Base glass, glass-ceramics, methods of making the same, glass articles, and end-use devices

Abstract

The embodiment of the present application provides a base glass, which comprises the following components in terms of mole percentage: Y2O3: 4-15%; Al2O3: 3-30%; SiO2: 40-75%; ZrO2: 0.5-4%; Li2O: 3-12%; Na2O: 1.5-9%; P2O5: 0.1-2%; and ZnO: 1-8%, and the base glass can be subjected to heat treatment crystallization and / or chemical ion strengthening treatment. The embodiment of the present application also provides a microcrystalline glass, a preparation method of the microcrystalline glass, a glass product and a terminal device. The base glass of the yttrium-aluminum-silicon system provided by the present application can be subjected to heat treatment microcrystallization to obtain a microcrystalline glass, and the microcrystalline glass can also be subjected to chemical strengthening treatment, so that the obtained microcrystalline glass has relatively high mechanical properties and optical properties.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of glass, in particular to a base glass, a microcrystalline glass, a preparation method of the microcrystalline glass, a glass product and a terminal device using the glass product. BACKGROUND

[0002] With the development of communication and electronic technology, the lightweight, thin, large size and high performance of mobile terminals have become the mainstream trend. Therefore, the use of transparent microcrystalline glass with more outstanding performance has become inevitable for the development of the mobile terminal industry.

[0003] At present, the research on microcrystalline glass of lithium-aluminum-silicon system is relatively mature. Although the microcrystalline glass of this system has good optical properties, the content of lithium oxide in its composition is relatively high, and the cost is relatively high. In addition, the elastic modulus of the lithium-aluminum-silicon system microcrystalline glass is relatively low, and the surface hardness is also relatively low. The lower elastic modulus is easy to break the glass during the drop test (i.e. after being subjected to a certain mechanical impact). The lower surface hardness is not resistant to scratches, easy to produce scratches, and the glass is easy to crack when impacted by a sharp object. SUMMARY

[0004] In view of this, in order to solve at least one of the above defects, the embodiments of the present application provide a yttrium-aluminum-silicon system base glass, which can be heat treated to crystallize and / or chemically ionically strengthened, and the microcrystalline glass prepared from the base glass has both high mechanical properties and optical properties.

[0005] In addition, the embodiments of the present application also provide a microcrystalline glass prepared from the base glass, a preparation method of the microcrystalline glass, a glass product and a terminal device using the glass product.

[0006] The first aspect of the embodiments of the present application provides a base glass, which comprises the following components in terms of mole percentage: yttrium trioxide (Y2O3): 4% to 15%;

[0007] aluminum trioxide (Al2O3): 3% to 30%;

[0008] silicon dioxide (SiO2): 40% to 75%;

[0009] zirconium dioxide (ZrO2): 0.5% to 4%;

[0010] lithium oxide (Li2O): 3% to 12%;

[0011] sodium oxide (Na2O): 1.5% to 9%;

[0012] phosphorus pentoxide (P2O5): 0.1% to 2%;

[0013] Zinc oxide (ZnO) 1% to 8%,

[0014] The base glass can be subjected to heat treatment crystallization and / or chemical ion strengthening treatment.

[0015] By limiting the specific components and the content of each component constituting the yttrium aluminum silicon base glass, a new type of yttrium aluminum silicon system base glass can be prepared. The batch composition of the base glass can be melted at a lower temperature. Through optimization of the heat treatment process, the base glass can precipitate crystal phases with specific crystal forms and sizes to form glass-ceramics. Moreover, the obtained glass-ceramics can be subjected to chemical ion exchange strengthening treatment. Thus, yttrium aluminum silicon system glass-ceramics with high mechanical properties, high transparency, low cost, and large-scale production are formed. It can be understood that the base glass itself can be directly subjected to chemical ion exchange strengthening treatment to obtain strengthened glass to meet different use requirements.

[0016] In combination with the first aspect, in some possible embodiments, the base glass has at least one of the following component ratio relationships:

[0017] The ratio of the mole percentage of Al2O3 to the mole percentage of Y2O3 is 0.2 to 7.5;

[0018] The sum of the mole percentage of Y2O3 and the mole percentage of Al2O3 is 7% to 45%;

[0019] The ratio of the mole percentage of Y2O3 to the mole percentage of Li2O is 0.33 to 8; and

[0020] The ratio of the mole percentage of Li2O to the mole percentage of Na2O is 0.33 to 8.

[0021] By limiting at least one of the above component ratio relationships, transparent yttrium aluminum silicon glass can be prepared, avoiding phase separation or devitrification of the glass. Then, the expected crystal phase types can be formed through controllable crystallization, and the crystal size and distribution can be controlled. Moreover, a better ion exchange effect can be obtained, thereby obtaining glass-ceramics with high strength, high transparency, and low cost.

[0022] In combination with the first aspect, in some possible embodiments, the base glass further includes 0 to 2% titanium dioxide (TiO2) in terms of mole percentage.

[0023] Titanium dioxide can be introduced as a crystal nucleus agent and compounded with ZrO2 and P2O5 to form a composite crystal nucleus agent. Titanium dioxide can improve the nucleation rate of the glass-ceramics. However, when the amount of titanium dioxide is too large, the glass-ceramics will be colored. Therefore, the amount of titanium dioxide is controlled to be within the range of 0 to 2%.

[0024] Further, the total mole percentage of ZrO2, TiO2 and P2O5 is 2% to 6%.

[0025] By controlling the total amount of the composite nucleating agent, a transparent yttrium aluminum silicon glass can be prepared, the crystallization is controllable, and thus the expected crystal phase type can be formed, and the crystal size and distribution can be regulated.

[0026] Further, the ratio of the mole percentage of Y2O3 to the total mole percentage of ZrO2+TiO2+P2O5 is 0.5 to 25.

[0027] By controlling the ratio of the total amount of Y2O3 and the composite nucleating agent, the crystallization of the yttrium-containing crystal phase is more controllable, and thus the expected main crystal phase type can be formed, and the crystal size and distribution can be regulated.

[0028] In combination with the first aspect, in some possible embodiments, the base glass further includes the following components in mole percentage:

[0029] Magnesium oxide (MgO): 0% to 2%;

[0030] Cerium oxide (CeO2): 0.1% to 0.5%;

[0031] Antimony trioxide (Sb2O3): 0.1% to 0.5%.

[0032] The introduction of MgO is beneficial to improve the melting and forming of the glass, but when the introduction amount is too large, the glass is prone to phase separation, and is not conducive to ion exchange. CeO2 and Sb2O3 are introduced as composite fining agents.

[0033] The second aspect of the embodiments of the present application provides a microcrystalline glass, which is obtained by heat treatment and crystallization of the base glass described in the first aspect of the embodiments of the present application, and the main crystal phase of the microcrystalline glass includes Y y Zr x O 1.5y+2x , Zr x Y y O 2x+1.5y and the composite crystal phase of one or more of ZrO2. Further, the main crystal phase of the microcrystalline glass includes the composite crystal phase of one or two of Y y Zr x O 1.5y+2x and Zr x Y y O 2x+1.5y .

[0034] The main crystal phase of the above type helps to improve the hardness, elastic modulus and fracture toughness of the glass-ceramics, and further improve the scratch resistance and impact resistance of the glass-ceramics. Specifically, the Young's modulus of the glass-ceramics is greater than or equal to 90 GPa; the microhardness of the glass-ceramics under the action of 0.2 Kgf is greater than or equal to 700 Hv; and the transmittance of the glass-ceramics at 550 nm in the visible light region is greater than or equal to 88%.

[0035] It can be understood that the crystal phase of the glass-ceramics can be other crystal phases in addition to the above main crystal phase, such as a composite crystal phase of one or more of ZnAl2O4, spodumene and quartz solid solution, etc.

[0036] In combination with the second aspect, in some possible embodiments, the crystallinity of the main crystal phase is greater than or equal to 5% and less than or equal to 90%, and the average crystal size of the main crystal phase is less than or equal to 100 nm.

[0037] The crystallinity of the main crystal phase affects the hardness, elastic modulus, fracture toughness and transmittance of the glass-ceramics. The greater the crystallinity, the greater the hardness, elastic modulus and fracture toughness of the glass-ceramics, but the transmittance is reduced, which is difficult to apply to mobile terminals. The smaller the crystallinity, although the transmittance of the glass-ceramics is improved, the hardness, elastic modulus and fracture toughness are too small, which is also difficult to apply to mobile terminals. Therefore, in the embodiments of the present application, the crystallinity of the main crystal phase is controlled to be greater than or equal to 5% and less than or equal to 90% during the heat treatment process.

[0038] The average crystal size of the main crystal phase and the uniformity of the distribution affect the mechanical properties and optical properties of the obtained glass-ceramics. If the average crystal size is too large, the optical properties are poor, such as low transmittance. If the average crystal size is too small, the mechanical properties will be reduced, such as poor strength and impact resistance. Therefore, in the embodiments of the present application, the average crystal size of the main crystal phase is controlled to be less than or equal to 100 nm during the heat treatment process.

[0039] In combination with the second aspect, in some possible embodiments, the glass-ceramics can be subjected to chemical ion strengthening treatment.

[0040] Through the optimization of the formula of the above base glass and the optimization of the heat treatment process, the obtained glass-ceramics can be subjected to chemical strengthening treatment to further increase the strength of the glass-ceramics, while ensuring that the optical properties are not lost.

[0041] Specifically, the stress layer depth DOC of the ion exchange after the chemical ion strengthening treatment of the glass-ceramics is greater than or equal to 90 μm; the surface compressive stress Cs50 is greater than or equal to 100 MPa; the surface compressive stress value Cs is greater than or equal to 260 MPa; the average tensile stress is greater than or equal to 60 MPa; the microhardness of the glass-ceramics after the chemical ion strengthening treatment is greater than or equal to 780 Hv under the action of 0.2 Kgf; and the four-point bending strength of a 0.7 mm thick sample of the glass-ceramics after the chemical ion strengthening treatment is greater than or equal to 600 MPa under the condition of an impact energy greater than or equal to 0.2 J.

[0042] In combination with the second aspect, in some possible embodiments, the glass transition temperature of the glass-ceramics is greater than or equal to 560 ℃.

[0043] The glass-ceramics obtained after heat treatment of the aforementioned base glass has a high glass transition temperature, and the glass network structure is relatively compact, which can improve the strength of the glass-ceramics and reduce the damage to the glass network structure in the chemical strengthening process.

[0044] The third aspect of the embodiments of the present application provides a preparation method of glass-ceramics, which comprises:

[0045] The batch corresponding to the chemical composition of the base glass is melted, shaped, and annealed to obtain the base glass, wherein the base glass comprises the following components in terms of molar percentage: yttrium oxide (Y2O3): 4% to 15%; aluminum oxide (Al2O3): 3% to 30%; silicon dioxide (SiO2): 40% to 75%; zirconium dioxide (ZrO2): 0.5% to 4%; lithium oxide (Li2O): 3% to 12%; sodium oxide (Na2O): 1.5% to 9%; phosphorus pentoxide (P2O5): 0.1% to 2%; zinc oxide (ZnO): 1% to 8%; and

[0046] The base glass is subjected to heat treatment to obtain the glass-ceramics.

[0047] Through the regulation of the base glass formula, the yttrium aluminum silicon base glass obtained can be subjected to heat treatment to obtain a crystal phase type including Y y Zr x O 1.5y+2x , Zr x Y y O 2x+1.5y , ZrO2, and the crystallinity and crystal size are controllable, so that the glass-ceramics with high mechanical properties and optical properties can be prepared.

[0048] In some possible embodiments, in combination with the third aspect, the heat treatment comprises a first step heat treatment and a second step heat treatment performed sequentially, wherein the first step heat treatment has a heat treatment temperature of 600-720℃ and a heat treatment time of 0.5-40h; the second step heat treatment has a heat treatment temperature of 730-850℃ and a heat treatment time of 0.5-8h.

[0049] By optimizing the heat treatment process, in combination with the regulation of the aforementioned components, the crystallinity and the crystal size of the main crystal phase in the glass-ceramics can be better controlled, so that the crystallinity and the crystal size are as small as possible, the specific crystallinity can be 5%-90%, and the average crystal size is less than or equal to 100nm, thereby reducing the refractive index of the glass-ceramics while ensuring that the glass-ceramics has high strength, so as to improve the transmittance of the glass-ceramics.

[0050] In some possible embodiments, in combination with the third aspect, after the step of obtaining the glass-ceramics, the preparation method further comprises:

[0051] The glass-ceramics is subjected to chemical ion strengthening treatment.

[0052] The obtained glass-ceramics can be subjected to chemical strengthening treatment, thereby further improving the mechanical properties of the glass-ceramics.

[0053] In some possible embodiments, in combination with the third aspect, the chemical ion strengthening treatment comprises at least one ion exchange, and the ion exchange is performed in a metal molten salt containing at least one of sodium ions and potassium ions. Specifically, the chemical ion strengthening treatment comprises a first ion exchange and a second ion exchange, wherein,

[0054] The metal molten salt for the first ion exchange contains sodium nitrate, potassium nitrate and lithium nitrate, the exchange temperature is 430℃-530℃, and the exchange time is 4h-12h;

[0055] The metal molten salt for the second ion exchange contains sodium nitrate, potassium nitrate and lithium nitrate, the exchange temperature is 400℃-500℃, and the exchange time is 0.5h-5h.

[0056] By controlling the chemical strengthening process, the depth of ion exchange can be increased, so that the depth of compressive stress layer DOC is greater than or equal to 90μm, the surface compressive stress Cs50 is greater than or equal to 100MPa, the surface compressive stress value Cs is greater than or equal to 260MPa, the average tensile stress is greater than or equal to 60Mpa, the microhardness of the glass-ceramics subjected to the strengthening treatment is greater than or equal to 780Hv under the action of 0.2Kgf, and the four-point bending strength of the glass-ceramics subjected to the strengthening treatment is greater than or equal to 600MPa under the condition of an impact energy greater than or equal to 0.2J.

[0057] In some possible embodiments, in combination with the third aspect, the melting temperature of the batch corresponding to the chemical composition of the base glass is 1500-1650℃.

[0058] The melting temperature of the batch corresponding to the chemical composition of the base glass is low, and the base glass can be prepared by using a conventional melting method, for example, can be melted by using a silicon-molybdenum furnace, an electric melting furnace, a flame kiln or other high-temperature melting equipment, without the need for special process preparation, and can realize large-scale production.

[0059] In some possible embodiments, in combination with the third aspect, there is at least one of the following matching relationships between the components of the base glass:

[0060] The ratio of the mole percentage of Al2O3 to the mole percentage of Y2O3 is 0.2-7.5;

[0061] The sum of the mole percentage of Y2O3 and the mole percentage of Al2O3 is 7%-45%;

[0062] The ratio of the mole percentage of Y2O3 to the mole percentage of Li2O is 0.33-8; and

[0063] The ratio of the mole percentage of Li2O to the mole percentage of Na2O is 0.33-8.

[0064] In some possible embodiments, in combination with the third aspect, the base glass further comprises 0-2% of titanium dioxide (TiO2) in terms of mole percentage.

[0065] Further, the total mole percentage of ZrO2, TiO2 and P2O5 is 2%-6%.

[0066] Further, the ratio of the mole percentage of Y2O3 to the mole percentage of ZrO2+TiO2+P2O5 is 0.5-25.

[0067] The fourth aspect of the embodiments of the present application provides a glass product, which is prepared from the base glass according to the first aspect of the embodiments of the present application, or is prepared from the glass ceramic according to the second aspect of the embodiments of the present application, or is prepared from the glass ceramic prepared by the preparation method of the glass ceramic according to the third aspect of the embodiments of the present application. Specifically, the glass product is a glass cover plate.

[0068] The glass ceramic prepared by using the aforementioned base glass of the yttrium-aluminum-silicon system has high optical performance and mechanical performance, and the glass product can be used as a protective material, and is applied to various mobile terminals or electronic products, for example, as a glass cover plate of various mobile terminals or electronic products.

[0069] The fifth aspect of the embodiments of the present application provides a terminal device, which comprises the glass product of the fourth aspect of the embodiments of the present application. Specifically, the glass product can be a glass cover plate of the terminal device. It can be understood that, in addition to the terminal device, the glass product can also be used in other products requiring surface protection. BRIEF DESCRIPTION OF DRAWINGS

[0070] Figure 1 FIG. 1 is a structural schematic diagram of a terminal device according to an embodiment of the present application.

[0071] Figure 2 FIG. 2 is a schematic diagram of a preparation process of the microcrystalline glass according to an embodiment of the present application.

[0072] Figure 3 FIG. 3 is a crystal diffraction diagram of the microcrystalline glass prepared in Embodiment 1 to Embodiment 4 and Comparative Example 1 of the present application.

[0073] Figure 4A FIG. 4 is a stress-depth curve diagram of the microcrystalline glass prepared in Embodiment 1 of the present application after ion exchange.

[0074] Figure 4B FIG. 5 is a Na ion concentration distribution diagram of the microcrystalline glass prepared in Embodiment 1 of the present application after ion exchange.

[0075] Figures 5A to 5D FIG. 6 is a crystal morphology diagram of Embodiment 1 to Embodiment 4 of the present application, respectively.

[0076] Main element symbol explanation

[0077] Device 100

[0078] Housing 10

[0079] Glass cover plate 20 DETAILED DESCRIPTION

[0080] The embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application. The data range involved in the present application should include the upper limit and the lower limit, and any range between the upper limit and the lower limit, unless otherwise specified. In addition, when the quantity, concentration or other numerical value or parameter is given in the form of a range, one or more preferred ranges, or a preferred upper limit value and a preferred lower limit value, it should be understood that all ranges formed by any combination of the upper limit or preferred value of any range and the lower limit or preferred value of any range are explicitly disclosed. It should also be understood that the various features disclosed in the specification and drawings can be used in any combination.

[0081] In the present application, the content of each component of the glass is expressed in terms of molar percentage of oxide, unless otherwise specified.

[0082] In addition, in the present application, the "base glass" refers to a glass which is not formed into crystals and is not subjected to a strengthening treatment. In the present application, the "microcrystalline glass" refers to a glass containing crystal phases which is obtained after the base glass is subjected to a heat treatment, or a heat treatment and a strengthening treatment. In the present application, the composition of the base glass and the corresponding microcrystalline glass is substantially equivalent.

[0083] The current lithium-aluminum-silicon microcrystalline glass system has the following problems: the content of lithium oxide is high, the cost is high; the elastic modulus is low, after being subjected to a certain mechanical impact, the glass is easy to break; and the surface hardness is low, not resistant to scratching, and when subjected to impact by a sharp object, the glass is easy to crack. However, the aforementioned problems are caused by the characteristics of the lithium-aluminum-silicon microcrystalline glass system itself, and the improvement space is very limited.

[0084] In view of this, the present inventors prepared a new yttrium-aluminum-silicon glass, and prepared a corresponding yttrium-aluminum-silicon microcrystalline glass through a heat treatment process. By adding yttrium oxide to the aluminum-silicon glass, yttrium ions can well fill the gaps in the glass, change the density of the glass, achieve high elastic modulus and high Vickers hardness of the glass, and thus improve the drop resistance of the glass. However, when the content of yttrium oxide is too high, because the melting point of yttrium oxide is as high as 2410℃, it will lead to difficulties in melting the glass, and special processes such as plasma need to be used for preparation, which is difficult to scale up. In addition, when the content of yttrium oxide is too high, it will also lead to a high refractive index of the glass, which seriously reduces the transmittance of the glass, especially the transmittance of the microcrystalline glass obtained after heat treatment is very low, and the optical performance is poor, which is difficult to apply in the field of terminal cover plates. When the content of yttrium oxide is too low, the glass network structure is loose, and the crystal content is also low, which leads to poor mechanical properties of the microcrystalline glass.

[0085] Therefore, the present inventors have repeatedly tested and researched, and optimized the specific components constituting the yttrium-aluminum-silicon glass system, the content of each component, and the content ratio between the specific components, thereby preparing a new base glass of the yttrium-aluminum-silicon system. The batch composition of the base glass can be melted at a relatively low temperature; the heat treatment process is also optimized, so that the base glass can precipitate crystal phases with specific crystal types and sizes to form a microcrystalline glass; and the obtained microcrystalline glass can also be subjected to a chemical ion exchange strengthening treatment, thereby forming a microcrystalline glass of the yttrium-aluminum-silicon system which has high strength, high transparency, low cost, and can be mass-produced.

[0086] The base glass provided by the embodiments of the present application mainly comprises the following components in terms of mole percentage: yttrium trioxide (Y2O3): 4% to 15%; aluminum trioxide (Al2O3): 3% to 30%; silicon dioxide (SiO2): 40% to 75%; zirconium dioxide (ZrO2): 0.5% to 4%; lithium oxide (Li2O): 3% to 12%; sodium oxide (Na2O): 1.5% to 9%; phosphorus pentoxide (P2O5): 0.1% to 2%; zinc oxide (ZnO): 1% to 8%.

[0087] After the base glass is formed, the crystallization can be prepared by heat treatment, and the main crystal phase of the glass-ceramics includes Y y Zr x O 1.5y+2x , Zr x Y y O 2x+1.5y , ZrO2, and the further main crystal phase of the glass-ceramics can include Y y Zr x O 1.5y+2x , ZrO2, and the further main crystal phase of the glass-ceramics can include Y x Zr y O 2x+1.5y The above type of main crystal phase helps to improve the hardness, elastic modulus and fracture toughness of the glass-ceramics, and further improves the scratch resistance and impact resistance of the glass-ceramics. It can be understood that the glass-ceramics contains other crystal phases with relatively small content in addition to the above main crystal phase, and the specific crystal phase can include one or more of the composite crystal phases of ZnAl2O4, spodumene and quartz solid solution.

[0088] The crystallinity of the main crystal phase affects the hardness, elastic modulus, fracture toughness and transmittance of the glass-ceramic. The greater the crystallinity, the greater the hardness, elastic modulus and fracture toughness of the glass-ceramic, but the transmittance is reduced, making it difficult to apply to mobile terminals. The smaller the crystallinity, the greater the transmittance of the glass-ceramic, but the hardness, elastic modulus and fracture toughness are too small, also making it difficult to apply to mobile terminals. Therefore, in the embodiments of the present application, the crystallinity of the main crystal phase is greater than or equal to 5% and less than or equal to 90% during the heat treatment process. If the crystallinity is too low, the mechanical properties of the glass, such as Young's modulus and Vickers hardness, are not good. If the crystallinity is too high, it is easy to generate impurities, and the transmittance of the glass is reduced. In some embodiments, the crystallinity of the main crystal phase is greater than or equal to 8%; in some embodiments, the crystallinity of the main crystal phase is greater than or equal to 10%; in some embodiments, the crystallinity of the main crystal phase is greater than or equal to 12%; in some embodiments, the crystallinity of the main crystal phase is greater than or equal to 15%; in some embodiments, the crystallinity of the main crystal phase is greater than or equal to 17%; in some embodiments, the crystallinity of the main crystal phase is greater than or equal to 20%; in some embodiments, the crystallinity of the main crystal phase is greater than or equal to 25%; and in some embodiments, the crystallinity of the main crystal phase is greater than or equal to 30%. Controlling the crystallinity of the main crystal phase within the above range can result in a glass-ceramic that has excellent optical properties while improving the mechanical properties such as hardness, elastic modulus and fracture toughness.

[0089] The size and uniformity of the average crystal size of the main crystal phase affect the mechanical and optical properties of the obtained glass-ceramics. If the average crystal size is too large, the optical properties, such as the transmittance, are poor. If the average crystal size is too small, the mechanical properties, such as the strength and impact resistance, are poor. Therefore, in the embodiments of the present application, the average crystal size of the main crystal phase is controlled to be less than or equal to 100 nm during the heat treatment. In some embodiments, the average crystal size of the main crystal phase is less than or equal to 95 nm. In some embodiments, the average crystal size of the main crystal phase is less than or equal to 90 nm. In some embodiments, the average crystal size of the main crystal phase is less than or equal to 85 nm. In some embodiments, the average crystal size of the main crystal phase is less than or equal to 80 nm. In some embodiments, the average crystal size of the main crystal phase is less than or equal to 75 nm. In some embodiments, the average crystal size of the main crystal phase is less than or equal to 70 nm. In some embodiments, the average crystal size of the main crystal phase is less than or equal to 65 nm. In some embodiments, the average crystal size of the main crystal phase is less than or equal to 60 nm. In some embodiments, the average crystal size of the main crystal phase is less than or equal to 55 nm. In some embodiments, the average crystal size of the main crystal phase is less than or equal to 50 nm. Controlling the average crystal size of the main crystal phase within the above range and controlling the uniform distribution of the main crystal phase can make the obtained glass-ceramics have excellent optical properties while improving the mechanical properties such as hardness, elastic modulus, and fracture toughness.

[0090] Y2O3 is a necessary component in the base glass, which can fill the glass gap well and effectively improve the packing degree of the base glass network structure. In addition, Y2O3 as a raw material can form Y y Zr x O 1.5y+2x , Zr x Y y O 2x+1.5yThe crystalline phase of at least one of Y2O3 and ZrO2 as a main component can improve the hardness, elastic modulus and fracture toughness of the glass-ceramics, and further improve the scratch resistance and impact resistance of the glass-ceramics. However, too high content of Y2O3 can increase the refractive index of the glass-ceramics and reduce the transmittance, and thus the glass-ceramics is difficult to be applied to mobile terminals, and thus the content of Y2O3 needs to be controlled in a certain range to balance the optical and mechanical properties of the glass-ceramics. Through a large number of experimental studies, the composition range of Y2O3 is determined: the lower limit is 5%, if too low, lower than 5%, the glass crystallization ability is weak, and the expected glass-ceramics cannot be prepared, the lower limit can be further 6%, the lower limit can be further 7%, and the lower limit can be further 7.5%. The upper limit of Y2O3 can be 15%, if too high, higher than 15%, since the melting point of Y2O3 is high, the component of the base glass is difficult to melt, and the refractive index of the obtained glass-ceramics is large and the transmittance is low, the upper limit can be further 14%, the upper limit can be further 12.5%, the upper limit can be further 11%, and the upper limit can be further 10%. It can be understood that in the embodiments of the present application, the content of Y2O3 can be in the range between any upper limit value and any lower limit value, for example, in the embodiments of the present application, the content of Y2O3 can be 5%-15%, further 6%-14%, further 6%-12.5%, further 7%-11%, and further 7.5%-10%. For example, the content of Y2O3 can be 5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, 10.5%, 11%, 11.5%, 12%, 12.5%, 13%, 13.5%, 14%, 14.5%, 15% or any two values between the above values. By controlling the content of Y2O3 in the above range, the glass-ceramics with good mechanical and optical properties can be obtained, and especially when the content of Y2O3 is in the range of 7.5%-10%, the optical and mechanical properties of the obtained glass-ceramics are obviously improved.

[0091] Al2O3 is a necessary component in the base glass. In the presence of sufficient free oxygen, it can participate in the construction of the glass network structure, which is beneficial to improve the strength and chemical stability of the glass. Appropriate amount of Al2O3 is beneficial to the ion exchange of the glass-ceramics. However, if the content of Al2O3 is too low, the network structure of the glass is loose, and the strength and chemical stability of the glass are low. If the content of Al2O3 is too high, the network structure of the glass is too dense, and the precipitation and growth of the crystal are difficult, thereby affecting the forming of the glass-ceramics. Therefore, the lower limit of the content of Al2O3 in the embodiments of the present application is 3%, the lower limit can be further 5%, the lower limit can be further 8%, and the lower limit can be further 10%. The upper limit of the content of Al2O3 can be 20%, the upper limit can be further 18%, the upper limit can be further 15%, and the upper limit can be further 14%. It can be understood that the content of Al2O3 in the embodiments of the present application can be in the range between any upper limit value and any lower limit value. For example, the content of Al2O3 in the embodiments of the present application can be 5% to 20%, further can be 5% to 18%, further can be 8% to 15%, and further can be 8% to 14%. For example, the content of Al2O3 can be 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, or a value between any two of the above values. By controlling the content in the above range, the strength and chemical stability of the glass can be improved, and sufficient space can be provided for the crystallization and crystal growth, which is beneficial to control the precipitation of the target crystal during the heat treatment. In particular, when the content of Al2O3 is between 8% and 15%, a more stable network structure can be formed, and sufficient space can be provided for the crystallization and crystal growth.

[0092] SiO2 is a necessary component in the base glass, mainly used to form the network structure of the glass, improve the chemical stability and thermal stability of the glass. If the content of SiO2 is below 40%, the glass forming performance of the glass becomes poor, the chemical stability becomes poor, and the glass is prone to phase separation, and even cannot form a glass. Therefore, the lower limit of the content of SiO2 can be 40% or more, and further 45% or more. However, when the content of SiO2 is too high, the melting and crystallization control of the glass-ceramic will become difficult, and therefore, the upper limit of the content of SiO2 can be limited to 75% or less, and further 65% or less. It can be understood that in the embodiments of the present application, the content of SiO2 can be in the range between any upper limit value and any lower limit value, for example, in the embodiments of the present application, the content of SiO2 can be 40% to 75%, and further 45% to 65%. For example, the content of SiO2 can be 45%, 50%, 55%, 60%, 65%, 70%, 75% or a value between any two values. By controlling the content of SiO2 in the above range, the chemical stability and thermal stability of the base glass can be improved, the difficulty of heat treatment crystallization is reduced, and the controllability of crystallization is improved.

[0093] ZrO2 is a necessary component in the base glass, mainly used to form the network structure of the glass, improve the chemical stability and thermal stability of the glass. If the content of SiO2 is below 40%, the glass forming performance of the glass becomes poor, the chemical stability becomes poor, and the glass is prone to phase separation, and even cannot form a glass. Therefore, the lower limit of the content of SiO2 can be 40% or more, and further 45% or more. However, when the content of SiO2 is too high, the melting and crystallization control of the glass-ceramic will become difficult, and therefore, the upper limit of the content of SiO2 can be limited to 75% or less, and further 65% or less. It can be understood that in the embodiments of the present application, the content of SiO2 can be in the range between any upper limit value and any lower limit value, for example, in the embodiments of the present application, the content of SiO2 can be 40% to 75%, and further 45% to 65%. For example, the content of SiO2 can be 45%, 50%, 55%, 60%, 65%, 70%, 75% or a value between any two values. By controlling the content of SiO2 in the above range, the chemical stability and thermal stability of the base glass can be improved, the difficulty of heat treatment crystallization is reduced, and the controllability of crystallization is improved.

[0094] Li2O is a necessary component in the base glass, which can reduce the viscosity of the base glass to facilitate melting, and is also the main component in the ion exchange process, which can increase the depth of the chemical ion strengthening compressive stress by replacing sodium ions and potassium ions. However, if the content of Li2O is less than 3%, on the one hand, it is not conducive to the melting of the glass, and on the other hand, it is difficult to obtain a deeper ion exchange depth. Therefore, the lower limit of the content of Li2O is 3%, and further 6%. If too much Li2O is contained, the chemical stability of the glass will be poor, and it will be difficult to control during crystallization, resulting in phase separation or change of the main crystal phase. Therefore, the upper limit of the content of Li2O is 12%, and further 11%, and further 10.5%. It can be understood that in the embodiments of the present application, the content of Li2O can be in the range between any upper limit value and any lower limit value, for example, in the embodiments of the present application, the content of Li2O can be 3% to 12%, and further can be 6% to 11%, and further can be 6% to 10.5%. For example, the content of Li2O can be 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, 10.5%, 11%, 11.5%, 12% or a value between any two of the above values.

[0095] Na2O is a necessary component in the base glass, which is obviously different from the low Na2O content in general microcrystalline glass. As an external body of the glass network, Na2O mainly provides free oxygen by breaking the network, and has a strong effect on inhibiting crystal precipitation. The low Na2O content in general microcrystalline glass is beneficial to crystal precipitation, but if the content of Na2O is too low in the embodiments of the present application, the content of Na ions and K ions exchanged during ion exchange is insufficient, and the surface compressive stress value is low, which affects the strength. Therefore, in the embodiments of the present application, the content of Na2O cannot be too low, and the lower limit can be 1.5%, and further 2%. If too much Na2O is contained in the glass, on the one hand, it will make the glass expansion coefficient larger, and the thermal stability will be poor, which will cause difficulty in annealing and the risk of explosion, on the other hand, it will also inhibit the precipitation of crystals, reduce the content of crystals, and thus reduce the strength of the microcrystalline glass. Therefore, in the embodiments of the present application, the upper limit of the content of Na2O can be 9%, and further 6%. It can be understood that in the embodiments of the present application, the content of Na2O can be in the range between any upper limit value and any lower limit value, for example, in the embodiments of the present application, the content of Na2O can be 1.5% to 9%, and further can be 2% to 6%. For example, the content of Na2O can be 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9% or a value between any two of the above values.

[0096] P2O5 is a necessary component in the base glass, and its introduction can increase the amount of zirconia introduced and make the glass network loose due to the effect of π bond. Therefore, a small amount of P2O5 can reduce the melting temperature of the glass and improve the ion exchange efficiency. However, too high content of P2O5 can cause the glass to phase separate, affect the optical performance, and even lose transparency. Therefore, the content of P2O5 is 0.1% to 2%, further 0.3-1%. Exemplarily, the content of P2O5 can be 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2% or any value between any two values.

[0097] ZnO is a necessary component in the base glass, and its introduction is beneficial to improve the melting, nucleation and crystallization properties of the glass, but when the amount introduced is too large, the glass is prone to phase separation. Therefore, the content of ZnO in the embodiments of the present application is 1% to 8%, further 3% to 5%. Exemplarily, the content of ZnO can be 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8% or any value between any two values.

[0098] MgO is an optional component in the base glass, and its introduction is beneficial to improve the melting and forming of the glass, but when the amount introduced is too large, the glass is prone to phase separation and is not conducive to ion exchange. Therefore, the content of MgO in the embodiments of the present application is 0% to 2%, further 0.5% to 1.5%. Exemplarily, the content of MgO can be 0, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2% or any value between any two values.

[0099] TiO2 is an optional component in the base glass, and its introduction as a nucleating agent can increase the nucleation rate of the glass-ceramic, but when the amount introduced is too large, the glass-ceramic will be colored. Therefore, the content of TiO2 in the embodiments of the present application is 0% to 2%, further 0.5% to 1.5%. Exemplarily, the content of TiO2 can be 0, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8%, 1.9%, 2% or any value between any two values.

[0100] CeO2and Sb2O3are introduced as composite fining agents, and thus the content of CeO2and Sb2O3in the embodiments of the present application can each be 0.1% to 0.5%, further 0.2% to 0.3%. Exemplarily, the content of CeO2and Sb2O3may each be 0.1%, 0.2%, 0.3%, 0.4%, 0.5% or a value between any two of the above values.

[0101] In addition, in order to be able to prepare transparent yttrium aluminum silicon glass, avoid phase separation or devitrification of the glass, and then form the expected crystal phase type by controllable crystallization, regulate the crystal size and distribution, and obtain a relatively optimal ion exchange effect, thereby obtaining microcrystalline glass with high strength, high transparency and low cost. The embodiments of the present application also limit at least one of the following component ratio relationships (1) to (6):

[0102] (1) The ratio of the mole percentage of Al2O3to the mole percentage of Y2O3may be 0.2 to 7.5, further 0.7 to 3, exemplarily, the ratio can be 0.2, 0.5, 0.7, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5 or a value between any two of the above values.

[0103] (2) The sum of the mole percentage of Y2O3and the mole percentage of Al2O3may be 7% to 45%, further 10% to 40%, exemplarily, the sum of the mole ratio can be 7%, 10%, 15%, 18%, 20%, 25%, 30%, 35%, 40%, 45% or a value between any two of the above values.

[0104] (3) The ratio of the mole percentage of Y2O3to the mole percentage of Li2O can be 0.33 to 8, further 0.33 to 5, exemplarily, the ratio can be 0.33, 0.35, 0.38, 0.4, 0.45, 0.5, 0.55, 0.6, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8 or a value between any two of the above values.

[0105] (4) The ratio of the mole percentage of Li2O to the mole percentage of Na2O can be 0.33 to 8, further 1 to 5, exemplarily, the ratio can be 0.33, 0.38, 0.4, 0.45, 0.5, 0.55, 0.6, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8 or a value between any two of the above values.

[0106] (5) When Ti02 is added in the formulation, the total mole percentage of Zr02, Ti02 and P205 as the composite nucleating agent can be 2% to 6%, further 2% to 5%, for example, the total mole percentage of the composite nucleating agent can be 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7% or any value between any two of the values.

[0107] (6) When Ti02 is added in the formulation, the ratio of the mole percentage of Y203 to the total mole percentage of Zr02+Ti02+P205 can be 0.5 to 25, further 1.5 to 14, for example, the ratio can be 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25 or any value between any two of the values.

[0108] In particular, the Young’s modulus of the glass-ceramics obtained by heat treatment of the base glass of the yttrium-aluminum-silicon system can be above 100 GPa. The microhardness of the glass-ceramics without chemical strengthening can be above 700 Hv, further above 750 Hv under the action of 0.2 Kgf. The glass-ceramics can be further subjected to chemical strengthening, and after chemical strengthening, the depth of the stress layer DOC of ion exchange is greater than or equal to 90 μm (0.6t), further greater than or equal to 110 μm. The microhardness of the strengthened glass-ceramics can be above 780 Hv, further above 820 Hv under the action of 0.2 Kgf. The transmittance of the glass-ceramics can be above 88% (550 nm), further above 90%; the haze is less than or equal to 0.5%, further less than or equal to 0.2%. The four-point bending strength of the strengthened glass-ceramics is greater than or equal to 600 MPa under the condition of an impact energy greater than or equal to 0.2 J for a 0.7 mm thick sample. The glass transition temperature of the glass-ceramics is greater than or equal to 560 °C.

[0109] Therefore, the glass-ceramics made of the base glass of the yttrium-aluminum-silicon system has high optical and mechanical properties, and can be used as a protective material, for example, as a glass cover plate of various mobile terminals or electronic products. The mobile terminal products include but are not limited to mobile phones, tablet computers, desktop computers, notebook computers, smart screens, displays, sound systems, glasses, watches, earphones, vehicle-mounted products, and other mobile office, smart home, sports health, audio-visual entertainment and smart travel related electronic terminal devices. It can be understood that in addition to terminal devices, the glass product can also be used in other products that require surface protection.

[0110] In some embodiments, referring to Figure 1The terminal device 100 can be a mobile phone, and the terminal device 10 includes a middle frame 10 and a glass cover plate 20 connected to the middle frame 10.

[0111] It can be understood that, in addition to the terminal device, the glass product can also be used in other products requiring surface protection.

[0112] It can also be understood that, according to different application scenarios, the base glass can also be directly subjected to chemical strengthening treatment to obtain a strengthened glass.

[0113] Based on the same inventive concept, please refer to Figure 2 The embodiment of the present application also provides a preparation method of the foregoing microcrystalline glass, comprising:

[0114] In step S1, a batch corresponding to the chemical composition of the base glass is melted, shaped, and annealed to obtain the base glass. The components of the base glass are described above and will not be repeated here.

[0115] Specifically, the chemical raw materials or mineral raw materials corresponding to the components of the base glass are melted by using a silicon-molybdenum furnace, an electric melting furnace, a flame kiln, or other high-temperature melting equipment, and are stirred by using a platinum-gold stirring paddle. Subsequently, the base glass is shaped by using a conventional process such as casting, calendering, float method, or down-draw method. After heat preservation and annealing treatment, the yttrium-aluminum-silicon system glass is obtained.

[0116] The melting temperature of the base glass formula of the embodiment of the present application is relatively low, and is approximately in the range of 1500°C to 1650°C. The base glass can be prepared by using a conventional melting method without special process preparation, and can be mass-produced.

[0117] The glass after annealing is cut with a margin on six sides to obtain a glass with a proper size. Then, the glass is subjected to size precision cutting, flat grinding, and edge sweeping by using a wire cutting machine, a CNC engraving machine, and a flat grinding and polishing machine to obtain a base glass with a certain size. The thickness of the base glass can be between 0.1 mm and 1.5 mm.

[0118] In step S2, the obtained base glass is subjected to heat treatment to obtain a microcrystalline glass.

[0119] In the one-step heat treatment, nucleation and growth are simultaneously performed. There are conditions such as crystal agglomeration, unstable generation of crystals, and co-growth of polycrystal phases. During the growth process, small crystals become smaller and large crystals become larger, resulting in coarse and uneven crystal size, and the subsequent crystallization and ion exchange are not ideal.

[0120] Therefore, the embodiment of the present application adopts a two-step heat treatment, specifically as follows:

[0121] The first heat treatment is to heat the base glass at a nucleation temperature of 600-720 °C for 0.5-40 h to form crystal nuclei slowly and sufficiently, i.e. a nucleation process.

[0122] In some embodiments, the nucleation temperature can be further 650-720 °C, and exemplarily, the nucleation temperature can be 600 °C, 610 °C, 620 °C, 630 °C, 640 °C, 650 °C, 660 °C, 670 °C, 680 °C, 690 °C, 700 °C, 710 °C, 720 °C or a value between any two of the above.

[0123] In some embodiments, the nucleation time can be further 5-30 h, 10-20 h, and exemplarily, the nucleation time can be 0.5 h, 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h, 8 h, 9 h, 10 h, 11 h, 12 h, 13 h, 14 h, 15 h, 16 h, 17 h, 18 h, 19 h, 20 h, 22 h, 25 h, 28 h, 30 h, 35 h, 40 h or a value between any two of the above.

[0124] The second heat treatment is to heat the nucleated glass sheet at a crystallization temperature of 730-850 °C for 0.5-8 h to precipitate crystals and further grow the crystals, i.e. a crystallization process, so as to obtain a glass-ceramic with uniform crystal size, no obvious crystal outline, and an average crystal size of 5-100 nm.

[0125] In some embodiments, the crystallization temperature can be further 750-780 °C, and exemplarily, the nucleation temperature can be 730 °C, 740 °C, 750 °C, 760 °C, 770 °C, 780 °C, 790 °C, 800 °C, 810 °C, 820 °C, 830 °C, 840 °C, 850 °C or a value between any two of the above.

[0126] In some embodiments, the crystallization time can be further 0.5-6 h, 1-4 h, and exemplarily, the nucleation time can be 0.5 h, 1 h, 1.5 h, 2 h, 2.5 h, 3 h, 3.5 h, 4 h, 4.5 h, 5 h, 5.5 h, 6 h, 6.5 h, 7 h, 7.5 h, 8 h or a value between any two of the above.

[0127] When the nucleation temperature is too high or the crystallization temperature is too low, it is difficult to form crystals with a specific size and uniform size distribution. When the nucleation temperature is too low or the crystallization temperature is too high, the temperature is too high for the base glass to normally crystallize, and the crystal size is prone to grow too large, reducing the transmittance. Therefore, within the above crystallization temperature and nucleation temperature ranges, it is beneficial to control the size and distribution of the crystals. In addition, the nucleation process has a longer heat treatment time, which can make the nucleation more sufficient and improve the uniformity of the crystal distribution. The crystallization stage has a shorter heat treatment time, which can control the size of the crystals from growing too large. Therefore, through the above heat treatment process, the microcrystalline glass with high mechanical properties and optical properties can be obtained.

[0128] By optimizing the heat treatment process and combining the regulation of the aforementioned components, the crystallinity and crystal size of the main crystal phase in the microcrystalline glass can be better controlled, and the crystallinity and crystal size are as small as possible. The specific crystallinity can be 5%-90%, and the average crystal size is less than or equal to 100 nm, thereby reducing the refractive index of the microcrystalline glass while ensuring that the microcrystalline glass has high strength, to improve the transmittance of the microcrystalline glass.

[0129] Step S3, the microcrystalline glass is subjected to chemical strengthening treatment.

[0130] The chemical strengthening treatment includes at least one ion exchange, and the ion exchange is performed in a metal molten salt, wherein the metal molten salt can include at least one of sodium ions, potassium ions, and lithium ions, etc.

[0131] Specifically, in the embodiments of the present application, the chemical strengthening treatment includes twice ion exchange.

[0132] The metal molten salt of the first ion exchange includes sodium nitrate, potassium nitrate, lithium nitrate, etc., the exchange temperature is 430-530°C, and the exchange time is 4-12h.

[0133] In some embodiments, the exchange temperature can be further 450-500°C, and can be further 450-480°C. For example, the exchange temperature can be 430°C, 440°C, 450°C, 460°C, 470°C, 480°C, 490°C, 500°C, 510°C, 520°C, 530°C, or a value between any two of the above values.

[0134] In some embodiments, the exchange time can be further 5-10h, and for example, the exchange time can be 4h, 5h, 6h, 7h, 8h, 9h, 10h, 11h, 12h, or a value between any two of the above values.

[0135] The metal molten salt for the second ion exchange includes sodium nitrate, potassium nitrate, lithium nitrate and the like, and the exchange time is 400-500℃, and the exchange time is 0.5h-5h.

[0136] In some embodiments, the exchange temperature can be further 430℃-480℃, and can be further 450℃-480℃. For example, the exchange temperature can be 400℃, 410℃, 420℃, 430℃, 440℃, 450℃, 460℃, 470℃, 480℃, 490℃, 500℃ or any value between any two of the above values.

[0137] In some embodiments, the exchange time can be further 1h-4h, and for example, the exchange time can be 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h or any value between any two of the above values.

[0138] In the strengthening process, the first ion exchange is mainly to increase the depth of the glass strengthening stress; the second ion exchange is mainly to increase the surface stress. By controlling the strengthening process, the glass stress can be optimized to improve the impact resistance and drop resistance of the glass.

[0139] The embodiments of the present application are further described below through specific examples. In different embodiments, the composition of the base glass and the preparation process conditions and strengthening process conditions of the glass-ceramics are different. The specific base glass formula and process conditions are shown in Table 1, and the corresponding characteristic parameters are shown in Table 2.

[0140] Table 1

[0141]

[0142] Table 2

[0143]

[0144] Note: The chemical strengthening conditions of the above embodiments 1-4 are two-step strengthening, in which the first step strengthening uses a salt bath of NaNO3(95%)+KNO3(5%), 490℃ salt bath for 8 hours; the second step strengthening uses a salt bath of KNO3(100%), 450℃, exchange for 1 hour. The thickness of the glass-ceramics is 0.65mm.

[0145] The method for the above performance test is as follows:

[0146] Elastic modulus: refer to GB / T 7962.6-2010, and determine by an elastic modulus meter.

[0147] Microhardness: refer to GB / T 37900-2019, and determine by a Vickers hardness meter.

[0148] Visible light transmittance: measured using a spectrophotometer in accordance with GB / T 2410-2008.

[0149] Haze: Refer to GB / T2410-2008, using Konica Minolta CM3600A colorimeter.

[0150] Cs50 after ion exchange: measured using a Zheyuan SLP series instrument.

[0151] Ion exchange depth: Measured using the Zheyuan SLP series instrument.

[0152] Surface compressive stress value: measured using the Zheyuan SLP series instrument.

[0153] Average tensile stress Ct-Av: measured using the Folding Origin SLP series instrument.

[0154] Falling ball impact test: A steel ball with a diameter of ￠20mm and a weight of 32.65g was used to impact the glass in free fall. The drop height h corresponding to glass breakage was recorded, and the impact energy was converted into the corresponding impact energy using the energy calculation formula: J=Mgh, where M is the mass of the steel ball, and g=9.8m / s². 2 h is the glass failure height.

[0155] In addition, such as Figure 3 The figure shows the diffraction patterns of the crystals in the glass-ceramics prepared in Examples 1-4 and Comparative Example 1. As can be seen from the figures, the main crystalline phase in the glass-ceramics of Examples 2-3 is Y4Zr3O. 12 Crystal phases: In the glass-ceramic of Example 1, the main crystalline phases besides Y4Zr3O are... 12 The crystalline phase also contains Li(AlSi2O6) crystalline phase; the main crystalline phase in the glass-ceramic of Example 4 is Zr. 0.72 Y 0.28 O 1.862 A composite crystalline phase consisting of three crystalline phases: Li(AlSi2O6) and Y2Si2O7. In contrast, the main crystalline phase in the microcrystalline glass of Comparative Example 1 is Zr. 0.9 Y 0.1 O 1.95 Y2Si2O7, Y4Zr3O 12 The composite crystalline phase of ZnAl2O4 indicates that when the composition design is inappropriate, crystals such as Li(AlSi2O6) and Y2Si2O7 are easily precipitated in the glass-ceramic, leading to a decrease in transmittance and an increase in haze.

[0156] like Figure 4A and Figure 4B The image shows the concentration distribution of Na ions in the microcrystalline glass of Example 1 after ion exchange. Figure 4AIt can be seen from the chemical fortification that Na + Ions are enriched in the glass surface layer, and with increasing depth, Na+ ions increase. + The ion concentration is decreasing. From Figure 4B As can be seen, after chemical strengthening, the ion exchange depth can reach 136 μm, and the compressive stress value is relatively high, while the tensile stress is more suitable.

[0157] like Figures 5A to 5D The figures show the morphology of the crystals in the glass-ceramics of Examples 1-4. As can be seen from the figures, the crystals in the glass-ceramics of Examples 1-4 are evenly distributed and uniform in size. The crystals formed are nanocrystals with a size of less than 100 nm, which can help improve the transmittance of the glass-ceramics.

[0158] It should be noted that the above are merely specific embodiments of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Where there is no conflict, the embodiments and features described in the embodiments of this application can be combined with each other. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A microcrystalline glass characterized in that, The microcrystalline glass is obtained by heat treatment of a base glass, and the main crystal phase of the microcrystalline glass comprises Y y Zr x O 1.5y+2x and Zr x Y y O 2x+1.5y and one or both of a composite crystal phase, wherein x and y are both greater than zero. The base glass comprises the following components in mole percentage: Yttrium trioxide (Y2O3): 4%~15%; Aluminum trioxide (Al2O3): 3%~30%; Silicon dioxide (SiO2): 40%~75%; Zirconium dioxide (ZrO2): 0.5%~4%; Lithium oxide (Li2O): 3%~12%; Sodium oxide (Na2O): 1.5%~9%; Phosphorus pentoxide (P2O5): 0.1%~2%; Zinc oxide (ZnO): 1%~8%, The base glass can be subjected to heat treatment crystallization and / or chemical ion strengthening treatment.

2. The glass-ceramic according to claim 1, characterized in that, The crystal phase of the glass-ceramics further comprises a composite crystal phase of one or more of ZnAl2O4, spodumene and quartz solid solution.

3. The glass-ceramic according to claim 1, characterized in that, The crystallinity of the main crystal phase is 5%~90%, and the average crystal size of the main crystal phase is less than or equal to 100nm.

4. The glass-ceramic according to claim 1, characterized in that, The Young's modulus of the glass-ceramics is greater than or equal to 90GPa; The microhardness of the glass-ceramics under the action of 0.2Kgf is greater than or equal to 700Hv.

5. The glass-ceramic according to claim 1, characterized in that, The transmittance of the glass-ceramics in the visible light region at 550nm is greater than or equal to 88%.

6. The glass-ceramic according to claim 1, characterized in that, The glass-ceramics can be subjected to chemical ion strengthening treatment.

7. The glass-ceramic according to claim 6, characterized in that, After the chemical ion strengthening treatment, the stress layer depth DOC of the glass-ceramics is greater than or equal to 90μm; The surface compressive stress Cs50 is greater than or equal to 100MPa; The surface compressive stress value Cs is greater than or equal to 260MPa; The average tensile stress is greater than or equal to 60Mpa; The microhardness of the glass-ceramics subjected to the chemical ion strengthening treatment under the action of 0.2Kgf is greater than or equal to 780Hv.

8. The glass-ceramic according to claim 6, characterized in that, The four-point bending strength of the glass-ceramics subjected to the chemical ion strengthening treatment is greater than or equal to 600MPa under the condition of impact energy greater than or equal to 0.2J.

9. The glass-ceramic according to claim 1, characterized in that, The glass transition temperature of the glass-ceramics is greater than or equal to 560℃.

10. The glass-ceramic according to claim 1, characterized in that, The base glass satisfies at least one of the following matching relationships among the components: The ratio of the mole percentage of Al2O3 to the mole percentage of Y2O3 is 0.2~7.5; The sum of the mole percentage of Y2O3 and the mole percentage of Al2O3 is 7%~45%; The ratio of the mole percentage of Y2O3 to the mole percentage of Li2O is 0.33~8; and The ratio of the mole percentage of Li2O to the mole percentage of Na2O is 0.33~8.

11. The glass-ceramic according to claim 1, characterized in that, The base glass further comprises 0~2% of titanium dioxide (TiO2) in mole percentage.

12. The glass-ceramic according to claim 11, characterized in that, The total mole percentage of ZrO2, TiO2 and P2O5 is 2%~6%.

13. The glass-ceramic according to claim 11, characterized in that, The ratio of the mole percentage of Y2O3 to the total mole percentage of ZrO2+TiO2+P2O5 is 0.5-25.

14. The glass-ceramic according to claim 1, characterized in that, The base glass further comprises the following components in mole percentage: Magnesium oxide (MgO): 0%~2%; Cerium oxide (CeO2): 0.1%~0.5%; Antimony trioxide (Sb2O3): 0.1%~0.5%.

15. A method for preparing microcrystalline glass, characterized in that, The base glass further comprises the following components in mole percentage: melting, shaping, annealing a batch corresponding to a chemical composition of a base glass to obtain the base glass, wherein the base glass comprises the following components in terms of mole percentage: Yttrium trioxide (Y2O3): 4%~15%; Aluminum trioxide (Al2O3): 3%~30%; Silicon dioxide (SiO2): 40%~75%; Zirconium dioxide (ZrO2): 0.5%~4%; Lithium oxide (Li2O): 3%~12%; Sodium oxide (Na2O): 1.5%~9%; Phosphorus pentoxide (P2O5): 0.1%~2%; Zinc oxide (ZnO): 1%~8%; and The base glass is heat treated to crystallize to obtain the glass-ceramic, the main crystal phase of the glass-ceramic includes Y y Zr x O 1.5y+2x and Zr x Y y O 2x+1.5y one or a composite crystal phase of two of Y x and y are both greater than zero.

16. The method of claim 15, wherein the glass-ceramic is prepared by the steps of: The heat treatment comprises a first step heat treatment and a second step heat treatment performed in sequence, wherein, the first step heat treatment has a heat treatment temperature of 600~720℃ and a heat treatment time of 0.5~40h; the second step heat treatment has a heat treatment temperature of 730~850℃ and a heat treatment time of 0.5~8h.

17. The method for preparing microcrystalline glass according to claim 15 or 16, characterized in that, After the step of obtaining the glass-ceramic, the preparation method further comprises: chemically ionically strengthening the glass-ceramic.

18. The method of claim 17, wherein the glass-ceramic is prepared by the steps of: The chemical ionically strengthening treatment comprises at least one ion exchange, and the ion exchange is performed in a metal molten salt containing at least one of sodium ions, potassium ions and lithium ions.

19. The method of claim 18, wherein the glass-ceramic is prepared by the steps of: The chemical ionically strengthening treatment comprises a first ion exchange and a second ion exchange, wherein, the metal molten salt for the first ion exchange contains sodium nitrate, potassium nitrate and lithium nitrate, the exchange temperature is 430℃~530℃, and the exchange time is 4h~12h; the metal molten salt for the second ion exchange contains sodium nitrate, potassium nitrate and lithium nitrate, the exchange temperature is 400℃~500℃, and the exchange time is 0.5h~5h.

20. The method of claim 15, wherein the glass-ceramic is prepared by the steps of: The melting temperature of the batch corresponding to the chemical composition of the base glass is 1500℃~1650℃.

21. The method of claim 15, wherein the glass-ceramic is prepared by the steps of: The components of the base glass satisfy at least one of the following ratio relationships: the ratio of the mole percentage of Al2O3 to the mole percentage of Y2O3 is 0.2~7.5; the sum of the mole percentage of Y2O3 and the mole percentage of Al2O3 is 7%~45%; the ratio of the mole percentage of Y2O3 to the mole percentage of Li2O is 0.33~8; and the ratio of the mole percentage of Li2O to the mole percentage of Na2O is 0.33~8.

22. The method of claim 15, wherein the glass-ceramic is prepared by the steps of: The base glass further comprises 0~2% of titanium dioxide (TiO2) in terms of mole percentage.

23. The method of claim 22, wherein the glass-ceramic is prepared by the steps of: The total mole percentage of ZrO2, TiO2 and P2O5 is 2%~6%.

24. The method of claim 22, wherein the glass-ceramic is prepared by the steps of: The ratio of the mole percentage of Y2O3 to the mole percentage of ZrO2+TiO2+P2O5 is 0.5~25.

25. A glass article, characterized by, The glass product is made of the glass-ceramic as claimed in any one of claims 1 to 14, or made of the glass-ceramic prepared by the preparation method as claimed in any one of claims 15 to 24.

26. The glass article of claim 25, wherein, The glass product is a glass cover plate.

27. A terminal device, comprising: comprising the glass product as claimed in claim 25 or 26.

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