Aluminosilicate glass composition and strengthening process thereof

Abstract

The invention relates to the field of glass, in particular to an aluminosilicate glass composition and a strengthening process thereof, and the aluminosilicate glass composition comprises SiO2, Al2O3, Na2O, K2O, Li2O, MgO, BaO, P2O5, B2O3, Y2O3, ScO2 and La2O3. According to the aluminosilicate glass composition disclosed by the invention, the ratio of each component is accurately controlled, the glass network structure is optimized, and the stability, hardness and wear resistance of the aluminosilicate glass composition are improved. Meanwhile, rare metal oxides such as Y2O3, ScO2 and La2O3 are introduced, so that glass network gaps can be filled, compactness can be enhanced, surface defects of the glass can be reduced, crack propagation can be effectively inhibited, the impact strength and toughness of the glass can be remarkably improved, the depth of a compressive stress layer and the surface compressive stress can be greatly increased, and the comprehensive performance of the glass can be further improved.

Description

Technical Field

[0001] The present invention relates to the field of glass, and particularly to an aluminosilicate glass composition and its strengthening process. Background Art

[0002] In recent years, devices such as smart phones and tablet computers have been continuously popularized, and show a development trend of being thinner and lighter. One problem brought by thinning is that the strength of the glass will decrease as the thickness decreases. In order to meet the usage requirements, the glass for display must still have high strength at a small thickness. To achieve this goal, the glass needs to be strengthened.

[0003] The Chinese invention patent with the application number 201610277766.3 discloses an aluminosilicate glass, which is expressed by the mass percentage based on the following oxides and includes the following components: 56.0% - 68.0% of silicon dioxide, 10.0% - 22.0% of aluminum oxide, 9.0% - 15.0% of sodium oxide, 2.0% - 8.0% of magnesium oxide, 0% - 9.0% of potassium oxide, and 0% - 1.5% of zirconium dioxide; wherein, the total mass percentage of silicon dioxide and aluminum oxide is greater than or equal to 70% and less than or equal to 85%, and the total mass percentage of sodium oxide and potassium oxide is greater than or equal to 9% and less than or equal to 23%; the chromaticity value of the silicate glass produced by this patent shows a neutral tone, has good light transmittance and low haze, but the glass has a large network gap, low compactness, many micro-defects, insufficient toughness, and defects such as easy cracking at the edge, which affect the user's use and experience. Summary of the Invention

[0004] In order to overcome the disadvantages and deficiencies existing in the prior art, the purpose of the present invention is to provide an aluminosilicate glass composition and its strengthening process.

[0005] The purpose of the present invention is achieved by the following technical solutions: an aluminosilicate glass composition, including the following components in mass percentage: SiO2: 55.3% - 64.8%, Al2O3: 12.4% - 19.7%, Na2O: 2.1% - 4.4%, K2O: 3.2% - 8.6%, Li2O: 1.9% - 6.5%, MgO: 1.5% - 5%, BaO: 1.5% - 4.2%, P2O5: 0.8% - 4.5%, B2O3: 0.5% - 2.5%, Y2O3: 0.1 - 1.5%, ScO2: 0.1% - 1%, and La2O3: 0.05% - 0.8%; wherein, the mass relationship of Y2O3, ScO2, and La2O3 satisfies: 0.8 ≤ Y2O3 + ScO2 + La2O3 ≤ 3.2.

[0006] The aluminosilicate glass composition of the present invention optimizes the glass network structure by precisely controlling the proportion of each component, thereby enhancing its stability, hardness, and wear resistance. Meanwhile, the introduction of rare metal oxides such as Y2O3, ScO2, and La2O3 can fill the gaps in the glass network during glass strengthening, enhance the compactness, reduce the surface defects of the glass, effectively inhibit crack propagation, significantly improve the impact resistance and toughness of the glass, and also greatly increase the depth of the compressive stress layer and the surface compressive stress, further enhancing the comprehensive performance of the glass.

[0007] Preferably, the aluminosilicate glass composition comprises the following components in mass percentages: SiO2: 57% - 63%, Al2O3: 14% - 18%, Na2O: 3% - 3.8%, K2O: 3.8% - 7.2%, Li2O: 2.3% - 5.5%, MgO: 2% - 4%, BaO: 1.8% - 3.8%, P2O5: 1.1% - 3.7%, B2O3: 0.7% - 2.3%, Y2O3: 0.2% - 1.2%, ScO2: 0.2% - 0.8%, and La2O3: 0.1% - 0.5%; wherein, the mass relationship of Y2O3, ScO2, and La2O3 satisfies: 1 ≤ Y2O3 + ScO2 + La2O3 ≤ 2.5.

[0008] The reasons for limiting the composition of the aluminosilicate glass composition within the above ranges are described as follows:

[0009] As a glass network former, SiO2 constructs a three-dimensional framework through Si-O-Si covalent bonds, determining the chemical stability, light transmittance, and mechanical strength of the glass. When the content of SiO2 is less than 53%, the glass network structure becomes loose, and the proportion of non-bridging oxygen increases, resulting in a decrease in glass hardness; when the content of SiO2 is higher than 65%, the melting temperature of the glass rises, the brittleness of the glass increases, and microcracks are likely to appear during hot processing. Therefore, the content of SiO2 is limited to 55.3% - 64.8%, and the preferred content is 57% - 63%.

[0010] As a network intermediate, Al2O3 participates in the formation of the glass network structure and can enhance the stability of the network structure. Al 3+ can form [AlO4] tetrahedrons to participate in network construction, improving the ion exchange rate and hardness. When the content of Al2O3 is less than 10%, the ion exchange efficiency decreases, the depth of the surface compressive stress layer is insufficient during glass strengthening, the bending resistance is poor, and the obtained glass product has poor stability and low mechanical strength; when the content of Al2O3 is greater than 23%, the viscosity of the glass increases, it is difficult to form profiled glass, and the oversaturation of Al2O3 is likely to cause crystallization. Therefore, the range of Al2O3 is limited to 12.4% - 19.7%, and the preferred content is 14% - 18%.

[0011] Na2O provides Na+ As the main ion source for chemical strengthening, it drives the surface K + replacement reaction. When the content of Na2O is less than 1.5%, the exchangeable Na + concentration is insufficient, the depth of the surface compressive stress layer is not enough, and the strengthening efficiency is low; when the content of Na2O is greater than 6%, it will lead to the weakening of the glass network structure, the decrease of water resistance, and the easy occurrence of stress relaxation at high temperatures. The range of Al2O3 is limited to 2.1% - 4.4%, and the preferred content is 3% - 3.8%.

[0012] K2O replenishes the strength of the surface compressive stress layer through the K + exchange with larger ions in the molten salt. When the content of K2O is less than 2%, the participation of K + is insufficient, the surface compressive stress gradient is gentle, and the scratch resistance is weak. When the content of K2O is higher than 9%, the K + mobility is low, and the excess will block the ion channels and inhibit the Na + / Li + diffusion. Therefore, the content of K2O is limited to 3.2% - 8.6%, and the preferred content is 3.8% - 7.2%.

[0013] The high mobility of Li in Li2O + can participate in deep ion exchange and increase the depth of the compressive stress layer. When the content of Li2O is less than 1.5%, the deep strengthening effect of the glass is weak, and the anti-bending fatigue life is short. When the content of Li2O is higher than 7%, the supersaturated Li + will cause glass phase separation (such as the precipitation of Li2SiO3), and at the same time, the acid resistance of the glass will also decrease. Therefore, the content of Li2O is limited to 1.9% - 6.5%, and the preferred content is 2.3% - 5.5%.

[0014] MgO can reduce the melting point of the glass, improve the uniformity, increase the hydrolysis resistance, and improve the durability. When the content of MgO is less than 1%, the increasing effects on the glass uniformity, hydrolysis resistance, and durability are limited; when the content of MgO is higher than 6%, it will overfill the voids in the glass network and inhibit the deep diffusion of Na + / Li + Therefore, the content of MgO is limited to 1.5% - 5%, and the preferred content is 2% - 4%.

[0015] BaO can reduce the thermal expansion coefficient of the glass, combine with the non-bridging oxygen in the SiO2 / Al2O3 network, cover voids of different sizes, and make the ion migration rate uniform. When the content of BaO is less than 1%, the effect of filling large-sized voids in the glass network is limited, and it cannot achieve the effect of reducing the thermal expansion coefficient of the glass; when the content of BaO is higher than 5%, the excessive Ba 2+ will block the Na + / Li+ The migration channels are reduced, and the depth of the compressive stress layer is decreased. Therefore, the content of BaO is limited to 1.5% - 4.2%, and the preferred content is 1.8% - 3.8%.

[0016] P2O5 can form [PO4] tetrahedrons in the glass, regulate the connectivity of the glass network, reduce the high-temperature viscosity, and inhibit phase separation. When the content of P2O5 is less than 0.5%, the uniformity of the glass melt is poor, and the effect of reducing the high-temperature viscosity is poor; when the content of P2O5 is higher than 6%, the increase in P-O-P chains leads to a decrease in chemical stability and corrosion resistance. Therefore, the content of P2O5 is limited to 0.8% - 4.5%, and the preferred content is 1.1% - 3.7%.

[0017] As an auxiliary glass network former, the BO3 / BO4 structure of B2O3 can reduce the melting temperature and improve the processability. When the content of B2O3 is less than 0.5%, the melting temperature is high, and it is difficult to process the glass; when the content of B2O3 is higher than 3%, the hydrolysis tendency of the B-O bond is enhanced, and the water resistance deteriorates significantly. Therefore, to balance energy conservation and water resistance, the content of B2O3 is limited to 0.5% - 2.5%, and the preferred content is 0.7% - 2.3%.

[0018] Y2O3 has a high charge density and preferentially occupies the tetrahedral interstitial sites in the glass network, forms strong bonds with [AlO4] or [SiO4] units, reduces the number of non-bridging oxygens, and densifies the network structure. At the same time, Y 3 + is enriched at the crack tip, inhibits crack propagation through the pinning effect, and improves the fracture toughness. When the content of Y2O3 is higher than 1.5%, Y 3 + supersaturation leads to phase separation of the glass, forming Y-Al-Si-O crystal phase precipitation, and at the same time, it also reduces the light transmittance. Therefore, the content of Y2O3 is limited to 0.1 - 1.5%, and the preferred content is 0.2% - 1.2%.

[0019] ScO2 can ionize Sc during strengthening 3+ , Sc 3+ is the smallest high-charge cation in rare earths and can be embedded in the tetrahedral interstitial sites of the glass network to optimize the local stress distribution; during strengthening, Sc 3+ forms a local electric field gradient with K + in the molten salt, accelerates the directional migration of Na + , strengthens the strengthening effect, and both the fatigue resistance and corrosion resistance are improved. When the content of ScO2 is higher than 1.5%, Sc 3+ competes for coordination with Al 3+ , resulting in the weakening of the Al2O3 network and a decrease in the glass hardness. Therefore, the content of ScO2 is limited to 0.1% - 1%, and the preferred content is 0.2% - 0.8%.

[0020] La2O3 can enhance the environmental tolerance of glass, reduce the high-temperature viscosity of glass, and improve the forming precision of profiled glass. When the content of La2O3 is higher than 1%, La 3+ competes with alkali metal ions for charge compensation, resulting in a decrease in the ion exchange rate and a reduction in the strengthening effect of the glass. Therefore, the content of La2O3 is limited to 0.05%-0.8%, and the preferred content is 0.1%-0.5%.

[0021] Y2O3, ScO2, and La2O3, as rare earth oxides, have high field strength and small ionic radii. They can be embedded in the interstitial positions of the aluminosilicate glass network, fill structural defects, significantly improve the density and mechanical strength of the glass, and at the same time enhance the ability to resist water, acid, and alkali erosion. When Y2O3 + ScO2 + La2O3 ≤ 0.5, the interstitial positions of the glass network cannot be effectively filled, resulting in a decrease in density and an increase in microdefects, and the effect of enhancing toughness and mechanical strength cannot be achieved. When Y2O3 + ScO2 + La2O3 ≥ 4, excessive rare earth oxides will over-crosslink the glass network, leading to an increase in glass brittleness, a decrease in impact resistance, and an increase in the risk of crystallization. Therefore, the content of these three rare metal oxides is limited to 0.8 ≤ Y2O3 + ScO2 + La2O3 ≤ 3.2, and the preferred content is 1 ≤ Y2O3 + ScO2 + La2O3 ≤ 2.8.

[0022] Preferably, the mass relationship of MgO, BaO, and SiO2 satisfies: (MgO + BaO) / SiO2 = 1:7.9 - 15.7. MgO and BaO, as mixed alkaline earth metals, optimize the ion migration inhibition ability through the "mixed alkaline earth effect". Mg 2+ fills small-sized voids, and Ba 2+ occupies large voids, and cooperatively fills the glass voids, which can improve the uniformity of ion diffusion. When (MgO + BaO) / SiO2 is greater than 1:7.9, excessive alkaline earth metals cause the glass to become brittle, and at the same time block the diffusion channels of Na + / K + , affecting the strengthening effect of the glass; when (MgO + BaO) / SiO2 is less than 1:15.7, the effect of filling the glass voids cannot be achieved. Therefore, (MgO + BaO) / SiO2 is limited to between 1:7.9 and 15.7.

[0023] Preferably, the mass relationship of P2O5, B2O3, SiO2 and Al2O3 satisfies: (P2O5 + B2O3) / (SiO2 + Al2O3) = 1:12.1 - 18.7. B2O3 can reduce the glass melting temperature, and P2O5 can reduce the high-temperature viscosity and improve the melting uniformity. The two work synergistically to facilitate the processing of special-shaped glass; P2O5 introduces [PO4] tetrahedrons, which cooperate with BO3 / BO4 of B2O3 to regulate the network connectivity. When (P2O5 + B2O3) / (SiO2 + Al2O3) is greater than 1:11.5, the ion exchange rate will be reduced and the strengthening effect will be weakened; when (P2O5 + B2O3) / (SiO2 + Al2O3) is less than 1:19, the effects of reducing the glass melting temperature, reducing the high-temperature viscosity and improving the melting uniformity cannot be achieved.

[0024] Another object of the present invention is achieved by the following technical solution: A strengthening process for aluminosilicate glass, comprising the following steps:

[0025] (1) First strengthening: Heat the aluminosilicate glass to 620 - 680 °C, and then perform rapid cooling treatment;

[0026] (2) Second strengthening: Heat the glass after the first strengthening to 300 - 350 °C, preheat for 1 - 2 h, put the preheated glass into the first molten salt, and strengthen at 385 - 405 °C for 3 - 4 h;

[0027] (3) Third strengthening: Put the glass after the second strengthening into the second molten salt, and strengthen at 420 - 430 °C for 8 - 10 h to obtain aluminosilicate glass.

[0028] The first strengthening improves the internal stress distribution of the glass through high-temperature heating and cooling treatment, laying a foundation for subsequent strengthening; the second and third strengthenings further optimize the stress distribution on the surface and inside of the glass through ion exchange in different molten salts, improving the impact resistance and scratch resistance of the glass. The strengthening process of the present invention combines physical strengthening and chemical strengthening, and at the same time adopts three strengthening treatments to gradually improve the hardness, toughness and fatigue resistance of the glass, so that compared with the existing chemical strengthening process only, the strength of the aluminosilicate glass after strengthening can be increased by more than 10%.

[0029] Preferably, in the step (1), the cooling rate of the rapid cooling treatment is 120 - 180 °C / s, and it is cooled to below 250 °C. After the surface layer of the glass treated by cold treatment is quickly solidified, the inside slowly shrinks, and the tensile stress and the surface compressive stress jointly form a "sandwich" structure, significantly enhancing the bending strength and impact resistance of the glass.

[0030] Preferably, in the step (1), the cooled aluminosilicate glass is subjected to surface polishing treatment, and the polishing depth is 4-10 μm. Before chemical strengthening, polishing the surface of the aluminosilicate glass that has undergone primary physical strengthening can eliminate the surface defects of physical strengthening, remove the surface damage layer, reduce the surface roughness, and ensure the uniformity of subsequent ion exchange.

[0031] Preferably, in the step (2), the first molten salt comprises raw materials in the following mass percentages: KNO3: 64%-76%, NaNO3: 21%-31%, and nano-silica dispersion: 3%-5%. Adding nano-silica dispersion to the first molten salt can improve the fluidity of the first molten salt and increase the K + / Na + exchange rate.

[0032] Preferably, in the step (3), the second molten salt comprises raw materials in the following weight percentages: KNO3: 70%-78%, NaNO3: 16%-24%, and nano-silica dispersion: 3-7%. Adding nano-silica dispersion to the second molten salt can improve the fluidity of the first molten salt and increase the K + / Na + exchange rate.

[0033] Preferably, the particle size of the nano-silica is 10-50 nm, and the surface is modified with a silane coupling agent. The "ball bearing effect" of the modified nano-SiO2 reduces the dynamic viscosity of the molten salt by 10%-15%, improving the fluidity of the molten salt and ensuring the uniformity of ion exchange for shaped glass; at the same time, the silane groups on the surface of SiO2 form hydrogen bonds with the Si-O network in the glass, locally opening the glass structure, accelerating the dissolution of Na + and the penetration of K + , and increasing the exchange rate by 20-30%.

[0034] The beneficial effects of the present invention are as follows: The aluminosilicate glass composition of the present invention optimizes the glass network structure by precisely controlling the proportions of various components, enhancing its stability, hardness, and wear resistance. At the same time, introducing rare metal oxides such as Y2O3, ScO2, and La2O3 can fill the gaps in the glass network during glass strengthening, enhance the compactness, reduce the surface defects of the glass, effectively inhibit crack propagation, significantly improve the impact strength and toughness of the glass, and also greatly increase the depth of the compressive stress layer and the surface compressive stress, further improving the comprehensive performance of the glass.

[0035] The strengthening process of the present invention combines physical strengthening and chemical strengthening, and simultaneously adopts three strengthening treatments to gradually improve the hardness, toughness, and fatigue resistance of the glass. Compared with the existing chemical strengthening process alone, the strength of the aluminosilicate glass after strengthening can be increased by more than 10%. Detailed implementation mode

[0036] For the convenience of understanding by those skilled in the art, the present invention will be further described below in conjunction with embodiments. The content mentioned in the implementation mode does not limit the present invention.

[0037] Embodiment 1

[0038] An aluminosilicate glass composition, comprising components in the following mass percentages: SiO2: 57%, Al2O3: 18%, Na2O: 3.8%, K2O: 7.2%, Li2O: 2.3%, MgO: 2%, BaO: 1.8%, P2O5: 3.7%, B2O3: 2.3%, Y2O3: 1.2%, ScO2: 0.2% and La2O3: 0.5%.

[0039] A strengthening process for aluminosilicate glass, comprising the following steps:

[0040] (1) First strengthening: heating the aluminosilicate to 620 °C to obtain heated glass, and then performing rapid cooling treatment;

[0041] (2) Second strengthening: heating the glass after the first strengthening to 300 °C, preheating for 2 h, putting the preheated glass into the first molten salt, and strengthening at 385 °C for 4 h;

[0042] (3) Third strengthening: putting the glass after the second strengthening into the second molten salt, and strengthening at 420 °C for 10 h to obtain aluminosilicate glass.

[0043] In step (1), the cooling rate of the cooling treatment is 120 °C / s. The aluminosilicate glass after the strengthening cooling in step (1) is subjected to surface polishing treatment, and the polishing depth is 4 μm.

[0044] In step (2), the first molten salt comprises components in the following mass percentages: KNO3: 64%, NaNO3: 31% and nano-silica dispersion: 5%.

[0045] In step (3), the second molten salt comprises components in the following mass percentages: KNO3: 70%, NaNO3: 24% and nano-silica dispersion: 6%.

[0046] Embodiment 2

[0047] An aluminosilicate glass composition comprising components in the following mass percentages: SiO2: 60%, Al2O3: 16%, Na2O: 3.4%, K2O: 6%, Li2O: 3.4%, MgO: 3%, BaO: 2.8%, P2O5: 2.4%, B2O3: 1.5%, Y2O3: 0.7%, ScO2: 0.5% and La2O3: 0.3%.

[0048] A strengthening process for an aluminosilicate glass, comprising the following steps:

[0049] (1) First strengthening: heating the aluminosilicate to 650 °C and then performing a rapid cooling treatment;

[0050] (2) Second strengthening: heating the glass after the first strengthening to 325 °C, preheating for 1.5 h, placing the preheated glass in a first molten salt, and strengthening at 395 °C for 3.5 h.

[0051] (3) Third strengthening: placing the glass after the second strengthening in a second molten salt and strengthening at 425 °C for 9 h to obtain the aluminosilicate glass.

[0052] In step (1), the cooling rate of the cooling treatment is 150 °C / s. The aluminosilicate glass after the strengthening cooling in step (1) is subjected to a surface polishing treatment, and the polishing depth is 7 μm.

[0053] In step (2), the first molten salt comprises components in the following mass percentages: KNO3: 70%, NaNO3: 26% and nano-silica dispersion: 4%.

[0054] In step (3), the second molten salt comprises components in the following mass percentages: KNO3: 74%, NaNO3: 21.5% and nano-silica dispersion: 4.5%.

[0055] Example 3

[0056] An aluminosilicate glass composition comprising components in the following mass percentages: SiO2: 63%, Al2O3: 14%, Na2O: 3%, K2O: 3.8%, Li2O: 5.5%, MgO: 4%, BaO: 3.8%, P2O5: 1.1%, B2O3: 0.7%, Y2O3: 0.2%, ScO2: 0.8% and La2O3: 0.1%.

[0057] A strengthening process for an aluminosilicate glass, comprising the following steps:

[0058] (1) First strengthening: heating the aluminosilicate to 680 °C to obtain a heated glass, and cooling the heated glass.

[0059] (2) Second strengthening: Heat the once-strengthened glass to 350 °C, preheat for 2 h, put the preheated glass into the first molten salt, and strengthen it at 405 °C for 3 h;

[0060] (3) Third strengthening: Put the twice-strengthened glass into the second molten salt, and strengthen it at 430 °C for 8 h to obtain aluminosilicate glass.

[0061] In step (1), the cooling rate of the cooling treatment is 180 °C / s. After the aluminosilicate glass is strengthened and cooled in step (1), surface polishing treatment is carried out, and the polishing depth is 10 μm.

[0062] In step (2), the first molten salt includes the following mass percentage components: KNO3: 76%, NaNO3: 21%, and nano-silica dispersion: 3%.

[0063] In step (3), the second molten salt includes the following mass percentage components: KNO3: 78%, NaNO3: 19%, and nano-silica dispersion: 3%.

[0064] Comparative Examples 1-4

[0065] The components of the aluminosilicate glass in Comparative Examples 1-4 are shown in the following table, and the strengthening process is the same as that of Example 2.

[0066] Component / % Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 <![CDATA[SiO2]]> 59.4 62.4 58.1 61.4 <![CDATA[Al2O3]]> 15.2 14.9 15.3 17.1 <![CDATA[Na2O]]> 5.3 4.2 4.5 3.3 <![CDATA[K2O]]> 5.6 3.2 6.3 5.4 <![CDATA[Li2O]]> 4.5 3.9 4.3 2.4 MgO 1.9 2.3 3.2 2.9 BaO 3.1 1.9 2.4 2.2 <![CDATA[P2O5]]> 3.2 3.9 3.1 3.4 <![CDATA[B2O3]]> 1.8 2.1 2.3 1.4 <![CDATA[Y2O3]]> — 1.2 — — <![CDATA[ScO2]]> — — 0.5 — <![CDATA[La2O3]]> — — — 0.5

[0067] Comparative Example 5

[0068] The difference between Comparative Example 5 and Example 2 above is that the first step of strengthening in step (1) is not carried out.

[0069] Comparative Example 6

[0070] The difference between Comparative Example 6 and Example 2 above is that the nano-silica dispersion is not added to the first molten salt in step (2) and the second molten salt in step (3).

[0071]

[0072] As can be seen from the above table, the aluminosilicate glass prepared in Examples 1-3 of the present invention optimizes the glass network structure by precisely controlling the proportion of each component, thereby improving its stability, hardness and wear resistance. At the same time, by introducing rare metal oxides such as Y2O3, ScO2 and La2O3, compared with Comparative Examples 1-4, when the glass is strengthened, it can fill the gaps in the glass network, enhance the compactness, reduce the surface defects of the glass, effectively inhibit the crack propagation, significantly improve the impact strength and toughness of the glass, and can also greatly increase the depth of the compressive stress layer and the surface compressive stress, further improving the comprehensive performance of the glass.

[0073] The strengthening process of Embodiments 1-3 of the present invention combines physical strengthening with chemical strengthening and adopts three strengthening treatments simultaneously to gradually improve the hardness, toughness and fatigue resistance of the glass, so that the strength of the aluminosilicate glass composition after strengthening can be increased by more than 10% compared with Comparative Example 5 that only adopts the chemical strengthening process; at the same time, a nano-silica dispersion modified by an alkane coupling agent is introduced into the first molten salt and the second molten salt, which can improve the fluidity of the molten salt and the K + / Na + exchange rate compared with Example 6 without adding this dispersion, thereby improving the mechanical properties of the aluminosilicate glass composition.

[0074] The above embodiments are preferred implementation schemes of the present invention. In addition, the present invention can also be implemented in other ways. Any obvious replacement without departing from the concept of the present invention is within the protection scope of the present invention.

Claims

1. An aluminosilicate glass composition, characterized in that: The aluminosilicate glass composition comprises components in the following mass percentages: SiO2: 55.3% - 64.8%, Al2O3: 12.4% - 19.7%, Na2O: 2.1% - 4.4%, K2O: 3.2% - 8.6%, Li2O: 1.9% - 6.5%, MgO: 1.5% - 5%, BaO: 1.5% - 4.2%, P2O5: 0.8% - 4.5%, B2O3: 0.5% - 2.5%, Y2O3: 0.1 - 1.5%, ScO2: 0.1% - 1% and La2O3: 0.05% - 0.8%; wherein, the mass relationship of Y2O3, ScO2 and La2O3 satisfies: 0.8 ≤ Y2O3 + ScO2 + La2O3 ≤ 3.

2.

2. The aluminosilicate glass composition according to claim 1, wherein: The aluminosilicate glass composition comprises components in the following mass percentages: SiO2: 57% - 63%, Al2O3: 14% - 18%, Na2O: 3% - 3.8%, K2O: 3.8% - 7.2%, Li2O: 2.3% - 5.5%, MgO: 2% - 4%, BaO: 1.8% - 3.8%, P2O5: 1.1% - 3.7%, B2O3: 0.7% - 2.3%, Y2O3: 0.2% - 1.2%, ScO2: 0.2% - 0.8% and La2O3: 0.1% - 0.5%; wherein, the mass relationship of Y2O3, ScO2 and La2O3 satisfies: 1 ≤ Y2O3 + ScO2 + La2O3 ≤ 2.

5.

3. An aluminosilicate glass composition according to claim 1, characterized in that: The mass relationship of MgO, BaO and SiO2 satisfies: (MgO + BaO) / SiO2 = 1:7.9 - 15.

7.

4. An aluminosilicate glass composition according to claim 1, wherein: The mass relationship of P2O5, B2O3, SiO2 and Al2O3 satisfies: (P2O5 + B2O3) / (SiO2 + Al2O3) = 1:12.1 - 18.

7.

5. A strengthening process for aluminosilicate glass, characterized in that: It includes the following steps: (1) First strengthening: Heat the aluminosilicate glass to 620 - 680 °C, and then perform rapid cooling treatment; (2) Second strengthening: Heat the glass after the first strengthening to 300 - 350 °C, preheat for 1 - 2 h, put the preheated glass into the first molten salt, and strengthen at 385 - 405 °C for 3 - 4 h; (3) Third strengthening: Put the glass after the second strengthening into the second molten salt, and strengthen at 420 - 430 °C for 8 - 10 h to obtain the aluminosilicate glass.

6. The strengthening process of an aluminosilicate glass according to claim 5, characterized in that: In the step (1), the cooling rate of the rapid cooling treatment is 120 - 180 °C / s, and it is cooled to below 250 °C.

7. The strengthening process of an aluminosilicate glass according to claim 5, characterized in that: In the step (1), the surface of the cooled aluminosilicate glass is polished, and the polishing depth is 4 - 10 μm.

8. The strengthening process of an aluminosilicate glass according to claim 5, characterized in that: In the step (2), the first molten salt comprises raw materials in the following mass percentages: KNO3: 64% - 76%, NaNO3: 21% - 31% and nano - silica dispersion liquid: 3% - 5%.

9. The strengthening process of an aluminosilicate glass according to claim 5, characterized in that: In the step (3), the second molten salt comprises raw materials in the following mass percentages: KNO3: 70% - 78%, NaNO3: 16% - 24% and nano - silica dispersion liquid: 3 - 7%.

10. The strengthening process of an aluminosilicate glass according to claim 8 or 9, characterized in that: The particle size of the nano-silica is 10 - 50 nm, and the surface is modified with a silane coupling agent.

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