Tempered glass ceramic, cover glass, electronic device and glass device

Abstract

The present application belongs to the technical field of glass ceramics. Provided are a tempered glass ceramic containing spinel, a cover glass, an electronic device and a glass device. A zinc aluminate spinel-magnesium aluminate spinel solid solution is used as the primary crystalline phase of the glass ceramic, so that the glass ceramic is endowed with high intrinsic strength. By means of chemically tempering the glass ceramic, the surface composition and stress distribution condition of the manufactured tempered glass ceramic satisfy specific requirements, especially the surface Na2O content, the surface K2O content, the diffusion depth of K+, and the depth of the position with the maximum Na+ concentration value satisfying specific requirements; and the thickness of the tempered glass ceramic, K+ diffusion depth DOL_K (or referred to as K+ exchange (layer) depth), |CT-AV|, and compressive stress layer depth DOL_0 satisfy equation A. Therefore, the mechanical properties of the tempered glass ceramic are remarkably improved, and the tempered glass ceramic is endowed with excellent compression resistance and impact resistance.

Description

Strengthened glass-ceramics, cover glasses, electronic devices, and glass articles

[0001] Cross Reference to Related Applications

[0002] This application claims priority to the Chinese patent application entitled "Strengthened glass-ceramics, cover glasses, electronic devices, and glass articles" with the application number 202410740144.4, filed on June 7, 2024, with the State Intellectual Property Office of China, the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0003] The present application relates to the technical field of glass-ceramics, in particular, to a strengthened glass-ceramics, a cover glass, an electronic device, and a glass article. BACKGROUND

[0004] In recent years, glass-ceramics are often used in many electronic devices, such as smart phones, smart wear, computers, tablets, video cameras, electronic watches, smart detection devices, and other similar devices, as window glass, protective cover glass, etc. While electronic devices used in different scenarios do not encounter exactly the same damage risk points, for example, as smart phones, tablets, etc., the damage risks encountered mainly include scratching, dropping and impact, etc., while electronic devices used in deep-sea exploration environments, diving environments, etc., may encounter not only impact problems, but also water pressure extrusion problems. In order to better meet the application requirements of electronic devices in different application scenarios and achieve better protection of electronic devices, it is necessary to develop glass-ceramic materials that can exhibit higher performance. However, the extrusion resistance and impact resistance of the existing glass-ceramics still need to be further improved.

[0005] It should be noted that this part of the present application only provides background technology related to the present application, and does not necessarily constitute prior art or public knowledge. SUMMARY

[0006] Spinel crystals have excellent properties such as high hardness and high modulus, and the use of glass-ceramics with spinel crystal phase as the main crystal phase for chemical strengthening to prepare strengthened glass-ceramics is more conducive to obtaining strengthened glass-ceramic materials with excellent extrusion resistance and impact resistance than the use of ordinary glass.

[0007] The purpose of the present application is to provide a strengthened glass-ceramic with spinel crystal phase as the main crystal phase, which has excellent impact resistance and excellent extrusion resistance.

[0008] In order to achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0009] In a first aspect, a strengthened glass ceramic is provided, wherein the strengthened glass ceramic comprises a main crystal phase of a zinc aluminate-magnesium aluminate spinel solid solution and a secondary crystal phase of zirconia; the strengthened glass ceramic has a compressive stress layer on the surface and a tensile stress in the interior;

[0010] The surface K2O mass percentage of the strengthened glass ceramic is 2.50% to 7.50% in terms of mass percentage of oxides, preferably the surface K2O mass percentage of the strengthened glass ceramic is 3.00% to 7.00%, more preferably the surface K2O mass percentage of the strengthened glass ceramic is 3.50% to 7.00%;

[0011] The surface Na2O mass percentage of the strengthened glass ceramic is less than or equal to 0.010% in terms of mass percentage of oxides, preferably the surface Na2O mass percentage of the strengthened glass ceramic is less than or equal to 0.005%, more preferably the surface Na2O mass percentage of the strengthened glass ceramic is less than or equal to 0.002%;

[0012] The strengthened glass ceramic satisfies 8.00 μm≤DOL_K≤20.00 μm, preferably 8.50 μm≤DOL_K≤18.00 μm, more preferably 9.00 μm≤DOL_K≤16.00 μm, wherein DOL_K is the depth of the K2O concentration maximum from the main surface of the strengthened glass ceramic; + diffusion depth;

[0013] The strengthened glass ceramic satisfies 30.00 μm≤DOL_Na≤60.00 μm, preferably 34.00 μm≤DOL_Na≤59.00 μm, more preferably 37.00 μm≤DOL_Na≤59.00 μm, wherein DOL_Na is the depth of the Na2O concentration maximum from the main surface of the strengthened glass ceramic; + diffusion depth;

[0014] The strengthened glass ceramic satisfies A=(t×DOL_K) / (|CT-AV|×(DOL_0 / t)), 850≤A≤4000, preferably 850≤A≤3000, more preferably 900≤A≤2000; wherein t is the thickness of the strengthened glass ceramic, in units of μm; DOL_K is the K2O diffusion depth from the main surface of the strengthened glass ceramic, in units of μm; |CT-AV| is the absolute value of the average tensile stress of the strengthened glass ceramic, in units of MPa; DOL_0 is the depth of the compressive stress layer of the strengthened glass ceramic, in units of μm; in formula A, the data is substituted into the formula according to the above unit requirements, and the calculation result is obtained, and the unit does not participate in the calculation. + diffusion depth, in units of μm; |CT-AV| is the absolute value of the average tensile stress of the strengthened glass ceramic, in units of MPa; DOL_0 is the depth of the compressive stress layer of the strengthened glass ceramic, in units of μm; in formula A, the data is substituted into the formula according to the above unit requirements, and the calculation result is obtained, and the unit does not participate in the calculation.

[0015] The present application obtains high intrinsic strength of the glass ceramic by taking the zinc-aluminum spinel-magnesium-aluminum spinel solid solution as the main crystal phase of the glass ceramic, and by chemically strengthening the glass ceramic and making the surface composition and stress distribution of the prepared strengthened glass ceramic meet specific requirements, especially making the surface Na2O content, surface K2O content, K + diffusion depth, Na + concentration maximum position meet specific requirements, and making the thickness, K + diffusion depth (or K + exchange (layer) depth) DOL_K, |CT-AV| and the compressive stress layer depth DOL_0 of the strengthened glass ceramic meet the requirements of formula A, which significantly improves the mechanical properties of the strengthened glass ceramic, and makes the strengthened glass ceramic obtain excellent extrusion resistance and impact resistance. In the present application, (Zn, Mg) Al2O4 represents the zinc-aluminum spinel-magnesium-aluminum spinel solid solution (or also referred to as zinc-magnesium spinel solid solution, zinc spinel-magnesium spinel solid solution, zinc-magnesium-aluminum spinel solid solution).

[0016] As an optional embodiment, the surface K2O mass percentage of the strengthened glass ceramic is 5.62%, 4.66%, 6.78%, 4.95%, 3.86%, 4.96%, 4.55%, 4.53%, 4.04%, 5.73%, 5.39%, 6.11% or 5.89%; and / or,

[0017] the surface Na2O mass percentage of the strengthened glass ceramic is 0% or 0.002%; and / or,

[0018] the DOL_K of the strengthened glass ceramic is 12.10 μm, 11.00 μm, 9.40 μm, 15.10 μm, 14.10 μm, 13.00 μm, 11.10 μm, 19.10 μm, 18.00 μm or 17.10 μm, and / or,

[0019] the DOL_Na of the strengthened glass ceramic is 46.10 μm, 40.00 μm, 55.10 μm, 45.40 μm, 47.10 μm, 58.10 μm, 48.00 μm, 51.10 μm, 38.00 μm, 43.10 μm, 50.30 μm, 50.20 μm or 56.40 μm; and / or,

[0020] the value of formula A is 1039, 1150, 1520, 910, 1542, 1469, 935, 995, 1780, 1054, 1500, 2010 or 2440.

[0021] As an optional implementation, the reinforced glass-ceramic satisfies: along the thickness direction of the reinforced glass-ceramic, K + The concentration of [something] decreases non-linearly from the main surface of the reinforced glass-ceramic towards its center; and / or,

[0022] Along the thickness direction of the reinforced glass ceramic, Na + The concentration of the precipitate first shows a non-linear increasing trend from the main surface of the reinforced glass ceramic towards the center of the reinforced glass ceramic, and then shows a non-linear decreasing trend.

[0023] As an optional implementation, the reinforced glass-ceramic satisfies:

[0024] In the K element concentration distribution curve, the horizontal axis represents the depth in μm from the main surface of the reinforced glass-ceramic, and the vertical axis represents the K element concentration as a mass percentage based on elemental composition:

[0025] The absolute value of the average slope P1 of the K element concentration distribution curve between a depth of 0 micrometers and a depth of DOL_K is 0.150–1.000, preferably 0.150–0.800, more preferably 0.150–0.600; and / or,

[0026] The absolute value of the average slope P of the K element concentration distribution curve between depths of 5 μm and 8 μm. 5-8 The preferred value is 0.50 to 2.50, P. 5-8 The value is 0.60 to 2.00, more preferably, P 5-8 The value is 0.70 to 1.50; and / or,

[0027] In the Na concentration distribution curve, the horizontal axis represents the depth in μm from the main surface of the reinforced glass-ceramic, and the vertical axis represents the Na concentration as a mass percentage based on elemental composition:

[0028] The absolute value of the average slope P2 of the Na element concentration distribution curve between a depth of 0 micrometers and a depth of DOL_Na is 0.01 to 0.05, preferably 0.01 to 0.04, and more preferably 0.01 to 0.03.

[0029] In this application, by ensuring that the average slope of the K element concentration distribution curve and / or Na element concentration distribution curve in different depth ranges of the reinforced glass ceramic meets specific requirements, it is beneficial to enable the reinforced glass ceramic to achieve the desired stress distribution structure, thereby enabling the reinforced glass ceramic to simultaneously obtain excellent impact resistance and extrusion resistance.

[0030] As an optional implementation, the reinforced glass-ceramic satisfies:

[0031] In the K element concentration distribution curve, the horizontal axis represents the depth in μm from the main surface of the reinforced glass-ceramic, and the vertical axis represents the K element concentration as a mass percentage based on elemental parameters:

[0032] The absolute value of the average slope P1 of the K element concentration distribution curve from depth 0 micrometers to depth DOL_K is 0.380, 0.315, 0.302, 0.530, 0.348, 0.193, 0.445, 0.452, 0.194, 0.440, 0.220, or 0.310; and / or,

[0033] The absolute value of the average slope P of the K element concentration distribution curve between depths of 5 μm and 8 μm. 5-8 For 0.74, 1.12, 1.22, 0.99, 1.04, 1.25, 0.76, 0.80, 0.79, 0.95, 0.66, 1.34, or 1.64; and / or

[0034] In the Na concentration distribution curve, the horizontal axis represents the depth in μm from the main surface of the reinforced glass-ceramic, and the vertical axis represents the Na concentration as a mass percentage based on elemental composition:

[0035] The absolute value of the average slope P2 of the Na element concentration distribution curve between a depth of 0 micrometers and a depth of DOL_Na is 0.02, 0.01, or 0.03.

[0036] As an optional implementation, the reinforced glass-ceramic satisfies:

[0037] In the SLP stress distribution curve, the horizontal axis represents the depth in μm from the main surface of the reinforced glass-ceramic, and the vertical axis represents the stress in MPa:

[0038] The absolute value of the average slope K of the SLP stress distribution curve between depths of 50 μm and 80 μm. 50-80 The value is preferably between 1.00 and 2.50, K. 50-80 The value is 1.00 to 2.40, more preferably, K 50-80 The range is 1.00 to 2.30; and / or,

[0039] The absolute value of the average slope K of the SLP stress distribution curve between depths of 80 μm and DOL_0 80-DOL-0 The value is preferably between 0.90 and 2.00, K. 80-DOL-0 The value is 0.90 to 1.80, more preferably, K 80-DOL-0 The range is 0.90 to 1.60.

[0040] In the present application, by making the average slope of the stress distribution curve of the strengthened glass ceramic in different depth ranges meet certain requirements, it is beneficial to make the strengthened glass ceramic achieve the desired stress distribution structure, and further beneficial to make the strengthened glass ceramic have excellent impact resistance and extrusion resistance at the same time.

[0041] As an optional embodiment, the strengthened glass ceramic satisfies:

[0042] In the SLP stress distribution curve with the horizontal axis being the depth in μm from the main surface of the strengthened glass ceramic and the vertical axis being the stress in MPa:

[0043] The absolute value K of the average slope of the SLP stress distribution curve between the depth of 50 μm and the depth of 80 μm 50-80 is 1.92, 1.48, 1.52, 1.38, 1.70, 1.03, 1.59, 1.28, 2.29, 1.50, 1.56 or 1.73; and / or,

[0044] The absolute value K of the average slope of the SLP stress distribution curve between the depth of 80 μm and the depth of DOL_0 80-DOL-0 is 1.35, 1.06, 1.05, 1.33, 1.17, 0.98, 1.29, 1.09, 1.42, 1.18 or 1.13.

[0045] As an optional embodiment, the strengthened glass ceramic is in the form of a plate, the thickness t of the strengthened glass ceramic is greater than 0.7 mm, preferably, the thickness t is not less than 0.8 mm, more preferably, the thickness t is 0.9 mm to 2.0 mm; and / or, the strengthened glass ceramic is 2D, 2.5D, 3D or special-shaped; and / or, the strengthened glass ceramic is of equal thickness or unequal thickness. In the present application, when the thickness of the strengthened glass ceramic is small, its compression resistance and impact resistance will be significantly reduced, and when the thickness is too large, on the one hand, it will lead to an increase in weight, which is not conducive to the light and thin electronic devices, and on the other hand, too large thickness will lead to a decrease in transmittance of the glass ceramic, making its transmittance worse.

[0046] As an optional embodiment, the strengthened glass ceramic comprises, in the composition at the center or the tensile stress layer, Al2O3 in a mass percentage of greater than or equal to 30.00% in terms of mass percentage of oxide.

[0047] In the present application, by controlling the mass percentage of Al2O3 in the glass-ceramic to be greater than or equal to 30%, on the one hand, the desired content of main crystal phase can be ensured, so that the glass-ceramic has high intrinsic strength (or also known as inherent strength), and on the other hand, a certain amount of alumina can also be contained in the glass phase, and the alumina existing in the glass phase can enter the glass network structure in the form of [AlO4] tetrahedron to form a unified grid with [SiO4], so that the degree of network connection is enhanced, the strength and stability of the glass network structure are improved, and thus the intrinsic strength of the glass-ceramic is further improved. At the same time, the [AlO4] tetrahedron in the glass phase can appropriately expand the ion exchange channel, improve the chemical strengthening effect of the glass-ceramic, and be more conducive to obtaining the strengthened glass-ceramic with excellent mechanical strength performance.

[0048] As an optional embodiment, the strengthened glass-ceramic comprises ZrO2 with a mass percentage greater than or equal to 3.00% at the center or in the composition of the tensile stress layer, in terms of mass percentage of oxides.

[0049] In the present application, by controlling the mass percentage of ZrO2 in the glass-ceramic to be greater than or equal to 3.00%, the intrinsic strength of the glass-ceramic is improved, and the surface stress level of the strengthened glass-ceramic obtained thereby is improved. On the one hand, as a nucleating agent, ZrO2 will disperse in the glass phase in the form of nanoscale grains after heat treatment, which can increase the hardness of the glass-ceramic, thereby effectively improving the shatter resistance of the glass-ceramic. On the other hand, ZrO2 exists in the glass phase in the form of [ZrO8] cubic, which can enhance the interionic force and make the glass structure more compact, thereby being conducive to improving the mechanical strength of the glass phase. At the same time, ZrO2 can significantly improve the surface compressive stress formed by ion exchange, thereby improving the surface stress level of the strengthened glass-ceramic obtained thereby.

[0050] As an optional embodiment, the mass percentage of Na2O [Na2O] and the mass percentage of Li2O [Li2O] in the composition of the strengthened glass-ceramic at the center or in the tensile stress layer satisfy the following relationship: [Na2O] / [Li2O] = 0.60-6.00, preferably 0.90-5.00, and more preferably 1.00-3.00, in terms of mass percentage of oxides; and / or

[0051] The mass percentage of Li2O [Li2O] and the mass percentage of SiO2 [SiO2] in the composition of the strengthened glass-ceramic at the center or in the tensile stress layer satisfy the following relationship: [Li2O] / [SiO2] = 0.03-0.20, preferably 0.04-0.15, and more preferably 0.04-0.10.

[0052] In the present application, on the basis of adjusting and controlling the content range of each oxide component, by adjusting and controlling the matching relationship between each oxide component, especially the mass percentage relationship between Na2O and Li2O and the mass percentage relationship between Li2O and SiO2, it is beneficial to improve the intrinsic strength and chemical strengthening effect of the glass ceramic, and further beneficial to obtain a strengthened glass ceramic with excellent mechanical strength performance.

[0053] As an optional embodiment, the composition at the center or the tensile stress layer of the strengthened glass ceramic comprises, in mass percentage of oxides: SiO2: 25.00% to 55.00%, Al2O3: 30.00% to 55.00%, ZrO2: 3.00% to 8.00%, MgO: 2.00% to 5.00%, ZnO: 5.00% to 15.00%, Na2O: 1.00% to 10.00%, K2O: 0% to 5.00%, Li2O: 1.00% to 6.00%, CaO: 0% to 6.00%, B2O3: 0% to 10.00%, BaO: 0% to 10.00%, Y2O3: 0% to 6.00%, La2O3: 0% to 12.00%.

[0054] In the present application, by adjusting and controlling the content range of each oxide component, it is beneficial to ensure that the strengthened glass ceramic meets the desired crystal structure and stress structure, and at the same time, it is beneficial to ensure that the strengthened glass ceramic has excellent optical performance and high intrinsic strength.

[0055] As an optional embodiment, the composition at the center or the tensile stress layer of the strengthened glass ceramic comprises, in mass percentage of oxides:

[0056] The mass percentage of SiO2 is 30.00% to 42.00%, preferably, the mass percentage of SiO2 is 35.00% to 40.00%; and / or,

[0057] The mass percentage of Al2O3 is 32.00% to 42.00%, preferably, the mass percentage of Al2O3 is 34.00% to 42.00%; and / or,

[0058] The mass percentage of ZrO2 is 4.00% to 7.00%, preferably, the mass percentage of ZrO2 is 5.00% to 6.00%; and / or,

[0059] The mass percentage of MgO is 2.50% to 4.00%, preferably, the mass percentage of MgO is 2.50% to 3.50%; and / or,

[0060] The mass percentage of ZnO is 9.00% to 13.00%, preferably, the mass percentage of ZnO is 9.00% to 11.00%; and / or,

[0061] Na2O in a mass percent of 1.00% to 8.00%, preferably in a mass percent of 2.00% to 6.00%; and / or,

[0062] K2O in a mass percent of 0% to 3.00%, preferably in a mass percent of 0% to 1.00%; and / or,

[0063] Li2O in a mass percent of 1.00% to 4.00%, preferably in a mass percent of 2.00% to 3.00%; and / or,

[0064] CaO in a mass percent of 0% to 3.00%, preferably in a mass percent of 0% to 1.50%; and / or,

[0065] B2O3 in a mass percent of 0% to 8.00%, preferably in a mass percent of 0% to 4.00%; and / or,

[0066] BaO in a mass percent of 0% to 7.00%, preferably in a mass percent of 0% to 4.00%; and / or,

[0067] Y2O3 in a mass percent of 0% to 4.00%, preferably in a mass percent of 0% to 2.00%; and / or,

[0068] La2O3 in a mass percent of 0% to 5.00%, preferably in a mass percent of 0% to 3.00%.

[0069] As an optional embodiment, the composition at the center of the strengthened glass ceramic or the composition of the compressive stress layer comprises, in mass percent of oxides:

[0070] SiO2 in a mass percent of 37.08%, 36.87%, 33.23%, 37.43%, 37.40%, 38.33%, 36.05%, 35.67%, or 32.39%; and / or,

[0071] Al2O3 in a mass percent of 35.83%, 36.98%, 36.27%, 37.52%, 36.60%, 37.07%, 34.84%, 34.55%, or 35.88%; and / or,

[0072] ZrO2 in a mass percent of 5.69%, 5.65%, 5.61%, 5.74%, 5.81%, 5.89%, 5.54%, or 5.48%; and / or,

[0073] 3.00%, 2.98%, 3.04%, 3.03%, 3.06%, 3.10%, 2.92%, or 2.89%; and / or,

[0074] 10.77%, 10.71%, 10.55%, 10.87%, 11.01%, 11.15%, 10.46%, or 10.37%; and / or,

[0075] 2.86%, 2.85%, 2.89%, 3.00%, 1.69%, 2.79%, or 2.76%; and / or,

[0076] preferably free of K2O; and / or,

[0077] 2.35%, 1.55%, 1.50%, 1.77%, 1.60%, 1.62%, 2.28%, 2.27%, or 2.24%; and / or,

[0078] 0%, 0.75%, 1.15%, or 0.92%; and / or,

[0079] 0%, or 7.07%; and / or,

[0080] 2.42%, 2.41%, 6.94%, 0%, 2.35%, or 2.32%; and / or,

[0081] 0%, 1.52%, or 0.60%; and / or,

[0082] 0%, 2.17%, or 3.69%.

[0083] As an optional embodiment, in the strengthened glass ceramic, the average crystal size is no more than 20 nm, preferably 1.0 nm to 10.0 nm, more preferably 4.0 nm to 9.0 nm, more preferably 4.0 nm to 8.0 nm; and / or

[0084] In the strengthened glass ceramic, the total crystalline phase content is 25% to 60%, preferably 30% to 55%, more preferably 40% to 50%, in terms of mass percentage.

[0085] In the present application, by making the glass ceramic satisfy the desired total crystalline phase content / crystallinity, appropriate average crystal size, it is beneficial to make the glass ceramic maintain excellent optical performance while satisfying excellent mechanical strength performance and high intrinsic strength.

[0086] As an optional embodiment, the average crystal size in the strengthened glass ceramic is 5.0 nm, 6.8 nm, 6.4 nm, 6.5 nm, 8.1 nm or 7.0 nm; and / or

[0087] The total content of the crystal phase in the strengthened glass ceramic is 48.69%, 45.11%, 49.52%, 47.85%, 54.07%, 51.56%, 45.49% or 44.77% in terms of mass percentage.

[0088] As an optional embodiment, the strengthened glass ceramic is transparent in the visible light wavelength range, preferably, the transmittance of the strengthened glass ceramic at a wavelength of 550 nm is ≥85.00%, preferably ≥87.00% at a thickness of 0.90 mm. The strengthened glass ceramic satisfying the transmittance can ensure better light transmittance, better transparent effect, and is suitable for use in electronic device display screens which have requirements on display effect.

[0089] As an optional embodiment, the Vickers hardness of the strengthened glass ceramic is greater than or equal to 750 kgf / mm 2 , preferably, the Vickers hardness of the strengthened glass ceramic is greater than or equal to 790 kgf / mm 2 ; and / or,

[0090] The fracture toughness value of the strengthened glass ceramic is greater than or equal to 1.00 MPa·m 0.5 , preferably, the fracture toughness value of the strengthened glass ceramic is greater than or equal to 1.20 MPa·m 0.5 , more preferably, the fracture toughness value of the strengthened glass ceramic is greater than or equal to 1.50 MPa·m 0.5 ; and / or,

[0091] The strengthened glass ceramic has a |CT_AV| greater than 20.00 MPa, |CT_AV| being the absolute value of the average tensile stress, preferably, the strengthened glass ceramic has a |CT_AV| of 30.00 MPa to 55.00 MPa; and / or,

[0092] The strengthened glass ceramic has a |CT_CV| greater than 25.00 MPa, |CT_CV| being the absolute value of the maximum tensile stress, preferably, the chemically strengthened glass ceramic has a |CT_CV| of 40.00 MPa to 75.00 MPa; and / or,

[0093] The strengthened glass ceramic has a CS_50 greater than 100 MPa, CS_50 being the compressive stress value at a depth of 50 μm from the main surface of the strengthened glass ceramic, preferably, the strengthened glass ceramic has a CS_50 of 140 MPa to 200 MPa; and / or,

[0094] the strengthened glass ceramic has a CS_80 of greater than 50 MPa, the CS_80 being a compressive stress value at a depth of 80 μm from a main surface of the strengthened glass ceramic, preferably, the strengthened glass ceramic has a CS_80 of 100 MPa to 150 MPa; and / or,

[0095] the strengthened glass ceramic has a DOL_0 of greater than 144 μm, the DOL_0 being a depth of compressive stress layer, preferably, the strengthened glass ceramic has a DOL_0 of 160 μm to 200 μm; and / or,

[0096] the strengthened glass ceramic satisfies: DOL_0 > 0.16t, wherein, DOL_0 is a depth of compressive stress layer, t is a thickness of the strengthened glass ceramic, preferably, DOL_0 > 0.18t, more preferably, DOL_0 ≥ 0.20t.

[0097] In the present application, by making the strengthened glass ceramic have high Vickers hardness and fracture toughness, the strengthened glass ceramic is not easy to break when subjected to extrusion or impact, which is beneficial to improve the compression resistance and impact resistance of the strengthened glass ceramic. And by making the strengthened glass ceramic satisfy a suitable stress structure, it is beneficial to play the improvement effect of the stress structure on the mechanical strength performance, especially the excellent compression resistance and excellent impact resistance improvement effect to be achieved in the present application.

[0098] As an optional embodiment, the Vickers hardness of the strengthened glass ceramic is 858 kgf / mm 2 , 875 kgf / mm 2 , 915 kgf / mm 2 , 850 kgf / mm 2 , 837 kgf / mm 2 , 900 kgf / mm 2 , 869 kgf / mm 2 , 889 kgf / mm 2 , 857 kgf / mm 2 , 865 kgf / mm 2 , or 825 kgf / mm 2 ; and / or,

[0099] the fracture toughness value of the strengthened glass ceramic is 1.67 MPa·m 0.5 , 1.69 MPa·m 0.5 , 1.75 MPa·m 0.5 , 1.65 MPa·m 0.5 , 1.94 MPa·m 0.5 , 1.73 MPa·m 0.5 , 1.68 MPa·m0.5 1.71 MPa-m 0.5 or 1.77 MPa-m 0.5 ; and / or,

[0100] |CT_AV| of the strengthened glass ceramic is 50.96 MPa, 41.74 MPa, 36.56 MPa, 45.01 MPa, 41.49 MPa, 40.48 MPa, 50.27 MPa, 49.49 MPa, 36.05 MPa, 45.43 MPa, 53.86 MPa, 40.86 MPa, or 35.91 MPa; and / or,

[0101] |CT_CV| of the strengthened glass ceramic is 65.70 MPa, 54.30 MPa, 46.07 MPa, 68.75 MPa, 53.70 MPa, 53.07 MPa, 66.96 MPa, 71.25 MPa, 42.73 MPa, 60.57 MPa, 81.79 MPa, 52.40 MPa, or 44.78 MPa; and / or,

[0102] CS_50 of the strengthened glass ceramic is 199.69 MPa, 155.95 MPa, 146.48 MPa, 181.94 MPa, 181.35 MPa, 141.02 MPa, 188.73 MPa, 168.30 MPa, 188.13 MPa, 162.61 MPa, 177.13 MPa, 190.71 MPa, or 204.29 MPa; and / or,

[0103] CS_80 of the strengthened glass ceramic is 142.01 MPa, 111.53 MPa, 100.86 MPa, 140.44 MPa, 130.30 MPa, 110.00 MPa, 140.99 MPa, 129.89 MPa, 119.54 MPa, 117.60 MPa, 130.38 MPa, 138.72 MPa, or 152.35 MPa; and / or,

[0104] DOL_0 of the strengthened glass ceramic is 185.12 pm, 185.63 pm, 176.34 pm, 185.81 pm, 191.19 pm, 192.04 pm, 189.59 pm, 199.08 pm, 164.11 pm, 187.76 pm, 191.43 pm, 197.80 pm, or 215.20 pm.

[0105] As an optional embodiment, the single rod static pressure strength of the strengthened glass ceramic is tested by using a 10 mm diameter round head metal pressure rod to apply a load step by step vertically downward at a rate of 10 mm / min to the center of the main surface of the strengthened glass ceramic with a thickness greater than 0.7 mm, and the single rod static pressure strength of the strengthened glass ceramic is greater than 800 N, preferably greater than 850 N; and / or,

[0106] The 2.5 m fixed point height drop test is performed on the strengthened glass ceramic with a thickness greater than 0.7 mm by using 80 mesh silicon carbide sandpaper, and if the glass sample does not break after dropping, it is recorded as passing, and the passing rate of the strengthened glass ceramic is ≥ 50%, preferably ≥ 60%, more preferably ≥ 70%; the passing rate is based on the test of at least 10 samples; and / or,

[0107] The center ball impact test is performed on the strengthened glass ceramic with a thickness greater than 0.7 mm by using a 130 g steel ball, and the center ball impact energy that the strengthened glass ceramic can withstand is tested, and the center ball impact energy that the strengthened glass ceramic can withstand is greater than 0.7 J, preferably greater than 0.8 J.

[0108] As an optional embodiment, the strengthened glass ceramic is prepared by chemical strengthening treatment of a glass ceramic with a fracture toughness not less than 1.40 MPa·m 0.5 , preferably, the strengthened glass ceramic is prepared by at least two steps of chemical strengthening treatment of a glass ceramic with a fracture toughness not less than 1.40 MPa·m 0.5 , more preferably, the strengthened glass ceramic is prepared by first step strengthening treatment of a glass ceramic with a fracture toughness not less than 1.40 MPa·m 0.5 , in a molten salt salt bath containing sodium salt with a mass percentage of sodium salt greater than or equal to 20%, and second step chemical strengthening treatment of the glass ceramic in a molten salt salt bath containing potassium salt with a mass percentage of potassium salt greater than or equal to 90%.

[0109] In this application, the strengthened glass ceramic is preferably subjected to at least two steps of chemical strengthening treatment for the purpose of forming a specific deep stress structure and a specific surface stress structure respectively, so as to achieve the desired stress distribution structure of the strengthened glass ceramic, and thus the improvement of the extrusion resistance and impact resistance of the strengthened glass ceramic is realized, so that the strengthened glass ceramic can simultaneously have excellent extrusion resistance and excellent impact resistance. Preferably, by using an inorganic salt composition containing Na + as the molten salt salt bath in the first step of strengthening treatment, ion exchange between Na + in the salt bath and Li + in the glass ceramic is achieved, so as to obtain a high depth of compressive stress layer DOL_0 and a high deep stress; by using an inorganic salt composition containing K +inorganic salt composition as a molten salt bath, K + Na + ion-exchanged, so that Na + in the glass ceramic is exchanged as much as possible to K + , and thus the strengthened glass ceramic obtains a high surface compressive stress level.

[0110] In a second aspect, there is provided a cover glass made of the strengthened glass ceramic according to any one of the embodiments of the first aspect, or comprising the strengthened glass ceramic according to any one of the embodiments of the first aspect.

[0111] In a third aspect, there is provided an electronic device comprising the strengthened glass ceramic according to any one of the embodiments of the first aspect.

[0112] As an optional embodiment, the electronic device comprises a housing assembled on the outside of the electronic device, and the housing comprises the strengthened glass ceramic according to any one of the embodiments of the first aspect.

[0113] As an optional embodiment, the housing comprises a display screen cover plate assembled on the front side of the electronic device, and the display screen cover plate comprises the strengthened glass ceramic according to any one of the embodiments of the first aspect.

[0114] As an optional embodiment, the housing comprises a rear cover assembled on the rear side of the electronic device, and the rear cover comprises the strengthened glass ceramic according to any one of the embodiments of the first aspect.

[0115] As an optional embodiment, the electronic device further comprises a camera assembly located inside the housing, and the housing comprises a camera protection cover plate covering the camera assembly, and the camera protection cover plate comprises the strengthened glass ceramic according to any one of the embodiments of the first aspect.

[0116] As an optional embodiment, the electronic device further comprises a middle frame, and the middle frame comprises the strengthened glass ceramic according to any one of the embodiments of the first aspect.

[0117] In some embodiments, the housing can be partially made of the strengthened glass ceramic, or can be entirely made of the strengthened glass ceramic. The electronic device in the present application can be one or more of a display screen cover plate, a rear cover, a camera protection cover plate, and a middle frame, which are made of the strengthened glass ceramic according to any one of the embodiments of the first aspect.

[0118] In a fourth aspect, there is provided a glass device comprising the strengthened glass ceramic according to any one of the embodiments of the first aspect.

[0119] Compared with the prior art, one or more of the above technical solutions provided in the present application have the following advantages:

[0120] The present application uses zinc-aluminum spinel-magnesium-aluminum spinel solid solution as the main crystal phase of the glass ceramic, so that the glass ceramic has high intrinsic strength. The glass ceramic is chemically strengthened, and the surface composition and stress distribution of the prepared strengthened glass ceramic meet specific requirements, especially the surface Na2O content, surface K2O content, K + diffusion depth, Na + concentration maximum position depth meet specific requirements, and the thickness, K + diffusion depth (or K + exchange (layer) depth) DOL_K, |CT-AV| and the compressive stress layer depth DOL_0 meet the requirements of formula A, which significantly improves the mechanical properties of the strengthened glass ceramic, so that the strengthened glass ceramic has excellent extrusion resistance and impact resistance. The application of the strengthened glass ceramic in electronic devices enables the electronic devices to meet the application environment with high requirements for extrusion resistance and / or impact resistance, such as better matching the application requirements in water environment (such as deep sea environment), and can be applied in deep water environment. BRIEF DESCRIPTION OF DRAWINGS

[0121] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor.

[0122] Figure 1 is a comparison chart of XRD patterns of the glass ceramic and the strengthened glass ceramic provided by the embodiment 1 of the present application.

[0123] Figure 2 is a comparison chart of transmittance curves of the glass ceramic and the strengthened glass ceramic provided by the embodiment 1 of the present application.

[0124] Figure 3 is a K element concentration distribution curve and a Na element concentration distribution curve of the strengthened glass ceramic of the embodiment 1 of the present application measured by EPMA.

[0125] Figure 4 is a SLP stress distribution curve of the strengthened glass ceramic of the embodiment 1 of the present application measured by SLP-2000.

[0126] Figure 5 is a structural schematic diagram of the strengthened glass ceramic of the present application.

[0127] Fig. 6 is a process diagram of single rod static pressure strength test provided by the embodiment of the present application, wherein 30 is a pressure rod, 31 is a strengthened glass ceramic sample / sheet to be tested, and 32 is a jig.

[0128] Fig. 7 is a structural diagram of a jig used in single rod static pressure strength test provided by the embodiment of the present application.

[0129] Fig. 8 is a cross-sectional structural diagram of a jig used in single rod static pressure strength test provided by the embodiment of the present application.

[0130] Fig. 9 is a structural diagram of the front side of an electronic device according to the embodiment of the present application.

[0131] Fig. 10 is a structural diagram of the back side of an electronic device according to the embodiment of the present application.

[0132] Fig. 11 is a structural diagram of an electronic device according to the embodiment of the present application.

[0133] Fig. 12 is a structural diagram of an electronic device according to the embodiment of the present application.

[0134] Reference signs: 1 - housing; 11 - display screen cover plate; 12 - back cover; 13 - camera protection cover plate; 2 - camera assembly; 3 - middle frame; 4 - display module;

[0135] 20 - strengthened glass ceramic, 21 - main surface of strengthened glass ceramic, 22 - surface layer compressive stress layer, 23 - deep layer compressive stress layer, 24 - tensile stress layer, t is the thickness of the strengthened glass ceramic, d1 is DOL_K, d2 is DOL_Na, and d3 is DOL_0. DETAILED DESCRIPTION

[0136] The embodiments of the present application will be described in detail below with reference to examples, but those skilled in the art will understand that the following examples are only for illustration of the present application and should not be regarded as limiting the scope of the present application. The specific conditions not mentioned in the examples are carried out according to the conventional conditions or the conditions recommended by the manufacturer. The reagents or instruments used are not marked with the manufacturer, which are all conventional products that can be purchased on the market.

[0137] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein. The terms "optional," "optional," or other similar expressions mean that they may or may not be included (or may or may not be present). The term "and / or" as used herein is inclusive; for example, "A and / or B" means only A, or only B, or both A and B.

[0138] Terminology and testing methods:

[0139] In this application, glass-ceramics are a type of solid composite material that simultaneously contains a glassy phase and a crystalline phase (or microcrystalline phase, crystalline phase, or crystal phase) prepared by targeted and controlled heat treatment of a substrate glass. Glass-ceramics are also known as microcrystalline glass, crystallized glass, or crystalline glass.

[0140] In this application, reinforced glass-ceramics refer to solid composite materials obtained by chemically strengthening glass-ceramics. It should be understood that during chemical strengthening, alkali metal ions with large ionic radii (e.g., potassium or sodium ions) in the molten salt bath (or molten salt bath) will replace alkali metal ions with small ionic radii (e.g., sodium or lithium ions) in the glass-ceramics, thereby generating a volume difference in exchange ions and producing compressive stress (or compressive stress) on the surface of the glass-ceramics.

[0141] In this application, the substrate glass refers to glass that has not undergone nucleation treatment, crystallization treatment, or strengthening treatment, or it is also called base glass.

[0142] In this application, the composition at the center of the reinforced glass ceramic refers to the composition at or near the center of the depth or thickness of the reinforced glass ceramic, that is, the composition of the region in the reinforced glass ceramic that has not undergone ion exchange. It should be understood that the composition at the center of the reinforced glass ceramic is the same as or substantially the same as the composition of the glass ceramic used to prepare the reinforced glass ceramic but which has not yet undergone chemical strengthening treatment.

[0143] In this application, the main crystalline phase (or principal crystalline phase) refers to a crystalline phase that has a higher weight content (or weight percentage, mass percentage) than other crystalline phases present in glass ceramics.

[0144] In this application, the total content of crystalline phases refers to the percentage of the total mass of crystalline phases or crystals in the glass ceramic to the mass of the glass ceramic, or the crystallinity of the glass ceramic.

[0145] In the present application, the main surface refers to the surface with the largest surface area, such as the upper surface or the lower surface of a horizontally placed glass-ceramic sheet.

[0146] In the present application, the visible light wavelength range refers to 360nm-740nm.

[0147] In the present application, when light of a certain wavelength is irradiated to the main surface of a glass-ceramic, the light will be reflected, absorbed and transmitted, and the ratio of the intensity of the transmitted part to the intensity of the incident light is the transmittance.

[0148] In the present application, the nucleation treatment refers to the formation of stable crystal nuclei in the base glass through heat treatment; the crystallization treatment refers to the precipitation of crystals or crystal phases in the base glass through heat treatment.

[0149] In the present application, |CT_AV| refers to the absolute value of the average tensile stress, with the unit of MPa, and specifically refers to the absolute value of the average of all tensile stresses in the tensile stress layer, which is obtained by SLP-2000 stress meter (or also known as a scattered light photoelastic stress meter).

[0150] In the present application, |CT_CV| refers to the absolute value of the maximum tensile stress, with the unit of MPa, and specifically refers to the absolute value of the maximum value of all tensile stresses in the tensile stress layer, which is obtained by SLP-2000 stress meter.

[0151] In the present application, CS_50 and CS_80 respectively refer to the compressive stress values at depths of 50μm and 80μm from the main surface of the self-strengthening glass-ceramic, with the unit of MPa, which are obtained by SLP-2000 stress meter.

[0152] In the present application, DOL_0 refers to the depth of the compressive stress layer, or the depth of the compressive stress layer, and specifically refers to the distance from any main surface of the strengthened glass-ceramic to the position close to the surface where the compressive stress is zero, which is obtained by SLP-2000 stress meter.

[0153] In the present application, the test method of the aforementioned stress performance is as follows: SLP 2000 stress meter is used to test |CT_CV|, |CT_AV|, CS_50, CS_80 and DOL_0 of the strengthened glass-ceramic. The related parameters of the stress meter are set as follows: the wavelength of the light source is 518nm, the SOC (photoelastic coefficient) is set to 25.5 [(nm / cm) / MPa], the refractive index is set to 1.60, and the exposure time is 300μsec.

[0154] In the present application, SOC, i.e. photoelastic coefficient, photoelasticity mainly refers to the birefringence phenomenon caused by anisotropy of transparent materials after being stressed. The value of the residual stress inside the material can be obtained by measuring the photoelastic coefficient and the birefringence.

[0155] In the present application, DOL_K refers to the depth of the compressive stress layer+ diffusion depth, or K + diffusion layer depth, or K + exchange (layer) depth, specifically, the depth from any major surface of the strengthened glass-ceramic to the K + depth at which the slope value of the concentration distribution curve (or also called K concentration distribution curve) is equal to 0.000 for the first time, obtained by Shimadzu electron probe EPMA-1720HT test. In this application, the K + depth in the concentration distribution curve, the surface of the glass-ceramic has a low concentration of K + diffused into the glass-ceramic after ion exchange, and as the depth increases, the K + amount in the glass-ceramic becomes less and less, and eventually reaches a maximum at the depth at which the slope value of the curve is equal to 0.000 for the first time. + no longer diffuses inward.

[0156] In this application, DOL_Na refers to the depth of the Na + concentration maximum, specifically, the depth from any major surface of the strengthened glass-ceramic to the Na + depth at which the slope value of the concentration distribution curve (or also called Na concentration distribution curve) is equal to 0.000 for the first time, obtained by Shimadzu electron probe EPMA-1720HT test. In this application, the Na + depth in the concentration distribution curve, the surface of the glass-ceramic has a low concentration of Na + because it is exchanged by K + , the concentration is low, or even 0, and as the depth increases, the K + exchange Na + becomes more and more difficult, and the Na + amount in the glass-ceramic becomes more and more, and eventually reaches a maximum at the depth at which the slope value of the curve is equal to 0.000 for the first time. + concentration.

[0157] Electron Probe Micro-Analysis (EPMA) test: a strengthened glass-ceramic sample to be tested is taken, one of the sides perpendicular to the main surface is mechanically ground to remove the strengthening layer (the amount of grinding removal is 500 μm or more), a cross-section sample is prepared, the ground cross-section is treated with 30 nm carbon spraying, a linear line in the thickness direction is selected by a focused electron beam along the ground cross-section, and element composition and element concentration distribution in the thickness direction are obtained. The electron probe X-ray microanalyzer used in the present application is EPMA-1720HT of Shimadzu, the acceleration voltage is 15 kV, the probe current is 100 nA, the beam size is MIN, the step interval is 1 μm, the time is 1 s / point; the light splitting crystal is RAP (Na Kα ray), the light splitting crystal is PET (K Kα ray); the test elements are Na and K.

[0158] In the present application, P1 refers to the absolute value of the average slope of the K element concentration distribution curve between the depth of 0 microns and the depth of DOL_K in the K element concentration distribution curve measured by EPMA. Specifically, P1 = (K element concentration at the depth of 0 microns - K element concentration at the depth of DOL_K) / DOL_K, the unit is wt% / μm.

[0159] In the present application, P2 refers to the absolute value of the average slope of the Na element concentration distribution curve between the depth of 0 microns and the depth of DOL_Na in the Na element concentration distribution curve measured by EPMA. Specifically, P2 = (Na element concentration at the depth of DOL_Na - Na element concentration at the depth of 0 microns) / DOL_Na, the unit is wt% / μm.

[0160] In the present application, P 5-8 refers to the absolute value of the average slope of the K element concentration distribution curve between the depth of 5 microns and the depth of 8 microns in the K element concentration distribution curve measured by EPMA. Specifically, P 5-8 = (K element concentration at the depth of 5 microns - K element concentration at the depth of 8 microns) / 3, the unit is wt% / μm.

[0161] In the present application, the SLP stress distribution curve refers to the corresponding relationship curve of stress and depth obtained by test using a scattered light photoelastic stress meter SLP-2000.

[0162] In the present application, K 50-80 refers to the absolute value of the average slope of the SLP stress distribution curve between the depth of 50 microns and the depth of 80 microns in the SLP stress distribution curve measured by SLP-2000. Specifically, K 50-80 = (stress value at the depth of 50 microns - stress value at the depth of 80 microns) / 30, the unit is MPa / μm.

[0163] In the present application, K 80-DOL refers to the absolute value of the average slope of the SLP stress distribution curve between the depth of 80 pm and the depth of DOL_0 in the SLP stress distribution curve measured by SLP-2000. Specifically, K 80-DOL = (stress value at the depth of 80 pm - stress value at the depth of DOL_0) / (DOL_0 - 80), in units of MPa / pm.

[0164] In the present application, Vickers hardness refers to a standard for indicating the hardness of a material proposed by Robert L. Smith and George E. Sandland of Vickers Ltd in 1921.

[0165] In the present application, the testing method of Vickers hardness is as follows: the glass-ceramic or strengthened glass-ceramic is made into a small disc with a diameter of 46 mm and a thickness of 0.9 mm, and a glass sample with a clean surface and no visible scratches, pits, cracks and other damages is selected as the test sample, and then the Vickers hardness is measured using a Vickers hardness tester. The Vickers hardness tester used in the present application is a digital small load Vickers hardness tester of model VTD405 from Beijing Keweikai Technology Co., Ltd. The test conditions are: load 300 gf, loading time 10 s, and the validity of the indentation meets the standard of GB / T37900-2019 Ultra-thin glass hardness and fracture toughness test method Small load Vickers hardness indentation method. Three different positions on the surface of the same test sample are selected for measurement, and the average of the three measurement results is taken as the Vickers hardness result of the test sample.

[0166] In the present application, the thickness of the glass-ceramic is obtained by micrometer testing. It should be understood that in the thickness direction, the ion exchange degree changes gradually from the surface to the center, and the total Na-K and / or Li-Na exchange amount increment (mass) generally does not exceed 1.5% of the total mass of the sample, so the expansion effect in the thickness direction is extremely slight, and the thickness can be approximately considered to have no change. That is, the thickness of the glass-ceramic changes very little before and after chemical strengthening, and can be basically ignored. The thickness of the glass-ceramic is basically the same as the thickness of the strengthened glass-ceramic prepared therefrom.

[0167] In the present application, the density of the glass-ceramic is tested by using an electronic density balance SD-200L of Japan ALFAMIRAGE. The measurement principle is Archimedes' principle.

[0168] In the present application, the size of the glass-ceramic sheet is tested by using a two-dimensional measuring machine (instrument model Miyu MY-YXCL-4030).

[0169] In the present application, the crystalline phase composition, total crystalline phase content (or also referred to as crystallinity), and average crystal size of the glass-ceramics are determined by XRD test, specifically as follows:

[0170] (1) XRD test: The glass-ceramics or strengthened glass-ceramics of the present application are crushed and ground into samples with a particle size of less than 75 μm, and the ground samples are tested by an X-ray diffractometer to obtain XRD diffraction peak curves and XRD diffraction data. The X-ray diffractometer used in the present application is Shimadzu XRD-6100, the target material is copper, 2θ = 10°-80°, the scanning speed is 2° / min, the working voltage is 40 kV, and the working current is 30 mA.

[0171] (2) Determination of crystalline phase: the XRD diffraction data are analyzed by Jade software (JADE Standard 8.6) to determine the crystalline phase in the sample.

[0172] (3) Determination of total crystalline phase content (or also referred to as crystallinity): the test results of XRD (RAW format) are imported into Jade software for fitting and calculation, so as to determine the total crystalline phase content of the sample. Specifically, the ratio of the peak area of the fitted crystalline phase to the total peak area of the fitted crystalline phase is recorded as the total crystalline phase content of the sample.

[0173] (4) Determination of average crystal size: the result data obtained by XRD test can be used to calculate the average crystal size (or also referred to as average grain size) of the sample according to the Scherrer formula D = Kλ / (βcosθ). Wherein, λ is the X-ray wavelength, λ = 0.154056 nm, β is the half-height width of the diffraction peak, K = 0.89, and θ is the Bragg diffraction angle. Specifically, the RAW format file output by the XRD instrument is curve-fitted in Jade software, and the fitting report is output by Jade. According to the angle 2θ value and the Peak FWHM value corresponding to each diffraction peak in the fitting report, the Peak FWHM value is converted to radian: β = (FWHM / 180×3.14), and the grain size of each diffraction peak is calculated by the Scherrer formula D = Kλ / (βcosθ) and then averaged to obtain the average crystal size in the sample.

[0174] In the present application, the transmittance of the glass-ceramics is tested by a spectrophotometer. Specifically, the transmittance of the light with different wavelengths of 5 pieces of glass-ceramics in the same batch is tested by the spectrophotometer. The average value of the transmittance at 550 nm wavelength of the 5 pieces of glass-ceramics is taken as the transmittance result of the glass-ceramics at 550 nm wavelength. The spectrophotometer used in the present application is a Konica Minolta Spectrophotometer CM-3600A from Japan, the light receiving system is transmission, the spectrophotometric method is plane diffraction grating, the wavelength range is 360 nm-740 nm, the wavelength interval is 10 nm, the illumination light source is pulse xenon lamp x 4, the environmental temperature for placing the instrument is 24°C, and the air humidity is 40%.

[0175] In the present application, the test method for the surface Na2O mass percentage (or also referred to as the surface Na2O concentration) of the strengthened glass-ceramics is as follows: the content of Na element on the surface of the strengthened glass-ceramics is measured by an X-ray fluorescence spectrometer (XRF), and then the surface Na2O mass percentage is calculated. The calculation method is as follows: surface Na2O mass percentage = (content of Na element on the surface x relative molecular mass of Na2O) / (relative atomic mass of Na element x 2). It should be understood that the content of Na element on the surface = mass of Na element / total mass of elements, and the total mass of elements = total mass of oxides. The equipment model of the X-ray fluorescence spectrometer (XRF) used is Thermo Scientific ARL PERFORM’X, the target material is Rh (rhodium), the light tube voltage is 30 kV, the current is 80 mA, the collimator is 0.40, the crystal selection is AxO3, the detector selection is FPC, the test range is a circle with a diameter of 29 mm, and the test method adopts the X_UQ method in the OXSAS analysis software.

[0176] In the present application, the test method for the surface K2O mass percentage (or also referred to as the surface K2O concentration) of the strengthened glass-ceramics is as follows: the content of K element on the surface of the strengthened glass-ceramics is measured by an X-ray fluorescence spectrometer (XRF), and then the surface K2O mass percentage is calculated. The calculation method is as follows: surface K2O mass percentage = (content of K element on the surface x relative molecular mass of K2O) / (relative atomic mass of K element x 2). It should be understood that the content of K element on the surface = mass of K element / total mass of elements, and the total mass of elements = total mass of oxides. The equipment model of the X-ray fluorescence spectrometer (XRF) used is Thermo Scientific ARL PERFORM’X, the target material is Rh (rhodium), the light tube voltage is 40 kV, the current is 60 mA, the collimator is 0.15, the crystal selection is LiF200, the detector selection is FPC, the test range is a circle with a diameter of 29 mm, and the test method adopts the X_UQ method in the OXSAS analysis software.

[0177] In the present application, the XRF instrument test uses no standard test, and the concentration of elements or oxides with atomic number 6 and below in the strengthened glass ceramic is not tested. The surface K2O mass percentage of the strengthened glass ceramic = K2O mass / total mass of oxides, and the surface Na2O mass percentage of the strengthened glass ceramic = Na2O mass / total mass of oxides, wherein the oxides include SiO2, Al2O3, ZrO2, Na2O, K2O, and other oxides that can be accurately tested by XRF, and do not include the content of B2O3 and other oxides that cannot be accurately tested by XRF.

[0178] In the present application, when testing with an XRF instrument, the strengthened glass ceramic sheet is directly cut into the appropriate size (such as 34mm*34mm), placed flat in the sample box, and covered with the test aperture, and the test can be performed.

[0179] In the present application, the test of fracture toughness is performed according to the standard of “GB / T 37900-2019 Ultra-thin glass hardness and fracture toughness test method small load Vickers hardness indentation method”.

[0180] Specifically, the indentation is prepared by the same method as measuring the Vickers hardness, the crack length 2C1, 2C2 in the diagonal direction of the indentation is measured, and the maximum value cannot exceed the thickness of the glass. At least 5 effective indentation morphologies are measured on one sample surface, and the average value is calculated as the final result value of the sample.

[0181] Indentation fracture toughness calculation formula:

[0182] Wherein, IFR: indentation fracture toughness, unit: megapascal two-thirds of the square meter (MPa·m 0.5 ); E: elastic modulus of the sample, unit: gigapascal (GPa); 2C1, 2C2: indentation diagonal crack propagation length, unit: millimeter (mm), d1, d2: indentation diagonal length, unit: millimeter (mm), F: test load value, unit: newton (N).

[0183] In the present application, the single-rod static pressure strength test: place the strengthened glass ceramic sample to be tested in a customized jig (as shown in FIG. 6), then place it on the bottom ring of a tensile testing machine (LT-850A), start the test software, and set the moving speed of the extrusion rod (rod diameter 10mm, ball head diameter 10mm) to 10mm / min, click start test, the extrusion rod will apply force to the center of the strengthened glass ceramic sample to be tested at the set moving speed, until the strengthened glass ceramic sample is broken, and the test process is shown in FIG. 6.

[0184] The test software will automatically read the force (N) at which the strengthened glass ceramic sample breaks, which is recorded as the single bar static pressure strength that it can withstand. Ten strengthened glass ceramic samples from the same batch are tested, and the average of the test results is taken as the single bar static pressure strength of the strengthened glass ceramic sample to be tested.

[0185] The custom jig in the test method is a cylindrical jig with a diameter of 65 mm and a height of 20 mm, and the specific structure of the custom jig is shown in FIGS. 7 and 8, where Φ1 = 65 mm, Φ2 = 46.02 mm, Φ3 = 44 mm, h1 = 20 mm, h2 = the thickness of the strengthened glass ceramic sample to be tested, and h3 = 15 mm. The height h2 of the sample slot in the custom jig is equal to the thickness of the strengthened glass ceramic sample to be tested, and the strengthened glass ceramic sample to be tested can be placed in the custom jig. The stepped blind hole for placing the sample for testing in the custom jig is coaxial with the custom jig. The material of the jig is acrylic material.

[0186] In the present application, a 2.5 m fixed-point height drop test is used to test the pass rate of the strengthened glass ceramic, which is used to characterize the anti-drop impact performance of the strengthened glass ceramic. The pass rate here refers to a plurality of identical strengthened glass ceramic samples, which are subjected to a drop test from a 2.5 m fixed-point height respectively, and the number of samples that pass the drop test is divided by the total number of test samples to obtain the pass rate. After the drop test, if the glass sample does not break, it is recorded as passing, otherwise it is recorded as not passing. In the present application, at least 10 identical strengthened glass ceramic samples from each batch are tested.

[0187] Specifically, the method for a single sample to undergo a 2.5 m fixed-point height drop test is as follows:

[0188] Step 1: Paste 80-mesh sandpaper on the lower surface of the 160g model machine, and place the model machine on the green chart LT-SKDL-CD type drop machine;

[0189] Step 2: Place the strengthened glass ceramic sample to be tested with a diameter of 46 mm and a thickness of 0.7 mm to 1.05 mm directly below the model machine, so that the strengthened glass ceramic sample faces the sandpaper. Make the model machine drop from a 2.5 m drop height once, and impact the strengthened glass ceramic sample directly below the model machine. If the strengthened glass ceramic sample does not break, it is recorded as passing, otherwise it is recorded as not passing.

[0190] In the present application, a 130g steel ball is used to perform drop ball impact test on the strengthened glass ceramic, to test the central drop ball impact energy that the strengthened glass ceramic can withstand, for representing the anti-drop ball impact performance of the strengthened glass ceramic. Specifically, a strengthened glass ceramic sample piece with a diameter of 46mm and a thickness of 0.7mm-1.05mm to be tested is placed in a customized fixture, at a test position of a drop ball impact testing machine (MY-GXDL-1500), a test software is started, the fixture position is calibrated by infrared rays, a 130g steel ball is used to perform limit drop ball test on the central point of the strengthened glass ceramic, the initial impact height of the drop ball is set to 0.3m, if the sample piece is not broken after the drop ball impacts the strengthened glass ceramic sample piece from the initial impact height, the drop ball impact height is increased by 0.05m each time, the strengthened glass ceramic sample piece is continuously impacted until the strengthened glass ceramic sample piece is broken.

[0191] The last drop ball impact height before the strengthened glass ceramic sample piece is broken is recorded as the anti-drop ball impact height. For example, if the limit drop ball test is performed by increasing the drop ball impact height by 0.05m each time, when the drop ball impact height at which the sample piece is broken is 0.5m, the anti-drop ball impact height of the sample piece is 0.45m.

[0192] Then, the central drop ball impact energy that the strengthened glass ceramic can withstand is calculated according to the formula: E=mgh.

[0193] Wherein: m is the mass of the steel ball; the unit is kg; h is the anti-drop ball impact height; the unit is m; g is the acceleration of gravity, the value is 9.8, and the unit is m / s 2 ; E is the central drop ball impact energy; the unit is J.

[0194] The electronic equipment used in deep sea exploration environment, diving environment and the like encounters damage risks including water pressure extrusion problem in addition to impact problem. Although the current glass ceramic has better performance than general glass, the anti-extrusion performance and the anti-impact performance still need to be further improved.

[0195] Without being limited by any theory, spinel crystal has excellent characteristics such as high hardness and high modulus, and the strengthened glass ceramic prepared by using glass ceramic with spinel crystal phase as the main crystal phase for chemical strengthening has better anti-extrusion performance and anti-impact performance than the strengthened glass ceramic prepared by using ordinary glass.

[0196] The chemical formula of the spinel crystal is AB2O4, wherein A is a divalent metal ion such as Zn, Fe or Mg with tetrahedral coordination, and B is a metal ion such as Al, Cr or Fe with octahedral coordination. Since Al-O, Mg-O and Zn-O can form strong ionic bonds, the structure is firm, the hardness is large, and the chemical properties are stable. The Mohs hardness of the spinel crystal is basically between 7 and 8, close to 8. Therefore, theoretically, a spinel glass ceramic with good mechanical properties can be obtained by controllably precipitating zinc spinel (or also referred to as zinc aluminum spinel) and / or magnesium spinel (or also referred to as magnesium aluminum spinel) and / or a zinc magnesium spinel solid solution (Zn, Mg)Al2O4 in the glass.

[0197] To this end, the present application adopts a glass ceramic containing spinel crystals satisfying specific composition and structure to prepare a strengthened glass ceramic material with desired extrusion resistance and impact resistance. The glass ceramic adopted in the present application is rich in high-strength spinel crystals and has a high-strength glass phase structure, and the mutual coordination of the crystal phase structure and the glass phase structure endows the glass ceramic with high inherent strength or intrinsic strength. The present application makes the surface composition and stress distribution of the glass ceramic after chemical strengthening satisfy specific requirements, so as to endow the prepared strengthened glass ceramic with a stress structure and stress level that realizes high extrusion resistance and high impact resistance, and thus obtain a strengthened glass ceramic with excellent extrusion resistance and excellent impact resistance.

[0198] It can be understood that the "surface composition" in the present application can be the material composition or the component distribution of the surface of the substrate glass, the glass ceramic or the strengthened glass ceramic, can also be the mass percentage of a certain component, the molar percentage of a certain component, the mass percentage relationship between two or more than two material components, the mass content relationship between two or more than two material components, can also be the molar content relationship between two or more than two material components, can also be the combination of the foregoing, and the like. For example: the mass percentage of Na2O on the surface of the strengthened glass ceramic or the mass percentage of K2O on the surface of the strengthened glass ceramic, for example: the mass percentage of Na2O on the surface of the strengthened glass ceramic and the mass percentage of K2O on the surface of the strengthened glass ceramic, for example: the mass percentage of K2O from the main surface of the strengthened glass ceramic, and the like. + (K element) diffusion depth and the depth of the position where the maximum value of the Na + concentration is located.

[0199] In some embodiments of the present application, a strengthened glass ceramic is provided, wherein the strengthened glass ceramic comprises a main crystal phase of a zinc aluminate-magnesium aluminate spinel solid solution and a secondary crystal phase of zirconia; the strengthened glass ceramic has a compressive stress layer on the surface and a tensile stress in the interior;

[0200] The surface K2O content of the strengthened glass ceramic is 2.50% to 7.50% by mass, preferably 3.00% to 7.00% by mass, and more preferably 3.50% to 7.00% by mass of oxides as measured by XRF;

[0201] The surface Na2O content of the strengthened glass ceramic is less than or equal to 0.010% by mass, preferably less than or equal to 0.005% by mass, and more preferably less than or equal to 0.002% by mass as measured by XRF;

[0202] The strengthened glass ceramic satisfies 8.00 μm ≤ DOL_K ≤ 20.00 μm, preferably 8.50 μm ≤ DOL_K ≤ 18.00 μm, and more preferably 9.00 μm ≤ DOL_K ≤ 16.00 μm, where DOL_K is the depth from the main surface of the strengthened glass ceramic to the K + diffusion depth;

[0203] The strengthened glass ceramic satisfies 30.00 μm ≤ DOL_Na ≤ 60.00 μm, preferably 34.00 μm ≤ DOL_Na ≤ 59.00 μm, and more preferably 37.00 μm ≤ DOL_Na ≤ 59.00 μm, where DOL_Na is the depth from the main surface of the strengthened glass ceramic to the Na + depth of the maximum concentration position;

[0204] The strengthened glass ceramic satisfies A = (t × DOL_K) / (|CT-AV| × (DOL_0 / t)), 850 ≤ A ≤ 4000, preferably 850 ≤ A ≤ 3000, and more preferably 900 ≤ A ≤ 2000, where t is the thickness of the strengthened glass ceramic in μm, DOL_K is the depth from the main surface of the strengthened glass ceramic to the K +Diffusion depth, measured by EPMA, unit: pm; |CT-AV| is the absolute value of the average tensile stress of the strengthened glass ceramic, measured by SLP_2000, unit: MPa; DOL_0 is the depth of the compressive stress layer of the strengthened glass ceramic, measured by SLP_2000, unit: pm; in formula A, the data are substituted into the formula according to the above unit requirements, and the calculation result is obtained, and the unit is not involved in the calculation.

[0205] In the present application, by simultaneously containing a certain amount of Li2O and Na2O in the glass ceramic, not only can the fracture toughness of the glass ceramic be increased, the overall strength of the glass phase (or also known as residual glass phase) can be improved, so that it is not easy to break when subjected to extrusion or impact, but also the chemical strengthening effect of the glass ceramic can be improved.

[0206] In the present application, by taking the zinc aluminum spinel-magnesium aluminum spinel solid solution as the main crystal phase of the glass ceramic, the glass ceramic obtains high intrinsic strength, and by chemically strengthening the glass ceramic and making the surface composition and stress distribution of the prepared strengthened glass ceramic meet specific requirements, especially the surface Na2O content, surface K2O content, K + Diffusion depth, Na + The depth of the position where the concentration maximum is located meets specific requirements, and at the same time, the thickness, K + Diffusion depth (or K + exchange (layer) depth) DOL_K, |CT-AV| and the depth of the compressive stress layer DOL_0 meet the requirements of formula A, and the mechanical properties of the strengthened glass ceramic are significantly improved, so that the strengthened glass ceramic simultaneously obtains excellent extrusion resistance and impact resistance.

[0207] In some embodiments, the surface K2O mass percentage of the strengthened glass ceramic can be 3.20% to 5.80%, 3.80% to 5.60%, or 4.10% to 5.5%. In some embodiments, the surface K2O mass percentage of the strengthened glass ceramic can be 2.50%, 3.00%, 3.50%, 4.00%, 4.50%, 5.00%, 5.50%, 6.00%, 6.50%, 7.00%, 7.50%, 5.62%, 4.66%, 6.78%, 4.95%, 3.86%, 4.96%, 4.55%, 4.53%, 4.04%, 5.73%, 5.39%, 6.11%, or 5.89%, or can be a value within a value range formed by any two specific values as endpoints, as long as the strengthened glass ceramic with the required performance of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as the strengthened glass ceramic with the required performance of the present application can be obtained.

[0208] In some embodiments, the surface Na20 content of the strengthened glass ceramic can be 0.000%, 0.002%, 0.003%, 0.004%, 0.005%, 0.006%, 0.007%, 0.008%, 0.009%, or 0.010%, or a value within a range having any two of the aforementioned specific numerical values as endpoints, as long as a strengthened glass ceramic having the desired properties herein is obtained. It will be understood that any of the above-mentioned ranges can be combined with any of the other ranges, as long as a strengthened glass ceramic having the desired properties herein is obtained.

[0209] In some embodiments, the DOL K of the strengthened glass ceramic can satisfy 10.00 pm < DOL K < 15.00 pm, 11.00 pm < DOL K < 14.00 pm, 15.00 pm < DOL K < 20.00 pm, or 12.00 pm < DOL K < 19.00 pm. In some embodiments, the DOL K of the strengthened glass ceramic can be 8.00 pm, 8.50 pm, 9.00 pm, 9.50 pm, 10.00 pm, 10.50 pm, 11.00 pm, 11.50 pm, 12.00 pm, 12.50 pm, 13.00 pm, 13.50 pm, 14.00 pm, 14.50 pm, 15.00 pm, 15.50 pm, 16.00 pm, 16.50 pm, 17.00 pm, 17.50 pm, 18.00 pm, 18.50 pm, 19.00 pm, 19.50 pm, 20.00 pm, 12.10 pm, 11.00 pm, 9.40 pm, 15.10 pm, 14.10 pm, 13.00 pm, 11.10 pm, 19.10 pm, 18.00 pm, or 17.10 pm, or a value within a range having any two of the aforementioned specific numerical values as endpoints, as long as a strengthened glass ceramic having the desired properties herein is obtained. It will be understood that any of the above-mentioned ranges can be combined with any of the other ranges, as long as a strengthened glass ceramic having the desired properties herein is obtained.

[0210] In some embodiments, the DOL Na of the strengthened glass-ceramic can satisfy: 40.00 pm ≤ DOL Na ≤ 55.00 pm, 43.00 pm ≤ DOL Na ≤ 52.00 pm, or 45.00 pm ≤ DOL Na ≤ 50.00 pm. In some embodiments, the DOL Na of the strengthened glass-ceramic can be 30.00 pm, 35.00 pm, 37.00 pm, 40.00 pm, 42.00 pm, 45.00 pm, 47.00 pm, 50.00 pm, 52.00 pm, 55.00 pm, 57.00 pm, 60.00 pm, 46.10 pm, 40.00 pm, 55.10 pm, 45.40 pm, 47.10 pm, 58.10 pm, 48.00 pm, 51.10 pm, 38.00 pm, 43.10 pm, 50.30 pm, 50.20 pm, or 56.40 pm, or can be a value within a range between any two of the above specifically named values as endpoints, as long as a strengthened glass-ceramic with the desired properties of the present application is obtained. It is understood that in specific embodiments, any of the above ranges can be combined with any of the other ranges, as long as a strengthened glass-ceramic with the desired properties of the present application is obtained.

[0211] In some embodiments, the value of Formula A can be 850, 950, 1050, 1150, 1250, 1350, 1450, 1550, 1650, 1750, 1850, 1950, 2050, 2150, 2250, 2350, 2450, 2550, 2650, 2750, 2850, 2950, 3050, 3150, 3250, 3350, 3450, 3550, 3650, 3750, 3850, 3950, 4000, 1039, 1150, 1520, 910, 1542, 1469, 935, 995, 1780, 1054, 1500, 2010, or 2440, or can be a value within a range between any two of the above specifically named values as endpoints, as long as a strengthened glass-ceramic with the desired properties of the present application is obtained. It is understood that in specific embodiments, any of the above ranges can be combined with any of the other ranges, as long as a strengthened glass-ceramic with the desired properties of the present application is obtained.

[0212] In some embodiments of the present application, the strengthened glass-ceramic satisfies: along the thickness direction of the strengthened glass-ceramic, the concentration of K + decreases nonlinearly from the main surface of the strengthened glass-ceramic to the center of the strengthened glass-ceramic. In the present application, in the K + concentration distribution curve from the main surface to the interior of the strengthened glass-ceramic measured by EPMA, the K+ After ion exchange, K + The amount of K + No longer diffuses inward.

[0213] In some embodiments of the present application, the strengthened glass ceramic satisfies: along the thickness direction of the strengthened glass ceramic, the concentration of Na + first increases nonlinearly and then decreases nonlinearly from the main surface of the strengthened glass ceramic to the center of the strengthened glass ceramic. In the present application, in the Na + concentration distribution curve of the strengthened glass ceramic from the main surface to the interior, the surface Na + is low, even possibly 0, due to being exchanged by K + , and with the increase of the depth, the difficulty of K + exchanging Na + increases gradually, and the amount of Na + in the glass ceramic increases gradually, and finally, when the depth at which the slope value of the curve is equal to 0.000 for the first time, the concentration of Na + reaches the maximum value.

[0214] In the present application, by making the average slope of the K element concentration distribution curve and / or the Na element concentration distribution curve in different depth ranges of the strengthened glass ceramic satisfy specific requirements, it is beneficial to make the strengthened glass ceramic achieve the desired stress distribution structure, and further beneficial to make the strengthened glass ceramic simultaneously obtain excellent impact resistance and extrusion resistance.

[0215] In some embodiments of the present application, the strengthened glass ceramic satisfies:

[0216] The K element concentration distribution curve is obtained by EPMA, in which the horizontal axis is the depth in μm from the main surface of the strengthened glass ceramic, and the vertical axis is the K element concentration in the mass percentage of element basis, and in the obtained K element concentration distribution curve: the absolute value P1 of the average slope of the K element concentration distribution curve between the depth of 0 μm and the depth of DOL_K is 0.150-1.000, preferably, P1 is 0.150-0.800, more preferably, P1 is 0.150-0.600.

[0217] In some embodiments, in the K element concentration distribution curve measured by EPMA: the absolute value of the average slope of the K element concentration distribution curve between a depth of 0 micrometers and a depth of DOL_K can be 0.150, 0.200, 0.250, 0.300, 0.350, 0.400, 0.450, 0.500, 0.550, 0.600, 0.650, 0.700, 0.750, 0.800, 0.850, 0.900, 0.950, 1.000, 0.380, 0.315, 0.302, 0.530, 0.348, 0.193, 0.445, 0.452, 0.194, 0.440, 0.220, or 0.310, or a value within a range of any two of the above specific values as endpoints, as long as a strengthened glass-ceramic having the desired properties herein is obtained. It will be appreciated that in specific embodiments, any of the above ranges can be combined with any of the other ranges, as long as a strengthened glass-ceramic having the desired properties herein is obtained.

[0218] In some embodiments of the present application, the strengthened glass-ceramic satisfies: a K element concentration distribution curve is obtained using EPMA with the horizontal axis as depth in micrometers from the main surface of the strengthened glass-ceramic, and the vertical axis as K element concentration in mass percent on an elemental basis, and in the obtained K element concentration distribution curve: the absolute value of the average slope of the K element concentration distribution curve between a depth of 5 micrometers and a depth of 8 micrometers, P 5-8 is 0.50-2.50, preferably, P 5- 8 is 0.60-2.00, more preferably, P 5-8 is 0.70-1.50.

[0219] In some embodiments, in the K element concentration distribution curve measured by EPMA: the absolute value of the average slope of the K element concentration distribution curve between a depth of 5 micrometers and a depth of 8 micrometers, P 5-80.50, 0.60, 0.70, 0.80, 0.90, 1.00, 1.10, 1.20, 1.30, 1.40, 1.50, 1.60, 1.70, 1.80, 1.90, 2.00, 2.10, 2.20, 2.30, 2.40, 2.50, 0.74, 1.12, 1.22, 0.99, 1.04, 1.25, 0.76, 0.80, 0.79, 0.95, 0.66, 1.34, or 1.64, or a value within a range defined by any two of the above specific numerical values as endpoints, as long as a strengthened glass-ceramic having the desired properties of the present application is obtained. It is to be understood that in specific embodiments, any of the above ranges can be combined with any of the other ranges, as long as a strengthened glass-ceramic having the desired properties of the present application is obtained.

[0220] In some embodiments of the present application, the strengthened glass-ceramic satisfies: a Na element concentration distribution curve is obtained by EPMA testing, with the horizontal axis being depth in pm from the main surface of the strengthened glass-ceramic, and the vertical axis being the Na element concentration in mass percent on an elemental basis, and in the obtained Na element concentration distribution curve:

[0221] The absolute value P2 of the average slope of the Na element concentration distribution curve between a depth of 0 pm and a depth of DOL Na is 0.01-0.05, preferably, P2 is 0.01-0.04, more preferably, P2 is 0.01-0.03.

[0222] In some embodiments, in the Na element concentration distribution curve measured by EPMA: the absolute value P2 of the average slope of the Na element concentration distribution curve between a depth of 0 pm and a depth of DOL Na can be 0.01, 0.02, 0.03, 0.04, or 0.05, or a value within a range defined by any two of the above specific numerical values as endpoints, as long as a strengthened glass-ceramic having the desired properties of the present application is obtained. It is to be understood that in specific embodiments, any of the above ranges can be combined with any of the other ranges, as long as a strengthened glass-ceramic having the desired properties of the present application is obtained.

[0223] In the present application, by causing the average slope of the stress distribution curve in different depth ranges of the strengthened glass-ceramic to satisfy specific requirements, it is beneficial to cause the strengthened glass-ceramic to achieve a desired stress distribution structure, and further beneficial to cause the strengthened glass-ceramic to simultaneously have excellent impact resistance and extrusion resistance.

[0224] In some embodiments of the present application, the strengthened glass-ceramic satisfies:

[0225] the SLP stress profile curve obtained by the SLP-2000 instrument test is a nonlinear curve, as shown in FIG. 4. 50-80 is 1.00-2.50, preferably, K 50-80 is 1.00-2.40, more preferably, K 50-80 is 1.00-2.30.

[0226] In some embodiments, in the SLP stress profile curve measured by the SLP-2000, the absolute value of the average slope of the SLP stress profile curve between the depth of 50 μm and the depth of 80 μm, K 50-80 may be 1.00, 1.10, 1.20, 1.30, 1.40, 1.50, 1.60, 1.70, 1.80, 1.90, 2.00, 2.10, 2.20, 2.30, 2.40, 2.50, 1.92, 1.48, 1.52, 1.38, 1.70, 1.03, 1.59, 1.28, 2.29, 1.50, 1.56, or 1.73, or a value within a range defined by any two of the above specific values as endpoints, as long as a strengthened glass ceramic with desired properties in the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a strengthened glass ceramic with desired properties in the present application can be obtained. In the present application, the SLP stress profile curve of the strengthened glass ceramic obtained by the SLP-2000 instrument test is a nonlinear curve, as shown in FIG. 4.

[0227] In some embodiments of the present application, the strengthened glass ceramic satisfies: the SLP stress profile curve obtained by the SLP-2000 test has a horizontal axis of depth in μm from the main surface of the strengthened glass ceramic and a vertical axis of stress in MPa, and in the SLP stress profile curve obtained, the absolute value of the average slope of the SLP stress profile curve between the depth of 80 μm and the depth of DOL_0, K 80-DOL-0 is 0.90-2.00, preferably, K 80-DOL-0 is 0.90-1.80, more preferably, K 80-DOL-0 is 0.90-1.60.

[0228] In some embodiments, in the SLP stress profile curve measured by the SLP-2000, the absolute value of the average slope of the SLP stress profile curve between the depth of 80 μm and the depth of DOL_0, K 80-DOL-0may be 0.90, 1.00, 1.10, 1.20, 1.30, 1.40, 1.50, 1.60, 1.70, 1.80, 1.90, 2.00, 1.35, 1.06, 1.05, 1.33, 1.17, 0.98, 1.29, 1.09, 1.42, 1.18, or 1.13, or a value within a range defined by any two of the above specifically named values as endpoints, as long as the strengthened glass-ceramic has the desired properties. It is understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as the strengthened glass-ceramic has the desired properties.

[0229] In some embodiments of the present application, the strengthened glass-ceramic is in the form of a plate, and the strengthened glass-ceramic has a thickness t of greater than 0.7 mm, preferably, a thickness t of not less than 0.8 mm, more preferably, a thickness t of 0.9 mm to 2.0 mm. In the present application, when the thickness of the strengthened glass-ceramic is small, the compression resistance and impact resistance of the strengthened glass-ceramic will be significantly reduced, and when the thickness of the strengthened glass-ceramic is too large, on the one hand, the weight will be increased, which is not conducive to the light and thin electronic devices, and on the other hand, the thickness is too large, which will result in the decrease of the transmittance of the glass-ceramic, and the transmittance performance of the glass-ceramic will be poor.

[0230] In some embodiments, the strengthened glass-ceramic has a thickness t of not less than 0.95 mm, not less than 1.00 mm, or not less than 1.05 mm. In some embodiments, the strengthened glass-ceramic has a thickness t of 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, or 1.5 mm, or a value within a range defined by any two of the above specifically named values as endpoints, as long as the strengthened glass-ceramic has the desired properties. It is understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as the strengthened glass-ceramic has the desired properties.

[0231] Unless subjected to an excessive ion exchange treatment, the composition and phase assembly of the strengthened glass-ceramic at a portion deeper than the depth of the compressive stress layer (DOL), such as the center of the strengthened glass-ceramic or the tensile stress layer, is the same as or substantially the same as the composition and phase assembly of the glass-ceramic.

[0232] It is to be understood that the strengthened glass-ceramics of the present application are made from a glass-ceramic that is chemically strengthened, and the composition of the center of the strengthened glass-ceramic or the composition of the compressive stress layer is the same or substantially the same as the composition of the glass-ceramic. The composition at the surface of the glass-ceramic article after the chemical strengthening process can be different from the composition of the glass-ceramic before the chemical strengthening process, because, during the chemical strengthening process, one type of alkali metal ion (e.g., Li + or Na + ) at the surface of the glass-ceramic is replaced by a larger alkali metal ion (e.g., Na + or K + ), respectively. However, in embodiments, the glass composition and the phase assembly at or near the center of the depth or thickness of the glass-ceramic article remain the same as the glass composition and the phase assembly of the as-formed glass-ceramic. That is, in the present application, the composition at the center of the strengthened glass-ceramic or the composition of the compressive stress layer is the same or substantially the same as the glass-ceramic that is not chemically strengthened.

[0233] Meanwhile, in the present application, the glass-ceramic used to make the strengthened glass-ceramic can be made from a base glass that is heat treated, and the composition of the base glass is the same or substantially the same as the composition of the glass-ceramic, in terms of mass percent of oxides.

[0234] In some embodiments of the present application, the composition of the center of the strengthened glass-ceramic or the composition of the glass-ceramic used to make the strengthened glass-ceramic or the composition of the base glass contains Al2O3 in an amount of greater than or equal to 30.00% in terms of mass percent of oxides.

[0235] In the present application, by controlling the mass percent of Al2O3 in the glass-ceramic to be greater than or equal to 30%, on one hand, it is able to ensure the precipitation of the desired amount of the main crystal phase, so that the glass-ceramic has high intrinsic strength (or also known as inherent strength), and on the other hand, it is able to make the glass phase also contain a certain amount of aluminum oxide, and the aluminum oxide present in the glass phase is able to enter the glass network structure in the form of [AlO4] tetrahedron to form a unified grid with [SiO4], so that the degree of network connection is enhanced, and the strength and stability of the glass network structure are improved, so that the intrinsic strength of the glass-ceramic is further improved. Meanwhile, the [AlO4] tetrahedron in the glass phase can appropriately expand the ion exchange channel, improve the chemical strengthening effect of the glass-ceramic, and be more conducive to making the strengthened glass-ceramic with excellent mechanical strength performance.

[0236] In some embodiments of the present application, the composition at the center of the strengthened glass-ceramic or the composition of the strengthened glass-ceramic or the composition of the glass-ceramic used to prepare the strengthened glass-ceramic or the composition of the substrate glass comprises Zr02in an amount of 3.00% or more by mass percent.

[0237] In the present application, by controlling the mass percent of Zr02in the glass-ceramic to be 3.00% or more, the intrinsic strength of the glass-ceramic is improved, and the surface stress level of the strengthened glass-ceramic prepared therefrom is also improved. On the one hand, as a nucleating agent, Zr02, after heat treatment, disperses in the glass phase in the form of nanoscale grains, which can increase the hardness of the glass-ceramic and thus effectively improve the shatter resistance of the glass-ceramic. On the other hand, Zr02exists in the glass phase in the form of a cube [Zr08], which can enhance the interionic force and make the glass structure more compact, thus improving the mechanical strength of the glass phase. At the same time, Zr02can significantly improve the surface compressive stress formed by ion exchange, thus improving the surface stress level of the strengthened glass-ceramic prepared therefrom.

[0238] In some embodiments of the present application, the composition at the center of the strengthened glass-ceramic or the composition of the strengthened glass-ceramic or the composition of the glass-ceramic used to prepare the strengthened glass-ceramic or the composition of the substrate glass comprises, by mass percent of oxides: Si02: 25.00% to 55.00%, Al203: 30.00% to 55.00%, Zr02: 3.00% to 8.00%, MgO: 2.00% to 5.00%, ZnO: 5.00% to 15.00%, Na20: 1.00% to 10.00%, K20: 0% to 5.00%, Li20: 1.00% to 6.00%, CaO: 0% to 6.00%, B203: 0% to 10.00%, BaO: 0% to 10.00%, Y203: 0% to 6.00%, La203: 0% to 12.00%. By adjusting and controlling the content range of each oxide component, it is beneficial to ensure that the strengthened glass-ceramic satisfying the desired crystal phase structure and stress structure is obtained, and it is also beneficial to ensure that the strengthened glass-ceramic has excellent optical properties and high intrinsic strength. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as the strengthened glass-ceramic having the desired properties of the present application can be obtained.

[0239] In the present application, SiO2 is a network former oxide of glass, and is an indispensable component of the glass network structure. The content of appropriate amount of SiO2 can increase the stability and mechanical strength of the glass, but excessive SiO2 will increase the viscosity of the base glass, making the glass melting more difficult, thereby reducing the formability of the base glass. In the present application, the mass percentage of SiO2 in the composition of the center of the strengthened glass ceramic or the composition of the tensile stress layer of the strengthened glass ceramic or the composition of the glass ceramic used for preparing the strengthened glass ceramic or the composition of the base glass is 25.00% to 55.00%, preferably 30.00% to 42.00%, more preferably 35.00% to 40.00%.

[0240] In some embodiments of the present application, the content of SiO2 in the composition of the center of the strengthened glass ceramic or the composition of the tensile stress layer of the strengthened glass ceramic or the composition of the glass ceramic used for preparing the strengthened glass ceramic or the composition of the base glass can be 25.00% to 55.00%, 25.00% to 40.00%, 40.00% to 55.00%, or 30.00% to 40.00% in terms of mass percentage of oxide.

[0241] In some embodiments of the present application, the content of Si02in the composition at the center of the strengthened glass-ceramic or the composition of the strengthened glass-ceramic or the composition of the glass-ceramic used to make the strengthened glass-ceramic or the composition of the substrate glass can be 25.00%, 25.50%, 26.00%, 26.50%, 27.00%, 27.50%, 28.00%, 28.50%, 29.00%, 29.50%, 30.00%, 30.50%, 31.00%, 31.50%, 32.00%, 32.50%, 33.00%, 33.50%, 34.00%, 34.50%, 35.00%, 35.50%, 36.00%, 36.50%, 37.00%, 37.50%, 38.00%, 38.50%, 39.00%, 39.50%, 40.00%, 40.50%, 41.00%, 41.50%, 42.00%, 42.50%, 43.00%, 43.50%, 44.00%, 44.50%, 45.00%, 45.50%, 46.00%, 46.50%, 47.00%, 47.50%, 48.00%, 48.50%, 49.00%, 49.50%, 50.00%, 50.50%, 51.00%, 51.50%, 52.00%, 52.50%, 53.00%, 53.50%, 54.00%, 54.50%, 55.00%, 37.08%, 36.87%, 33.23%, 37.43%, 37.40%, 38.33%, 36.05%, 35.67%, or 32.39% in mass percent of the oxide, or a value within a range defined by any two of the above specific numerical values as endpoints, as long as a glass-ceramic or strengthened glass-ceramic with the desired properties of the present application is obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass-ceramic or strengthened glass-ceramic with the desired properties of the present application is obtained.

[0242] In the present application, Al2O3 is one of the components of the main crystal phase of zinc magnesium spinel solid solution crystal phase formed after the crystallization of the substrate glass. The increase of Al2O3 can promote the precipitation of spinel and inhibit the precipitation of other impurities such as quartz, which will directly affect the content of the main crystal phase (Zn, Mg) Al2O4. With the increase of the content of Al2O3, the strength of the glass phase in the glass-ceramic is also enhanced, and the mechanical properties of the glass-ceramic are enhanced. At the same time, since the volume of [AlO4] is larger than that of [SiO4], it can provide more space for ion exchange, which is beneficial to promote the chemical strengthening. However, excessive Al2O3 will increase the viscosity of the substrate glass, which will reduce the formability of the substrate glass, and will also easily lead to the rapid precipitation rate, which will cause the substrate glass to devitrify during the normal cooling process. In the present application, the mass percentage of Al2O3 in the composition of the center of the strengthened glass-ceramic or the composition of the tensile stress layer of the strengthened glass-ceramic or the composition of the glass-ceramic used to prepare the strengthened glass-ceramic or the composition of the substrate glass is 30.00% to 55.00%, preferably 32.00% to 42.00%, and more preferably 34.00% to 42.00%.

[0243] In some embodiments of the present application, the content of Al2O3 in the composition of the center of the strengthened glass-ceramic or the composition of the tensile stress layer of the strengthened glass-ceramic or the composition of the glass-ceramic used to prepare the strengthened glass-ceramic or the composition of the substrate glass can be 30.00% to 55.00%, 30.00% to 40.00%, or 40.00% to 55.00% in terms of mass percentage of oxide.

[0244] In some embodiments of the present application, the content of Al2O3 in the composition of the center of the strengthened glass ceramic or the composition of the strengthened glass ceramic or the composition of the glass ceramic used to prepare the strengthened glass ceramic or the composition of the base glass can be 30.00%, 30.50%, 31.00%, 31.50%, 32.00%, 32.50%, 33.00%, 33.50%, 34.00%, 34.50%, 35.00%, 35.50%, 36.00%, 36.50%, 37.00%, 37.50%, 38.00%, 38.50%, 39.00%, 39.50%, 40.00%, 40.50%, 41.00%, 41.50%, 42.00%, 42.50%, 43.00%, 43.50%, 44.00%, 44.50%, 45.00%, 45.50%, 46.00%, 46.50%, 47.00%, 47.50%, 48.00%, 48.50%, 49.00%, 49.50%, 50.00%, 50.50%, 51.00%, 51.50%, 52.00%, 52.50%, 53.00%, 53.50%, 54.00%, 54.50%, 55.00%, 35.83%, 36.98%, 36.27%, 37.52%, 36.60%, 37.07%, 34.84%, 34.55%, or 35.88%, or a value within a range defined by any two of the above specific numerical values as endpoints, as long as a glass ceramic or a strengthened glass ceramic with desired properties of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass ceramic or a strengthened glass ceramic with desired properties of the present application can be obtained.

[0245] In the present application, ZrO2 is an effective nucleating agent. During heat treatment of the glass, ZrO2 is precipitated in the form of crystals, and the ZrO2 crystals become crystal nuclei for the growth of subsequent crystals. Within a certain range of glass composition, the content of ZrO2 affects the formation of the glass, the crystal shape, the crystal type, and the crystal size of the glass ceramic obtained after heat treatment of the glass, etc. By adjusting the composition of the glass, ZrO2 can be precipitated preferentially at the same temperature, followed by the growth of the main crystal phase spinel crystals. When the content of ZrO2 is too low, the precipitation of the main crystal phase zinc-magnesium spinel solid solution phase will be affected. When the content of ZrO2 is too high, the melting of the base glass will become difficult, and white unmelted substances will be produced in the base glass. In the present application, the mass percentage of ZrO2 in the composition of the center of the strengthened glass ceramic or the composition of the strengthened glass ceramic or the composition of the glass ceramic used to prepare the strengthened glass ceramic or the composition of the base glass is 3.00%-8.00%, preferably 4.00%-7.00%, and more preferably 5.00%-6.00%.

[0246] In some embodiments of the present application, the content of Zr02in the composition at the center of the strengthened glass-ceramic or the composition of the tension stress layer or the composition of the glass-ceramic used to prepare the strengthened glass-ceramic or the composition of the base glass can be 3.00% to 8.00%, 3.00% to 6.00%, or 6.00% to 8.00% by mass percent of oxide.

[0247] In some embodiments of the present application, the content of Zr02in the composition at the center of the strengthened glass-ceramic or the composition of the tension stress layer or the composition of the glass-ceramic used to prepare the strengthened glass-ceramic or the composition of the base glass can be 3.00%, 3.20%, 3.50%, 3.70%, 4.00%, 4.20%, 4.50%, 4.70%, 5.00%, 5.20%, 5.50%, 5.70%, 6.00%, 6.50%, 7.00%, 7.50%, 8.00%, 5.69%, 5.65%, 5.61%, 5.74%, 5.81%, 5.89%, 5.54%, or 5.48% by mass percent of oxide, or a value within a range defined by any two of the above specific values as endpoints, as long as a glass-ceramic or strengthened glass-ceramic with the desired properties of the present application is obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass-ceramic or strengthened glass-ceramic with the desired properties of the present application is obtained.

[0248] In the present application, ZnO provides the zinc necessary for the base glass to form the main crystal phase of the zinc-magnesium spinel solid solution crystal phase after crystallization. ZnO can reduce the thermal expansion coefficient of the glass, improve the chemical stability, thermal stability, and refractive index of the glass. MgO provides the magnesium necessary for the base glass to form the main crystal phase of the zinc-magnesium spinel solid solution crystal phase after crystallization. MgO can slow down the hardening speed of the glass, improve the forming properties of the glass; MgO can also reduce the crystallization tendency and crystallization speed, increase the high-temperature viscosity of the glass, and improve the chemical stability and mechanical strength of the glass. However, the addition of excessive amounts of MgO and ZnO tends to easily lead to excessively large spinel grains, and it is difficult to obtain a glass-ceramic with high transparency. In the present application, the mass percent of ZnO in the composition at the center of the strengthened glass-ceramic or the composition of the tension stress layer or the composition of the glass-ceramic used to prepare the strengthened glass-ceramic or the composition of the base glass is 5.00% to 15.00%, preferably 9.00% to 13.00%, and more preferably 9.00% to 11.00%; the mass percent of MgO is 2.00% to 5.00%, preferably 2.50% to 4.00%, and more preferably 2.50% to 3.50%.

[0249] In some embodiments of the present application, the content of ZnO in the composition at the center of the strengthened glass-ceramic or the composition of the strengthened glass-ceramic or the composition of the glass-ceramic used to prepare the strengthened glass-ceramic or the composition of the base glass can be 5.00%, 5.50%, 6.00%, 6.50%, 7.00%, 7.50%, 8.00%, 8.50%, 9.00%, 9.50%, 10.00%, 10.50%, 11.00%, 11.50%, 12.00%, 12.50%, 13.00%, 14.00%, 15.00%, 10.77%, 10.71%, 10.55%, 10.87%, 11.01%, 11.15%, 10.46%, or 10.37% in terms of mass percentage of oxide, or can be a value within a range between any two of the above specific values as endpoints, as long as a glass-ceramic or strengthened glass-ceramic with desired properties of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass-ceramic or strengthened glass-ceramic with desired properties of the present application can be obtained.

[0250] In some embodiments of the present application, the content of MgO in the composition at the center of the strengthened glass-ceramic or the composition of the strengthened glass-ceramic or the composition of the glass-ceramic used to prepare the strengthened glass-ceramic or the composition of the base glass can be 2.00%, 2.50%, 3.00%, 3.50%, 4.00%, 4.50%, 5.00%, 2.98%, 3.04%, 3.03%, 3.06%, 3.10%, 2.92%, or 2.89% in terms of mass percentage of oxide, or can be a value within a range between any two of the above specific values as endpoints, as long as a glass-ceramic or strengthened glass-ceramic with desired properties of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass-ceramic or strengthened glass-ceramic with desired properties of the present application can be obtained.

[0251] In the present application, the increase of the content of Na2O helps to obtain higher surface compressive stress, while the melting temperature and the temperature of crystal precipitation can be reduced. However, excessive addition of Na2O can cause the glass to be ceramized during annealing, or cause other impurity phases to precipitate during heat treatment, which affects the transmittance of the glass-ceramic, and thus the transmittance of the obtained glass-ceramic is reduced. Too low content of Na2O can cause the heat treatment temperature to increase, and directly cause phase separation or precipitation of impurity phases during heat treatment, and thus the glass-ceramic obtained is opaque or has poor transparency. In the present application, the mass percentage of Na2O in the composition at the center of the strengthened glass-ceramic or the composition of the strengthened glass-ceramic or the composition of the glass-ceramic used to prepare the strengthened glass-ceramic or the composition of the base glass is 1.00% to 10.00%, preferably 1.00% to 8.00%, and more preferably 2.00% to 6.00%.

[0252] In some embodiments of the present application, the content of Na20 in the composition of the center of the strengthened glass ceramic or the composition of the glass ceramic used to prepare the strengthened glass ceramic or the composition of the base glass can be 1.00%, 1.50%, 2.00%, 2.50%, 3.00%, 3.50%, 4.00%, 4.50%, 5.00%, 5.50%, 6.00%, 6.50%, 7.00%, 7.50%, 8.00%, 8.50%, 9.00%, 9.50%, 10.00%, 2.86%, 2.85%, 2.89%, 3.00%, 1.69%, 2.79%, or 2.76% in terms of mass percentage of oxide, or can be a value within a value range with any two of the above specific values as endpoints, as long as a glass ceramic or strengthened glass ceramic with the desired properties of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass ceramic or strengthened glass ceramic with the desired properties of the present application can be obtained.

[0253] In the present application, Li20 helps to obtain a higher compressive stress layer depth, increase the Young's modulus and fracture toughness; at the same time, it can reduce the melting temperature and the temperature of crystal precipitation, but excessive addition of Li20 will lead to ceramming of the glass during annealing, or lead to precipitation of other impurity phases affecting the transmittance of the glass ceramic during heat treatment, or lead to excessive growth of crystals during heat treatment, resulting in a decrease in the transmittance of the obtained glass ceramic. Too low an amount of Li20 will lead to an increase in the heat treatment temperature and a decrease in the deep stress. In the present application, the mass percentage of Li20 in the composition of the center of the strengthened glass ceramic or the composition of the glass ceramic used to prepare the strengthened glass ceramic or the composition of the base glass is 1.00% to 6.00%, preferably 1.00% to 4.00%, and more preferably 2.00% to 3.00%.

[0254] In some embodiments of the present application, the content of Li20 in the composition of the strengthened glass-ceramic at the center or the composition of the tensile stress layer of the strengthened glass-ceramic or the composition of the glass-ceramic used to prepare the strengthened glass-ceramic or the composition of the base glass can be 1.00%, 1.50%, 2.00%, 2.50%, 3.00%, 3.50%, 4.00%, 4.50%, 5.00%, 5.50%, 6.00%, 2.35%, 1.55%, 1.50%, 1.77%, 1.60%, 1.62%, 2.28%, 2.27% or 2.24% in terms of mass percentage of oxide, or can be a value within a value range with any two of the above specific values as endpoints, as long as a glass-ceramic or strengthened glass-ceramic with the desired properties of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass-ceramic or strengthened glass-ceramic with the desired properties of the present application can be obtained.

[0255] In the present application, K20 can be added as an optional component in an amount of 0-5.00% in terms of mass percentage, preferably 0-3.00%, more preferably 0-1.00%. In some embodiments, the composition of the strengthened glass-ceramic at the center or the composition of the tensile stress layer of the strengthened glass-ceramic or the composition of the glass-ceramic used to prepare the strengthened glass-ceramic or the composition of the base glass preferably does not contain K20.

[0256] In the present application, CaO can be added as an optional component in an appropriate amount, which is beneficial to reduce the viscosity of the glass, improve the formability, strain point and Young's modulus of the base glass, and can improve the ion exchange capacity, while calcium oxide can also increase the gloss and transparency of the glass, reduce the tendency of the glass to crystallize, and slow down the hardening speed of the glass. However, too much CaO will increase the density and CTE of the glass composition, significantly reducing the ion exchange performance of the glass-ceramic. In the present application, the mass percentage of CaO in the composition of the strengthened glass-ceramic at the center or the composition of the tensile stress layer of the strengthened glass-ceramic or the composition of the glass-ceramic used to prepare the strengthened glass-ceramic or the composition of the base glass is 0%-6.00%, preferably 0%-3.00%, more preferably 0%-1.50%.

[0257] In some embodiments of the present application, the content of CaO in the composition of the center of the strengthened glass-ceramics or the composition of the tensile stress layer of the strengthened glass-ceramics or the composition of the glass-ceramics used to prepare the strengthened glass-ceramics or the composition of the base glass can be 0%, 0.50%, 1.00%, 1.50%, 2.00%, 2.50%, 3.00%, 3.50%, 4.00%, 4.50%, 5.00%, 5.50%, 6.00%, 0.75%, 1.15%, or 0.92% in terms of mass percentage of oxide, or can be a value within a value range consisting of any two of the above specific numerical values as endpoints, as long as a glass-ceramics or a strengthened glass-ceramics with the required properties of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass-ceramics or a strengthened glass-ceramics with the required properties of the present application can be obtained.

[0258] In the present application, B2O3 is an optional component. An appropriate amount of B2O3 is beneficial to greatly reduce the melting difficulty of the glass and promote the precipitation of spinel. However, an excessive amount of B2O3 will cause opalescence during heat treatment of the base glass to prepare the glass-ceramics, and may also cause the precipitation of other crystal phases that seriously affect the transparency of the glass. In the present application, the mass percentage of B2O3 in the composition of the center of the strengthened glass-ceramics or the composition of the tensile stress layer of the strengthened glass-ceramics or the composition of the glass-ceramics used to prepare the strengthened glass-ceramics or the composition of the base glass is 0% to 10.00%, preferably 0% to 8.00%, and more preferably 0% to 4.00%.

[0259] In some embodiments of the present application, the content of B2O3 in the composition of the center of the strengthened glass-ceramics or the composition of the tensile stress layer of the strengthened glass-ceramics or the composition of the glass-ceramics used to prepare the strengthened glass-ceramics or the composition of the base glass can be 0%, 0.50%, 1.00%, 1.50%, 2.00%, 2.50%, 3.00%, 3.50%, 4.00%, 4.50%, 5.00%, 5.50%, 6.00%, 6.50%, 7.00%, 7.50%, 8.00%, 8.50%, 9.00%, 9.50%, 10.00%, or 7.07% in terms of mass percentage of oxide, or can be a value within a value range consisting of any two of the above specific numerical values as endpoints, as long as a glass-ceramics or a strengthened glass-ceramics with the required properties of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass-ceramics or a strengthened glass-ceramics with the required properties of the present application can be obtained.

[0260] In the present application, BaO is an optional component. Appropriate amount of BaO is beneficial to improve the melting effect of the glass, increase the density of the glass, improve the Young's modulus, and to a certain extent, inhibit the growth of the crystal grains and improve the optical performance of the glass ceramic. However, excessive BaO has a strong inhibitory effect on the exchange process of Na ions and K ions. In the present application, the mass percentage of BaO in the composition of the center of the strengthened glass ceramic or the tensile stress layer, the composition of the glass ceramic used for preparing the strengthened glass ceramic, or the composition of the base glass is 0% to 10.00%, preferably 0% to 7.00%, and more preferably 0% to 4.00%.

[0261] In some embodiments of the present application, the content of BaO in the composition of the center of the strengthened glass ceramic or the tensile stress layer, the composition of the glass ceramic used for preparing the strengthened glass ceramic, or the composition of the base glass, in terms of mass percentage of oxides, can be 0%, 0.50%, 1.00%, 1.50%, 2.00%, 2.50%, 3.00%, 3.50%, 4.00%, 4.50%, 5.00%, 5.50%, 6.00%, 6.50%, 7.00%, 7.50%, 8.00%, 8.50%, 9.00%, 9.50%, 10.00%, 2.42%, 2.41%, 6.94%, 2.35%, or 2.32%, or can be a value within a value range with any two of the above specific values as endpoints, as long as a glass ceramic or a strengthened glass ceramic with the required performance of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass ceramic or a strengthened glass ceramic with the required performance of the present application can be obtained.

[0262] In the present application, Y2O3 is an optional component. Y2O3 has the effect of making the glass structure compact. Appropriate amount of Y2O3 can increase the packing density inside the glass, which is manifested as increasing the density of the glass, thereby being beneficial to improve the intrinsic strength of the glass. For ion exchange performance, it can increase the stress effect of unit ion exchange of Li + + plasma in the chemical strengthening process, but may reduce the exchange speed. However, excessive addition of Y2O3 is not conducive to obtaining transparent spinel glass ceramics. In the present application, the mass percentage of Y2O3 in the composition of the center of the strengthened glass ceramic or the tensile stress layer, the composition of the glass ceramic used for preparing the strengthened glass ceramic, or the composition of the base glass is 0% to 6.00%, preferably 0% to 4.00%, and more preferably 0% to 2.00%.

[0263] ​In some embodiments of the present application, the content of Y2O3 in the composition of the center of the strengthened glass ceramic or the composition of the tensile stress layer of the strengthened glass ceramic or the composition of the glass ceramic used to prepare the strengthened glass ceramic or the composition of the base glass can be 0%, 0.50%, 1.00%, 1.50%, 2.00%, 2.50%, 3.00%, 3.50%, 4.00%, 4.50%, 5.00%, 5.50%, 6.00%, 1.52%, or 0.60% in terms of mass percentage of oxide, or can be a value within a value range formed by any two of the above specific values as endpoints, as long as a glass ceramic or strengthened glass ceramic with the required performance of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass ceramic or strengthened glass ceramic with the required performance of the present application can be obtained.

[0264] In the present application, La2O3 is a network modifier component of the glass as an optional component. An appropriate amount of La2O3 helps to increase the refractive index of the glass, reduce the high-temperature viscosity of the glass, and improve the glass melting effect and eliminate its internal defects. At the same time, an appropriate amount of La2O3 can significantly improve the Young's modulus and micro Vickers hardness of the glass, and also has the effect of improving the chemical strengthening performance of the glass ceramic and increasing the stress effect per ion exchange of the strengthened glass ceramic. However, too much La2O3 is not conducive to obtaining transparent spinel glass ceramics. In the present application, the mass percentage of La2O3 in the composition of the center of the strengthened glass ceramic or the composition of the tensile stress layer of the strengthened glass ceramic or the composition of the glass ceramic used to prepare the strengthened glass ceramic or the composition of the base glass is 0% to 12.00%, preferably 0% to 5.00%, and more preferably 0% to 3.00%.

[0265] In some embodiments of the present application, the content of Y2O3 in the composition of the center of the strengthened glass ceramic or the composition of the tensile stress layer of the strengthened glass ceramic or the composition of the glass ceramic used to prepare the strengthened glass ceramic or the composition of the base glass can be 0%, 0.50%, 1.00%, 1.50%, 2.00%, 2.50%, 3.00%, 3.50%, 4.00%, 4.50%, 5.00%, 5.50%, 6.00%, 1.52%, or 0.60% in terms of mass percentage of oxide, or can be a value within a value range formed by any two of the above specific values as endpoints, as long as a glass ceramic or strengthened glass ceramic with the required performance of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass ceramic or strengthened glass ceramic with the required performance of the present application can be obtained.

[0266] In the present application, by adjusting the content of each oxide component and controlling the content range, and by adding an appropriate amount of Y2O3 and / or La2O3, the content relationship of each oxide component is adjusted, which is conducive to improving the strength, hardness, stability and deformation resistance of the strengthened glass ceramic.

[0267] In the present application, in order to obtain the strengthened glass ceramic with excellent performance as desired in the present application, in addition to Y2O3 and La2O3, metal oxides of cerium, praseodymium, neodymium, promethium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium or scandium, or a mixture of the foregoing metal oxides, can also be added to the composition of the glass ceramic used for preparing the strengthened glass ceramic or the composition of the base glass, as long as the glass ceramic or the strengthened glass ceramic with the desired performance in the present application can be obtained. If the foregoing metal oxides are added to the composition of the glass ceramic used for preparing the strengthened glass ceramic or the composition of the base glass, the strengthened glass ceramic obtained should also contain these metal oxides in the composition at the center or the compressive stress layer.

[0268] In the present application, by adjusting and controlling the mass percentage relationship between each oxide component, especially the mass percentage relationship between Na2O and Li2O and between Li2O and SiO2, the intrinsic strength and the chemical strengthening effect of the glass ceramic are improved, and thus the strengthened glass ceramic with excellent mechanical strength performance is obtained.

[0269] In some embodiments of the present application, in the composition at the center or the compressive stress layer of the strengthened glass ceramic or the composition of the glass ceramic used for preparing the strengthened glass ceramic or the composition of the base glass, the mass percentage of Na2O [Na2O] and the mass percentage of Li2O [Li2O] satisfy the following relationship: [Na2O] / [Li2O] = 0.60-6.00, preferably 0.90-5.00, and more preferably 1.00-3.00, in terms of the mass percentage of oxides.

[0270] In some embodiments, the ratio of the mass percent of Na20 [Na20] to the mass percent of Li20 [Li20] [Na20] / [Li20] in the composition of the center of the strengthened glass-ceramic or the composition of the tensile stress layer or the composition of the glass-ceramic used to make the strengthened glass-ceramic or the composition of the base glass can be 0.60, 0.9, 1.00, 1.50, 2.00, 2.50, 3.00, 3.50, 4.00, 4.50, 5.00, 5.50, or 6.00, or can be a value within a range bounded by any two of the above specifically named values, as long as a glass-ceramic or strengthened glass-ceramic having the desired properties of the present application is obtained. It should be appreciated that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass-ceramic or strengthened glass-ceramic having the desired properties of the present application is obtained.

[0271] In some embodiments of the present application, the mass percent of Li20 [Li20] to the mass percent of Si02 [Si02] in the composition of the center of the strengthened glass-ceramic or the composition of the tensile stress layer or the composition of the glass-ceramic used to make the strengthened glass-ceramic or the composition of the base glass, in terms of mass percent of oxides, satisfies the following relationship: [Li20] / [Si02] = 0.03 to 0.20, preferably 0.04 to 0.15, more preferably 0.04 to 0.10.

[0272] In some embodiments, the ratio of the mass percent of Li20 [Li20] to the mass percent of Si02 [Si02] [Li20] / [Si02] in the composition of the center of the strengthened glass-ceramic or the composition of the tensile stress layer or the composition of the glass-ceramic used to make the strengthened glass-ceramic or the composition of the base glass can be 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, or 0.20, or can be a value within a range bounded by any two of the above specifically named values, as long as a glass-ceramic or strengthened glass-ceramic having the desired properties of the present application is obtained. It should be appreciated that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass-ceramic or strengthened glass-ceramic having the desired properties of the present application is obtained.

[0273] In the present application, the (Zn, Mg) Al204and tetragonal Zr02crystal phases do not contain alkali metal ions, and thus do not participate in the ion exchange in the chemical strengthening process. Therefore, the crystal phase structure of the strengthened glass ceramic obtained by the chemical strengthening process is basically the same as that of the glass ceramic used for chemical strengthening. That is, the crystal phase content, crystal composition, and crystal size of the strengthened glass ceramic obtained by the chemical strengthening process are basically the same as those of the glass ceramic used for chemical strengthening. As shown in FIG. 1, the XRD patterns of the glass ceramic before chemical strengthening and the strengthened glass ceramic after chemical strengthening are basically the same. In addition, as shown in FIG. 2, the transmittance of the glass ceramic before and after chemical strengthening is basically the same as that of the strengthened glass ceramic. That is, in the present application, the glass ceramic with high transmittance can be used to obtain a strengthened glass ceramic product with excellent transmittance by chemical strengthening.

[0274] It should be understood that the stress structure generated by the chemical strengthening process can appropriately improve the mechanical properties of the glass product. Therefore, in the present application, the mechanical properties of the glass ceramic, such as Young's modulus and Vickers hardness, do not decrease after the glass ceramic is chemically strengthened to obtain a strengthened glass ceramic.

[0275] In the present application, by satisfying the desired total crystal phase content / crystallinity and appropriate average crystal size, the glass ceramic can maintain excellent optical properties while meeting excellent mechanical strength properties and high intrinsic strength.

[0276] In some embodiments of the present application, the average crystal size of the strengthened glass ceramic or the glass ceramic used to prepare the strengthened glass ceramic is not more than 20 nm, preferably 1.0 nm to 10.0 nm, more preferably 4.0 nm to 9.0 nm, and more preferably 4.0 nm to 8.0 nm. The appropriate average crystal size / average grain size is conducive to the glass ceramic having excellent optical properties and high intrinsic strength. However, if the average crystal size is too high, the glass ceramic is prone to lose transparency, and the chemical strengthening effect is also affected. In the present application, by satisfying the appropriate average crystal size, the glass ceramic can have excellent optical properties while having better impact resistance and better compression resistance, and the chemical strengthening effect is improved.

[0277] In some embodiments, the average crystallite size in the strengthened glass-ceramic or the glass-ceramic used to make the strengthened glass-ceramic can be 4.0 nm, 5.0 nm, 6.0 nm, 7.0 nm, 8.0 nm, 9.0 nm, 10.0 nm, 6.8 nm, 6.4 nm, 6.5 nm, or 8.1 nm, or can be a value within a range defined by any two of the specifically named values as endpoints, as long as a glass-ceramic or strengthened glass-ceramic having the desired properties of the present application is obtained. It is to be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a glass-ceramic or strengthened glass-ceramic having the desired properties of the present application is obtained.

[0278] In some embodiments of the present application, the total crystalline phase content in the strengthened glass-ceramic or the glass-ceramic used to make the strengthened glass-ceramic is 25% to 60%, preferably 30% to 55%, and more preferably 40% to 50% by mass. The higher the total crystalline phase content of the glass-ceramic or strengthened glass-ceramic, the more beneficial it is for the glass-ceramic or strengthened glass-ceramic to obtain high impact resistance and high compressive strength. However, if the total crystalline phase content is too high, it not only affects the chemical strengthening effect of the glass-ceramic, prolonging the chemical strengthening time for the glass-ceramic to obtain a strengthened glass-ceramic having a high stress level, but also can affect the optical properties of the glass-ceramic. In the present application, by having the glass-ceramic satisfy the desired total crystalline phase content, it is beneficial to allow the glass-ceramic to obtain good impact resistance and good compressive strength while ensuring that the glass-ceramic has excellent optical properties, and it is also beneficial to improve the chemical strengthening effect thereof.

[0279] In some embodiments, the total crystalline phase content of the strengthened glass-ceramic or the glass-ceramic used to make the strengthened glass-ceramic can be 30.00%, 30.50%, 31.00%, 31.50%, 32.00%, 32.50%, 33.00%, 33.50%, 34.00%, 34.50%, 35.00%, 35.50%, 36.00%, 36.50%, 37.00%, 37.50%, 38.00%, 38.50%, 39.00%, 39.50%, 40.00%, 40.50%, 41.00%, 41.50%, 42.00%, 42.50%, 43.00%, 43.50%, 44.00%, 44.50%, 45.00%, 45.50%, 46.00%, 46.50%, 47.00%, 47.50%, 48.00%, 48.50%, 49.00%, 49.50%, 50.00%, 48.69%, 45.11%, 49.52%, 47.85%, 54.07%, 51.56%, 45.49%, or 44.77%, or a value within a range having any two of the above specifically stated values as endpoints, as long as the glass-ceramic or strengthened glass-ceramic has the desired properties. It should be understood that any of the above ranges can be combined with any of the other ranges, as long as the glass-ceramic or strengthened glass-ceramic has the desired properties.

[0280] In some embodiments of the present application, the strengthened glass-ceramic or the glass-ceramic used to make the strengthened glass-ceramic is transparent in the visible wavelength range, preferably, the strengthened glass-ceramic or the glass-ceramic used to make the strengthened glass-ceramic has a transmittance of > 85.00% at 550 nm wavelength, preferably, a transmittance of > 87.00% at 0.90 mm thickness. The glass-ceramic or strengthened glass-ceramic meeting this transmittance can ensure better light transmittance, better transparency, and is suitable for use in display screens that require display effects. The "visible wavelength range" herein refers to light having a wavelength of 360 nm to 740 nm.

[0281] In some embodiments, the strengthened glass-ceramics or the glass-ceramics used to prepare the strengthened glass-ceramics can have a transmittance at 550 nm wavelength of 86.00%, 86.50%, 87.00%, 87.50%, 88.00%, 88.50%, 89.00%, 89.10%, 89.20%, 89.30%, 89.40%, 89.50%, 89.60%, 89.70%, 89.80%, 89.90%, 90.00%, 90.10%, 90.20%, 90.30%, 90.40%, 90.50%, 91.00%, 92.00%, 89.73%, 89.48%, 89.87%, 89.66%, 89.15%, 89.43%, 89.65%, 89.71%, or 89.14% at a thickness of 0.90 mm, or a value within a range having any two of these specifically endpoints, as long as the glass-ceramics or the strengthened glass-ceramics having the desired properties of the present application can be obtained. It should be understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as the glass-ceramics or the strengthened glass-ceramics having the desired properties of the present application can be obtained.

[0282] In the present application, by making the strengthened glass-ceramics have high Vickers hardness and fracture toughness, the strengthened glass-ceramics is not easy to break when subjected to extrusion or impact, which is beneficial to improve the compression resistance and impact resistance of the strengthened glass-ceramics. And by making the strengthened glass-ceramics satisfy the appropriate stress structure, it is beneficial to play the improvement effect of the stress structure on the mechanical strength performance, especially the excellent compression resistance and impact resistance.

[0283] In some embodiments of the present application, the Vickers hardness of the strengthened glass-ceramics is greater than or equal to 750 kgf / mm 2 , preferably, the Vickers hardness of the strengthened glass-ceramics is greater than or equal to 790 kgf / mm 2 . The Vickers hardness of the strengthened glass-ceramics in the above range indicates that the strengthened glass-ceramics has high hardness and high intrinsic strength, thereby ensuring excellent mechanical properties.

[0284] In some embodiments, the Vickers hardness of the strengthened glass-ceramics can be: 790 kgf / mm 2 , 795 kgf / mm 2 , 800 kgf / mm 2 , 805 kgf / mm 2 , 810 kgf / mm 2 , 815 kgf / mm 2 , 820 kgf / mm 2 , 830 kgf / mm 2, 835 kgf / mm 2 , 840 kgf / mm 2 , 845 kgf / mm 2 , 855 kgf / mm 2 , 860 kgf / mm 2 , 870 kgf / mm 2 , 875 kgf / mm 2 , 880 kgf / mm 2 , 885 kgf / mm 2 , 890 kgf / mm 2 , 895 kgf / mm 2 , 858 kgf / mm 2 , 875 kgf / mm 2 , 915 kgf / mm 2 , 850 kgf / mm 2 , 837 kgf / mm 2 , 900 kgf / mm 2 , 869 kgf / mm 2 , 889 kgf / mm 2 , 857 kgf / mm 2 , 865 kgf / mm 2 or 825 kgf / mm 2 , or can be a value within a range of values between any two of the above-mentioned specific numerical values as endpoints, as long as the strengthened glass-ceramic has the desired properties. It should be understood that in specific embodiments, any of the above-mentioned ranges can be combined with any of the other ranges, as long as the strengthened glass-ceramic has the desired properties.

[0285] In some embodiments of the present application, the fracture toughness value of the strengthened glass-ceramic is greater than or equal to 1.00 MPa-m 0.5 , preferably, the fracture toughness value of the strengthened glass-ceramic is greater than or equal to 1.20 MPa-m 0.5 , more preferably, the fracture toughness value of the strengthened glass-ceramic is greater than or equal to 1.50 MPa-m 0.5 . The fracture toughness value of the strengthened glass-ceramic is within the above-mentioned range, so that the strengthened glass-ceramic is less likely to break when subjected to a crush or impact, thereby facilitating the achievement of excellent crush resistance and excellent impact resistance.

[0286] In some embodiments, the fracture toughness value of the strengthened glass-ceramic can be 1.50 MPa-m 0.5 , 1.60 MPa-m 0.5 , 1.70 MPa-m 0.5 , 1.80 MPa-m 0.51.85 MPa·m 0.5 1.90 MPa·m 0.5 1.95 MPa·m 0.5 2.00 MPa·m 0.5 1.67 MPa·m 0.5 1.69 MPa·m 0.5 1.75 MPa·m 0.5 1.65 MPa·m 0.5 1.94 MPa·m 0.5 1.73 MPa·m 0.5 1.68 MPa·m 0.5 1.71 MPa·m 0.5 Or 1.77 MPa·m 0.5 Alternatively, the value can be any value within a range defined by any two of the above specific values ​​as endpoints, as long as it yields the reinforced glass-ceramic with the performance required by this application. It should be understood that, in specific embodiments, any of the above ranges can be combined with any other range, as long as it yields the reinforced glass-ceramic with the performance required by this application.

[0287] In some embodiments of this application, the reinforced glass ceramic has a |CT_AV| greater than 20.00 MPa, where |CT_AV| is the absolute value of the average tensile stress, measured by SLP_2000. Preferably, the reinforced glass ceramic has a |CT_AV| of 30.00 MPa to 55.00 MPa.

[0288] In some embodiments, the strengthened glass-ceramics can have a |CT AV| of 20.00 MPa, 22.00 MPa, 24.00 MPa, 26.00 MPa, 28.00 MPa, 30.00 MPa, 32.00 MPa, 34.00 MPa, 36.00 MPa, 38.00 MPa, 40.00 MPa, 42.00 MPa, 44.00 MPa, 46.00 MPa, 48.00 MPa, 50.00 MPa, 52.00 MPa, 54.00 MPa, 56.00 MPa, 58.00 MPa, 60.00 MPa, 50.96 MPa, 41.74 MPa, 36.56 MPa, 45.01 MPa, 41.49 MPa, 40.48 MPa, 50.27 MPa, 49.49 MPa, 36.05 MPa, 45.43 MPa, 53.86 MPa, 40.86 MPa, or 35.91 MPa, or a value within a range having any two of the above specifically stated values as endpoints, as long as a strengthened glass-ceramic having the desired properties herein is obtained. It should be understood that any of the above ranges can be combined with any of the other ranges, as long as a strengthened glass-ceramic having the desired properties herein is obtained.

[0289] In some embodiments of the application, the strengthened glass-ceramics have a |CT CV| greater than 25.00 MPa, |CT CV| being the absolute value of the maximum tensile stress, measured by SLP_2000, and preferably, the chemically strengthened glass-ceramics have a |CT CV| of 40.00 MPa to 75.00 MPa.

[0290] In some embodiments, the strengthened glass-ceramics can have a |CT_CV| of 25.00 MPa, 30.00 MPa, 35.00 MPa, 40.00 MPa, 45.00 MPa, 50.00 MPa, 55.00 MPa, 60.00 MPa, 65.00 MPa, 70.00 MPa, 75.00 MPa, 80.00 MPa, 85.00 MPa, 90.00 MPa, 95.00 MPa, 100.00 MPa, 65.70 MPa, 54.30 MPa, 46.07 MPa, 68.75 MPa, 53.70 MPa, 53.07 MPa, 66.96 MPa, 71.25 MPa, 42.73 MPa, 60.57 MPa, 81.79 MPa, 52.40 MPa, or 44.78 MPa, or a value within a range bounded by any two of the foregoing specific values, as appropriate to provide a strengthened glass-ceramic having the desired properties. It should be appreciated that any of the foregoing ranges can be combined with any other range, as appropriate to provide a strengthened glass-ceramic having the desired properties.

[0291] In some embodiments of the application, the strengthened glass-ceramics have a CS_50 greater than 100 MPa, CS_50 being the compressive stress value at a depth of 50 μm from the major surface of the strengthened glass-ceramic, as measured by SLP_2000, preferably, the strengthened glass-ceramics have a CS_50 of 140 MPa to 200 MPa.

[0292] In some embodiments, the strengthened glass-ceramics can have a CS_50 of 100.00 MPa, 105.00 MPa, 110.00 MPa, 115.00 MPa, 120.00 MPa, 125.00 MPa, 130.00 MPa, 135.00 MPa, 140.00 MPa, 145.00 MPa, 150.00 MPa, 155.00 MPa, 160.00 MPa, 165.00 MPa, 170.00 MPa, 175.00 MPa, 180.00 MPa, 185.00 MPa, 190.00 MPa, 195.00 MPa, 200.00 MPa, 205.00 MPa, 210.00 MPa, 215.00 MPa, 220.00 MPa, 225.00 MPa, 230.00 MPa, 235.00 MPa, 240.00 MPa, 199.69 MPa, 155.95 MPa, 146.48 MPa, 181.94 MPa, 181.35 MPa, 141.02 MPa, 188.73 MPa, 168.30 MPa, 188.13 MPa, 162.61 MPa, 177.13 MPa, 190.71 MPa, or 204.29 MPa, or a value within a range defined by any two of the above specifically named values as endpoints, as long as a strengthened glass-ceramic having the desired properties of the present application is obtained. It is understood that in specific embodiments, any of the above ranges can be combined with any other range, as long as a strengthened glass-ceramic having the desired properties of the present application is obtained.

[0293] In some embodiments of the present application, the strengthened glass-ceramics have a CS_80 of greater than 50 MPa, where CS_80 is the compressive stress value at a depth of 80 μm from the major surface of the strengthened glass-ceramic, as measured by SLP_2000, and preferably, the strengthened glass-ceramics have a CS_80 of 100 MPa to 150 MPa.

[0294] In some embodiments, the strengthened glass-ceramics can have a CS_80 of 50.00 MPa, 55.00 MPa, 60.00 MPa, 65.00 MPa, 70.00 MPa, 75.00 MPa, 80.00 MPa, 85.00 MPa, 90.00 MPa, 95.00 MPa, 100.00 MPa, 105.00 MPa, 110.00 MPa, 115.00 MPa, 120.00 MPa, 125.00 MPa, 130.00 MPa, 135.00 MPa, 140.00 MPa, 145.00 MPa, 150.00 MPa, 155.00 MPa, 160.00 MPa, 165.00 MPa, 170.00 MPa, 175.00 MPa, 180.00 MPa, 185.00 MPa, 190.00 MPa, 195.00 MPa, 200.00 MPa, 142.01 MPa, 111.53 MPa, 100.86 MPa, 140.44 MPa, 130.30 MPa, 110.00 MPa, 140.99 MPa, 129.89 MPa, 119.54 MPa, 117.60 MPa, 130.38 MPa, 138.72 MPa, or 152.35 MPa, or a value within a range bounded by any two of the foregoing specific values, as appropriate to achieve the desired properties of the strengthened glass-ceramics. It should be appreciated that any of the foregoing ranges can be combined with any other range, as appropriate to achieve the desired properties of the strengthened glass-ceramics.

[0295] In some embodiments of the application, the strengthened glass-ceramics have a DOL_0 greater than 144 μm, where DOL_0 is the depth of compressive stress layer determined by SLP_2000, preferably, the strengthened glass-ceramics have a DOL_0 of 160 μm to 200 μm.

[0296] In some embodiments, the strengthened glass-ceramic can have a DOL_0 of 144 μιη, 150 μιη, 155 μιη, 160 μιη, 165 μιη, 170 μιη, 175 μιη, 180 μιη, 185 μιη, 190 μιη, 195 μιη, 200 μιη, 205 μιη, 210 μιη, 215 μιη, 220 μιη, 225 μιη, 230 μιη, 235 μιη, 240 μιη, 185.12 μιη, 185.63 μιη, 176.34 μιη, 185.81 μιη, 191.19 μιη, 192.04 μιη, 189.59 μιη, 199.08 μιη, 164.11 μιη, 187.76 μιη, 191.43 μιη, 197.80 μιη, or 215.20 μιη, or a value within a range bounded by any two of the foregoing specific values, as long as the strengthened glass-ceramic has the desired properties. It will be appreciated that in specific embodiments, any of the foregoing ranges can be combined with any other range, as long as the strengthened glass-ceramic has the desired properties.

[0297] In some embodiments of the application, the strengthened glass-ceramic has a DOL_0 > 0.16t, where DOL_0 is the depth of compressive stress layer measured by SLP_2000, and t is the thickness of the strengthened glass-ceramic, preferably DOL_0 > 0.18t, more preferably DOL_0 > 0.20t.

[0298] In some embodiments, the strengthened glass-ceramic can have a DOL_0 of 0.17t, 0.18t, 0.19t, 0.20t, 0.21t, 0.22t, 0.23t, 0.24t, or 0.25t, or a value within a range bounded by any two of the foregoing specific values, as long as the strengthened glass-ceramic has the desired properties. It will be appreciated that in specific embodiments, any of the foregoing ranges can be combined with any other range, as long as the strengthened glass-ceramic has the desired properties.

[0299] In some embodiments of the application, the single bar static compressive strength of the strengthened glass-ceramic is greater than 800 N, preferably greater than 850 N, as measured by pressing the center of the primary surface of the strengthened glass-ceramic having a thickness greater than 0.7 mm using a 10 mm diameter round nose metal indenter with a stepwise vertical downward load at 10 mm / min.

[0300] In some embodiments of the present application, the strengthened glass-ceramics with a thickness of more than 0.7 mm are subjected to a 2.5 m drop test using 80 mesh silicon carbide sandpaper. If the glass sample does not break after dropping, it is recorded as passing. The passing rate of the strengthened glass-ceramics is ≥ 50%, preferably ≥ 60%, and more preferably ≥ 70%. The passing rate is based on the test of at least 10 samples.

[0301] In some embodiments of the present application, the strengthened glass-ceramics with a thickness of more than 0.7 mm are subjected to a drop ball impact test using a 130 g steel ball to test the central drop ball impact energy that the strengthened glass-ceramics can withstand. The central drop ball impact energy that the strengthened glass-ceramics can withstand is greater than 0.7 J, and preferably greater than 0.8 J.

[0302] In some embodiments of the present application, the glass-ceramics or strengthened glass-ceramics are 2D, 2.5D, 3D or profiled. In some embodiments of the present application, the glass-ceramics or strengthened glass-ceramics are of equal thickness or unequal thickness. The skilled person can select according to the needs. "Unequal thickness" means that the glass-ceramics or strengthened glass-ceramics contain at least two parts with different thicknesses.

[0303] After the foregoing introduction of the composition, crystal phase structure and stress structure of the strengthened glass-ceramics, the preparation method of the strengthened glass-ceramics is described in detail below.

[0304] In the present application, the preparation process of the strengthened glass-ceramics mainly includes the preparation process of the glass-ceramics and the chemical strengthening process, and the preparation process of the glass-ceramics mainly includes the preparation process of the base glass and the heat treatment process of the base glass.

[0305] In the present application, the base glass can be prepared by using the forming method in the prior art, and the present application does not have any limitation thereon. For example, the forming method of the base glass can include but is not limited to float method, overflow, calendering or casting process. For example, the components are mixed according to the formula, melted and formed, and then subjected to cooling and annealing treatment, so as to obtain the base glass.

[0306] For example, the raw materials (industrial conventional raw materials) are proportioned according to the formula, a clarifying agent is added, and then the mixture is mixed for a period of time to obtain a raw material mixture with uniform mixing. The raw material mixture is placed in a platinum crucible, heated to 1450-1800°C, preferably the melting temperature is 1550-1680°C, and preferably the temperature is maintained for 3-12 hours, and then poured into a forming mold to cool and form, preferably cooled to 800-1000°C, and then placed in an annealing furnace for annealing treatment, preferably the annealing temperature is 500-700°C, and the annealing time is preferably 4-48 hours; then the furnace is cooled to room temperature, and the base glass is obtained. Those skilled in the art can select the type and amount of clarifying agent according to the needs, without the need for creative labor. Further, the clarifying agent can include, but is not limited to, one or more of sodium chloride, tin oxide, antimony oxide, or arsenic oxide, and the amount of clarifying agent added can be 0-1 wt% of the total amount of raw materials.

[0307] In some embodiments of the present application, the heat treatment process of the base glass can include nucleation treatment and / or crystallization treatment, preferably both nucleation treatment and crystallization treatment. In some embodiments, the crystallization treatment can include one-step crystallization treatment or multi-step crystallization treatment.

[0308] In some embodiments of the present application, in order to obtain the desired physical and chemical properties of the glass-ceramic, the base glass can be subjected to one-step heat treatment, two-step or multi-step heat treatment. If one-step heat treatment is performed, it means that the nucleation treatment (i.e., nucleation treatment) is not performed separately, and one-step temperature rising is directly performed, and the nucleation and target crystal growth are performed at the temperature reached in the one-step temperature rising process, which can be understood as directly performing crystallization treatment. If two-step heat treatment is performed, it means that two-step temperature rising process is performed, and nucleation treatment (i.e., nucleation treatment) is performed first, and then crystal growth treatment (i.e., crystallization treatment) is performed.

[0309] In the present application, in order to obtain the desired crystal phase of the glass-ceramic and the desired physical and chemical properties, further, the temperature of the nucleation treatment can be 600-850°C, and the time of the nucleation treatment can be 0-72h, preferably 0-10h; the temperature of the crystallization treatment can be 700-1000°C, and the time of the crystallization treatment can be 0.10-24h, preferably 0.1-6h. When the heat treatment is performed, the temperature rising rate is preferably controlled to be 5-15°C / min, and more preferably the temperature rising rate is 10°C / min. The temperature of the nucleation treatment refers to the temperature at which the crystal nucleus can form. The temperature of the crystallization treatment refers to the temperature at which the target crystal can grow controllably.

[0310] After the heat treatment, the skilled person can also perform other conventional steps to obtain a glass-ceramic sample that meets the required specifications or requirements, for example, it is possible to perform a shaping treatment, a cutting treatment (for example using a multi-wire saw), a CNC machining treatment (computer numerical control), a thinning treatment or a polishing treatment, among others.

[0311] In some embodiments of the present application, the glass-ceramic described above is subjected to a specific chemical strengthening treatment, which allows obtaining a strengthened glass-ceramic that meets the desired properties.

[0312] In the present application, the chemical strengthening treatment, i.e. the ion exchange method, is performed by immersing the glass-ceramic in a molten salt bath, so that the alkali metal ions with a smaller ionic radius in the glass-ceramic are exchanged with the alkali metal ions with a larger ionic radius in the molten salt bath, thus forming a compressive stress layer on the surface of the glass-ceramic and obtaining a strengthened glass-ceramic with better mechanical properties.

[0313] In some embodiments of the present application, the chemical strengthening treatment can be performed using a single-step strengthening method or a multi-step strengthening method. The molten salt bath used for the chemical strengthening treatment is a molten salt bath containing sodium and / or potassium salts. Preferably, in the present application, the chemical strengthening is performed using a two-step strengthening method, preferably the salt bath used for the first step of the strengthening ion exchange is a pure NaNO3salt bath, in which the Na + with the Li + ions in the glass-ceramic are exchanged, so that a high stress layer depth DOL_0and a high deep stress are obtained. Preferably, the salt bath used for the second step of the strengthening ion exchange is a pure KNO3salt bath, in which the K + with the Na + ions in the glass-ceramic are exchanged, so that the Na + ions in the glass-ceramic, as far as possible, are exchanged for K + ions, so that a high surface compressive stress level is obtained. When performing the second step of the strengthening ion exchange, the K +The relative atomic mass of potassium is large, and stress relaxation is prone to occur, so the diffusion depth and distribution of potassium ions need to be strictly controlled. Meanwhile, the deep stress formed in the first step of strengthening ion exchange may decrease during the second step of ion exchange. That is, when high surface compressive stress is formed in the second step of strengthening ion exchange, deep stress may decrease, which is not conducive to improving the impact resistance (e.g., drop impact resistance) of the strengthened glass ceramic. Therefore, the distribution of sodium ions and the deep stress structure also need to be strictly controlled in the second step of strengthening ion exchange. The temperature of the molten salt bath is preferably 380-600°C, and more preferably 400-500°C. In some embodiments of the present application, a certain amount (e.g., 0-0.5wt%) of lithium salt can be added to the salt bath. In some embodiments of the present application, the chemical strengthening treatment time is preferably 0.1-48h, and more preferably 0.1-24h. The sodium salt can be selected from at least one of sodium nitrate, sodium sulfate, and sodium carbonate, and is preferably sodium nitrate; the potassium salt can be selected from at least one of potassium nitrate, potassium sulfate, and potassium carbonate, and is preferably potassium nitrate; and the lithium salt can be selected from at least one of lithium nitrate, lithium sulfate, and lithium carbonate, and is preferably lithium nitrate.

[0314] In some embodiments of the present application, the strengthened glass ceramic is prepared by chemical strengthening treatment of a glass ceramic having a fracture toughness of not less than 1.40 MPa·m 0.5 In some embodiments of the present application, the strengthened glass ceramic is prepared by chemical strengthening treatment of a glass ceramic having a fracture toughness of not less than 1.40 MPa·m 0.5 In some embodiments of the present application, the strengthened glass ceramic is prepared by chemical strengthening treatment of a glass ceramic having a fracture toughness of not less than 1.40 MPa·m 0.5 In some embodiments of the present application, the strengthened glass ceramic is prepared by chemical strengthening treatment of a glass ceramic having a fracture toughness of not less than 1.40 MPa·m

[0315] In the present application, the strengthened glass ceramic is prepared by at least two steps of ion exchange to meet a specific stress structure. This is conducive to making the prepared strengthened glass ceramic have excellent extrusion resistance and excellent impact resistance (e.g., excellent drop impact resistance).

[0316] Without being bound by any theory, in the first step of the strengthening process, the main purpose is to form a specific deep stress structure, so as to effectively inhibit or hinder the crack propagation caused by drop impact and the like. As the ions diffuse into the glass-ceramic, the deep stress will gradually decrease. Therefore, in the first step of the strengthening process, the purpose is to obtain a high stress depth of layer DOL_0 and a high deep stress, so as to make the strengthened glass-ceramic meet the specific deep stress structure. At this time, in combination with the second step of the chemical strengthening process, the strengthened glass-ceramic meets the specific surface stress structure, and the surface compressive stress level of the strengthened glass-ceramic is improved. Finally, by making the strengthened glass-ceramic meet the specific deep stress structure and the specific surface stress structure, the strengthened glass-ceramic obtains a specific stress structure, and at the same time realizes the improvement of the extrusion resistance and the impact resistance of the strengthened glass-ceramic, so that the strengthened glass-ceramic can simultaneously have excellent extrusion resistance and excellent impact resistance.

[0317] The glass-ceramic or the strengthened glass-ceramic provided by the present application has excellent performance (especially excellent extrusion resistance and excellent impact resistance), and can be used in electronic devices, including but not limited to mobile phones, tablet computers, handheld game consoles, portable digital devices (such as digital cameras), vehicle-mounted central control, electronic whiteboard glass, smart home, smart wear (such as smart bracelet, smart watch, smart glasses), and can also be used in vehicles, aircraft or vessels, and can also be used in any required glass-ceramic or strengthened glass-ceramic glass device. For example, it can be used in the display screen, cover glass, touch screen, glass inner screen or inner frame of an electronic device; for example, it can be used in the windshield of a vehicle, aircraft or vessel, such as the front windshield or side windshield. For example, it can be used in worktops, other surfaces, appliance doors, floor tiles, wall panels or storage containers, etc. Other surfaces can include but are not limited to exterior wall surfaces, stair tread surfaces, column facings or counter surfaces, etc., and storage containers can include but are not limited to cups, plates, medicine bottles or beverage bottles, etc.

[0318] For example, the glass-ceramic or the strengthened glass-ceramic provided by the present application has excellent performance, and can be used to manufacture glass devices. The glass devices referred to herein can be regular or irregular, and those skilled in the art can manufacture them according to requirements.

[0319] Exemplarily, the glass-ceramics or strengthened glass-ceramics with excellent performance provided by the present application can be used to manufacture cover glasses, which can be display screen cover plates, back covers or camera protection cover plates of electronic devices. Exemplarily, the glass-ceramics or strengthened glass-ceramics with excellent performance provided by the present application can be used in electronic devices. Referring to FIGS. 9, 10, 11 and 12, in some embodiments of the present application, an electronic device, which can be a mobile phone, a tablet computer, a smart wearable device or the like, is provided, and the electronic device comprises a housing 1 assembled on the outer side of the electronic device, the housing 1 comprising a display screen cover plate 11 assembled on the front side and a back cover 12 assembled on the back side, the display screen cover plate 11 being covered on a display module 4, wherein the display screen cover plate 11 and / or the back cover 12 are made of the aforementioned glass-ceramics or strengthened glass-ceramics. In the present application, the display screen cover plate 11 and the back cover 12 can be made of the aforementioned glass-ceramics or strengthened glass-ceramics entirely or partially.

[0320] In some embodiments of the present application, as shown in FIG. 10, the electronic device further comprises a camera assembly 2 located inside the housing 1, the housing 1 can comprise a camera protection cover plate 13, the camera protection cover plate 13 being covered on the camera assembly 2 for protecting the camera assembly 2, and the camera protection cover plate 13 is made of the aforementioned glass-ceramics or strengthened glass-ceramics. In the present application, the camera protection cover plate 13 can be made of the aforementioned glass-ceramics or strengthened glass-ceramics partially or entirely. In the present application, the camera protection cover plate 13 can be located on the front side of the electronic device or on the back side of the electronic device according to the location of the camera assembly 2. In some embodiments of the present application, the camera protection cover plate 13 can be in a separate structure from the display screen cover plate 11 or the back cover 12. In another embodiments of the present application, the camera protection cover plate 13 can be in an integrated structure with the display screen cover plate 11 or the back cover 12.

[0321] In some embodiments of the present application, as shown in FIG. 11, the electronic device further comprises a middle frame 3 located between the display module 4 and the housing 1, and the middle frame 3 can comprise the aforementioned glass-ceramics or strengthened glass-ceramics.

[0322] In the embodiments of the present application, the display screen cover plate, the back cover, the camera protection cover plate, and the middle frame in the electronic device can be any one, any two, any three, or all of the four, which adopt the aforementioned glass ceramic or strengthened glass ceramic.

[0323] In some embodiments of the present application, the display screen cover plate, the back cover, the camera protection cover plate, or the middle frame in the electronic device can be 2D, 2.5D, 3D, or special-shaped. In some embodiments of the present application, the display screen cover plate, the back cover, the camera protection cover plate, or the middle frame in the electronic device can be of equal thickness or unequal thickness.

[0324] The technical solutions of the present application are further described in detail below in combination with embodiments. The embodiments of the present application described in detail below are exemplary and are only used to explain the present application and cannot be understood as a limitation of the present application.

[0325] Embodiment 1

[0326] A strengthened glass ceramic is prepared as follows:

[0327] (1) Preparation of base material glass:

[0328] The raw materials (industrial conventional raw materials) are configured according to the proportions of the components in Table 1, the total mass of the configured raw materials is 1000g, 5g of clarifying agent sodium chloride (NaCl) is added to the configured raw materials, and then the V-shaped mixer is used for mixing for 30 minutes to obtain a raw material mixture with uniform mixing.

[0329] The raw material mixture is transferred to a platinum crucible, melted in the platinum crucible at 1650℃ for 5 hours, then poured into a forming mold for cooling, cooled to 900℃, then placed in a 600℃ annealing furnace for annealing for 24 hours, and then cooled to room temperature with the furnace, to obtain a base material glass brick.

[0330] (2) Preparation of glass ceramic: according to the heat treatment process in Table 2, the base material glass brick is placed in an annealing furnace, heated from room temperature to 750℃ at a rate of 10℃ / min for nucleation treatment, kept at this temperature for 240min, then heated to 765℃ at a rate of 10℃ / min for crystallization treatment, kept at this temperature for 120min, then cooled to room temperature at a rate of 1℃ / min, to obtain a glass ceramic sample brick. The composition of the prepared glass ceramic is the same as that of the base material glass, and is shown in Table 1 in terms of mass percentage of oxides.

[0331] After the obtained glass-ceramic sample bricks are subjected to cutting, CNC processing (the CNC instrument used in the present application is of RCG500S type), and polishing, cold processing, glass-ceramic samples meeting the required specifications and requirements can be prepared. In Examples 1-13 and Comparative Examples 1-13 of the present application, the glass-ceramic sample bricks are subjected to the aforementioned cold processing to prepare glass-ceramic samples with thicknesses of 0.70 mm, 0.90 mm, 0.95 mm, or 1.05 mm. Specifically, circular glass-ceramic polished pieces with a diameter of 46 mm and thicknesses of 0.70 mm, 0.90 mm, 0.95 mm, or 1.05 mm are prepared.

[0332] Test conditions for the glass-ceramic samples / pieces obtained in Example 1:

[0333] The crystal phase composition, average crystal size, total content of crystal phase, transmittance (at a wavelength of 550 nm), density, Vickers hardness, and fracture toughness of the glass-ceramic samples / pieces are tested, respectively, and the results are shown in Table 2.

[0334] (3) Preparation of strengthened glass-ceramic: The obtained glass-ceramic samples / pieces are placed in a strengthening furnace cavity for preheating for 5 min according to the chemical strengthening process in Table 3, and then quickly placed in a molten salt bath at 450°C for first-step strengthening treatment. The composition of the molten salt is 100 wt% NaNO3, and the chemical strengthening treatment time is 4 h. Then, the glass-ceramic samples / pieces are placed in a molten salt bath at 420°C for second-step strengthening treatment. The composition of the molten salt is 100 wt% KNO3, and the chemical strengthening treatment time is 4 h. After that, the glass-ceramic samples / pieces are taken out and slowly cooled to room temperature on the furnace body of the strengthening furnace. The salt on the surface of the glass-ceramic is washed off with clean water, and the glass-ceramic samples are dried to obtain strengthened glass-ceramic.

[0335] Test conditions for the strengthened glass-ceramic samples / pieces obtained in Example 1:

[0336] I. The surface Na2O mass percentage and surface K2O mass percentage of the strengthened glass-ceramic after the first-step strengthening treatment and the second-step strengthening treatment are determined by XRF, and the results are shown in Table 3.

[0337] II. The CS_50, CS_80, DOL_0, |CT_CV|, and |CT_AV| of the strengthened glass-ceramic are measured under SLP-2000 stress instrument (the light source wavelength used is 518 nm, SOC = 25.5 (nm / cm) / MPa, the refractive index is set to 1.60, and the exposure time is 300 μsec). The value of formula A is calculated, and the absolute value K of the average slope at different depth segments is calculated according to the SLP stress distribution curve. 50-80 , K80-DOL The results are shown in Table 4.

[0338] III, The strengthened glass ceramic is subjected to micro-area composition analysis by Shimadzu electron probe EPMA-1720HT using characteristic X-rays generated after the sample is subjected to electron beam action, DOL_K and DOL_Na are measured, and P1, P2, P3 and P4 are calculated according to the absolute value of the average slope of different depth segments calculated from the K element concentration distribution curve and the Na element concentration distribution curve. 5-8 The results are shown in Table 3-Table 4.

[0339] IV, The single rod static pressure strength and the center ball impact energy that the strengthened glass ceramic can withstand, the passing rate of the strengthened glass ceramic in the 80-mesh sandpaper, 2.5m height drop test, and the Vickers hardness and fracture toughness of the strengthened glass ceramic are tested, and the results are shown in Table 4.

[0340] Examples 2-13

[0341] Each of them is carried out with reference to Example 1, except that the raw material composition of each example, different process parameters and their corresponding test results are shown in Table 1-Table 4.

[0342] Among them, the XRD pattern comparison chart of the glass ceramic and the strengthened glass ceramic of Example 1 is shown in Figure 1. From the figure, ① the main crystal phase of the glass ceramic and the strengthened glass ceramic is (Zn, Mg) Al2O4, and the secondary crystal phase is ZrO2; ② the XRD patterns of the glass ceramic and the strengthened glass ceramic are basically coincident, indicating that the crystal structure is basically unchanged before and after chemical strengthening.

[0343] The transmittance curve comparison chart of the glass ceramic and the strengthened glass ceramic of Example 1 is shown in Figure 2, from which it can be seen that the glass ceramic and the strengthened glass ceramic prepared therefrom are both transparent in the visible light range, both have high transmittance, and the transmittance remains basically unchanged before and after chemical strengthening.

[0344] Comparative Examples 1-13

[0345] Each of them is carried out with reference to Example 1, except that the raw material composition of each example, different process parameters and their corresponding test results are shown in Table 1-Table 4.

[0346] Table 1 Note: In Table 1, the oxide content of "0" means that the component is not actively or intentionally added to the glass composition during the initial batching process, but the component may exist as an impurity.

[0347] Table 2 Note: In Table 2, " / " means that the operation is not performed.

[0348] Table 3 Note: 1. In Table 3, the surface K2O mass percentage and the surface Na2O mass percentage of the strengthened glass-ceramics measured after the first strengthening treatment are denoted as the ① surface K2O concentration and the ① surface Na2O concentration, and the surface K2O mass percentage and the surface Na2O mass percentage of the strengthened glass-ceramics measured after the second strengthening treatment are denoted as the ② surface K2O concentration and the ② surface Na2O concentration. If only the first strengthening treatment is performed in a scheme, then the ① surface K2O concentration and the ① surface Na2O concentration are the surface K2O mass percentage and the surface Na2O mass percentage of the strengthened glass-ceramics finally prepared in the scheme; if two strengthening treatments are performed in a scheme, then the ② surface K2O concentration and the ② surface Na2O concentration are the surface K2O mass percentage and the surface Na2O mass percentage of the strengthened glass-ceramics finally prepared in the scheme. 2. In Table 3, the data in the column of “surface K2O concentration” or the column of “surface Na2O concentration” are recorded as “0.000”, indicating that the content of K element or Na element contained in the strengthened glass-ceramics of the tested scheme is lower than 0.0013%, i.e., lower than the test precision (0.0013%) of the XRF instrument used in the present application. Since the content lower than the test precision of the XRF instrument will not be displayed by the instrument, “0.000” is used in the present application for recording. 3. In Table 3, “ / ” indicates that the operation is not performed or the parameter is not involved or the corresponding parameter is not tested. 4. In Table 3, P1 refers to the absolute value of the average slope of the K element concentration distribution curve (measured by EPMA) from the depth of 0 microns to the depth of DOL_K in the strengthened glass-ceramics finally prepared. 5. In Table 3, P2 refers to the absolute value of the average slope of the Na element concentration distribution curve (measured by EPMA) from the depth of 0 microns to the depth of DOL_Na in the strengthened glass-ceramics finally prepared. 6. In Table 3, P 5-8 is the absolute value of the average slope of the K element concentration distribution curve (measured by EPMA) from the depth of 5 microns to the depth of 8 microns in the strengthened glass-ceramics finally prepared. 7. In Table 3, if K element is not intentionally added in the composition of the substrate glass and the salt bath containing K is not used in the first strengthening treatment in each scheme, then the data of the ① surface K2O concentration measured after the first strengthening treatment is the impurity K contained in the raw materials for preparing the substrate glass.

[0349] Table 4 Note: 1. In the table, A = (t x DOL_K) / (|CT-AV| x (DOL_0 / t), t is in units of pm, DOL_K is in units of pm, |CT-AV| is in units of MPa, DOL_0 is in units of pm, in formula A, data is substituted according to the above unit requirements to calculate and obtain the calculation result, and the unit does not participate in the calculation. 2. In the table, K 50-80 refers to the absolute value of the average slope of the SLP stress distribution curve (measured by SLP-2000) between a depth of 50 pm and a depth of 80 pm in the finally prepared strengthened glass ceramic. 3. In the table, K 80-DOL refers to the absolute value of the average slope of the SLP stress distribution curve (measured by SLP-2000) between a depth of 80 pm and a depth of DOL_0 in the finally prepared strengthened glass ceramic. 4. In the table, "0*" indicates that the strengthened glass ceramic is broken after the steel ball impacts the strengthened glass ceramic after falling from the lowest height (or also referred to as the initial height) in the drop ball test, so the central drop ball impact energy is not calculated. 5. In the table, " / " indicates that the parameter is not involved.

[0350] From the examples and comparative examples in Tables 1-4 above, it can be seen that, by using zinc aluminate-magnesium aluminate spinel solid solution as the main crystal phase of the glass ceramic, the glass ceramic of each example of the present application has high intrinsic strength, high Vickers hardness and high fracture toughness. By chemically strengthening the glass ceramic and making the surface composition and stress distribution of the prepared strengthened glass ceramic meet specific requirements, especially by making the surface Na2O content, surface K2O content, K + diffusion depth, the depth of the position where the Na + concentration maximum meets specific requirements, and by making the thickness, K + diffusion depth (or K + exchange (layer) depth) DOL_K, |CT-AV| and the compressive stress layer depth DOL_0 of the strengthened glass ceramic meet the requirements of formula A, the mechanical properties of the strengthened glass ceramic are significantly improved, and the strengthened glass ceramic simultaneously has excellent extrusion resistance and impact resistance.

[0351] In the schemes of Comparative Examples 1-13, the composition of the glass ceramic used to prepare the strengthened glass ceramic, the surface composition or stress distribution of the prepared strengthened glass ceramic do not meet the specific requirements of the present application, which ultimately leads to the fact that the extrusion resistance and / or impact resistance of the prepared strengthened glass ceramic is significantly inferior to that of the examples meeting the requirements of the schemes of the present application.

[0352] Some comparative examples are analyzed as follows:

[0353] The substrate glass composition of Comparative Example 1 does not contain Li2O, and does not satisfy the composition requirement of the present application. The Vickers hardness of the glass-ceramic prepared after heat treatment is 650 kgf / mm 2 , and the fracture toughness value is 1.32 MPa·m 0.5 . After chemical strengthening of the glass-ceramic, the DOL_K, the surface K2O concentration, the DOL_Na and the relationship A of the strengthened glass-ceramic do not satisfy the requirements of the strengthened glass-ceramic of the present application. Finally, the single rod static pressure strength that the strengthened glass-ceramic can withstand is only 605 N, the 80-mesh sandpaper-2.5 m drop test cannot be passed, and the ball impact test is broken at the initial height. The impact resistance and the compression resistance of the strengthened glass-ceramic are obviously lower than those of the embodiment of the present application.

[0354] The substrate glass composition of Comparative Example 2 contains 0.87% of Na2O, which is too low and does not satisfy the composition requirement of the present application. The Vickers hardness of the glass-ceramic prepared after heat treatment is 721 kgf / mm 2 , and the fracture toughness value is 1.47 MPa·m 1 / 2 . After chemical strengthening of the glass-ceramic, the DOL_Na of the strengthened glass-ceramic does not satisfy the requirements of the strengthened glass-ceramic of the present application. Finally, the single rod static pressure strength that the strengthened glass-ceramic can withstand is only 558 N, and the ball impact test is broken at the initial height. The impact resistance and the compression resistance of the strengthened glass-ceramic are obviously lower than those of the embodiment of the present application.

[0355] The substrate glass composition of Comparative Example 3 contains 0.79% of Li2O, which is too low and does not satisfy the composition requirement of the present application. The Vickers hardness of the glass-ceramic prepared after heat treatment is 670 kgf / mm 2 , and the fracture toughness value is 1.38 MPa·m 0.5 . After chemical strengthening of the glass-ceramic, the relationship A of the strengthened glass-ceramic does not satisfy the requirements of the strengthened glass-ceramic of the present application. Finally, the single rod static pressure strength that the strengthened glass-ceramic can withstand is only 690 N, and the ball impact test is broken at the initial height. The impact resistance and the compression resistance of the strengthened glass-ceramic are obviously lower than those of the embodiment of the present application.

[0356] Comparative Examples 4 to 13 are obtained by using the glass-ceramic of Example 1 under different thicknesses and different strengthening conditions. However, the surface composition and the stress distribution of the strengthened glass-ceramics prepared in Comparative Examples 4 to 13, especially the surface Na2O content, the surface K2O content, the K + diffusion depth, the Na +The depth of the location of the maximum concentration and the relationship A cannot simultaneously meet the requirements of this application for reinforced glass ceramics. Ultimately, tests showed that the reinforced glass ceramics prepared in Comparative Examples 4 to 13 either had a single-bar static compressive strength of less than 800N, a pass rate of less than 50% in the 80-grit sandpaper - 2.5m drop test, or a center ball impact energy of less than 0.7J. The impact resistance and compressive strength of these reinforced glass ceramics were significantly lower than those of the embodiments in this application.

[0357] The above description is merely a specific embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application. Industrial applicability

[0358] This application achieves high intrinsic strength in glass-ceramics by using a zinc-aluminum spinel-magnesium-aluminum spinel solid solution as the main crystalline phase. Furthermore, by chemically strengthening this glass-ceramic and ensuring that the surface composition and stress distribution meet specific requirements, particularly regarding the surface Na₂O content, surface K₂O content, and K₂O content, this application further enhances its effectiveness. + Diffusion depth, Na + The depth at the location of the maximum concentration meets specific requirements, while simultaneously ensuring the thickness and K of the reinforced glass ceramic. + Diffusion depth (or K) + The exchange (layer) depth (DOL_K), |CT-AV|, and compressive stress layer depth (DOL_0) satisfy the requirements of Formula A, significantly improving the mechanical properties of the reinforced glass ceramic, thus enabling it to simultaneously achieve excellent compressive strength and impact resistance. Applying this reinforced glass ceramic to electronic devices allows them to meet the requirements of applications with high compressive and / or impact resistance, such as better matching the application requirements of aquatic environments (e.g., deep-sea environments), and thus making it suitable for deep-sea applications.

Claims

1. A strengthened glass-ceramic, characterized in that, The strengthened glass ceramic contains a main crystal phase of a zinc aluminate-magnesium aluminate spinel solid solution and a secondary crystal phase of zirconia; the strengthened glass ceramic has a compressive stress layer on the surface and a tensile stress in the interior; The surface K2O content of the strengthened glass ceramic is 2.50% to 7.50% by mass percentage of oxides, preferably, the surface K2O content of the strengthened glass ceramic is 3.00% to 7.00% by mass percentage of oxides, more preferably, the surface K2O content of the strengthened glass ceramic is 3.50% to 7.00% by mass percentage of oxides; The surface Na2O content of the strengthened glass ceramic is less than or equal to 0.010% by mass percentage of oxides, preferably, the surface Na2O content of the strengthened glass ceramic is less than or equal to 0.005% by mass percentage of oxides, more preferably, the surface Na2O content of the strengthened glass ceramic is less than or equal to 0.002% by mass percentage of oxides; The strengthened glass-ceramic satisfies: 8.00 pm < DOL_K < 20.00 pm, preferably, 8.50 pm < DOL_K < 18.00 pm, more preferably, 9.00 pm < DOL_K < 16.00 pm, wherein DOL_K is the K + diffusion depth; The strengthened glass-ceramic satisfies: 30.00 pm ≤ DOL_Na ≤ 60.00 pm, preferably 34.00 pm ≤ DOL_Na ≤ 59.00 pm, more preferably 37.00 pm ≤ DOL_Na ≤ 59.00 pm, wherein DOL_Na is the Na + depth of the location of the maximum concentration; The strengthened glass ceramic satisfies: A = (t x DOL_K) / (|CT-AV| x (DOL_0 / t)), 850≤A≤4000, preferably, 850≤A≤3000, more preferably, 900≤A≤2000; wherein t is the thickness of the strengthened glass ceramic, in units of μm; DOL_K is the K + diffusion depth, in units of μm; |CT-AV| is the absolute value of the average tensile stress of the strengthened glass ceramic, in units of MPa; DOL_0 is the depth of the compressive stress layer of the strengthened glass ceramic, in units of μm; in the formula A, the data is substituted into the formula according to the above unit requirements, and the calculation result is obtained, and the unit does not participate in the calculation.

2. The strengthened glass ceramic of claim 1, wherein, The strengthened glass ceramic satisfies: along a thickness direction of the strengthened glass ceramic, a concentration of K + decreases nonlinearly from a main surface of the strengthened glass ceramic to a center of the strengthened glass ceramic; and / or, The concentration of Na + increases nonlinearly from the main surface of the strengthened glass ceramic to the center of the strengthened glass ceramic and then decreases nonlinearly along the thickness direction of the strengthened glass ceramic.

3. The strengthened glass ceramic of any one of claims 1-2, wherein, The strengthened glass ceramic satisfies: In a K element concentration distribution curve in which the horizontal axis is the depth in μm from the main surface of the strengthened glass ceramic, and the vertical axis is the K element concentration in mass percentage on an element basis: The absolute value P1 of the average slope of the K element concentration distribution curve between the depth of 0 μm and the depth of DOL_K is 0.150 to 1.000, preferably, P1 is 0.150 to 0.800, more preferably, P1 is 0.150 to 0.600; and / or, the absolute value P of the average slope of the K element concentration profile between the depth of 5 μm and the depth of 8 μm 5-8 P is 0.50 to 2.50, preferably P 5-8 P is 0.60 to 2.00, more preferably P 5-8 P is 0.70 to 1.50; and / or, In a Na element concentration distribution curve in which the horizontal axis is the depth in μm from the main surface of the strengthened glass ceramic, and the vertical axis is the Na element concentration in mass percentage on an element basis: The absolute value P2 of the average slope of the Na element concentration distribution curve between the depth of 0 μm and the depth of DOL_Na is 0.01 to 0.05, preferably, P2 is 0.01 to 0.04, more preferably, P2 is 0.01 to 0.

03.

4. The strengthened glass ceramic of any one of claims 1-3, wherein, The strengthened glass ceramic satisfies: In a SLP stress distribution curve in which the horizontal axis is the depth in μm from the main surface of the strengthened glass ceramic, and the vertical axis is the stress in MPa: The absolute value K of the average slope of the SLP stress profile between the depth of 50 μm and the depth of 80 μm 50-80 is 1.00 to 2.50, preferably, K 50-80 is 1.00 to 2.40, more preferably, K 50-80 is 1.00 to 2.30; and / or, The absolute value K of the average slope of the SLP stress profile between the depth of 80 μm and the depth of DOL_0 80-DOL-0 K is 0.90 to 2.00, preferably 80-DOL-0 K is 0.90 to 1.80, more preferably 80-DOL-0 K is 0.90 to 1.

60.

5. The strengthened glass ceramic of any one of claims 1-4, wherein, The thickness t of the strengthened glass ceramic is greater than 0.7 mm, preferably, the thickness t is not less than 0.8 mm, more preferably, the thickness t is 0.9 mm to 2.0 mm; and / or, The strengthened glass ceramic is 2D, 2.5D, 3D or shaped; and / or, The strengthened glass ceramic is equal-thickness or unequal-thickness.

6. The strengthened glass ceramic of any one of claims 1-5, wherein, The composition at the center of the strengthened glass ceramic or the tensile stress layer contains Al2O3 in a mass percentage of not less than 30.00% by mass percentage of oxides; and / or, the composition at the center of the strengthened glass ceramic or the tensile stress layer contains ZrO2 in a mass percentage of not less than 3.00% by mass percentage of oxides.

7. The strengthened glass ceramic of any one of claims 1-6, wherein, The mass percentage of Na2O [Na2O] and the mass percentage of Li2O [Li2O] in the composition at the center of the strengthened glass ceramic or the tensile stress layer satisfy the following relationship: [Na2O] / [Li2O] = 0.60-6.00, preferably 0.90-5.00, and more preferably 1.00-3.00; and / or The mass percentage of Li2O [Li2O] and the mass percentage of SiO2 [SiO2] in the composition at the center of the strengthened glass ceramic or the tensile stress layer satisfy the following relationship: [Li2O] / [SiO2] = 0.03-0.20, preferably 0.04-0.15, and more preferably 0.04-0.

10.

8. The strengthened glass ceramic of any one of claims 1-7, wherein, The composition at the center of the strengthened glass ceramic or the tensile stress layer comprises, in mass percentage of oxides: SiO2: 25.00%-55.00%, Al2O3: 30.00%-55.00%, ZrO2: 3.00%-8.00%, MgO: 2.00%-5.00%, ZnO: 5.00%-15.00%, Na2O: 1.00%-10.00%, K2O: 0%-5.00%, Li2O: 1.00%-6.00%, CaO: 0%-6.00%, B2O3: 0%-10.00%, BaO: 0%-10.00%, Y2O3: 0%-6.00%, La2O3: 0%-12.00%.

9. The strengthened glass ceramic of any one of claims 1-8, wherein, The composition at the center of the strengthened glass ceramic or the tensile stress layer comprises, in mass percentage of oxides: The mass percentage of SiO2 is 30.00%-42.00%, preferably the mass percentage of SiO2 is 35.00%-40.00%; and / or, The mass percentage of Al2O3 is 32.00%-42.00%, preferably the mass percentage of Al2O3 is 34.00%-42.00%; and / or, The mass percentage of ZrO2 is 4.00%-7.00%, preferably the mass percentage of ZrO2 is 5.00%-6.00%; and / or, The mass percentage of MgO is 2.50%-4.00%, preferably the mass percentage of MgO is 2.50%-3.50%; and / or, The mass percentage of ZnO is 9.00%-13.00%, preferably the mass percentage of ZnO is 9.00%-11.00%; and / or, The mass percentage of Na2O is 1.00%-8.00%, preferably the mass percentage of Na2O is 2.00%-6.00%; and / or, The mass percentage of K2O is 0%-3.00%, preferably the mass percentage of K2O is 0%-1.00%; and / or, The mass percentage of Li2O is 1.00%-4.00%, preferably the mass percentage of Li2O is 2.00%-3.00%; and / or, CaO is 0% to 3.00%, preferably CaO is 0% to 1.50%; and / or, B2O3 is 0% to 8.00%, preferably B2O3 is 0% to 4.00%; and / or, BaO is 0% to 7.00%, preferably BaO is 0% to 4.00%; and / or, Y2O3 is 0% to 4.00%, preferably Y2O3 is 0% to 2.00%; and / or, La2O3 is 0% to 5.00%, preferably La2O3 is 0% to 3.00%.

10. The strengthened glass ceramic of any one of claims 1 to 9, wherein, The average crystal size in the strengthened glass ceramic is no more than 20 nm, preferably 1.0 nm to 10.0 nm, more preferably 4.0 nm to 9.0 nm, more preferably 4.0 nm to 8.0 nm; and / or The total content of the crystal phase in the strengthened glass ceramic is 25% to 60% by mass, preferably 30% to 55%, more preferably 40% to 50%.

11. The strengthened glass ceramic of any one of claims 1 to 10, wherein, The strengthened glass ceramic is transparent in the visible light wavelength range, preferably the transmittance of the strengthened glass ceramic at a wavelength of 550 nm is ≥ 85.00% at a thickness of 0.90 mm, preferably ≥ 87.00%.

12. The strengthened glass ceramic of any one of claims 1-11, wherein, the strengthened glass-ceramic has a Vickers hardness greater than or equal to 750 kgf / mm 2 , preferably, the strengthened glass-ceramic has a Vickers hardness greater than or equal to 790 kgf / mm 2 ; and / or, the strengthened glass-ceramic has a fracture toughness value of 1.00 MPa.m or greater 0.5 , preferably, the strengthened glass-ceramic has a fracture toughness value of 1.20 MPa.m or greater 0.5 , more preferably, the strengthened glass-ceramic has a fracture toughness value of 1.50 MPa.m or greater 0.5 ; and / or, The strengthened glass ceramic has a |CT_AV| greater than 20.00 MPa, |CT_AV| being the absolute value of the average tensile stress, preferably the strengthened glass ceramic has a |CT_AV| of 30.00 MPa to 55.00 MPa; and / or, The strengthened glass ceramic has a |CT_CV| greater than 25.00 MPa, |CT_CV| being the absolute value of the maximum tensile stress, preferably the chemically strengthened glass ceramic has a |CT_CV| of 40.00 MPa to 75.00 MPa; and / or, The strengthened glass ceramic has a CS_50 greater than 100 MPa, CS_50 being the compressive stress value at a depth of 50 μm from the main surface of the strengthened glass ceramic, preferably the strengthened glass ceramic has a CS_50 of 140 MPa to 200 MPa; and / or, The strengthened glass ceramic has a CS_80 greater than 50 MPa, CS_80 being the compressive stress value at a depth of 80 μm from the main surface of the strengthened glass ceramic, preferably the strengthened glass ceramic has a CS_80 of 100 MPa to 150 MPa; and / or, The strengthened glass ceramic has a DOL_0 greater than 144 μm, DOL_0 being the depth of the compressive stress layer, preferably the strengthened glass ceramic has a DOL_0 of 160 μm to 200 μm; and / or, The strengthened glass ceramic satisfies: DOL_0 > 0.16t, wherein DOL_0 is the depth of the compressive stress layer, and t is the thickness of the strengthened glass ceramic, preferably DOL_0 > 0.18t, more preferably DOL_0 ≥ 0.20t.

13. The strengthened glass ceramic of any one of claims 1-12, wherein, the surface K2O mass percent of the strengthened glass-ceramic is 5.62%, 4.66%, 6.78%, 4.95%, 3.86%, 4.96%, 4.55%, 4.53%, 4.04%, 5.73%, 5.39%, 6.11%, or 5.89%; and / or, the surface Na2O mass percent of the strengthened glass-ceramic is 0% or 0.002%; and / or, the DOL_K of the strengthened glass-ceramic is 12.10 pm, 11.00 pm, 9.40 pm, 15.10 pm, 14.10 pm, 13.00 pm, 11.10 pm, 19.10 pm, 18.00 pm, or 17.10 pm, and / or, the DOL_Na of the strengthened glass-ceramic is 46.10 pm, 40.00 pm, 55.10 pm, 45.40 pm, 47.10 pm, 58.10 pm, 48.00 pm, 51.10 pm, 38.00 pm, 43.10 pm, 50.30 pm, 50.20 pm, or 56.40 pm; and / or, the value of Equation A is 1039, 1150, 1520, 910, 1542, 1469, 935, 995, 1780, 1054, 1500, 2010, or 2440.

14. The strengthened glass ceramic of any one of claims 1 to 13, wherein, the strengthened glass-ceramic satisfies: in a K element concentration distribution curve in which the horizontal axis is depth in pm from a major surface of the strengthened glass-ceramic, and the vertical axis is K element concentration in mass percent on an element basis: the absolute value of the average slope of the K element concentration distribution curve between a depth of 0 micrometers and a depth of DOL_K is 0.380, 0.315, 0.302, 0.530, 0.348, 0.193, 0.445, 0.452, 0.194, 0.440, 0.220, or 0.310; and / or, the absolute value P of the average slope of the profile of the concentration of K between the depth of 5 μm and the depth of 8 μm 5-8 0.74, 1.12, 1.22, 0.99, 1.04, 1.25, 0.76, 0.80, 0.79, 0.95, 0.66, 1.34 or 1.64; and / or, in a Na element concentration distribution curve in which the horizontal axis is depth in pm from a major surface of the strengthened glass-ceramic, and the vertical axis is Na element concentration in mass percent on an element basis: the absolute value of the average slope of the Na element concentration distribution curve between a depth of 0 micrometers and a depth of DOL_Na is 0.02, 0.01, or 0.

03.

15. The strengthened glass ceramic of any one of claims 1 to 14, wherein, the strengthened glass-ceramic satisfies: in a SLP stress distribution curve in which the horizontal axis is depth in pm from a major surface of the strengthened glass-ceramic, and the vertical axis is stress in MPa: The absolute value K of the average slope of the SLP stress profile between the depth of 50 pm and the depth of 80 pm 50-80 1.92, 1.48, 1.52, 1.38, 1.70, 1.03, 1.59, 1.28, 2.29, 1.50, 1.56, or 1.73; and / or, The absolute value K of the average slope of the SLP stress profile between the depth of 80 pm and the depth of DOL_0 80-DOL-0 is 1.35, 1.06, 1.05, 1.33, 1.17, 0.98, 1.29, 1.09, 1.42, 1.18, or 1.

13.

16. The strengthened glass ceramic of any one of claims 1 to 15, wherein, the composition of the strengthened glass-ceramic at the center or the compressive stress layer, in mass percent on an oxide basis, comprises: the mass percent of SiO2 is 37.08%, 36.87%, 33.23%, 37.43%, 37.40%, 38.33%, 36.05%, 35.67%, or 32.39%; and / or, the mass percentage of Al2O3 is 35.83%, 36.98%, 36.27%, 37.52%, 36.60%, 37.07%, 34.84%, 34.55%, or 35.88%; and / or, the mass percentage of ZrO2 is 5.69%, 5.65%, 5.61%, 5.74%, 5.81%, 5.89%, 5.54%, or 5.48%; and / or, the mass percentage of MgO is 3.00%, 2.98%, 3.04%, 3.03%, 3.06%, 3.10%, 2.92%, or 2.89%; and / or, the mass percentage of ZnO is 10.77%, 10.71%, 10.55%, 10.87%, 11.01%, 11.15%, 10.46%, or 10.37%; and / or, the mass percentage of Na2O is 2.86%, 2.85%, 2.89%, 3.00%, 1.69%, 2.79%, or 2.76%; and / or, preferably free of K2O; and / or, the mass percentage of Li2O is 2.35%, 1.55%, 1.50%, 1.77%, 1.60%, 1.62%, 2.28%, 2.27%, or 2.24%; and / or, the mass percentage of CaO is 0%, 0.75%, 1.15%, or 0.92%; and / or, the mass percentage of B2O3 is 0% or 7.07%; and / or, the mass percentage of BaO is 2.42%, 2.41%, 6.94%, 0%, 2.35%, or 2.32%; and / or, the mass percentage of Y2O3 is 0%, 1.52%, or 0.60%; and / or, the mass percentage of La2O3 is 0%, 2.17%, or 3.69%.

17. The strengthened glass ceramic of any one of claims 1 to 16, wherein, the average crystal size in the strengthened glass ceramic is 5.0 nm, 6.8 nm, 6.4 nm, 6.5 nm, 8.1 nm, or 7.0 nm; and / or the total content of crystalline phases in the strengthened glass ceramic is 48.69%, 45.11%, 49.52%, 47.85%, 54.07%, 51.56%, 45.49%, or 44.77% by mass percentage.

18. The strengthened glass ceramic of any one of claims 1-17, wherein, the strengthened glass ceramic has a Vickers hardness of 858 kgf / mm 2 875 kgf / mm 2 915 kgf / mm 2 850 kgf / mm 2 837 kgf / mm 2 900 kgf / mm 2 869 kgf / mm 2 889 kgf / mm 2 857 kgf / mm 2 865 kgf / mm 2 or 825 kgf / mm 2 ; and / or, the strengthened glass ceramic has a fracture toughness value of 1.67 MPa-m 0.5 , 1.69 MPa-m 0.5 , 1.75 MPa-m 0.5 , 1.65 MPa-m 0.5 , 1.94 MPa-m 0.5 , 1.73 MPa-m 0.5 , 1.68 MPa-m 0.5 , 1.71 MPa-m 0.5 or 1.77 MPa-m 0.5 ; and / or, the |CT_AV| of the strengthened glass ceramic is 50.96 MPa, 41.74 MPa, 36.56 MPa, 45.01 MPa, 41.49 MPa, 40.48 MPa, 50.27 MPa, 49.49 MPa, 36.05 MPa, 45.43 MPa, 53.86 MPa, 40.86 MPa, or 35.91 MPa; and / or, the |CT_CV| of the strengthened glass ceramic is 65.70 MPa, 54.30 MPa, 46.07 MPa, 68.75 MPa, 53.70 MPa, 53.07 MPa, 66.96 MPa, 71.25 MPa, 42.73 MPa, 60.57 MPa, 81.79 MPa, 52.40 MPa, or 44.78 MPa; and / or, the |CT_CV| of the strengthened glass ceramic is 65.70 MPa, 54.30 MPa, 46.07 MPa, 68.75 MPa, 53.70 MPa, 53.07 MPa, 66.96 MPa, 71.25 MPa, 42.73 MPa, 60.57 MPa, 81.79 MPa, 52.40 MPa, or 44.78 MPa; and / or, The strengthened glass ceramic has a CS_50 of 199.69 MPa, 155.95 MPa, 146.48 MPa, 181.94 MPa, 181.35 MPa, 141.02 MPa, 188.73 MPa, 168.30 MPa, 188.13 MPa, 162.61 MPa, 177.13 MPa, 190.71 MPa, or 204.29 MPa; and / or, The strengthened glass ceramic has a CS_80 of 142.01 MPa, 111.53 MPa, 100.86 MPa, 140.44 MPa, 130.30 MPa, 110.00 MPa, 140.99 MPa, 129.89 MPa, 119.54 MPa, 117.60 MPa, 130.38 MPa, 138.72 MPa, or 152.35 MPa; and / or, The strengthened glass ceramic has a DOL_0 of 185.12 µm, 185.63 µm, 176.34 µm, 185.81 µm, 191.19 µm, 192.04 µm, 189.59 µm, 199.08 µm, 164.11 µm, 187.76 µm, 191.43 µm, 197.80 µm, or 215.20 µm.

19. The strengthened glass ceramic of any of Claims 1 to 18, wherein, The strengthened glass ceramic is tested for single bar static compression strength by applying a vertical downward step load at a rate of 10 mm / min to the center of the main surface of the strengthened glass ceramic having a thickness of greater than 0.7 mm using a 10 mm diameter round head metal compression rod, and the strengthened glass ceramic has a single bar static compression strength of greater than 800 N, preferably greater than 850 N; and / or, The strengthened glass ceramic is tested for single bar static compression strength by applying a vertical downward step load at a rate of 10 mm / min to the center of the main surface of the strengthened glass ceramic having a thickness of greater than 0.7 mm using a 10 mm diameter round head metal compression rod, and the strengthened glass ceramic has a single bar static compression strength of greater than 800 N, preferably greater than 850 N; and / or, The strengthened glass ceramic is tested for single bar static compression strength by applying a vertical downward step load at a rate of 10 mm / min to the center of the main surface of the strengthened glass ceramic having a thickness of greater than 0.7 mm using a 10 mm diameter round head metal compression rod, and the strengthened glass ceramic has a single bar static compression strength of greater than 800 N, preferably greater than 850 N; and / or, 20. The strengthened glass ceramic of any of Claims 1 to 19, wherein, said strengthened glass-ceramic is obtained from a glass-ceramic having a fracture toughness not lower than 1.40 MPa.m 0.5 said strengthened glass-ceramic is obtained from a glass-ceramic having a fracture toughness not lower than 1.40 MPa.m 0.5 said strengthened glass-ceramic is obtained from a glass-ceramic having a fracture toughness not lower than 1.40 MPa.m 0.5 said strengthened glass-ceramic is obtained from a glass-ceramic having a fracture toughness not lower than 1.40 MPa.m 21. A cover glass, characterized by The cover glass is made of, or comprises, the strengthened glass ceramic of any one of claims 1-20.

22. An electronic device, comprising: The electronic device comprises the strengthened glass ceramic of any one of claims 1-20.

23. The electronic device of claim 22, wherein, The electronic device comprises a housing comprising the strengthened glass ceramic of any one of claims 1-20.

24. The electronic device of claim 23, wherein, The housing comprises a display cover comprising the strengthened glass ceramic of any one of claims 1-20.

25. The electronic device of claim 23 or 24, wherein, The housing comprises a back cover comprising the strengthened glass ceramic of any one of claims 1-20.

26. The electronic device of any of claims 23-25, wherein, The electronic device further includes a camera assembly, the housing includes a camera cover plate that covers the camera assembly, the camera cover plate includes the strengthened glass ceramic of any of claims 1-20.

27. The electronic device of any of claims 22-26, wherein, The electronic device further includes a middle frame, the middle frame includes the strengthened glass ceramic of any of claims 1-20.

28. A glass article, characterized by, The glass article includes the strengthened glass ceramic of any of claims 1-20.

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