CN110615611B

CN110615611B - Aluminosilicate glass, tempered glass, preparation method of aluminosilicate glass and display device

Info

Publication number: CN110615611B
Application number: CN201910965502.0A
Authority: CN
Inventors: 周翔磊; 平文亮; 肖子凡; 王琰; 刘红刚; 陈志鸿
Original assignee: Qingyuan Nanbo Energy Saving New Material Co ltd; CSG Holding Co Ltd
Current assignee: Qingyuan Nanbo Energy Saving New Material Co ltd; CSG Holding Co Ltd
Priority date: 2019-10-10
Filing date: 2019-10-10
Publication date: 2021-04-13
Anticipated expiration: 2039-10-10
Also published as: CN110615611A; WO2021068423A1

Abstract

The invention relates to aluminosilicate glass, tempered glass, preparation methods of the aluminosilicate glass and the tempered glass, and a display device. The aluminosilicate glass comprises the following components in percentage by mass: SiO 2₂ 55％～67％、Al₂O₃ 13％～25％、B₂O₃ 0.5％～4.0％、Li₂O 1％～8％、Na₂O 6％～14％、ZrO₂ 1％～6％、K₂0-4% of O and 0-4% of MgO. The aluminosilicate glass can be chemically strengthened, and the extrusion crack threshold of the chemically strengthened glass is greater than 7.5.

Description

Aluminosilicate glass, tempered glass, preparation method of aluminosilicate glass and display device

Technical Field

The invention relates to the field of glass, in particular to aluminosilicate glass, tempered glass, preparation methods of the aluminosilicate glass and the tempered glass, and a display device.

Background

Thin plate glass is often used as a cover glass for protecting a display device or a cover glass for a housing of a portable terminal device. In recent years, display devices such as mobile phones and PDAs are becoming thinner and more functional, and are required to have high mechanical strength. Therefore, it is generally necessary to chemically strengthen the thin glass substrate to obtain a tempered glass. Such a tempered glass can be chemically strengthened by ion exchange treatment in a molten salt containing potassium or sodium, so that alkali metal ions on the glass surface are exchanged with potassium ions or sodium ions in the ion exchange salt, thereby forming a compressive stress layer on the glass surface.

The traditional glass cover plate market mainly takes (boron) aluminum silicon glass and lithium (boron) aluminum silicon glass as main materials, such as Gorilla glass of corning, T2X-1 of NEG, dragon mark glass of Asahi glass, panda glass of Asahi rainbow and KK3 glass of Nanbo in China, and the like, and has the greatest advantages of being capable of carrying out rapid chemical toughening and forming a compressive stress layer on the surface of the glass so as to achieve the purposes of increasing the mechanical strength, the impact resistance, the friction resistance, the sand and stone fall resistance and the like of the glass. However, the traditional glass has a low extrusion crack threshold value, and cannot play a good protection role when smart devices such as mobile phones and the like fall on the ground carelessly.

Disclosure of Invention

Based on this, there is a need to provide an aluminosilicate glass having a high extrusion crack threshold.

In addition, the tempered glass, the preparation method of the tempered glass and the display device are also provided.

An aluminosilicate glass comprising, in mass percent: SiO 2₂ 55％～67％、Al₂O₃ 13％～25％、B₂O₃ 0.5％～4.0％、Li₂O 1％～8％、Na₂O 6％～14％、ZrO₂ 1％～6％、K₂0-4% of O and 0-4% of MgO.

In one embodiment, the Li₂O, said Na₂O and said K₂The total mass percent of O is greater than or equal to 9.8 percent.

In one embodiment, B is₂O₃The Li₂O and the ZrO₂The mass percentage of (A) satisfies the following relationship: 3.5% or more and 11.0% or less of A, and 0.5 XB₂O₃Mass percent + Li₂O mass percent + ZrO₂And (4) percent by mass.

In one embodiment, the method comprises the following steps by mass percent: SiO 2₂ 58％～66％、Al₂O₃ 16％～22％、B₂O₃ 1％～3％、Li₂O 3％～6％、Na₂O 7％～12％、K₂0.5 to 2.0 percent of O, 0.5 to 2.0 percent of MgO and ZrO ₂2% to 5%, wherein, the Li₂O, said Na₂O and said K₂The total mass percent of O is more than or equal to 10 percent, and A is more than or equal to 5.5 percent and less than or equal to 11.0 percent, A is 0.5 XB₂O₃Mass percent + Li₂O mass percent + ZrO₂And (4) percent by mass.

In one embodiment, the method comprises the following steps by mass percent: SiO 2₂ 60％～64％、Al₂O₃ 18％～20％、B₂O₃ 1％～2％、Li₂O 4％～5％、Na₂O 8％～10％、K₂0.5 to 1.0 percent of O, 0.5 to 1.0 percent of MgO and ZrO₂3% to 4%, wherein, the Li₂O, said Na₂O and said K₂The total mass percent of O is more than or equal to 12.8 percent, and A is more than or equal to 8 percent and less than or equal to 9 percent.

In one embodiment, the aluminosilicate glass further comprises, by mass, not more than 2% SrO, not more than 4% ZnO, and not more than 4% P₂O₅TiO with the mass percent not more than 2 percent₂SnO with mass percent not more than 2%₂And CeO with the mass percent not more than 1 percent₂At least one of (1).

In one embodiment, the aluminosilicate glass further comprises ZnO with the mass percent not more than 3% and P with the mass percent not more than 2%₂O₅TiO with the mass percent not more than 1 percent₂SnO with mass percent not more than 1%₂And CeO with the mass percent not more than 0.5 percent₂At least one of (1).

In one embodiment, the aluminosilicate glass further comprises P with the mass percent not more than 1%₂O₅。

A strengthened glass is obtained by chemically strengthening the aluminosilicate glass.

A preparation method of tempered glass comprises the following steps:

providing the above aluminosilicate glass; and

firstly, the aluminosilicate glass is treated at 390-420 ℃ and NaNO with the mass ratio of 3: 7-7: 3₃And KNO₃The mixed molten liquid is toughened for 2 to 6 hours, and then NaNO with the temperature of 380 to 400 ℃ and the mass ratio of 2: 98 to 20:80₃And KNO₃The mixed molten liquid is toughened for 2 to 4 hours to obtain the strengthened glass.

In one embodiment, the aluminosilicate glass is firstly subjected to NaNO treatment at the temperature of 390-420 ℃ and the mass ratio of 3: 7-7: 3₃And KNO₃The temperature ratio in the step of tempering the mixed molten liquid for 2 to 6 hours is that NaNO with the mass ratio of 2: 98 to 20:80 is between 380 and 400 DEG C₃And KNO₃The temperature in the step of tempering the mixed molten liquid for 2 to 4 hours is 10 to 20 ℃.

A display device comprising the above aluminosilicate glass or the above tempered glass or a tempered glass produced by the above method for producing a tempered glass.

The aluminosilicate glass is obtained by controlling the components and the proportion thereof in the glass. The aluminosilicate glass can improve the strength through chemical strengthening, the extrusion crack threshold value of the glass after the chemical strengthening is larger than 7.5, and other performances are not influenced, so that the aluminosilicate glass can better protect equipment when being used as protective glass of the equipment.

Drawings

FIG. 1 is a process flow diagram of a method of making an embodiment of an aluminosilicate glass;

FIG. 2 is a process flow diagram of a method of making a strengthened glass according to one embodiment;

FIG. 3 is a schematic diagram of the calculation modes of a and b in the calculation formula of the crack threshold;

FIG. 4 is a graph showing the relationship between the crack threshold K of the strengthened glasses of examples 1 to 21 and the value of A in the aluminosilicate glass.

Detailed Description

In order that the invention may be more fully understood, reference will now be made to the following description taken in conjunction with the accompanying drawings. The detailed description sets forth the preferred embodiments of the invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

An aluminosilicate glass of an embodiment, comprising, in mass percent: SiO 2₂ 55％～67％、Al₂O₃13％～25％、B₂O₃ 0.5％～4.0％、Li₂O 1％～8％、Na₂O 6％～14％、ZrO₂ 1％～6％、K₂0-4% of O and 0-4% of MgO.

In one embodiment, the aluminosilicate glass further comprises SrO with the mass percent not more than 2%, ZnO with the mass percent not more than 4%, and P with the mass percent not more than 4%₂O₅And TiO with the mass percent not more than 2 percent₂At least one of (1).

Further, the aluminosilicate glass also comprises ZnO with the mass percent not more than 3 percent and P with the mass percent not more than 2 percent₂O₅And TiO with the mass percent not more than 1 percent₂At least one of (1).

Further, the aluminosilicate glass also comprises P with the mass percent not more than 1 percent₂O₅。

In another embodiment, the aluminosilicate glass further comprises SnO₂And CeO₂At least one of (1). Specifically, SnO₂Is not more than 2% by mass. Further, SnO₂Is not more than 1% by mass. CeO (CeO)₂Is not more than 1% by mass. Further, CeO₂Is not more than 0.5 percent.

In this embodiment, K is defined as₂The mass percentages of O and MgO may be, independently of one another, zero. And in this example SrO, ZnO, P₂O₅、TiO₂、SnO₂And CeO₂May be omitted.

SiO₂(silica) is an important glass-forming oxide and is an essential component for forming a glass skeleton. SiO 2₂The strength, chemical stability and the like of the glass can be improved, and the glass can obtain higher strain point and lower thermal expansion coefficient. Therefore, in the present embodiment, SiO₂The mass percentage of (b) is preferably 55 to 67%. SiO 2₂The mass percentage of (b) is more preferably 58 to 66%. SiO 2₂The mass percentage of (b) is most preferably 60% to 64%. If SiO₂The mass percent of (A) is less than 55%, the glass main body network structure is poor, the mechanical property is poor, and the weather resistance is poor. If SiO₂The mass percent of the silica-alumina composite glass is over 67 percent, the melting temperature of the glass in the production process is too high, the energy consumption is increased, the defects of frequent bubbles, stones and the like are easily caused, meanwhile, the proportion of the silica-alumina framework structure is higher, the network gaps are smaller, the chemical strengthening ion exchange is not facilitated, and the chemical strengthening efficiency is influenced.

Al₂O₃The (aluminum oxide) can participate in the network to play a role of a network forming body, can reduce the crystallization tendency of the glass, and can improve the chemical stability, the thermal stability, the mechanical strength and the hardness of the glass, and is also an essential component for improving the elastic modulus of the tensile glass. But Al₂O₃If Al is added, the viscosity of the glass is increased₂O₃If the amount is too large, it is difficult to obtain glass having a long glass quality, and it is difficult to mold the glass. Further, Al in the glass³⁺Tend to form an alundum tetrahedral network (AlO)₄]This is compared to the silicon-oxygen tetrahedron [ SiO ]₄]The network is much larger, leaving larger voids as channels for ion diffusion, and therefore high Al in the glass₂O₃In an amount which promotes the migration and replacement rate of alkali metal ions, Al₂O₃The higher the content is, the larger the gaps of the skeleton network is, the more favorable the ion exchange is, however, the thermal expansion coefficient can not be further reduced because of the overhigh content, and on the contrary, the high-temperature viscosity of the glass is obviously increased, the melting temperature in the production process is overhigh, the energy consumption is increased, and the defects of controlling bubbles, stones and the like are also not facilitated. However, Al₂O₃At lower contents, the network space becomes smaller, which is detrimental to ion transport and seriously affects the efficiency of chemical enhancement. Therefore, in the present embodiment, Al₂O₃The mass percentage of (b) is preferably 13 to 25%. Al (Al)₂O₃The mass percentage of (b) is more preferably 16% to 22%. Al (Al)₂O₃The mass percentage of (b) is most preferably 18% to 20%.

B₂O₃(boron oxide) is one of the important components of the boroaluminosilicate glass, belongs to a formed oxide, and can reduce the thermal expansion coefficient of the aluminosilicate glass and improve the thermal stability and the chemical stability of the aluminosilicate glass. B is₂O₃Too high a content of (A) and boron volatilization at high temperature is severe due to its viscosity-reducing effect, while B₂O₃Too high content of (A) can narrow the forming temperature, and brings difficulty to the precision control of wall thickness and pipe diameter in the tube drawing and forming of the boron-aluminum silicate glass. In addition when B₂O₃When the amount of introduction is too high, boron oxygen trigonal [ BO ] is introduced₃]Increasing the expansion coefficient of the boron-aluminum silicate glass, and the like, but increasing the expansion coefficient, and the like, causing an abnormal phenomenon, B₂O₃At too high a content, the ion exchange capacity of the glass is significantly reduced. Therefore, in the present embodiment, B₂O₃The content of (b) is preferably 0.5 to 4.0% by mass. B is₂O₃The mass percentage of (b) is more preferably 1% to 3%. B is₂O₃The mass percentage of (B) is most preferably 1 to 2%.

Li₂O (lithium oxide) is an ideal flux and is a main component for ion exchange, since Li⁺Has a polarization characteristic of effectively reducing high-temperature viscosity at high temperature, and Li⁺Has a small radius, can be filled in the air of a vitreous body to balance free oxygen, and is suitable for Li₂O can obviously enhance the mechanical strength, the surface hardness, the chemical resistance and the like of the glass body. Because the invention uses NaNO in the strengthening process₃With KNO₃Mixed molten salt of (2), by Li in glass⁺With Na in the molten salt⁺The ion exchange is carried out, so that the depth of the compressive stress layer can be increased in a short time, and the glass has more excellent mechanical impact resistance. In the present embodiment, if Li₂With O less than 1% by mass, it is substantially difficult to obtain a higher stress depth of layer for the glass. If Li₂The mass percentage of O is higher than 8 percent, the manufacturing cost of the glass is increased, the expansion coefficient of the glass is obviously increased, the crystallization tendency of the glass is too high, and the probability of generating stone defects of the glass is obviously increased. Therefore, in the present embodiment, Li₂The mass percentage of O is preferably 1% to 8%. Li₂The mass percentage of O is more preferably 3% to 6%. Li₂The mass percentage of O is most preferably 4% to 5%.

Na₂O (sodium oxide) is an exo-oxide of the boroaluminosilicate glass network and provides free oxygen to break Si-O bonds, thereby lowering the viscosity and melting temperature of the aluminosilicate glass. Na (Na)₂Too high content of O increases linear thermal expansion coefficient and decreases chemical stability, and Na₂The amount of O volatilized increases, resulting in non-uniformity of the aluminosilicate glass composition. Na (Na)₂The content of O is too low to be beneficial to melting and forming of glass, and is not beneficial to chemical exchange of Na ions and K ions so as to form a compressive stress layer on the surface of the glass and achieve the purpose of enhancing the mechanical strength of the glass₂The O component plays a role in exchanging with K ions in molten liquid to form pressure stress on the surface of the glass during tempering, and directly influences the strength performance of the glass. In this embodiment, Na₂The mass percentage of O is preferably 6 to 14%. Na (Na)₂The mass percentage of O is more preferably 7% to 12%. Na (Na)₂The mass percentage of O is most preferably 8 to 10%.

K₂O (potassium oxide) and Na₂O is an alkali metal oxide and acts similarly in the glass structure, with a small amount of K₂Substitution of O for Na₂O can exert the mixed alkali effect"to improve a series of properties of the glass, is a component for improving melting properties and for improving ion exchange rate in chemical strengthening to obtain a desired surface compressive stress and depth of stress layer. If K₂If the content of O is too high, the weather resistance is lowered. In the invention, K is set through analyzing the content of alkali metal in the glass₂The preferable mass percentage of O is 0-4%. K₂The mass percentage of O is more preferably 0.5% to 2.0%. K₂The mass percentage of O is preferably 0.5 to 1.0%.

MgO (magnesium oxide) is a network exoxide, and MgO helps to lower the melting point of glass, lower the viscosity of glass at high temperature, promote melting and clarification of glass, improve uniformity and increase hydrolysis resistance. MgO stabilizes the glass, improves the durability of the glass, prevents the glass from crystallizing, and suppresses the movement of alkali metal ions in the glass, and similarly has a function of improving the elastic modulus of the glass. MgO can enhance the spatial stability of the glass network at low temperatures and can reduce the coefficient of thermal expansion of the glass to some extent, but it has a hindering effect on ion exchange and is therefore not an essential component. If the MgO content is higher than 4% by mass, Mg²⁺The ion exchange capacity of the glass is severely hindered, resulting in a significant reduction in the depth of the compressive stress layer. Therefore, in the present embodiment, the mass percentage of MgO is preferably 0 to 4%. The mass percentage of MgO is more preferably 0.5% to 2.0%. The MgO is most preferably 0.5 to 1.0% by mass.

SrO (strontium oxide) and calcium oxide and magnesium oxide are similar in that they can lower the high-temperature viscosity of the glass and facilitate melting, but because of their large ionic radius, they do not hinder the Li-Na-K ion exchange process in the glass structure, so that a small amount of strontium oxide is used to replace part of the calcium oxide and magnesium oxide. In the present embodiment, the mass percentage of SrO is preferably 0 to 2%.

ZnO (zinc oxide) belongs to a divalent metal oxide array, also has the function of an alkaline earth metal oxide, and partial ZnO material is added into a silicate glass system, so that the melting temperature of the glass can be effectively reduced, and the transition temperature T of the glass is reduced_gAnd simultaneously can improve the glassAlkali resistance of the substrate; in aluminosilicate glass bodies, Zn is often in [ ZnO ]₆]And [ ZnO ]₄]Of the two ligands, [ ZnO ]₄]The invention adopts partial zinc oxide to replace calcium oxide and magnesium oxide, which is beneficial to maintaining the chemical stability of the glass and promoting the rapid proceeding of ion exchange. In the present embodiment, the mass percentage of ZnO is preferably 0 to 4%. The ZnO content is more preferably 0 to 3% by mass.

ZrO₂In silicate glasses mainly cubic [ ZrO ]₈]The coordination form exists, because the ionic radius is larger, the glass structure belongs to a network exosome, and the solubility of the coordination form in the glass is smaller, the viscosity of the glass can be obviously increased, so the addition amount of the coordination form is not more than 6 percent, and the acid-base resistance and the refractive index of the glass can be improved. In the present embodiment, ZrO₂The mass percentage of (b) is preferably 1% to 6%. ZrO (ZrO)₂The mass percentage of (b) is more preferably 2% to 5%. ZrO (ZrO)₂The mass percentage of (b) is most preferably 3% to 4%.

TiO₂Acting on ZrO₂Similarly, the glass belongs to transition elements, has certain coloring capability, shows yellow color, and can improve the chemical stability of the glass and the color temperature of the glass. Thus TiO is in this embodiment₂The mass percentage of (B) is 0-2%. TiO 2₂The content of (b) is further 0 to 1% by mass.

SnO₂And CeO₂The glass often exists in a plurality of valence states in the glass body, can increase the uvioresistant performance of the glass, prevent the color change caused by the valence change of coloring ions, and can increase the high-temperature bubble-removing capability of the glass body by adding the glass body singly or in a mixture way, thereby being a commonly used clarifying agent. In this embodiment, SnO₂The mass percentage of (B) is preferably 0 to 2%. SnO₂The content of (b) is more preferably 0 to 1% by mass. CeO (CeO)₂The mass percentage of (B) is preferably 0 to 1%. CeO (CeO)₂The content of (b) is more preferably 0 to 0.5% by mass.

The aluminosilicate glass with the proportion can improve the strength through chemical strengthening, and the strengthened glass after the chemical strengthening has the surface compressive stress of more than 900MPa, the maximum stress depth of more than 145 mu m, and the extrusion crack threshold value of more than 7.5. The aluminosilicate glass has high strength, and can protect equipment when being used as protective glass of the equipment.

Further, in some embodiments, Li₂O、Na₂O and K₂The total mass percent of O is greater than or equal to 9.8 percent. Alkali metals as typical glass network modifiers, which can significantly lower the melting temperature of the glass; in addition, in the invention, alkali metal ions are the key to whether the glass can be subjected to ion exchange through chemical strengthening so as to obtain enough compressive stress layer on the surface of the glass, and the inventor finds that when Li is used in a large number of experimental processes₂O、Na₂O and K₂When the total mass percentage of O is 9.8% or more, the obtained aluminosilicate glass has a larger surface stress value and a better strength.

In some embodiments, B₂O₃、Li₂O and ZrO₂The mass percentage of (A) satisfies the following relationship: 3.5% or more and 11.0% or less of A, and 0.5 XB₂O₃Mass percent + Li₂O mass percent + ZrO₂And (4) percent by mass.

B₂O₃The main function in the glass is that the glass exists as a network intermediate, the glass is mainly combined with oxygen to generate a boron-oxygen triangle and a boron-oxygen tetrahedron, the boron-oxygen triangle generally exists in a gap of a glass structure, the boron-oxygen tetrahedron participates in the construction process of a glass structure framework, and the boron-oxygen tetrahedron and the glass structure framework can be mutually converted under certain conditions, so that the stability of the glass structure is improved, the toughness of the glass is increased, the tip stress of cracks in the glass is dispersed, and the strength of the glass is improved; and Li₂O exists in the vitreous body as a network outer body, can be combined with free oxygen in the vitreous body to exist in the gap of the glass structure, and has very high field strength due to the very small radius of Li ions, so that the glass structure can be contracted, the glass has higher performance of resisting impact and erosion of the outer body, and the tip stress of the crack of the vitreous body can be dispersed; ZrO (ZrO)₂Usually also only in the interstices of the glass structure, but too much owing to their atomic radiusLarge and therefore unable to resemble Li₂The Zr ions have a large ionic radius but have high field strength because of carrying +4 positive charges, and can also tighten the glass structure in the structural gaps, so that the glass body has very good mechanical strength, hardness, erosion resistance and other properties; synthesis of the above B₂O₃、Li₂O and ZrO₂The inventor collects data through a large number of experiments and analyzes the data, and finds that the value A is between 3.5% and 11%, the aluminosilicate glass has very good crack resistance, the value A is near 9%, the crack threshold value K of the aluminosilicate glass is an extreme value, and the glass has optimal fracture toughness, namely the glass has higher impact strength and higher mechanical processing performance. Thus, in some embodiments, 3.5% ≦ A ≦ 11.0%.

One conventional technique discloses thin lithium-aluminum-silicon glass, the central tension of the toughened glass is less than 50Mpa, the surface compressive stress of the glass is 600-1200 Mpa, and the bending strength of the glass can reach 500Mpa, so that the depth of the stress layer of the glass is less than 50 μm. After the aluminosilicate glass in the embodiment is strengthened, the depth of the stress layer needs to be more than 145A, which is far greater than the depth of the stress layer of the toughened glass in the technology.

Another conventional technique is B₂O₃And ZrO₂Is lower than that of (B) in the present embodiment₂O₃And ZrO₂The content of the glass is more than 0.1 percent, the glass participates in the skeleton forming the glass body structure, the processing of the glass substrate in the later period is facilitated, the fracture toughness of the glass is increased, the surface stress value which is more than 900MPa and the compressive stress value which is more than 350MPa in the depth of 10 mu m are formed after toughening, and the mechanical strength and the anti-falling performance of the glass are enhanced.

Therefore, the traditional glass cover plate can be rapidly and chemically tempered, a compression stress layer with the stress depth of more than 600MPa is formed on the surface of the glass, the depth of the stress layer is generally higher than 35 mu m, the depth of the stress layer of the lithium aluminosilicate glass can reach more than 100 mu m through a special tempering process, and the purposes of increasing the mechanical strength, the shock resistance, the friction resistance, the sand and stone ground falling resistance and the like of the glass are facilitated. But the strength of conventional glass is still low.

The aluminosilicate glass has at least the following advantages:

(1) the aluminosilicate glass is prepared by selecting raw materials with specific mixture ratio, so that the prepared glass has 80.8 multiplied by 10 at the temperature of 20-300 DEG C^-7～92.1×10^-7The coefficient of thermal expansion of (a). Melting temperature T₂At 1536 ℃ to 1613 ℃. Glass transition temperature T_gAt a temperature of between 482 and 558 ℃. The strengthened glass obtained after chemical strengthening has>The surface compressive stress CS0 of 900MPa and the compressive stress CS10 of which the depth is 10 mu m from the surface of the glass still exceeds 300MPa, the composite compressive stress generated by ion exchange is reduced to the stress depth Dol0 of 0MPa (the detection limit of an instrument) which is more than 145 mu m, and the stress layer depth Dol600 of which the composite compressive stress is 600MPa is more than 5.5 mu m.

(2) The reinforced aluminosilicate glass has an extrusion crack threshold value of more than 7.5, and can well protect intelligent equipment such as mobile phones and the like.

In some of the embodiments, preferably, the aluminosilicate glass comprises, in mass percent: SiO 2₂ 58％～66％，Al₂O₃ 16％～22％，B₂O₃ 1％～3％，Li₂O 3％～6％，Na₂O 7％～12％，K₂0.5 to 2 percent of O, 0.5 to 2.0 percent of MgO and ZrO ₂2 to 5 percent. Wherein Li₂O、Na₂O and K₂O is greater than or equal to 10% by total mass, and B₂O₃、Li₂O and ZrO₂The mass percentage of (A) satisfies the following relationship: 5.5% to 11.0% of A, 0.5 XB₂O₃Mass percent + Li₂O mass percent + ZrO₂And (4) percent by mass.

In this embodiment, the aluminosilicate glass may further include ZnO, P₂O₅And TiO₂At least one of (1). Specifically, the mass percentage of ZnO is not more than 3%. P₂O₅Is not more than 2% by mass. TiO 2₂Quality of (1)The amount percentage does not exceed 1%. In this embodiment, the aluminosilicate glass may also include SnO₂And CeO₂At least one of (1). Wherein SnO₂Is not more than 1% by mass. CeO (CeO)₂Is not more than 0.5 percent. In this example, ZnO and P are used₂O₅、TiO₂、SnO₂And CeO₂May be omitted.

The glass prepared from the raw materials in the proportion has 82.9 multiplied by 10 at the temperature of 20-300 DEG C^-7～89.8×10^-7The coefficient of thermal expansion of (a). Melting temperature T₂At 1566-1611 ℃. The glass transition temperature Tg is from 485 ℃ to 546 ℃. The strengthened glass obtained after chemical strengthening has>The surface compressive stress CS0 of 900MPa and the compressive stress CS10 of which the depth is 10 mu m from the surface of the glass still exceeds 300MPa, the composite compressive stress generated by ion exchange is reduced to the stress depth Dol0 of 0MPa (the detection limit of an instrument) which is more than 155 mu m, and the stress layer depth Dol600 of which the composite compressive stress is 600MPa is more than 6 mu m. And the glass obtained from the aluminosilicate glass has a crack threshold value of more than 11.

In other embodiments, it is further preferred that the aluminosilicate glass comprises, in mass percent: SiO 2₂60％～64％、Al₂O₃ 18％～20％、B₂O₃ 1％～2％、Li₂O 4％～5％、Na₂O 8％～10％、K₂0.5 to 1 percent of O, 0.5 to 1.0 percent of MgO and ZrO₂3 to 4 percent. Wherein Li₂O、Na₂O and K₂O is greater than or equal to 12.8% by total mass, and B₂O₃、Li₂O and ZrO₂The mass percentage of (A) satisfies the following relationship: a is more than or equal to 8% and less than or equal to 9%, and A is 0.5 XB₂O₃Mass percent + Li₂O mass percent + ZrO₂And (4) percent by mass.

In this embodiment, the aluminosilicate glass may further include P in an amount of not more than 1% by mass₂O₅。

The glass prepared from the raw materials in the proportion has the temperature of 80.8 multiplied by 10 at the temperature of 20-300 DEG C^-7～85.6×10^-7The coefficient of thermal expansion of (a). The melting temperature T2 is between 1578 ℃ and 1603 ℃. The glass transition temperature Tg is from 500 ℃ to 527 ℃. The strengthened glass after chemical strengthening treatment has>The surface compressive stress CS0 of 950MPa and the compressive stress CS10 of which the depth is 10 mu m from the surface of the glass still exceeds 350MPa, the composite compressive stress generated by ion exchange is reduced to the stress depth Dol0 of 0MPa (the detection limit of an instrument) which is more than 160 mu m, and the stress layer depth Dol600 of which the composite compressive stress is 600MPa is more than 7 mu m. And the glass obtained from the aluminosilicate glass has a crack threshold of more than 24.

Referring to fig. 1, a method for manufacturing an aluminosilicate glass according to an embodiment is a method for manufacturing an aluminosilicate glass according to the above embodiment, and specifically includes the following steps:

step S110: weighing the following raw materials in percentage by mass: SiO 2₂ 55％～67％、Al₂O₃ 13％～25％、B₂O₃ 0.5％～4.0％、Li₂O 1％～8％、Na₂O 6％～14％、ZrO₂ 1％～6％、K₂0-4% of O and 0-4% of MgO.

Further, Li₂O、Na₂O and K₂O is greater than or equal to 9.8% by total mass, and B₂O₃、Li₂O and ZrO₂The mass percentage of (A) satisfies the following relationship: a is more than or equal to 3.5 percent and less than or equal to 11.0 percent.

Step S120: and mixing the raw materials, and melting to obtain the glass slurry.

In one embodiment, the temperature for melting in step S120 is 1650 ℃. The melting time is 8 h. And stirring by a platinum stirring paddle during the melting process.

Step S130: and homogenizing the glass slurry.

Specifically, the temperature of the homogenization treatment in step S130 is 1500 ℃. The time for the homogenization treatment was 1 h.

Step S140: and forming the glass slurry, and then annealing to obtain the aluminosilicate glass.

Specifically, in the step of molding the glass paste, a casting molding manner is adopted. In one embodiment, the homogenized glass slurry is poured on an iron mold preheated to 450 ℃ to solidify and shape the glass slurry. In one embodiment, the temperature of the annealing process is 580 to 600 ℃.

In the above-described method for producing an aluminosilicate glass, the glass can be obtained in a conventional process for producing a flat glass, and the production method is not limited to a float forming process, an overflow down-draw method, a draw-up method, a flat-draw method, a rolling method, and the like.

The preparation method of the aluminosilicate glass has simple process and is easy for industrial production.

The strengthened glass of an embodiment is obtained by chemically strengthening the aluminosilicate glass of the above embodiment. The extrusion crack threshold value of the tempered glass is larger than 7.5, so that the situation that the screen or other cover glass is broken due to the fact that intelligent equipment such as a mobile phone falls down to the ground carelessly can be effectively avoided or reduced.

Referring to fig. 2, a method for manufacturing a strengthened glass according to an embodiment of the present invention is a method for manufacturing a strengthened glass according to the above embodiment, and specifically includes the following steps:

step S210: the aluminosilicate glass is provided.

Step S220: firstly, the aluminosilicate glass is treated at 390-420 ℃ and NaNO with the mass ratio of 3: 7-7: 3₃And KNO₃The mixed molten liquid is toughened for 2 to 6 hours.

Further, NaNO in step S220₃And KNO₃The mass ratio of (A) to (B) is 9: 11-11: 9.

Step S230: then, the aluminosilicate glass is treated with NaNO at the temperature of 380-400 ℃ and the mass ratio of 2: 98-20: 80₃And KNO₃The mixed molten liquid is toughened for 2 to 4 hours.

Further, NaNO in step S230₃And KNO₃The mass ratio of (A) to (B) is 5: 95-15: 85.

The aluminosilicate glass is strengthened by adopting a two-step mixed salt mode, and the strengthening method has the following effects: ion species exchange is selectively carried out through a two-step chemical toughening method, the first step is mainly Li ions in glass and Na ions and K ions in toughening salts, Na-Li exchange can generate a compressive stress layer with a small compressive stress value and high stress depth, and a large stress is formed to make up for the problem of low stress value in the high depth direction along with partial Li-K and Na-K exchange; and secondly, tempering by using tempering salt with low temperature and high K ion content, rapidly exchanging Na ions in the glass and K ions in the tempering salt, forming a compact stress layer with low stress depth and high pressure stress value on the surface of the glass, and finally forming a composite stress layer, wherein the composite stress layer is mainly characterized in that the surface of the glass is provided with a high stress layer with the stress depth of more than 900MPa, and the depth direction of the stress layer is more than 145 microns or even higher.

Setting the mass ratio of sodium nitrate to potassium nitrate in the step S220 to be 3: 7-7: 3 mainly realizes chemical exchange between Na ions and Li ions in the glass to form a stress layer with enough depth, but because the radiuses of the Na ions and the Li ions are not very different and enough space is formed in the glass structure to meet the conversion of the Na-Li ions, the depth of the formed stress layer is deep, but the stress value is low; the method is characterized in that the exchange of Li-K and Na-K is realized in the stress direction by adding K with large ionic radius into the toughened salt, and the partial compressive stress value is increased, so that the mass ratio of sodium nitrate to potassium nitrate in the first step is 3: 7-7: 3.

In the step S230, the mass ratio of the sodium nitrate to the potassium nitrate is set to be 2: 98-20: 80, so that Na ions in the glass and K ions in toughened salt are mainly replaced, a stress layer with a high compressive stress value is formed on the surface of the glass, and a composite compressive stress layer is formed with the first-step toughening, so that the strength and the toughness of the glass are improved.

In the two-step chemical tempering process, the temperature of the mixed melt in step S220 is generally 10 to 20 ℃ higher than that of the mixed melt in step S230. Because for two elements in the tempering process: temperature and time, the longer the same tempering salt treatment, the higher the temperature, the deeper the depth of the stress layer formed, however the stress value is significantly reduced. According to the purpose of the two-step toughening method of the invention, the first step is to form a stress layer with enough depth (more than 100 μm), and the second step is that the higher the stress value is, the better, so that the higher temperature is selected in the first step, generally 390-420 ℃, and the time is 2-6 hours. The second step is to form a high-stress layer (more than 700MPa) with a certain depth, so the second step needs a lower temperature, a shorter time, usually 380-400 ℃, for 2-4 hours, and the reasons of not selecting a long time are mainly that the tempering period is too long, the efficiency and the yield are low, the cost is high, and the mass production is not suitable.

The extrusion crack threshold of the strengthened glass of the aluminosilicate glass strengthened by the method is larger than 7.5, so that the situation that the screen or other cover glass of intelligent equipment such as a mobile phone is broken due to the fact that the intelligent equipment falls down to the ground carelessly can be effectively avoided or reduced.

A display device of an embodiment includes the aluminosilicate glass of the above embodiment or the strengthened glass produced by the method for producing the strengthened glass of the above embodiment.

The following are specific examples:

the aluminosilicate glasses of examples 1 to 21 were prepared as follows:

the components (mass percent) of the components of the embodiments 1 to 21 are respectively designed according to the tables 1 to 3, and are fully and uniformly mixed, melted at 1650 ℃ for 8 hours by using a platinum crucible, stirred by using a platinum stirring paddle, cooled to 1500 ℃ after the stirring paddle is drawn out, kept warm for 1 hour for homogenization, cast on an iron mold to form a glass block with the size of about 80mm multiplied by 160mm, preheated to 450 ℃ before the mold casting, immediately transferred to an annealing furnace for annealing at 590 ℃ after the glass block is hardened, kept warm for 2 hours, cooled to 140 ℃ after 6 hours, naturally cooled to obtain a glass product, and taken out for later use.

The strengthening process of the aluminosilicate glass of examples 1 to 12 is specifically as follows:

the aluminosilicate glasses obtained in examples 1 to 12 were processed into double-side polished glass sheets of 50 mm. times.50 mm. times.0.7 mm, and subjected to NaNO at 400 ℃ in a mass ratio of 3: 2₃And KNO₃After 4 hours of tempering treatment in the mixed molten liquid, the mixture is further temperedTransferring to NaNO at 385 deg.C and 1: 9 mass ratio₃And KNO₃The mixed molten liquid is toughened for 2 hours to obtain the strengthened glass.

The strengthening process of the aluminosilicate glass of the embodiment 13 to the embodiment 14 is specifically as follows:

the aluminosilicate glasses obtained in examples 13 to 14 were processed into double-side polished glass pieces of 50 mm. times.50 mm. times.0.7 mm, and subjected to NaNO at 390 ℃ in a mass ratio of 3: 7₃And KNO₃The mixed molten liquid is subjected to tempering treatment for 6 hours, and then transferred to NaNO with the temperature of 380 ℃ and the mass ratio of 2: 98₃And KNO₃The mixed molten liquid is toughened for 4 hours to obtain the strengthened glass.

The strengthening process of the aluminosilicate glass of the embodiment 15 to the embodiment 21 is specifically as follows:

the aluminosilicate glasses obtained in examples 15 to 21 were processed into double-side polished glass pieces of 50 mm. times.50 mm. times.0.7 mm, and subjected to NaNO at a temperature of 420 ℃ in a mass ratio of 7:3₃And KNO₃After 2 hours of tempering treatment in the mixed molten liquid, the mixed molten liquid is transferred to NaNO with the temperature of 400 ℃ and the mass ratio of 20:80₃And KNO₃The mixed molten liquid is toughened for 2 hours to obtain the strengthened glass.

The production processes of the aluminosilicate glasses of comparative examples 1 to 19 are similar to those of example 1 to example 21, except that the raw material formulation of the aluminosilicate glasses of comparative examples 1 to 19 is shown in tables 4 to 6.

The strengthening process of the aluminosilicate glass of comparative examples 1 to 14 is the same as that of the aluminosilicate glass of examples 1 to 12, and is not described again.

The strengthening process for the aluminosilicate glass of comparative example 15 is specifically as follows:

the aluminosilicate glass prepared in comparative example 15 was processed into a double-side polished glass sheet of 50 mm. times.50 mm. times.0.7 mm, and subjected to NaNO at a temperature of 400 ℃ in a mass ratio of 3: 2₃And KNO₃The mixed molten liquid is toughened for 4 hours to obtain the strengthened glass.

The strengthening process of the aluminosilicate glass of comparative example 16 is specifically as follows:

the aluminosilicate glass of comparative example 16 was processed into a double-side polished glass sheet of 50 mm. times.50 mm. times.0.7 mm, and subjected to NaNO at a temperature of 385 ℃ in a mass ratio of 1: 9₃And KNO₃The mixed molten liquid is toughened for 2 hours to obtain the strengthened glass.

The strengthening process for the aluminosilicate glass of comparative example 17 is specifically as follows:

the aluminosilicate glass of comparative example 17 was processed into a double-side polished glass sheet of 50 mm. times.50 mm. times.0.7 mm, and subjected to NaNO at a temperature of 385 ℃ in a mass ratio of 3: 2₃And KNO₃After 4 hours of tempering treatment in the mixed molten liquid, the mixed molten liquid is transferred to NaNO with the temperature of 400 ℃ and the mass ratio of 1: 9₃And KNO₃The mixed molten liquid is toughened for 2 hours to obtain the strengthened glass.

The strengthening process for the aluminosilicate glass of comparative example 18 is specifically as follows:

the aluminosilicate glass of comparative example 18 was processed into a double-side polished glass sheet of 50 mm. times.50 mm. times.0.7 mm, and subjected to NaNO at a temperature of 400 ℃ in a mass ratio of 1: 9₃And KNO₃The mixed molten liquid is tempered for 4 hours, and then transferred to NaNO with the temperature of 385 ℃ and the mass ratio of 3: 2₃And KNO₃The mixed molten liquid is toughened for 2 hours to obtain the strengthened glass.

Comparative example 19

The aluminosilicate glass of comparative example 19 was processed into a double-side polished glass sheet of 50 mm. times.50 mm. times.0.7 mm, and subjected to NaNO at a temperature of 400 deg.C₃After 4 hours of tempering treatment in the molten liquid, the molten liquid is transferred to KNO with the temperature of 385 DEG C₃The molten liquid is toughened for 2 hours to obtain the strengthened glass.

The following are test sections:

the aluminosilicate glasses prepared in the above examples 1 to 21 and comparative examples 1 to 14 were processed into glass samples having a diameter of 5mm × 50mm, and a thermal expansion curve was measured at a temperature rise rate of 4 ℃/min using a relaxation-resistant thermal expansion instrument NETZSCH-DIL 402PC, and the measurement was performed by software provided thereinObtaining the strain point Tg and the expansion softening point T of the glass_sAnd a coefficient of thermal expansion CTE in the range of 20 ℃ to 300 ℃ and are reported in tables 1 to 5.

The aluminosilicate glasses prepared in examples 1 to 21 and comparative examples 1 to 14 were measured for high temperature viscosity using 250g of a high temperature viscometer model RSV-1600 through ORTON, and the temperature at which the viscosity is 102dPa.S was defined as the glass melting temperature T₂The temperatures at which the viscosities are 103dPa.S, 104dPa.S and 105dPa.S are defined as T, respectively₃、T₄、T₅And the measured values are recorded in tables 1 to 5.

The tempered glasses obtained in examples 1 to 21 and comparative examples 1 to 19 were tested for surface stress value CS0, compressive stress value CS10 at a depth of 10 μm, stress layer depth Dol600 at maximum stress layer depth Dol0 and 600MPa, respectively, by japanese bending stress tester FSM6000UV and SLP1000, and recorded correspondingly in tables 1 to 6.

The strengthened glasses obtained in examples 1 to 21 and comparative examples 1 to 19 were processed into glass samples of 50mm × 50mm × 0.7 mm. The surface vickers hardness was then measured with a HV-50MDX vickers hardness tester, No. heigh, selecting test forces of 0.2kgf, 0.5kgf, 1kgf, 2kgf, 3kgf, 5kgf, 10kgf, 20kgf and 30kgf, respectively, maintaining the pressure for 20s, and then measuring the indentation diagonal and crack size under a fatka DM2500 microscope by the following formula: the press crack threshold K is F × a/b, where F is the minimum applied force (unit N) at which a crack occurs, a is the diagonal length of the indentation, b is the length of the crack in the diagonal direction of the indentation, and a and b are calculated in a specific manner as shown in fig. 3. The extrusion crack threshold values obtained by testing the glass samples of the respective examples and comparative examples are correspondingly recorded in tables 1 to 5.

The aluminosilicate glass of the embodiment 1 to the embodiment 7 in the table 1 comprises the following components by mass percent: SiO 2₂ 55％～67％、Al₂O₃ 13％～25％、B₂O₃ 0.5％～4.0％、Li₂O 1％～8％、Na₂O 6％～14％、ZrO2 1％～6％、K₂O 0～4％、MgO 0～4％、SrO 0～2％、ZnO 0～4％、P₂O₅ 0～4％，TiO ₂ 0～2％、SnO ₂0 to 2% and CeO ₂0 to 1 percent. Wherein Li₂O、Na₂O and K₂O is greater than or equal to 9.8% by total mass, and B₂O₃、Li₂O and ZrO₂The mass percentage of (A) satisfies: a is more than or equal to 3.5 percent and less than or equal to 11.0 percent.

As can be seen from Table 1 with respect to the aluminosilicate glasses prepared in the above examples 1 to 7, glasses having the above composition characteristics have 82.4X 10 at 20 ℃ to 300 ℃^-7～92.1×10^-7The coefficient of thermal expansion of (a). Melting temperature T₂At 1536 ℃ to 1613 ℃. Glass transition temperature T_gAt a temperature of between 482 and 558 ℃.

In addition, the aluminosilicate glasses of examples 1 to 7 were subjected to NaNO at 400 ℃₃∶KNO₃Tempering the melt at 3: 2 for 4 hours, transferring to NaNO at 385 deg.C₃∶KNO₃The tempered glass obtained after 2 hours tempering in the mixed melt of 1: 9 has>The surface compressive stress CS0 of 900MPa and the compressive stress CS10 of which the depth is 10 mu m from the surface of the glass still exceeds 300MPa, the composite compressive stress generated by ion exchange is reduced to the stress depth Dol0 of 0MPa (the detection limit of an instrument) which is more than 145 mu m, and the stress layer depth Dol600 of which the composite compressive stress is 600MPa is more than 5.5 mu m. The tempered glass has an extrusion crack threshold greater than 7.5.

TABLE 1 compositions and Experimental data for aluminosilicate glasses of examples 1-7

Remarking: CS 0: a surface stress value; CS 10: a compressive stress value of 10 μm depth; dol 0: maximum stress layer depth; dol 600: stress depth at 600 MPa.

Preferred formulations for aluminosilicate glasses are listed in table 2. The aluminosilicate glass of the embodiment 8 to the embodiment 14 comprises the following components by mass percent: SiO 2₂ 58％～66％、Al₂O₃ 16％～22％、B₂O₃ 1％～3％、Li₂O 3％～6％、Na₂O 7％～12％、K₂O 0.5％～2％、MgO 0.5％～2％、ZrO ₂ 2％～5％、ZnO 0～3％、P₂O₅0～2％、TiO ₂ 0～1％、SnO ₂0 to 1% and CeO ₂0 to 0.5 percent. Wherein Li₂O、Na₂O and K₂O is greater than or equal to 10% by total mass, and B₂O₃、Li₂O and ZrO₂The mass percentage of (A) satisfies: a is more than or equal to 5.5 percent and less than or equal to 11.0 percent.

As can be seen from Table 2, the aluminosilicate glass having the above compositional characteristics has 82.9X 10 at 20 ℃ to 300 ℃^-7～89.8×10^-7The coefficient of thermal expansion of (a). Melting temperature T₂At 1566-1611 ℃. The glass transition temperature Tg is from 485 ℃ to 546 ℃.

In addition, the aluminosilicate glasses of examples 8 to 14 were subjected to NaNO at 400 ℃₃∶KNO₃Tempering the melt at 3: 2 for 4 hours, transferring to NaNO at 385 deg.C₃∶KNO₃The tempered glass obtained after 2 hours tempering in the mixed melt of 1: 9 has>The surface compressive stress CS0 of 900MPa and the compressive stress CS10 of which the depth is 10 mu m from the surface of the glass still exceeds 300MPa, the composite compressive stress generated by ion exchange is reduced to the stress depth Dol0 of 0MPa (the detection limit of an instrument) which is more than 155 mu m, and the stress layer depth Dol600 of which the composite compressive stress is 600MPa is more than 6 mu m. The tempered glass has a crush crack threshold greater than 11.

TABLE 2 compositions and Experimental data for the aluminosilicate glasses of examples 8-14

Further details of the aluminosilicate glasses are given in Table 3The preferred formulation, the aluminosilicate glass of the embodiment 15 to the embodiment 21, comprises the following components by mass percent: SiO 2₂ 60％～64％、Al₂O₃ 18％～20％、B₂O₃ 1％～2％、Li₂O 4％～5％、Na₂O 8％～10％、K₂O 0.5％～1％、MgO 0.5％～1.0％、ZrO₂3 to 4 percent and P₂O₅0 to 1% of Li₂O、Na₂O and K₂O is greater than or equal to 12.8% by total mass, and B₂O₃、Li₂O and ZrO₂The mass percentage of (A) satisfies: a is more than or equal to 8 percent and less than or equal to 9 percent.

As can be seen from Table 3, the aluminosilicate glass having the above composition ratio has a glass composition of 80.8X 10 at 20 ℃ to 300 ℃^-7～85.6×10^-7The coefficient of thermal expansion of (a). Melting temperature T₂At 1578 ℃ to 1603 ℃. The glass transition temperature Tg is from 500 ℃ to 527 ℃.

In addition, the aluminosilicate glasses of examples 15 to 21 were subjected to NaNO at 400 ℃₃∶KNO₃Tempering the melt at 3: 2 for 4 hours, transferring to NaNO at 385 deg.C₃∶KNO₃The tempered glass obtained after 2 hours tempering in the mixed melt of 1: 9 has>The surface compressive stress CS0 of 950MPa and the compressive stress CS10 of which the depth is 10 mu m from the surface of the glass still exceeds 350MPa, the composite compressive stress generated by ion exchange is reduced to the stress depth Dol0 of 0MPa (the detection limit of an instrument) which is more than 160 mu m, and the stress layer depth Dol600 of which the composite compressive stress is 600MPa is more than 7 mu m. The tempered glass has an extrusion crack threshold greater than 24.

TABLE 3 compositions and Experimental data for the aluminosilicate glasses of examples 15-21

The press crack threshold K of the tempered glass of examples 1 to 21 and a of the aluminosilicate glass were 0.5 xb₂O₃+Li₂O+ZrO₂The relationship of (A) was investigated to obtain the relationship shown in FIG. 4The relationship shown is a graph.

As can be seen from FIG. 4, the strengthened glass has a strong crack resistance when the A value is in the range of 3.5% to 11.0% in the aluminosilicate glass. When the A value in the aluminosilicate glass is between 5.5 and 11.0 percent, the strengthened glass has a better crack threshold value. When the A value of the aluminosilicate glass is between 8 and 9 percent, the aluminosilicate glass has the best extrusion crack threshold value K, and has the highest anti-crack capability and the highest mechanical strength.

The compositions and experimental data of the aluminosilicate glasses of comparative examples 1 to 7 are shown in table 4 below. As can be seen from Table 4, the aluminosilicate glass of comparative example 1 has no B₂O₃And the value of a is 8%, but since no boron oxide is involved in the network structure of the glass, there is no buffer structure and stress concentration is easily formed when the glass is subjected to external impact force, so that the crack threshold of the aluminosilicate glass of comparative example 1 is significantly lowered as compared with that of the aluminosilicate glass of example 1. Aluminosilicate glass of comparative example 2 in which B is present₂O₃The percentage of (b) is 5%, and the content is high, so that the ion exchange capacity of the glass is remarkably reduced, and therefore, the CS0 value, Dol600 value and crack threshold value are remarkably reduced, and the strength of the glass is reduced.

As can be seen from the comparison of comparative examples 3 to 5 with examples 3 to 5, Al₂O₃The content increases, resulting in a significant increase in high-temperature viscosity. Al (Al)₂O₃At lower contents, the crack threshold is significantly reduced and the strength of the glass is reduced. SiO 2₂When the content of (A) is higher, the melting temperature is increased, a silicon-oxygen tetrahedral structure with a stable structure is formed, and the chemical strengthening ion exchange is not facilitated, so that the CS0 value, Dol600 value and the crack threshold are obviously reduced, and the strength of the glass is reduced.

As can be seen from the comparison of comparative examples 6 to 7 with examples 6 to 7, Li₂When the content of O is increased, the expansion coefficient of the glass is obviously increased, and the stable space skeleton structure of the glass body is damaged, so that the strength of the glass is obviously reduced. Li₂When the O content is low, Li-Na ion exchange is not facilitated, and a sufficiently deep compressive stress layer cannot be formed, so thatDol0 was only 92 μm, and the strength was low, and it was difficult to use it as a cover glass.

TABLE 4 glass Components and associated Performance data for comparative examples 1-7

The compositions and experimental data of the aluminosilicate glasses of comparative examples 8 to 14 are shown in table 5 below. As can be seen from Table 5, ZrO in the aluminosilicate glass of comparative example 8₂When the content of (A) is low, a sufficient and stable glass structure space cannot be formed, and when the glass is impacted by external force, stress concentration is easy to generate, so that the glass is easy to break, and the crack threshold of the glass is obviously reduced; ZrO in the aluminosilicate glass of comparative example 9₂When the content of (b) is increased, the viscosity of the glass is significantly increased, so that the glass design formula cannot be practically produced in large quantities, and the crystallization is easy to occur.

It can be seen from comparative examples 10 and 11 that when the a value is less than 3.5% or the a value is greater than 11%, which is the composition of the main components forming the structural voids of the aluminosilicate glass body, the boroxide trigones, the high field strength lithium oxide and the zirconia, the a value is greater than 11%, the structural voids occupy more space throughout the glass body, reducing the structural strength of the glass, and the a value is less than 3.5%, which is the structural void filler ion, cannot form sufficient structural voids, cannot achieve the rapid exchange and migration of the three ions Li-Na-K, and improves the strength of the glass, and therefore the crack threshold of the aluminosilicate glass is less than the crack threshold of the aluminosilicate glass when the a value is between 3.5% and 11%.

As can be seen from comparative examples 12 and 13, the content of sodium oxide is too high or too low, which is not favorable for the increase of the glass strength; the high content of sodium oxide directly results in the destruction of the network skeleton of the glass and the reduction of the strength of the glass body, while the low content of sodium oxide is used as the main ion for the ion exchange of chemical tempering and can not play the role of improving the strength of the glass through the ion exchange.

It can be seen from comparative example 14 that, when the content of potassium oxide is high, potassium oxide as an external network body significantly damages the framework structure of the glass, so that the crack threshold of the glass is significantly reduced, and the glass cannot be protected.

TABLE 5 compositions and Experimental data for the aluminosilicate glasses of comparative examples 8 to 14

The compositions and experimental data of the aluminosilicate glasses of comparative examples 15 to 19 are shown in table 6 below. As can be seen from Table 6, the strengthening process of comparative example 15, in which only the first step of strengthening was performed and thus Na-K ion exchange and Li-K ion exchange were not performed, had a surface stress value of 386MPa, a maximum stress layer depth of 135 μm, a press crack threshold of 4.84, a crack threshold of 17.83 lower than that of example 8, and a maximum stress depth of 37 μm lower than that of example 8.

The strengthening process of comparative example 16 performed only the second-step strengthening, and thus did not perform Li-Na ion exchange, performed only Li-K and Na-K exchange, and the glass surface had a high compressive stress value, but the maximum stress depth was only about 10.2 μm, which was much lower than the maximum stress depth 178 μm of example 9, and the CS10 was only 36MPa, resulting in a crack threshold of only 4.32.

The first-step strengthening temperature is lower than the second-step strengthening temperature in the strengthening process of the comparative example 17, and as the first-step strengthening mainly forms the stress layer with enough depth, the depth of the stress layer can be formed when the strengthening temperature is lower; the second step of strengthening mainly improves the stress value of the stress layer, when the strengthening temperature is higher, the stress relaxation phenomenon occurs, and the formed surface compressive stress is only 754MPa and is far lower than 936MPa in the embodiment.

In the strengthening process of the comparative example 18, the proportion of the sodium nitrate and the potassium nitrate for the first-step strengthening and the second-step strengthening is out of the range of the proportion, so that the depth of the maximum stress layer is less than 100 micrometers, the surface stress value is only 584MPa, and the chemical toughening effect is far lower than that of the example, so that the crack threshold is only 4.86.

In the strengthening process of comparative example 19, the melt in the first step contained only sodium nitrate and the melt in the second step contained only potassium nitrate, so that Li-K and Na-K exchange could not be performed in the first strengthening step and Li-Na ion exchange could not be performed in the second strengthening step, resulting in a decrease in strength of the glass and a lower crack threshold.

TABLE 6 compositions and Experimental data for the aluminosilicate glasses of comparative examples 15 to 19

From the above experimental results, it can be seen that the aluminosilicate glasses prepared in examples 1 to 21 have extrusion crack thresholds after being chemically strengthened of more than 7.5, which are better than the extrusion crack thresholds after being chemically strengthened of the aluminosilicate glasses in the comparative examples.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. A preparation method of tempered glass is characterized by comprising the following steps:

providing an aluminosilicate glass, wherein the aluminosilicate glass comprises the following components in percentage by mass: SiO 2₂ 62％、Al₂O₃18.5％、B₂O₃ 1.5％、Li₂O 4.5％、Na₂O 8.5％、K₂O0.8%, MgO 0.7% and ZrO₂3.5 percent; and

firstly, the aluminosilicate glass is treated at the temperature of 420 ℃ and the mass ratio of NaNO to NaNO of 7:3₃And KNO₃The mixed molten liquid is toughened for 2 hours, and then NaNO with the mass ratio of 20:80 is added at the temperature of 400 DEG C₃And KNO₃The mixed molten liquid is toughened for 2 hours to obtain the strengthened glass.

2. A tempered glass produced by the method for producing a tempered glass according to claim 1.

3. A display device comprising the strengthened glass of claim 2.