenness B of the arc-shaped microcrystalline glass plate is ≤0.4%, where B = d / L × 100%; when the arc-shaped microcrystalline glass plate is placed on a horizontal surface with its opening facing downwards, the top of the arc-shaped microcrystalline glass plate bends downwards along the axial direction to form a curved arc, and the maximum distance from the curved arc to the line connecting the midpoints of the two curved sides of the arc-shaped microcrystalline glass plate is d; L is the length of the arc-shaped microcrystalline glass plate along the axial direction; d and L have the same unit.

[0059] In this embodiment, the roughness of the inner surface of the arc-shaped microcrystalline glass plate is ≤0.06μm, including but not limited to point values ​​of any one of 0.05μm, 0.04μm, 0.03μm, 0.02μm, and 0.01μm, or a range between any two.

[0060] In this embodiment, the roughness of the outer surface of the arc-shaped microcrystalline glass plate is ≤0.06μm, including but not limited to point values ​​of any one of 0.05μm, 0.04μm, 0.03μm, 0.02μm, and 0.01μm, or a range of values ​​between any two.

[0061] It is understood that the curved microcrystalline glass plate provided in this disclosure has an inner surface roughness of ≤0.06μm, an outer surface roughness of ≤0.06μm, and both inner and outer surfaces have a roughness of ≤0.06μm. The surface is flat and smooth, which can avoid optical scattering, and its flatness is good.

[0062] In this disclosure, roughness was measured using a Mitutoyo SJ-210 according to the ISO 1997 method, with λc set to 2.5.

[0063] In this embodiment, referring to Figure 1, the arc-shaped microcrystalline glass plate is arc-shaped, or arched. It is understood that the arc-shaped microcrystalline glass plate includes two arc-shaped edges and two straight edges, and the arc-shaped microcrystalline glass plate includes four vertices, i.e., the intersections of the arc-shaped edges and the straight edges. Optionally, the vertices can be right angles, chamfers, or rounded corners.

[0064] In this embodiment, the vertices are chamfered or rounded, that is, the curved edges and the two straight edges are chamfered or rounded.

[0065] In this embodiment, the radial unevenness A of the arc-shaped microcrystalline glass plate is ≤0.4%, including but not limited to point values ​​of any one of 0.35%, 0.3%, 0.25%, 0.2%, 0.15%, 0.1%, and 0.05%, or range values ​​between any two.

[0066] In this embodiment, A = h / L × 100%. Referring to Figure 2, when the arc-shaped microcrystalline glass plate is placed on a horizontal surface with its opening facing downwards (at this time, the arc-shaped edge is n-shaped), three vertices of the arc-shaped microcrystalline glass plate are in contact with the horizontal surface, and the distance from the other vertex to the horizontal surface is h; L is the length of the arc-shaped microcrystalline glass plate along the axial direction. Wherein, h and L have the same unit.

[0067] In this embodiment, the axial unevenness B of the arc-shaped microcrystalline glass plate is ≤0.4%, including but not limited to the point value of any one of 0.35%, 0.3%, 0.25%, 0.2%, 0.15%, 0.1%, and 0.05%, or the range between any two.

[0068] In this embodiment, B = d / L × 100%. Referring to Figure 3, when the arc-shaped microcrystalline glass plate is placed on a horizontal surface with its opening facing downwards (at which point the arc-shaped edge is n-shaped), the top end of the arc-shaped microcrystalline glass plate bends downwards along its axial direction to form a curved arc (i.e., the outer side of the top end of the arc-shaped microcrystalline glass plate is concave). The maximum distance between the curved arc and the line connecting the midpoints of the two arc-shaped edges of the arc-shaped microcrystalline glass plate is d; L is the length of the arc-shaped microcrystalline glass plate along its axial direction; where d and L have the same unit.

[0069] In some alternative embodiments, a straight line is drawn at the midpoint of the two curved sides of the curved microcrystalline glass plate, or a calibrated straight metal tube is placed so that both ends of the metal tube contact the midpoints of the two curved sides of the curved microcrystalline glass plate. Since the top of the curved microcrystalline glass plate is concave downwards, there is a certain distance between the concave part and the straight line or metal tube. The maximum gap between the concave part and the straight line or metal tube is d, and this gap d can be measured by a feeler gauge conforming to GB / T 22523. The feeler gauge is a pre-fabricated steel sheet, wherein the thickness of the steel sheet is an integer multiple of 0.05 mm, such as 0.05 mm, 0.10 mm, 0.15 mm, etc.

[0070] In some optional embodiments, the coefficient of thermal expansion of the curved microcrystalline glass plate at temperatures ranging from 40 to 700°C is <0.5ppm / °C. The curved microcrystalline glass plate provided in this disclosure has the advantage of low expansion and can withstand instantaneous temperature differences of up to 750°C. That is, the curved microcrystalline glass plate is placed in a muffle furnace at 780°C and kept at a constant temperature for at least 30 minutes. After being removed, it is immediately immersed in room temperature water and remains completely submerged without breaking or showing any visible cracks.

[0071] Secondly, this disclosure provides a method for preparing the aforementioned arc-shaped microcrystalline glass plate, comprising the following steps:

[0072] S1: Obtain a flat microcrystalline substrate with double-sided polishing.

[0073] Among them, microcrystalline base glass refers to a glass plate that has been melted in a glass melting furnace and rolled into a flat plate shape. It is uncrystallized and can also be called base glass.

[0074] S2: The double-sided polished flat microcrystalline plate is placed on a refractory material mold and placed in a heating furnace for heat treatment to form and crystallize. After cooling, the arc-shaped microcrystalline glass plate is obtained.

[0075] Among them, refractory material molds are used, which do not deform at high temperatures.

[0076] Understandably, during the heat treatment process, the double-polished flat microcrystalline plate softens when heated. Under the influence of gravity, the center of gravity of the microcrystalline plate continues to drop, eventually adhering tightly to the refractory material mold and forming an arc shape.

[0077] The temperature, time, and heating rate of the heat treatment can be any parameters commonly used in the art, and this disclosure does not limit them.

[0078] The method for preparing the arc-shaped microcrystalline glass plate disclosed herein adopts a step of polishing followed by crystallization, which can effectively control the roughness of the inner and outer surfaces of the arc-shaped microcrystalline glass plate to ≤0.06μm. The roughness remains almost unchanged before and after heat treatment. The low-expansion arc-shaped microcrystalline glass plate prepared by this method has a smooth and flat surface with good flatness and no scratches.

[0079] The method for preparing the curved microcrystalline glass plate disclosed herein involves polishing first and then crystallizing, which can save time. Furthermore, the method of polishing first makes it very easy to industrially polish flat plates, resulting in a low breakage rate and high polishing quality during the polishing process.

[0080] Meanwhile, the preparation method of the arc-shaped microcrystalline glass plate provided in this disclosure is simple, and it is formed in one step without subsequent grinding, cutting, polishing and other processes.

[0081] Furthermore, this disclosure uses refractory materials instead of traditional metal alloy materials to manufacture molds. Molds made of refractory materials can be used for a long time without deformation and can be recycled multiple times. This solves the problem of "warping" that easily occurs when using metal materials in existing technologies.

[0082] In some alternative embodiments, the apex of the double-polished flat microcrystalline substrate is chamfered and / or rounded.

[0083] In some alternative embodiments, the four edges of the double-polished flat microcrystalline substrate are chamfered and / or rounded.

[0084] That is, the appearance requirements of the corners and edges of the flat microcrystalline substrate are subject to corresponding machining treatments during the preparation of the microcrystalline substrate.

[0085] In some optional embodiments, in step S1, the method for obtaining the double-sided polished flat microcrystalline substrate includes: S11: calculating the size of the flat microcrystalline substrate corresponding to the curved microcrystalline glass plate, wherein the design size of the flat microcrystalline substrate is larger than the product size of the curved microcrystalline glass plate;

[0086] S21: Polish the flat microcrystalline substrate on both sides and cut the flat microcrystalline substrate to the design size;

[0087] S23: Obtain the flat microcrystalline substrate with double-sided polishing.

[0088] In S11, the size of the flat microcrystalline substrate corresponding to the curved microcrystalline glass plate is calculated. Considering the volume shrinkage during the crystallization process, the design size of the flat microcrystalline substrate is selected to be slightly larger than the final size of the curved microcrystalline glass plate product.

[0089] In S21, a large-sized flat microcrystalline substrate is taken, polished on both sides, and cut to the designed flat substrate size. It can be understood that polishing can be done before or after cutting. Then, the four edges are trimmed to make the ends chamfered or rounded.

[0090] In some alternative embodiments, the double-sided polished flat microcrystalline substrate is placed horizontally, and the horizontal placement of the double-sided polished flat microcrystalline substrate can be corrected using a level.

[0091] In some optional embodiments, the material of the flat microcrystalline substrate includes LAS microcrystalline glass (i.e., flat LAS microcrystalline glass substrate), but is not limited thereto. The method for preparing the arc-shaped microcrystalline glass panel provided in this disclosure can also be applied to other types of microcrystalline glass panels that need to be prepared into an arc shape.

[0092] Among them, the glass transition point of the flat LAS microcrystalline glass substrate, that is, the uncrystallized base glass, is about 700℃, while the glass transition point of the crystallized microcrystalline glass is as high as 900℃ or more, that is, the softening temperature is also as high as 900℃ or more. Therefore, it is difficult to crystallize LAS microcrystalline glass before bending it into shape.

[0093] In some optional implementations, step S2 includes:

[0094] S21: Place the double-polished flat microcrystalline plate on the refractory material mold.

[0095] S22: The double-sided polished flat microcrystalline plate is first preheated, then softened and nucleated, and then crystallized to obtain the arc-shaped microcrystalline glass plate.

[0096] In some alternative embodiments, during the preheating process in step S22, the heating rate is 2–30 K / min, raising the furnace temperature from room temperature to the softening temperature Ts of the flat microcrystalline substrate. The heating rate can be as high as possible while ensuring that the flat microcrystalline substrate and the refractory mold do not crack due to thermal expansion.

[0097] In some optional embodiments, during the softening and nucleation process in step S22, an arc-shaped microcrystalline substrate is formed. The softening temperature Ts is 20–110°C above the Tg point (glass transition point), typically 710–820°C, and is maintained for 10–60 minutes. The softening process can be constant temperature or gradual heating. The total holding time varies depending on the difficulty of forming the microcrystalline panel. Arc-shaped substrates with larger central angles are more affected by gravity, and the softening time may be shorter. If the Ts temperature is too low, the glass viscosity is high, resulting in slow descent under gravity, excessive time consumption, and even potential incomplete bending. If the Ts temperature is too high, crystal growth and increased crystallinity are likely to occur. Increased crystallinity significantly affects viscosity, making the glass difficult to soften and deform, also leading to incomplete bending. Incomplete bending here refers to the final microcrystalline panel having a gap more than 1mm between the lowest point of the outer arc surface and the inner surface of the mold, resulting in a visible void. The temperature in this step is below Tc but above Tg, so the softening temperature generally coincides with the nucleation temperature, and nucleation is completed during the softening process. The softening process can achieve good axial flatness, meaning that the arc-shaped microcrystalline substrate formed after high-temperature softening can usually fit tightly into the mold.

[0098] In some optional embodiments, an arc-shaped microcrystalline glass plate is formed after crystallization in step S22. During the crystallization process, the temperature continues to rise to the crystallization temperature Tc, with a heating rate of 2–15 K / min. The Tc temperature is generally in the range of -30 to +100°C from the Tp point temperature. The Tp temperature is obtained by measuring the thermal effect of the original microcrystalline plate, using conventional testing equipment such as DSC or DTA. The Tc temperature is held for 10–45 minutes, during which crystal growth is achieved. The crystallization temperature range of LAS microcrystalline glass is relatively wide; crystallization can occur not only during the Tc holding stage but also during the pre-crystallization heating stage. Generally, the highest set temperature, Tp point temperature -30 to +100°C, is referred to as the crystallization temperature Tc, and the temperature is held at this temperature. The heating rate can be 1–15 K / min, with the maximum heating rate limited to prevent breakage of the microcrystalline glass and refractory material mold. The holding time is 10 to 45 minutes. Excessive holding time or excessively high holding temperature will cause the high quartz crystal phase to transform into the hydrothermal quartz crystal phase, which will greatly increase the coefficient of expansion. Insufficient holding time or excessively low holding temperature will result in insufficient crystallization and failure to meet the performance requirements of low expansion.

[0099] In some alternative embodiments, the refractory material used in the refractory material mold includes at least one of zirconium refractory material, corundum refractory material, magnesia refractory material, calcium-magnesia refractory material, and silica refractory material.

[0100] In some optional embodiments, the thickness of the refractory material mold is ≤15mm, including but not limited to any one of 14mm, 13mm, 12mm, 11mm, 10mm, 8mm, 6mm, 5mm, 3mm, and 2mm, or a range between any two. It can be selected as 2 to 15mm.

[0101] It is understandable that refractory materials have extremely poor thermal conductivity. When manufacturing refractory material molds, if the transverse temperature difference (with the axis of the arc-shaped microcrystalline plate as the transverse direction) is large, the volume shrinkage during crystallization will cause axial deformation, forming an arch towards the center. The inventors discovered that the thinner the refractory material mold, the smaller the transverse temperature difference, and the better the flatness of the microcrystalline panel, especially the axial flatness. However, refractory material molds with a thickness of <2mm face significant challenges in mold preparation, being prone to breakage during use and processing. Therefore, this disclosure addresses the issue of visual distortion near the arc-shaped edge caused by prior art's failure to consider axial flatness. This ensures better temperature uniformity of the refractory material mold and controls the axial unevenness of both the mold and the resulting arc-shaped microcrystalline glass plate.

[0102] In some alternative embodiments, the maximum thickness of the refractory mold is ≤15mm.

[0103] In some alternative embodiments, the thickness of the refractory mold varies at different bends, with the thickness at the center of the refractory mold being greater than that at both ends. The thickness at the center of the refractory mold (the bottom end when the opening is facing upwards) is the greatest, as shown in Figure 4, while the thickness at both ends is slightly less than that at the center.

[0104] In some alternative implementations, thinner refractory molds are prone to breakage during mold processing or crystallization. In such cases, an auxiliary method can be used, namely, designing side supports on the outside of the refractory mold, to reduce the occurrence of breakage during refractory mold processing or crystallization.

[0105] In some optional embodiments, the roughness of the inner surface of the refractory material mold is 0.05–4.00 μm, including but not limited to point values ​​or ranges between any one of 0.05 μm, 0.10 μm, 0.20 μm, 0.30 μm, 0.50 μm, 0.80 μm, 1.00 μm, 2.00 μm, 3.00 μm, and 4.00 μm. This disclosure uses polished microcrystalline substrates, which are prone to adsorption with the glass phase in the refractory material during crystallization, leading to surface damage of the microcrystalline panel. Increasing the roughness of the inner surface of the refractory material mold can avoid this problem. However, the roughness of the inner surface of the refractory material mold should not be too large; if it is too large, small particles on the surface of the refractory material mold are easily shed during crystallization, thus forming defects such as pits and white spots on the surface of the microcrystalline panel.

[0106] In some alternative embodiments, the central angle θ of the curved microcrystalline glass plate is greater than 114°, including but not limited to a point value or a range of any one of 115°, 116°, 118°, 120°, 130°, 140°, and 160°.

[0107] In some optional embodiments, the refractory material mold is arc-shaped. The refractory material mold has auxiliary sides connected to two sides along its axial direction, as shown in Figure 4. These auxiliary sides are plate-shaped, and their ends are connected to the ends of the refractory material mold. The refractory material mold and the two auxiliary sides are either fixedly connected or detachably connected. When the refractory material mold is placed with its opening facing upwards, the angle α between the auxiliary side and the horizontal plane satisfies the following relationship: α > (21750 - 2490000 / θ). 1 / 2 Where θ is the central angle of the arc-shaped microcrystalline glass plate, i.e., the central angle of the arc, in degrees (°). This ensures that no scratches are generated on the surface of the microcrystalline plate during the drop process.

[0108] That is, the auxiliary side can be an integral structure with the refractory material mold, or it can be a separate structure that is fixed to the required structure by an external bracket.

[0109] This disclosure enables the fabrication of arc-shaped microcrystalline plates with a central angle >114° by setting auxiliary side edges on both sides of the mold. This solves the problem that conventional concave molds are unable to produce arc-shaped microcrystalline plates with a central angle >114° when the length of the base glass exceeds 2R (R being the inner diameter of the arc of the concave mold).

[0110] In some alternative embodiments, after double-sided polishing, the roughness of both surfaces (i.e., the upper surface and the lower surface) of the double-sided polished flat microcrystalline substrate is ≤0.06μm.

[0111] The curved microcrystalline glass plate prepared in this disclosure has an outer surface (the contact surface with the refractory material mold) and an inner surface roughness that is almost identical to that of the flat microcrystalline original plate. The heat treatment process causes almost no degradation in roughness.

[0112] Thirdly, this disclosure provides the application of the aforementioned curved microcrystalline glass panels in the fields of architecture and decoration.

[0113] In the construction field, it includes, but is not limited to, applications in glass curtain walls and wall decorations; in the decoration field, it includes, but is not limited to, applications in interior home decoration, art production, aquariums and fish tanks, and courtyard landscaping.

[0114] The embodiments of this disclosure will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of this disclosure. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0115] In the embodiments and comparative examples disclosed herein, roughness was measured using a Mitutoyo SJ-210 according to the ISO 1997 method, with λc set to 2.5.

[0116] Example 1

[0117] This embodiment provides an arc-shaped microcrystalline panel (i.e., an arc-shaped microcrystalline glass plate) with an arc radius R = 300 mm, an arc chord height d = 173.2 mm, an axial length L = 400 mm, and a thickness of 4 mm. The preparation method includes the following steps:

[0118] (1) Take a flat LAS microcrystalline glass plate, process it to a thickness of 4.05mm, and polish it on both sides to a roughness of 0.026μm. Then cut it into a rectangle with a size of 696.7mm×404mm and trim the four sides to make rounded corners.

[0119] (2) A refractory mold is made using quartz ceramic refractory material (i.e., silica refractory material). The refractory mold is arc-shaped with a thickness ≤8mm. The thickness is greatest at the center of the mold (the bottom end when the opening is facing upwards), at 8mm, while the thickness of other parts is slightly less than 8mm. The arc radius of the refractory mold is 304mm, the central angle of the mold is 180°, and the axial length of the mold is 450mm, exceeding the length of the microcrystalline substrate (405mm axial length) by 45mm. The surface roughness of the inner surface of the refractory mold is 3.86μm.

[0120] The refractory material mold has auxiliary sides connected to two sides along its axial direction. The auxiliary sides are flat and have the same shape and size. The auxiliary sides are 450mm long and have the same length as the refractory material mold. The width of the auxiliary sides (i.e., the direction extending outward from the opening of the refractory material mold) is 90mm. The refractory material mold and the two auxiliary sides are a fixed integrated structure. When the refractory material mold is placed with the opening facing upward, the angle α between the auxiliary sides and the horizontal plane is 55°.

[0121] (3) The double-sided polished flat microcrystalline plate obtained in step (1) is placed horizontally on the refractory material mold obtained in step (2), as shown in Figure 5, and placed in a heating furnace for heat treatment to form and crystallize. Then it is quickly cooled to room temperature to obtain the arc-shaped microcrystalline glass plate, which is arc-shaped.

[0122] The heat treatment specifically includes: preheating from room temperature to 720℃ at a heating rate of 15 K / min for approximately 46 min; then heating to 780℃ for 30 min at a heating rate of 2 K / min to complete the softening and nucleation process; and finally heating to 880℃ at a heating rate of 5 K / min for 20 min, followed by holding at 880℃ for 30 min to complete crystallization.

[0123] The linear expansion coefficient curve of the arc-shaped microcrystalline panel prepared in this embodiment is shown in Figure 6. It can be seen that the thermal expansion coefficient of the arc-shaped microcrystalline panel prepared in Example 1 is 0.29 ppm / ℃ from 40 to 700℃.

[0124] The visible light transmittance curve of the arc-shaped microcrystalline panel prepared in this embodiment is shown in Figure 7. It can be calculated that the visible light transmittance (400-700nm) of the arc-shaped microcrystalline panel prepared in Example 1 is 86.67%. The transmittance was tested according to the method specified in GB / T 2680-1994, using a Hunterlab ColorQuest XE device with a visible light detection wavelength range of 400-700nm.

[0125] Examples 2 to 3

[0126] The differences between Examples 2 and 3 and Example 1 are shown in Table 1.

[0127] Examples 4 to 6

[0128] The differences between Examples 4, 5, and 6 and Example 1 are shown in Table 2.

[0129] Example 7

[0130] The preparation method of the arc-shaped microcrystalline panel provided in this embodiment is basically the same as that in Embodiment 1, except that the refractory material quartz ceramic refractory material is replaced with corundum ceramic refractory material (i.e., corundum refractory material).

[0131] The coefficient of thermal expansion is related to the heat treatment process. The heat treatment processes of Examples 2 to 7 are the same as those of Example 1. Therefore, the coefficient of thermal expansion of the arc-shaped microcrystalline panels obtained in Examples 2 to 7 at 40 to 700°C is basically the same as that of the arc-shaped microcrystalline panel in Example 1.

[0132] Light transmittance is related to heat treatment process and surface roughness. The heat treatment process of Examples 2 to 7 is the same as that of Example 1, and the surface roughness is basically the same as that of Example 1. Therefore, the visible light transmittance of the arc-shaped microcrystalline panels obtained in Examples 2 to 7 is basically the same as that of the arc-shaped microcrystalline panel in Example 1.

[0133] Comparative Examples 1 to 2

[0134] The differences between Comparative Examples 1 and 2 and Example 1 are shown in Table 1. In Comparative Example 1, the maximum mold thickness is 25 mm. In Comparative Example 2, α does not satisfy >(21750-2490000 / θ). 1 / 2 .

[0135] Comparative Examples 3 to 4

[0136] The differences between Comparative Examples 3 and 4 and Example 1 are shown in Table 2. The surface roughness Ra of the mold inner surface of Comparative Example 3 is 0.031 μm. The surface roughness Ra of the mold inner surface of Comparative Example 4 is 4.045 μm.

[0137] Comparative Example 5

[0138] The preparation method of the arc-shaped microcrystalline panel provided in this comparative example is basically the same as that in Example 1. The difference is that in step (2), an arc-shaped iron-based mold (without auxiliary sides) is used instead of a refractory material mold.

[0139] Table 1. Differences in parameters among the groups

[0140] Table 2 shows the differences in parameters between each group.

[0141] As can be seen from Tables 1 and 2, the curved microcrystalline glass plates prepared in each embodiment have a smooth and flat surface with good flatness, no scratches, a central angle >114°, and a low coefficient of thermal expansion.

[0142] The mold of Comparative Example 1 has a maximum thickness of 25mm, which leads to a significant increase in radial and axial unevenness, and higher values ​​for A and B.

[0143] In Comparative Example 2, α does not satisfy >(21750-2490000 / θ). 1 / 2 This resulted in multiple scratches on the surface of the curved microcrystalline glass plate.

[0144] The inner surface roughness of the mold in Comparative Example 3 was too low, resulting in multiple delaminations on the outer surface of the curved microcrystalline glass plate (the contact surface with the mold). This was because the microcrystalline plate adhered to the mold, causing abnormal molding and failure to fit the mold.

[0145] The inner surface roughness of the mold in Comparative Example 4 is too high. Small particles on the mold surface fall off during the crystallization process, resulting in multiple white spots on the outer surface of the curved microcrystalline glass plate. Such defects must be removed by subsequent machining, which does not meet the requirement of this disclosure that no further machining is required.

[0146] Furthermore, Comparative Example 5, due to the use of an iron-based mold without auxiliary sides, exhibited a significantly increased radial unevenness, with a radial unevenness A of 1.70%. Moreover, the use of an iron-based mold in Comparative Example 5 resulted in the unavoidable high-temperature oxidation during heating, producing a large amount of debris that existed between the microcrystalline panel and the mold. Although the debris itself easily detached from the surface of the microcrystalline panel, it caused numerous small pits to appear on the contact surface between the microcrystalline panel and the mold, significantly increasing the surface roughness.

[0147] Although this disclosure has been illustrated and described with specific embodiments, it should be understood that the above embodiments are only used to illustrate the technical solutions of this disclosure and not to limit them; those skilled in the art should understand that modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein, without departing from the spirit and scope of this disclosure; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this disclosure; therefore, this means that all such substitutions and modifications that fall within the scope of this disclosure are included in the appended claims. Industrial applicability

[0148] This disclosure provides an arc-shaped microcrystalline glass plate, its preparation method, and its application. The arc-shaped microcrystalline glass plate has a smooth and flat surface with a surface roughness Ra of ≤0.06μm on both the inner and outer surfaces, which can avoid optical scattering, meet visibility requirements, and has good flatness with low radial and axial unevenness, no "warping" phenomenon, and no obvious visual distortion at the arc edge. It solves the problems of existing arc-shaped microcrystalline panels that are difficult to meet the requirement of double-sided roughness ≤0.06μm and poor radial and axial flatness.

Claims

1. An arc-shaped microcrystalline glass plate, characterized in that, The roughness of the inner surface of the arc-shaped microcrystalline glass plate is ≤0.06μm, and the roughness of the outer surface of the arc-shaped microcrystalline glass plate is ≤0.06μm. The arc-shaped microcrystalline glass plate is arc-shaped; The radial unevenness A of the arc-shaped microcrystalline glass plate is ≤0.4%, where A = h / L × 100%; when the arc-shaped microcrystalline glass plate is placed on a horizontal surface with its opening facing down, three vertices of the arc-shaped microcrystalline glass plate are in contact with the horizontal surface, and the distance h from the other vertex to the horizontal surface is; L is the length of the arc-shaped microcrystalline glass plate along the axial direction; h and L have the same unit; The axial unevenness B of the arc-shaped microcrystalline glass plate is ≤0.4%, where B = d / L × 100%; when the arc-shaped microcrystalline glass plate is placed on a horizontal surface with its opening facing downwards, the top of the arc-shaped microcrystalline glass plate bends downwards along the axial direction to form a curved arc, and the maximum distance from the curved arc to the line connecting the midpoints of the two curved sides of the arc-shaped microcrystalline glass plate is d; L is the length of the arc-shaped microcrystalline glass plate along the axial direction; d and L have the same unit.

2. The arc-shaped microcrystalline glass plate according to claim 1, characterized in that, The coefficient of thermal expansion of the arc-shaped microcrystalline glass plate is <0.5ppm / ℃ at temperatures ranging from 40 to 700℃.

3. The method for preparing the arc-shaped microcrystalline glass plate as described in claim 1 or 2, characterized in that, Includes the following steps: Obtain a flat microcrystalline substrate with double-sided polishing; The double-polished flat microcrystalline plate is placed on a refractory material mold and then subjected to heat treatment for shaping and crystallization to obtain the arc-shaped microcrystalline glass plate.

4. The method for preparing the arc-shaped microcrystalline glass plate according to claim 3, characterized in that, The apex of the double-sided polished flat microcrystalline substrate is chamfered and / or rounded.

5. The method for preparing the arc-shaped microcrystalline glass plate according to claim 3 or 4, characterized in that, The four edges of the double-polished flat microcrystalline substrate are chamfered and / or rounded.

6. The method for preparing the arc-shaped microcrystalline glass plate according to any one of claims 3-5, characterized in that, The material of the flat microcrystalline substrate includes LAS microcrystalline glass.

7. The method for preparing the arc-shaped microcrystalline glass plate according to any one of claims 3-6, characterized in that, The refractory material in the refractory material mold includes at least one of zirconium refractory material, corundum refractory material, magnesia refractory material, calcium-magnesia refractory material and silica refractory material.

8. The method for preparing the arc-shaped microcrystalline glass plate according to any one of claims 3-7, characterized in that, The thickness of the refractory material mold is ≤15mm.

9. The method for preparing the arc-shaped microcrystalline glass plate according to any one of claims 3-8, characterized in that, The roughness of the inner surface of the refractory material mold is 0.05 to 4.00 μm.

10. The method for preparing the arc-shaped microcrystalline glass plate according to any one of claims 3-9, characterized in that, The central angle of the arc-shaped microcrystalline glass plate is >114°.

11. The method for preparing the arc-shaped microcrystalline glass plate according to claim 10, characterized in that, The refractory material mold is arc-shaped; auxiliary sides are connected to two sides along its axial direction, and the auxiliary sides are flat. The refractory material mold is fixedly connected to the two auxiliary sides or detachably connected. When the refractory material mold is placed with its opening facing upward, the angle α between the auxiliary side and the horizontal plane satisfies: α>(21750-2490000 / θ) 1 / 2 Where θ is the central angle of the arc-shaped microcrystalline glass plate, in degrees.

12. The method for preparing the arc-shaped microcrystalline glass plate according to any one of claims 3-11, characterized in that, The step of placing the double-polished flat microcrystalline plate on a refractory material mold and then subjecting it to heat treatment for shaping and crystallization to obtain the arc-shaped microcrystalline glass plate specifically includes: The double-sided polished flat microcrystalline plate is placed on a refractory material mold. The double-sided polished flat microcrystalline plate is first preheated, then softened and nucleated, and then crystallized to obtain the arc-shaped microcrystalline glass plate.

13. The method for preparing the arc-shaped microcrystalline glass plate according to any one of claims 3-12, characterized in that, The steps for obtaining the double-sided polished flat microcrystalline substrate specifically include: Calculate the dimensions of the flat microcrystalline substrate corresponding to the curved microcrystalline glass plate, wherein the design dimensions of the flat microcrystalline substrate are larger than the product dimensions of the curved microcrystalline glass plate; The flat microcrystalline substrate is polished on both sides and then cut to the designed size. The flat microcrystalline substrate is obtained with double-sided polishing.

14. The application of the curved microcrystalline glass panel as described in claim 1 or 2 in the fields of architecture and decoration.

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