A microcrystalline glass, its manufacturing method, housing, and electronic device

Abstract

This disclosure provides a microcrystalline glass, its manufacturing method, housing, and electronic device. The microcrystalline glass comprises, by weight percentage: SiO2: 54.5wt%-61.0wt%; Al2O3: 7.5wt%-12.5wt%; Li2O+Na2O: 13.5wt%-18.5wt%; ZrO2: 7.5wt%-12.5wt%; P2O5: 3.5wt%-6.5wt%; Y2O3: 1.5wt%-5.5wt%. By adjusting the content of each component in the microcrystalline glass, this disclosure allows the microcrystalline glass to achieve a ceramic appearance effect at a lower heat treatment temperature. Simultaneously, it reduces the shaping temperature required for subsequent shaping processes in actual production, which is beneficial for industrial production.

Description

Technical Field

[0001] This disclosure relates to the field of materials technology, and in particular to a microcrystalline glass and its manufacturing method, housing, and electronic device. Background Technology

[0002] As living standards improve, users not only demand higher performance from electronic devices, but also greater attention to their appearance and the durability of their materials. To enhance the premium feel of electronic devices, zirconia ceramic, with its warm, ceramic-like appearance, is often used for the back cover, as it is popular due to its good mechanical properties and aesthetic appeal. However, zirconia ceramic has a high density and poor drop resistance.

[0003] Microcrystalline glass, due to its lower density, superior mechanical properties compared to zirconia ceramics, and ability to exhibit the appearance of glass or ceramics, is increasingly being used in the manufacture of back covers for electronic devices. Currently, when microcrystalline glass achieves a white ceramic appearance, the manufacturing process requires high-temperature hot bending treatment, which is quite challenging to achieve in actual production. Summary of the Invention

[0004] To overcome the problems existing in related technologies, this disclosure provides a microcrystalline glass, a method for manufacturing the same, a housing, and an electronic device.

[0005] According to a first aspect of this disclosure, a microcrystalline glass is provided, wherein the components of the microcrystalline glass, by weight percentage, comprise:

[0006] SiO2: 54.5wt%-61.0wt%; Al2O3: 7.5wt%-12.5wt%; Li2O+Na2O: 13.5wt%-18. 5wt%; ZrO2: 7.5wt%-12.5wt%; P2O5: 3.5wt%-6.5wt%; Y2O3: 1.5wt%-5.5wt%.

[0007] In some embodiments of this disclosure, the mass percentage ratio C1 = SiO2 / Al2O3 ranges from 4.4 to 8.0.

[0008] In some embodiments of this disclosure, the microcrystalline glass contains, by weight percentage, 11.5 wt% - 15.5 wt% Li₂O and 1.5 wt% - 3.5 wt% Na₂O.

[0009] In some embodiments of this disclosure, the mass percentage ratio C2 = (SiO2 + Al2O3) / Li2O ranges from 4.1 to 6.0.

[0010] In some embodiments of this disclosure, the glass-ceramic includes a microcrystalline phase, which includes a first crystalline phase and a second crystalline phase. The first crystalline phase includes β-spodumene and / or β-nepheline, and the second crystalline phase includes one or more of lithium disilicate, lithium metasilicate, and zirconium oxide.

[0011] In a unit mass of the glass-ceramic, the ratio of the mass of the microcrystalline phase to the unit mass is greater than 80%.

[0012] In some embodiments of this disclosure, the first crystalline phase accounts for 40%-60% of the mass of the microcrystalline glass per unit mass, and the second crystalline phase accounts for 30%-40% of the mass.

[0013] In some embodiments of this disclosure, the microcrystalline phase grains are spherical and / or rod-shaped, and the grain size ranges from 50 nm to 500 nm.

[0014] In some embodiments of this disclosure, the glass-ceramic further includes a glass phase, wherein the grains of every two adjacent microcrystalline phases are interlocked by the glass.

[0015] In some embodiments of this disclosure, the microcrystalline glass comprises, by weight percentage:

[0016] SiO2: 55wt%-60wt%; Al2O3: 8wt%-12wt%; Li2O+Na2O: 14wt%-18wt%; ZrO2: 8wt%-12wt%; P2O5: 4wt%-6wt%; Y2O3: 2wt%-5wt% ; B2O3: 0wt%-5wt%; TiO2: 0wt%-4wt%; MgO: 0wt%-2wt%; ZnO: 0wt%-2wt%; SrO: 0wt%-2wt%; CaO: 0wt%-2wt%; Clarifying agent: 0wt%-2wt%.

[0017] In some embodiments of this disclosure, the clarifying agent includes one or more of Sb2O3, SnO2, SnO, and CeO2.

[0018] In some embodiments of this disclosure, the Vickers hardness of the glass-ceramic is greater than 900 HV50 / 10; the fracture toughness of the glass-ceramic is greater than 0.9 MPa·m. 1 / 2 .

[0019] According to a second aspect of this disclosure, a method for manufacturing a microcrystalline glass is provided, for manufacturing the microcrystalline glass provided in the first aspect of this disclosure, the method comprising:

[0020] Based on the mass percentage of each component, under a first preset condition, the components are melted to obtain a microcrystalline glass melt.

[0021] The microcrystalline glass melt is injected into a mold at a preset temperature to form a precursor glass ingot;

[0022] Under the second preset conditions, the precursor glass ingot is annealed to obtain a microcrystalline glass ingot;

[0023] Under the third preset condition, the microcrystalline glass ingot is subjected to heat treatment.

[0024] In some embodiments of this disclosure, the first preset conditions include: a melting temperature of 1500℃-1600℃ and a melting time of 2h-8h; and / or,

[0025] The preset temperature is 750℃-830℃; and / or,

[0026] The second preset conditions include: an annealing temperature of 500℃-800℃ and an annealing time of 5h-12h; and / or,

[0027] The third preset conditions include: a heat treatment temperature of 700℃-800℃ and a heat treatment duration of 5h-20h.

[0028] In some embodiments of this disclosure, the method for manufacturing the microcrystalline glass further includes:

[0029] The microcrystalline glass ingot that has undergone the heat treatment is then sequentially cut, ground, and polished to obtain a microcrystalline glass semi-finished product.

[0030] Under the fourth preset condition, the microcrystalline glass semi-finished product is subjected to ion exchange treatment to obtain the microcrystalline glass.

[0031] In some embodiments of this disclosure, the microcrystalline glass semi-finished product undergoes ion exchange treatment, including:

[0032] The microcrystalline glass semi-finished product is immersed in a molten first mixed salt for a first treatment;

[0033] The microcrystalline glass semi-finished product that has completed the first treatment is immersed in a molten second mixed salt for a second treatment;

[0034] Both the first mixed salt and the second mixed salt include NaNO3 and KNO3.

[0035] In some embodiments of this disclosure, the mass ratio of NaNO3 to KNO3 in the first mixed salt is 4:6;

[0036] In the second mixed salt, the mass ratio of NaNO3 to KNO3 is 3:7.

[0037] In some embodiments of this disclosure, the fourth preset condition corresponding to the first treatment includes: the temperature of the first mixed salt is 450℃-550℃, and the soaking time is 4h-8h.

[0038] The fourth preset conditions corresponding to the second treatment include: the temperature of the second mixed salt is 420℃-520℃, and the soaking time is 0.1h-0.5h.

[0039] According to a third aspect of this disclosure, a housing is provided, the housing being made of the microcrystalline glass provided in the first aspect of this disclosure.

[0040] According to a fourth aspect of this disclosure, an electronic device is provided, the electronic device comprising the housing provided in the third aspect of this disclosure.

[0041] The technical solutions provided by the embodiments of this disclosure may include the following beneficial effects: by adjusting the content of each component in the glass-ceramic, the glass-ceramic can achieve a ceramic appearance effect through a lower heat treatment temperature, and at the same time, the shaping temperature of the glass-ceramic when it needs to be shaped in the subsequent actual production process can be reduced, which is beneficial to industrial production.

[0042] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0043] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0044] Figure 1 This is a flowchart illustrating a method for manufacturing microcrystalline glass according to an exemplary embodiment.

[0045] Figure 2 This is a differential scanning calorimetry curve of a microcrystalline glass according to an exemplary embodiment.

[0046] Figure 3 This is a morphological image of a microcrystalline glass after it has been corroded by hydrofluoric acid, according to an exemplary embodiment. Detailed Implementation

[0047] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the invention as detailed in the appended claims.

[0048] Microcrystalline glass, due to its lower density, superior mechanical properties compared to zirconia ceramics, and ability to exhibit the appearance of glass or ceramics, is increasingly being used in the manufacture of back covers for electronic devices. Currently, to achieve the white ceramic-like appearance of microcrystalline glass, a relatively high heat treatment temperature (approximately 850℃-1000℃) is required during its fabrication to facilitate grain growth. Consequently, when microcrystalline glass is used to manufacture housings, it requires high hot bending temperatures (approximately 900℃-1100℃) to shape it into the desired form. However, in actual production, this hot bending temperature exceeds the upper operating temperature limit of commonly used hot bending machines, making the fabrication of housings using microcrystalline glass quite challenging.

[0049] In view of this, the present disclosure provides a microcrystalline glass. By adjusting the content of each component in the microcrystalline glass, the microcrystalline glass can achieve a ceramic appearance effect through a lower heat treatment temperature. At the same time, it can reduce the shaping temperature of the microcrystalline glass when it needs to be shaped in the subsequent actual production process, which is beneficial to industrial production.

[0050] In an exemplary embodiment of this disclosure, a microcrystalline glass is provided, comprising, by weight percentage: SiO2: 54.5 wt% - 61.0 wt%; Al2O3: 7.5 wt% - 12.5 wt%; Li2O + Na2O: 13.5 wt% - 18.5 wt%; ZrO2: 7.5 wt% - 12.5 wt%; P2O5: 3.5 wt% - 6.5 wt%; Y2O3: 1.5 wt% - 5.5 wt%.

[0051] Glass-ceramic, also known as glass-ceramic, is a multiphase material consisting of a microcrystalline phase and a glassy phase. It differs from both ceramics and glass. The key difference lies in the microcrystalline phase: in glass microcrystallization, the microcrystalline phase originates from a single, homogeneous glassy phase or a region where phase separation has occurred, forming a dense material through primary phase nucleation and crystal growth. In contrast, the crystalline phases in ceramic materials, aside from recrystallization or new crystalline phases arising from solid-state reactions, are mostly introduced directly into the composition during ceramic preparation. The difference between glass-ceramic and glass is that glass-ceramic is a multiphase material composed of a microcrystalline phase and residual glass, while glass is amorphous or non-crystalline. Although the structure and properties of glass-ceramic differ somewhat from both glass and ceramics, it possesses both the basic properties of glass and the polycrystalline characteristics of ceramics, combining the features of both while exhibiting superior performance compared to similar glass and ceramic materials. The composition of the glass-ceramic according to the embodiments is discussed independently below. It should be understood that any range stated in each component can be combined individually with any range stated in any other component.

[0052] SiO2 forms an irregular, continuous network of silicon-oxygen tetrahedral structural units to create the framework of the glass-ceramic, stabilizing the components within the glass-ceramic. Simultaneously, SiO2 is also an essential component for the formation of the microcrystalline phase. Higher SiO2 content (i.e., the mass percentage of this component in the glass-ceramic, hereinafter the same) results in better mechanical properties of the glass-ceramic, but also increases the viscosity of the melt, leading to reduced melt solubility and difficulty in clarification. Furthermore, it increases the heat treatment temperature and the temperature required for shaping in subsequent glass-ceramic fabrication processes. If the SiO2 content is below 54.5 wt%, the resulting glass-ceramic has low crystallinity, making it impossible to obtain the desired microcrystalline phase. Therefore, in the glass-ceramic of this disclosure, the mass percentage of SiO2 is limited to between 54.5 wt% and 61.0 wt%. In some examples, the mass percentage of SiO2 ranges from 55 wt% to 60 wt%. In some examples, the mass percentage of SiO2 ranges from 57 wt% to 60 wt%.

[0053] Al₂O₃ can form a glass network structure to create a microcrystalline glass framework. When combined with SiO₂, it can substantially improve the mechanical properties of the glass and help stabilize the microcrystalline glass structure. Simultaneously, Al₂O₃ can improve the thermal conductivity of the microcrystalline glass and is also an essential component for the formation of the microcrystalline phase. If the Al₂O₃ content is below 7.5 wt%, the desired optimal effect cannot be achieved. Since Al₂O₃ has a high melting point of 2054 °C, if its content exceeds 12.5 wt%, the meltability and devitrification resistance during microcrystalline glass melting will be adversely affected, and the heat treatment temperature and the temperature required for shaping in subsequent manufacturing processes will also increase. Therefore, in the microcrystalline glass disclosed herein, the mass percentage of Al₂O₃ is limited to between 7.5 wt% and 12.5 wt%. In some examples, the mass percentage of Al₂O₃ ranges from 8 wt% to 12 wt%. In some examples, the mass percentage of Al₂O₃ ranges from 8 wt% to 10 wt%.

[0054] Alkali metals Li₂O and Na₂O can reduce the melting difficulty of glass-ceramics and improve their low-temperature melting properties, thereby lowering the forming temperature and the subsequent shaping temperature required for glass-ceramics. Simultaneously, alkali metals can also promote the precipitation of microcrystalline phases in glass-ceramics. To ensure the alkali metals achieve optimal effects, the sum of the mass percentages of Li₂O and Na₂O in the glass-ceramics disclosed herein is limited to between 13.5 wt% and 18.5 wt%. In some examples, the sum of the mass percentages of Li₂O and Na₂O ranges from 14 wt% to 18 wt%. In some examples, the sum of the mass percentages of Li₂O and Na₂O ranges from 15 wt% to 16 wt%.

[0055] Among alkali metals, Li₂O is used to improve the low-temperature melting properties of glass-ceramics, reduce the heat treatment temperature during glass-ceramic fabrication, and lower the shaping temperature required for subsequent shaping. Simultaneously, Li₂O can promote the formation of low-expansion phases such as β-nepheline and β-spodumene in glass-ceramics; that is, Li₂O is an essential component for the formation of microcrystalline phases. If the Li₂O content is less than 11.5 wt%, the glass-ceramic is difficult to melt, and the heat treatment and shaping temperatures are higher, which is detrimental to industrial production. If the Li₂O content is too high, it can easily lead to an increase in the average linear expansion coefficient of the glass-ceramic or a decrease in its chemical durability, resulting in poor stability. Therefore, in the glass-ceramics disclosed herein, the mass percentage of Li₂O is limited to between 11.5 wt% and 15.5 wt%. In some examples, the mass percentage of Li₂O ranges from 12 wt% to 15 wt%. In some examples, the mass percentage of Li₂O ranges from 12 wt% to 13 wt%.

[0056] Na₂O, an alkali metal, is an oxide on the glass network. Sodium ions can reside in the cavities of the glass network, thereby providing free oxygen, increasing the oxygen / silicon ratio in the glass-ceramic structure, causing bond breaking, reducing the viscosity of the glass-ceramic melt, and making the glass-ceramic easier to melt. Simultaneously, Na₂O can also promote the precipitation of microcrystalline phases in the glass-ceramic. If the Na₂O content is less than 1.5 wt%, the melting of the glass-ceramic is difficult, which is not conducive to industrial production. If the Na₂O content is too high, it can easily lead to a decrease in the mechanical strength and chemical stability of the glass-ceramic. Therefore, in the glass-ceramic of this disclosure, the mass percentage of Na₂O is limited to between 1.5 wt% and 3.5 wt%. In some examples, the mass percentage of Na₂O is between 2 wt% and 3 wt%.

[0057] ZrO2 can improve the chemical stability, refractive index, hardness, elasticity, and UV transmittance of glass-ceramics. Simultaneously, ZrO2 can form microcrystalline phases within the glass-ceramic and reduce the energy required for crystal nucleation, allowing nucleation to occur at lower temperatures and promoting crystal formation, thus acting as a nucleating agent. Since ZrO2 has a high melting point of 2680℃, if its content exceeds 12.5 wt%, the meltability and devitrification resistance during glass-ceramic melting will be adversely affected, and the heat treatment temperature and shaping temperature required in subsequent manufacturing processes will also increase. Therefore, in the glass-ceramics disclosed herein, the mass percentage of ZrO2 is limited to between 7.5 wt% and 12.5 wt%. In some examples, the mass percentage of ZrO2 ranges from 8 wt% to 12 wt%. In some examples, the mass percentage of ZrO2 ranges from 8 wt% to 10 wt%.

[0058] P2O5 helps lower the melting temperature and UV transmittance of the glass-ceramic melt, improves its dispersion coefficient and light transmittance, and can also form microcrystalline phases within the glass-ceramic. Furthermore, P2O5 reduces the energy required for crystal nucleation, allowing nucleation to occur at lower temperatures and promoting crystal formation, thus acting as a nucleating agent. However, excessive P2O5 content can lead to a decrease in the devitrification resistance of the glass-ceramic. Therefore, in the glass-ceramic disclosed herein, the mass percentage of P2O5 is limited to between 3.5 wt% and 6.5 wt%. In some examples, the mass percentage of P2O5 ranges from 4 wt% to 6 wt%. In other examples, the mass percentage of P2O5 ranges from 4.5 wt% to 5.5 wt%.

[0059] Because Y₂O₃ has a vacancy-deficient crystal structure, ions from other components in the glass-ceramic can enter these vacancy gaps, increasing the compactness of the glass-ceramic structure and thus improving its skeletal strength and flexural strength during use. As the Y₂O₃ content increases, the coefficient of thermal expansion of the glass-ceramic increases, and its chemical stability decreases. Therefore, in the glass-ceramic disclosed herein, the mass percentage of Y₂O₃ is limited to between 1.5 wt% and 5.5 wt%. In some examples, the mass percentage of Y₂O₃ ranges from 2 wt% to 5 wt%. In some examples, the mass percentage of Y₂O₃ ranges from 2 wt% to 3 wt%.

[0060] In some examples, by reasonably controlling the mass percentage ratio C1 = SiO2 / Al2O3 within the range of 4.4-8.0, the glass-ceramic can possess good skeletal strength, good formability of the melt, and good mechanical strength due to the microcrystalline phase formed within it. In some examples, the mass percentage ratio C1 = SiO2 / Al2O3 can be between 4.6-7.5.

[0061] In some examples, by reasonably controlling the mass percentage ratio C2 = (SiO2 + Al2O3) / Li2O within the range of 4.1-6.0, it is possible to ensure the formation of the required microcrystalline phase in the glass-ceramic, resulting in good mechanical strength and stability, while simultaneously ensuring lower heat treatment and shaping temperatures during subsequent glass-ceramic fabrication, thus improving the industrial applicability of the glass-ceramic. In some examples, the mass percentage ratio C2 = (SiO2 + Al2O3) / Li2O can be between 4.2-6.0.

[0062] For example, since glass-ceramics are multiphase materials comprising a glass phase and a microcrystalline phase, they include multiple microcrystalline phases. Based on the mass percentage of each microcrystalline phase in a unit mass of glass-ceramics, the microcrystalline phases are distinguished into a first crystalline phase and a second crystalline phase, with the first crystalline phase having a greater mass percentage than the second crystalline phase. In a unit mass of glass-ceramics, the ratio of the total mass of the first and second crystalline phases to the unit mass is greater than 80%, meaning that in glass-ceramics, the mass percentage of the microcrystalline phase is greater than 80%, and the mass percentage of the glass phase is less than 20%. For example, in 100 kg of glass-ceramics, the total mass of the microcrystalline phase exceeds 80 kg, and the total mass of the glass phase is less than 20 kg.

[0063] In some embodiments, the first crystalline phase may include β-spodumene (Li₂O·Al₂O₃·4SiO₂) and / or β-nepheline (β-LiAlSiO₄). β-spodumene is a tetragonal crystal with a near-zero or even negative coefficient of thermal expansion, while β-nepheline has a quartz-like structure with a large coefficient of thermal expansion and a low density. Both of these properties contribute to the good thermal shock resistance and dimensional stability of the glass-ceramic, thus extending its service life. For example, the first crystalline phase accounts for 40%-60% of the mass of a unit mass of glass-ceramic.

[0064] The second crystalline phase can include one or more of lithium disilicate (Li₂Si₂O₅), lithium metasilicate (Li₂SiO₃), and zirconium oxide. Lithium disilicate crystals have a cubic structure and a rod-like microstructure, which can improve the mechanical properties of glass-ceramics. Lithium metasilicate has orthorhombic symmetry, and its (Si₂O₆) chains are parallel to the c-axis and linked together by lithium ions. Lithium metasilicate crystals can be easily dissolved from glass-ceramics in dilute hydrofluoric acid. Zirconia crystals have a body-centered cubic structure, which has good stability and high density, giving glass-ceramics high hardness, strength, wear resistance, and corrosion resistance. It is understood that the second crystalline phase can also include other crystals in minute amounts, such as lithium phosphate, cristobalite, rutile, etc. For example, the mass percentage of the second crystalline phase in a unit mass of glass-ceramics is 40%-60%.

[0065] In some embodiments, the grains of the microcrystalline phase can exhibit rod-like, spherical, or a mixture of rod-like and spherical structures. Rod-like grains impart good mechanical strength (flexural strength and fracture toughness) to the glass-ceramic, while spherical grains impart good hardness and strength. This disclosure controls the grain size range to 50 nm-500 nm, making the glass-ceramic transparent, translucent, or opaque in the visible light spectrum, with a transmittance between 20-80%. It should be noted that the grain size in the glass-ceramic can be adjusted based on the heat treatment process during fabrication. When the grain size is small, the glass-ceramic can be transparent or translucent; when the grain size is large, the glass-ceramic is opaque, and its appearance is white, exhibiting a warm, ceramic-like appearance. In some embodiments, the grain size of the microcrystalline phase can be between 100 nm and 250 nm. In some embodiments, the grain size of the microcrystalline phase can be between 250 nm and 500 nm.

[0066] In some embodiments, since the microcrystalline phase in the glass-ceramic is formed from the glass phase or regions where phase separation has occurred, the glass-ceramic also includes an uncrystallized residual glass phase. The microcrystalline grains are closely packed, and the glass phase exists between the grains, allowing the grains to interlock with other adjacent grains in any direction through the glass phase. Thus, a microstructure with high fracture toughness is formed inside the glass-ceramic. This microstructure can prevent crack initiation and propagation, giving the glass-ceramic good reliability. For example, the fracture toughness of the glass-ceramic provided in this disclosure can be greater than 0.9 MPa·m. 1 / 2 .

[0067] Understandably, the high content of hard components such as SiO2, Al2O3, and ZrO2 in glass-ceramics, along with the presence of various high-hardness microcrystalline phases within them, contributes to the high hardness of glass-ceramics, thereby enhancing the abrasion and scratch resistance of structural parts formed from them. For example, the Vickers hardness of glass-ceramics can exceed 900 HV50 / 10, meaning that when the glass-ceramic material is subjected to a test force of 50 kg for 10 seconds, the hardness value remains greater than 900 HV.

[0068] In some embodiments, the microcrystalline glass obtained by using the microcrystalline glass formulation provided in this disclosure, after melting, forming, annealing, heat treatment, and ion exchange, has a white, translucent or opaque appearance similar to ceramics, and good mechanical properties, with a fracture toughness greater than 0.9 MPa·m. 1 / 2 The Vickers hardness is greater than 900 HV50 / 10. Furthermore, when shaping this microcrystalline glass, for example, bending or folding the sides of a sheet-like microcrystalline glass, a shaping temperature needs to be applied to the material at the bending or folding point so that at least part of that point is in a molten state to facilitate shaping. Because the microcrystalline glass formulation provided in this disclosure controls the content ratio of each component and the content ratio of Li2O+Na2O, the melt-to-solid transition temperature of the microcrystalline glass is reduced. This lowers the shaping temperature required for subsequent processing of the microcrystalline glass, allowing the shaping temperature to be between 750℃ and 830℃, significantly lower than the shaping temperature required by existing technologies, which is beneficial for the industrial production and application of microcrystalline glass.

[0069] In one exemplary embodiment, the microcrystalline glass comprises, by weight percentage: SiO2: 55wt%-60wt%; Al2O3: 8wt%-12wt%; Li2O+Na2O: 14wt%-18wt%; ZrO2: 8wt%-12wt%; P2O5: 4wt%-6wt%; Y2O3: 2wt%-5wt%; B2O3: 0wt%-5wt%; TiO2: 0wt%-4wt%; MgO: 0wt%-2wt%; ZnO: 0wt%-2wt%; SrO: 0wt%-2wt%; CaO: 0wt%-2wt%; and clarifying agent: 0wt%-2wt%.

[0070] In this embodiment, the roles of components such as SiO2, Al2O3, Li2O, Na2O, ZrO2, P2O5, and Y2O3 have been described in detail in the above embodiments and will not be repeated here.

[0071] B2O3 can be included in glass-ceramics. When B2O3 is present, it helps to lower the melting temperature and viscosity of the glass-ceramic melt, and promotes crystal growth, especially the growth of large crystals with high aspect ratios. Furthermore, B2O3 helps to achieve an interlocked crystal microstructure, improving the damage resistance of the glass-ceramic. However, if the B2O3 content is too high, it can easily lead to a decrease in the chemical durability and mechanical strength of the glass-ceramic. In embodiments, the mass percentage of B2O3 contained in the glass-ceramic is typically greater than or equal to 0 wt%, for example, between 0 wt% and 5 wt%.

[0072] Microcrystalline glass may contain TiO2. When TiO2 is present, it acts as a nucleating agent, promoting the formation of the β-spodumene crystal phase and the minor rutile crystal phase. Simultaneously, TiO2 can also provide the microcrystalline glass with a rich white, cream, or other opaque colors, allowing it to exhibit a warm, ceramic-like appearance. Furthermore, TiO2 can improve the fracture toughness and chemical stability of the microcrystalline glass. In embodiments, the mass percentage of TiO2 contained in the microcrystalline glass is typically greater than or equal to 0 wt%, for example, between 0 wt% and 4 wt%.

[0073] Microcrystalline glass may contain MgO. When MgO is included, it can improve the chemical stability and mechanical strength of the microcrystalline glass, and also provide the magnesium necessary for the formation of spinel solid solutions in the microcrystalline glass. In embodiments, the mass percentage of MgO contained in the microcrystalline glass is typically greater than or equal to 0 wt%, for example, between 0 wt% and 2 wt%.

[0074] Microcrystalline glass may contain ZnO. When ZnO is included, it can reduce the coefficient of thermal expansion of the microcrystalline glass, and improve its chemical stability, thermal stability, and refractive index. When the microcrystalline glass contains a large amount of free oxygen, ZnO can form zinc oxide tetrahedra and enter the glass's structural network, improving its structural stability. Simultaneously, ZnO can also provide the zinc necessary for the formation of zinc spinel-spinel in the microcrystalline glass. In embodiments, the mass percentage of ZnO contained in the microcrystalline glass is typically greater than or equal to 0 wt%, for example, between 0 wt% and 2 wt%.

[0075] The glass-ceramic may contain SrO, which provides the strontium necessary for the formation of monoclinic strontium feldspar in the glass-ceramic. In embodiments, the mass percentage of SrO contained in the glass-ceramic is typically greater than or equal to 0 wt%, for example, between 0 wt% and 2 wt%.

[0076] Glass-ceramics can contain CaO. When CaO is present, it can accelerate the melting and clarification processes of the components within the glass-ceramic. Simultaneously, it can lower the crystallization activation energy of the glass-ceramic, which is beneficial for crystal precipitation. It can also improve the chemical stability of the glass-ceramic. Furthermore, when CaO is present, diopside, anorthite, and other similar crystal phases can precipitate from the glass-ceramic. In some embodiments, the mass percentage of CaO contained in the glass-ceramic is typically greater than or equal to 0 wt%, for example, between 0 wt% and 2 wt%.

[0077] Microcrystalline glass may contain a clarifying agent. Since bubbles are easily generated in the molten microcrystalline glass during the melting process, the clarifying agent can decompose or vaporize during melting to generate gas, thereby promoting the elimination of bubbles in the molten microcrystalline glass and clarifying the molten glass. This prevents bubbles from remaining in the final microcrystalline glass product, avoiding or reducing the impact of bubbles on the mechanical properties and product consistency of the microcrystalline glass. For example, the clarifying agent may include one or more of Sb₂O₃, SnO₂, SnO, and CeO₂. In some embodiments, the mass percentage of the clarifying agent contained in the microcrystalline glass is typically greater than or equal to 0 wt%, for example, between 0 wt% and 2 wt%.

[0078] This disclosure also provides a method for manufacturing microcrystalline glass, which can be used to manufacture the microcrystalline glass provided in one or more of the above embodiments of this disclosure. (Refer to...) Figure 1 As shown, Figure 1 This is a flowchart illustrating a method for manufacturing glass-ceramics using an exemplary embodiment. The method for manufacturing glass-ceramics may include the following steps:

[0079] Step S101: Based on the mass percentage of each component, under the first preset conditions, each component is melted to obtain a microcrystalline glass melt;

[0080] Step S102: Inject the molten microcrystalline glass into a mold at a preset temperature to form a precursor glass ingot;

[0081] Step S103: Under the second preset conditions, the precursor glass ingot is annealed to obtain a microcrystalline glass ingot;

[0082] Step S104: Under the third preset conditions, the microcrystalline glass ingot is subjected to heat treatment.

[0083] In step S101, the components of the microcrystalline glass may include SiO2, Al2O3, Li2O, Na2O, ZrO2, P2O5, Y2O3, and may also include one or more of B2O3, TiO2, MgO, ZnO, SrO, CaO, and clarifying agents. Based on the range of mass percentages of each component provided in the above embodiments, the raw materials are prepared such that the sum of the mass percentages of each component in the microcrystalline glass equals 100%. For example, the raw materials corresponding to SiO2 may include quartz sand, sandstone, quartzite, etc.; the raw materials corresponding to Al2O3 may be pure Al2O3 or wax stone; the raw materials corresponding to Li2O may include lithium carbonate; the raw materials corresponding to Na2O may include soda ash, sodium sulfate, etc., and the raw materials for other components may be commonly used chemical raw materials, as long as the sum of the mass percentages of each component equals 100%, this disclosure does not impose any restrictions.

[0084] The raw materials corresponding to each component are mixed evenly after being processed by crushing, pulverizing, and sieving. The raw material components are then added to a furnace and melted under first preset conditions to obtain a microcrystalline glass melt. The first preset conditions can be conditions suitable for melting the raw material components, such as melting temperature and melting time. In some embodiments, the first preset conditions may include: a melting temperature between 1500℃ and 1600℃, and a melting time between 2 hours and 8 hours. That is, the raw material components are added to a furnace at a temperature between 1500℃ and 1600℃, and within this temperature range, the raw material components are kept in a molten state and continuously melted for 2 hours to 8 hours to obtain the microcrystalline glass melt.

[0085] In step S102, the molten microcrystalline glass undergoes a shaping process, which may include casting, pressing, drawing, or calendering. In this embodiment, the molten microcrystalline glass is injected into a mold at a preset temperature, and centrifugal casting or gravity casting is used to shape the molten microcrystalline glass into a precursor glass ingot corresponding to the shape of the mold, completing the transformation from molten to solid state. Before injecting the molten microcrystalline glass into the mold, the mold is preheated to a preset temperature, which is lower than the temperature of the molten microcrystalline glass. The preset temperature can be the transition temperature of the molten microcrystalline glass from the molten state to the solid state. For example, based on the proportions of the raw materials in the molten microcrystalline glass provided in this disclosure, the preset temperature can be any temperature between 750℃ and 830℃. In some examples, the preset temperature can be between 780℃ and 810℃.

[0086] In step S103, under the second preset conditions, the formed precursor glass ingot is annealed. Annealing can eliminate stress in the precursor glass ingot, relax its structure, and enhance the mobility of atoms within it, allowing liquid-phase separation to occur. Liquid-phase separation can affect the nucleation, crystal growth, and crystal transformation processes of the glass-ceramic. For example, in the case of liquid-phase separation, nucleating agents can form within the dispersed phase or at the interface between the dispersed and continuous phases to form densely packed primordial crystals, each of which acts as a crystal nucleus. In other words, the glass-ceramic ingot obtained after annealing may contain primordial crystals capable of forming grains.

[0087] The second preset condition can be the conditions for annealing the precursor glass ingot with the specified proportions, such as a suitable annealing temperature and annealing time. In some embodiments, the second preset condition may include: an annealing temperature between 500℃ and 800℃, and an annealing time between 5h and 12h. That is, the formed precursor glass ingot is placed in an annealing furnace at a temperature between 500℃ and 800℃, and held at this temperature for 5h to 12h before being cooled in the furnace to complete the annealing process and obtain a microcrystalline glass ingot. In some examples, the second preset condition may include: an annealing temperature between 500℃ and 650℃, and an annealing time between 5h and 10h.

[0088] In step S104, since the microcrystalline phase in the glass-ceramic ingot has not yet formed, the glass-ceramic ingot is heat-treated under a third preset condition. This allows the desired microcrystalline phase to form in the heat-treated glass-ceramic, and the shape and size of the grains meet the requirements of the desired microstructure, ensuring that the obtained glass-ceramic has good mechanical properties. The third preset condition can be the conditions for heat-treating the glass-ceramic ingot with the specified composition ratio. For example, it may include a suitable heat treatment temperature and time, as well as the heating rate of the glass-ceramic ingot from conventional room temperature (25°C) to the heat treatment temperature.

[0089] For example, the differential scanning calorimetry profile of the glass-ceramic can be measured to determine the appropriate heat treatment temperature. Figure 2 This is a differential scanning calorimetry curve of a microcrystalline glass provided in an exemplary embodiment, for reference. Figure 2 As shown, the glass-ceramic exhibits a significant exothermic peak at around 746.0℃, indicating that the glass-ceramic can undergo good crystallization and crystal growth at this temperature, thus determining the suitable heat treatment temperature range for the glass-ceramic.

[0090] In some embodiments, the third preset condition may include: a heat treatment temperature between 700°C and 800°C, and a heat treatment duration between 5 hours and 20 hours. The microcrystalline glass ingot is placed in a heat treatment furnace, and the temperature inside the furnace is controlled to rise from the normal room temperature (25°C) to the heat treatment temperature for 4 hours to 6 hours. During the heat treatment process, the furnace can be heated uniformly at a rate of 2.8°C / min to 3.2°C / min. As the temperature of the microcrystalline glass ingot increases and the time extends, metastable crystalline phases nucleate and grow in the microcrystalline glass ingot. The metastable crystalline phase is not the microcrystalline phase at the composition point of the original glass on the phase diagram, but rather an intermediate state of the microcrystalline phase; it can be a nascent crystal or a transformation from a nascent crystal. As the temperature continues to rise, reaching the heat treatment temperature (700℃-800℃), it is held at this temperature for 5-20 hours. During this process, the metastable crystalline phase undergoes interactions, decomposition, solvent removal, and allotropic transformation. Simultaneously, crystals continuously precipitate within the glass-ceramic ingot to form a stable final microcrystalline phase, resulting in glass-ceramic glass with a stable microcrystalline phase. In some examples, the heat treatment temperature can be between 720℃ and 760℃.

[0091] It should be noted that the melting time of 2-8 hours in the first preset condition is applicable to the melting of small quantities of microcrystalline glass raw materials (e.g., the total mass of the component raw materials is between 3 kg and 5 kg). Similarly, the annealing time in the second preset condition, the heat treatment time in the third preset condition, and the heating time during heat treatment are also applicable to the production of small quantities of microcrystalline glass raw materials. In industrial production, when large furnaces are used for melting, for example, when the total mass of the microcrystalline glass component raw materials exceeds 1 ton, the melting time can exceed 100 hours at a melting temperature of 1500℃-1600℃ to ensure that each component is fully melted, thereby ensuring that the microcrystalline glass can form the required microstructure and achieve the desired performance. Because the forming molds used in industrial production are larger, and the sizes of the precursor glass ingot and microcrystalline glass ingot are also larger, the annealing time during annealing can exceed 20 hours, the heating time during heat treatment can exceed 20 hours, and the heat treatment time can exceed 80 hours.

[0092] In some possible implementations, after completing step S104 of the above embodiments, the method for manufacturing microcrystalline glass further includes:

[0093] Step S105: The heat-treated microcrystalline glass ingot is cut, ground and polished in sequence to obtain a microcrystalline glass semi-finished product;

[0094] Step S106: Under the fourth preset conditions, the microcrystalline glass semi-finished product is subjected to ion exchange treatment to obtain microcrystalline glass.

[0095] To ensure the final microcrystalline glass exhibits good resistance to damage, the heat-treated microcrystalline glass ingot requires ion exchange treatment to form a stress-compression layer on its surface. However, in industrial production, the molds used for forming are large, resulting in large ingots after heat treatment. If cutting is performed after ion exchange treatment, at least one side of the cut product will lack the stress-compression layer, leading to poor resistance to damage. Therefore, the heat-treated microcrystalline glass ingot is cut before ion exchange treatment. Understandably, the cut surface and the forming surface in contact with the mold may be rough. To avoid affecting the subsequent use of the microcrystalline glass product, the cut semi-finished product undergoes grinding and polishing processes to obtain the required size.

[0096] After obtaining a semi-finished glass-ceramic of suitable size, it undergoes ion exchange treatment under a fourth preset condition to form a stress-compression layer on its surface, thereby obtaining a glass-ceramic with good resistance to damage. Ion exchange treatment involves immersing the semi-finished glass-ceramic in an ion exchange solution. On the surface of the semi-finished glass-ceramic and in the material at a certain depth below the surface, smaller alkali metal ions (lithium ions, sodium ions) are replaced by larger alkali metal ions (sodium ions, potassium ions), forming a stress-compression layer on the surface of the semi-finished glass-ceramic, thus giving the glass-ceramic good resistance to damage. It is understood that the fourth preset condition can be a condition suitable for the exchange of alkali metal ions, such as the temperature of the ion exchange solution and the duration of immersion of the semi-finished glass-ceramic in the ion exchange solution.

[0097] In some possible implementations, in step S106 of the above embodiments, when performing ion exchange treatment on the microcrystalline glass semi-finished product, the microcrystalline glass semi-finished product can be sequentially immersed in a first mixed salt in a molten state for a first treatment, and immersed in a second mixed salt in a molten state for a second treatment. The first and second mixed salts are salts containing sodium and potassium ions, such as nitrates, nitrites, phosphates, sulfates, etc. In some examples, both the first and second mixed salts include NaNO3 and KNO3. In other examples, both the first and second mixed salts include NaNO3, KNO3, and LiNO3.

[0098] The essence of ion exchange treatment is to exchange smaller alkali metal ions on the surface of the microcrystalline glass semi-finished product and at a certain depth from that surface with larger alkali metal ions in a mixed salt. During the first treatment of the microcrystalline glass semi-finished product, the larger K ions in the first mixed salt... + The content of Na with a smaller radius+ The ratio of Na content can be within a small range so that the Na content in the first mixed salt is... + It can fully interact with the Li in the microcrystalline glass semi-finished product + The exchange is performed. For example, when the first mixed salt comprises NaNO3 and KNO3, the mass ratio of NaNO3 to KNO3 is 4:6. When a microcrystalline glass semi-finished product with a thickness of 0.5mm-1mm undergoes the first treatment, the temperature of the molten first mixed salt is between 450℃ and 550℃, and the microcrystalline glass semi-finished product is continuously immersed in the molten first mixed salt at this temperature for 4h-8h to complete the first treatment.

[0099] During the second processing of the microcrystalline glass semi-finished product, due to the fact that most of the Li in the microcrystalline glass semi-finished product... + It has been replaced with Na + The second mixed salt has a larger K radius. + The content of Na with a smaller radius + The ratio of the contents can be in a wide range, meaning that the first mixed salt contains a higher content of KNO3, so that the resulting stress-compression layer contains as many K atoms with larger radii as possible. + This is done to improve the damage resistance of the obtained glass-ceramic. For example, when the second mixed salt includes NaNO3 and KNO3, the mass ratio of NaNO3 to KNO3 is 3:7. When a glass-ceramic semi-finished product with a thickness of 0.5mm-1mm undergoes the second treatment, the temperature of the molten second mixed salt is between 420℃ and 520℃, and the glass-ceramic semi-finished product is continuously immersed in the molten second mixed salt at this temperature for 0.1h-0.5h to complete the second treatment.

[0100] To more clearly explain the technical solution of this disclosure, the following are specific embodiments using the microcrystalline glass provided by this disclosure. The components, mass percentages, and performance parameters of each embodiment are shown in Tables 1 and 2. The samples tested in each embodiment and comparative example have undergone polishing and ion exchange treatment. The dimensions and shapes of the samples tested in each embodiment and comparative example are identical. For example, the samples tested are all microcrystalline glass plates with a length * width * height of 165mm * 70mm * 0.6mm.

[0101] Table 1. Composition and performance parameters of the microcrystalline glass corresponding to Examples 1-8

[0102] category Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 <![CDATA[SiO2(wt%)]]> 59.00 57.00 61.00 58.00 57.50 55.00 56.00 58.20 <![CDATA[Al2O3(wt%)]]> 9.00 9.00 8.50 9.00 9.00 11.00 9.50 12.00 <![CDATA[Li2O(wt%)]]> 13.00 13.00 12.30 13.00 13.00 12.00 13.80 14.00 <![CDATA[Na2O(wt%)]]> 2.50 2.50 2.20 2.50 2.50 2.10 3.00 2.50 <![CDATA[P2O5(wt%)]]> 5.00 5.00 4.50 5.00 5.20 3.80 3.50 3.50 <![CDATA[ZrO2(wt%)]]> 8.50 9.00 8.50 8.50 9.10 7.90 8.20 7.50 <![CDATA[Y2O3(wt%)]]> 2.50 3.00 2.50 2.50 2.50 3.20 2.00 1.50 <![CDATA[B2O3(wt%)]]> / 1.00 / 0.60 / 1.80 0.50 / <![CDATA[TiO2(wt%)]]> / / / / 0.20 1.00 0.10 0.20 MgO (wt%) / / / / 0.30 0.80 0.50 / ZnO (wt%) / / / 0.30 / 0.50 / / SrO (wt%) / / / / 0.20 / 0.90 / CaO (wt%) / / / 0.10 / 0.20 1.20 / Clarifying agent (wt%) 0.50 0.50 0.50 0.50 0.50 0.70 0.80 0.60 Transmittance (%) 30 45 60 25 40 30 35 40 <![CDATA[Fracture toughness (MPa·m 1 / 2 )]]> 1.02 1.05 1.08 1.01 1.04 1.03 1.06 1.04 Drop ball height (cm) 155 165 160 150 160 155 155 160 Vickers hardness (HV) 912 907 904 901 910 915 906 905 Plasticizing temperature (°C) 805 802 793 812 807 789 803 796

[0103] Table 2 shows the composition and performance parameters of the microcrystalline glass corresponding to Examples 9-14 and Comparative Examples 1-2.

[0104]

[0105]

[0106] Transmittance was tested using a UV-Vis spectrophotometer, measuring the wavelength range of visible light (350nm-780nm). Fracture toughness characterizes the ability of the glass-ceramic plate to prevent crack propagation; it measures the glass-ceramic's resistance to brittle fracture. A higher fracture toughness value indicates stronger resistance to crack propagation and greater reliability of the glass-ceramic plate. The fracture toughness of the glass-ceramic provided in this disclosure is greater than 0.9 MPa·m. 1 / 2 Microcrystalline glass has good resistance to brittle fracture.

[0107] The drop height is used to characterize the impact resistance of the glass-ceramic sheet; the higher the drop height, the better the impact resistance. During testing, the glass-ceramic sheet is fixed on a rubber frame, with the sheet as the horizontal plane. A 32g steel ball is dropped from a certain height onto the sheet. The maximum drop height that the glass-ceramic sheet can withstand without breaking is recorded as the "drop height" in Tables 1 and 2. It should be noted that in the impact resistance test, each embodiment started at a height of 40cm. Without breaking the glass-ceramic sheet, the height of each subsequent test was 5cm greater than the height of the previous test. The drop height of the glass-ceramic provided in this disclosure is greater than or equal to 150cm, indicating that the glass-ceramic has good impact resistance.

[0108] Vickers hardness is used to characterize the hardness of glass-ceramic sheets, reflecting their abrasion resistance and scratch resistance. During testing, a 50 kg load is applied, and a square pyramidal diamond indenter with an angle of 136° between its opposing faces is pressed into the surface of the glass-ceramic sheet. After holding the indentation for 10 seconds, the hardness is calculated based on the surface area of ​​the indentation. The glass-ceramic disclosed in this invention exhibits a fracture toughness greater than 900 HV, demonstrating excellent hardness and abrasion resistance.

[0109] The shaping temperature is the temperature at which the edge of a microcrystalline glass plate with dimensions of 165mm*70mm*0.6mm (length*width*height) after polishing and ion exchange treatment is hot-bent and shaped. The shaping temperature of the microcrystalline glass plate provided in this embodiment is significantly lower than that of the microcrystalline glass plate provided in the comparative example, which is beneficial for the industrial application of microcrystalline glass.

[0110] For example, further measurements were performed on the microcrystalline glass plate corresponding to Example 2, referring to... Figure 3 , Figure 3 The morphology was obtained by scanning electron microscopy after etching the microcrystalline glass plate corresponding to Example 2 with dilute hydrofluoric acid. The glass phase in the microcrystalline glass plate was etched by dilute hydrofluoric acid, and what remained was the microcrystalline phase. (Refer to...) Figure 3The microcrystalline glass plate contains relatively large grains, ranging from 100nm to 250nm, and the grain shapes include rod-like and spherical. Therefore, it exhibits low transmittance and a ceramic-like appearance. Simultaneously, its Vickers hardness is 907HV50 / 10, and its fracture toughness is 1.05MPa·m. 1 / 2 The ball drop height is 165cm, and the molding temperature is 802℃. It has good mechanical properties and a low molding temperature.

[0111] In one exemplary embodiment, this disclosure also provides a housing made of the microcrystalline glass provided in the above embodiments of this disclosure. The housing can serve as the casing for electronic devices such as mobile phones, tablets, and watches. Because microcrystalline glass has a ceramic-like appearance and a density lower than that of zirconia ceramic, the housing simultaneously possesses advantages such as good appearance, light weight, and good mechanical properties. The housing can be a 2D, 2.5D, or 3D structure. Due to the low hot bending temperature of microcrystalline glass, existing hot bending machines can easily shape the microcrystalline glass when making 2.5D or 3D structure housings, which is beneficial for the industrial application of microcrystalline glass.

[0112] In one exemplary embodiment, this disclosure also provides an electronic device, which may be a mobile phone, tablet computer, fitness tracker, watch, or other device. The electronic device includes the housing provided in the above embodiments of this disclosure. The housing can be used as the back cover of the electronic device and is in close contact with the battery of the electronic device. The housing of the electronic device provided by this disclosure, while having the same appearance as existing ceramic housings, has the advantages of being lightweight and having superior mechanical properties compared to existing ceramic housings. This gives the electronic device good mechanical properties, which is beneficial for achieving a lightweight feel and improving the user experience.

[0113] Other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of the invention are indicated by the following claims.

[0114] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.

Claims

1. A microcrystalline glass, characterized in that, The components of the glass-ceramic, by weight percentage, include: SiO2: 54.5wt%-61wt%; Al2O3: 7.5wt%-12.5wt%; Li2O+Na2O: 13.5wt%-18.5 wt%; ZrO2: 7.5wt%-12.5wt%; P2O5: 3.5wt%-6.5wt%; Y2O3: 1.5wt%-5.5wt%; By mass percentage, the microcrystalline glass contains 11.5 wt% to 15.5 wt% Li₂O. The mass percentage ratio C2 = (SiO2 + Al2O3) / Li2O ranges from 4.52 to (59.50 + 9.00) / 11.50; The glass-ceramic comprises a microcrystalline phase, which includes a first crystalline phase and a second crystalline phase. The first crystalline phase includes β-spodumene and / or β-nepheline, and the second crystalline phase includes one or more of lithium disilicate, lithium metasilicate, and zirconium oxide. In a unit mass of the glass-ceramic, the mass ratio of the microcrystalline phase to the unit mass is greater than 80%. The grain size of the microcrystalline phase can be 100 nm. Between 500nm; The transmittance of the microcrystalline glass in the visible light band is less than 80%.

2. The microcrystalline glass according to claim 1, characterized in that, The mass percentage ratio C1 = SiO2 / Al2O3 ranges from 4.4 to 8.

0.

3. The microcrystalline glass according to claim 1, characterized in that, The microcrystalline glass contains Na2O: 1.5wt%-3.5wt% by mass percentage.

4. The microcrystalline glass according to claim 1, characterized in that, In a unit mass of the microcrystalline glass, the mass percentage of the first crystalline phase is 40%-60%; and the mass percentage of the second crystalline phase is 30%-40%.

5. The microcrystalline glass according to claim 1, characterized in that, The microcrystalline phase has spherical and / or rod-shaped grains.

6. The microcrystalline glass according to claim 1, characterized in that, The microcrystalline glass also includes a glass phase, and the grains of every two adjacent microcrystalline phases are interlocked by the glass.

7. The microcrystalline glass according to any one of claims 1-6, characterized in that, The components of the glass-ceramic, by weight percentage, include: SiO2: 55wt%-60wt%; Al2O3: 8wt%-12wt%; Li2O+Na2O: 14wt%-18wt%; ZrO2: 8wt%-12wt%; P2O5: 4wt%-6wt%; Y2O3: 2wt%-5wt% ; B2O3: 0wt%-5wt%; TiO2: 0wt%-4wt%; MgO: 0wt%-2wt%; ZnO: 0wt%-2wt%; SrO: 0wt%-2wt%; CaO: 0wt%-2wt%; Clarifying agent: 0wt%-2wt%.

8. The microcrystalline glass according to claim 7, characterized in that, The clarifying agent includes one or more of Sb2O3, SnO2, SnO, and CeO2.

9. The microcrystalline glass according to any one of claims 1-6, characterized in that, The microcrystalline glass has a Vickers hardness greater than 900 HV50 / 10; the microcrystalline glass has a fracture toughness greater than 0.9 MPa·m. 1 / 2 .

10. A method for manufacturing microcrystalline glass, characterized in that, A method for manufacturing the microcrystalline glass according to any one of claims 1-9, comprising: Based on the mass percentage of each component, under a first preset condition, the components are melted to obtain a microcrystalline glass melt. The microcrystalline glass melt is injected into a mold at a preset temperature to form a precursor glass ingot; Under the second preset conditions, the precursor glass ingot is annealed to obtain a microcrystalline glass ingot; Under the third preset condition, the microcrystalline glass ingot is subjected to heat treatment.

11. The method for manufacturing microcrystalline glass according to claim 10, characterized in that, The first preset conditions include: a melting temperature of 1500℃-1600℃ and a melting time of 2h-8h; and / or, The preset temperature is 750℃-830℃; and / or, The second preset conditions include: an annealing temperature of 500℃-800℃ and an annealing time of 5h-12h; and / or, The third preset conditions include: a heat treatment temperature of 700℃-800℃ and a heat treatment duration of 5h-20h.

12. The method for manufacturing microcrystalline glass according to claim 10 or 11, characterized in that, The method for manufacturing the microcrystalline glass further includes: The microcrystalline glass ingot that has undergone the heat treatment is then sequentially cut, ground, and polished to obtain a microcrystalline glass semi-finished product. Under the fourth preset condition, the microcrystalline glass semi-finished product is subjected to ion exchange treatment to obtain the microcrystalline glass.

13. The method for manufacturing microcrystalline glass according to claim 12, characterized in that, The microcrystalline glass semi-finished product is subjected to ion exchange treatment, including: The microcrystalline glass semi-finished product is immersed in a molten first mixed salt for a first treatment; The microcrystalline glass semi-finished product that has completed the first treatment is immersed in a molten second mixed salt for a second treatment; Both the first mixed salt and the second mixed salt include NaNO3 and KNO3.

14. The method for manufacturing microcrystalline glass according to claim 13, characterized in that, In the first mixed salt, the mass ratio of NaNO3 to KNO3 is 4:6; In the second mixed salt, the mass ratio of NaNO3 to KNO3 is 3:

7.

15. The method for manufacturing microcrystalline glass according to claim 13, characterized in that, The fourth preset conditions corresponding to the first treatment include: the temperature of the first mixed salt is 450℃-550℃, and the soaking time is 4h-8h; The fourth preset conditions corresponding to the second treatment include: the temperature of the second mixed salt is 420℃-520℃, and the soaking time is 0.1h-0.5h.

16. A housing, characterized in that, The housing is made of the microcrystalline glass according to any one of claims 1-9.

17. An electronic device, characterized in that, The electronic device includes the housing as described in claim 16.

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