阅读说明：本技术 一种晶种增韧锂铝硅酸微晶玻璃复合材料及其制备方法 (Crystal toughened lithium-aluminum-silicate microcrystalline glass composite material and preparation method thereof ) 是由 李青 李赫然 田鹏 闫智勇 王博 郝艺 闫冬成 史伟华 胡恒广 于 2020-12-09 设计创作，主要内容包括：本公开涉及一种晶种增韧锂铝硅酸微晶玻璃组合物及其制备方法,其中,以微晶玻璃组合物的总重量为基准,所述微晶玻璃中含有50-68％重量份的SiO_2、8-25％重量份的Al_2O_3、3-8％重量份的Na_2O、5-10％重量份的Li_2O、0-2％重量份的MgO、3-5％重量份的CaO、0-5％重量份的SrO、1-4％重量份的ZrO_2、0-5％重量份的P_2O_5和0-2％重量份的TiO_2；所述ZrO_2形成晶相氧化锆。该微晶玻璃组合物透光率较高、断裂韧性好、具有良好的抗划伤与抗跌落性能。(The invention relates to a crystal toughening lithium aluminosilicate microcrystalline glass composition and a preparation method thereof, wherein the microcrystalline glass contains 50-68 wt% of SiO (silicon dioxide) based on the total weight of the microcrystalline glass composition 2 8-25% by weight of Al 2 O 3 3-8% of Na 2 O, 5-10% by weight of Li 2 O, 0-2% of MgO, 3-5% of CaO, 0-5% of SrO and 1-4%ZrO in parts by weight 2 0-5% by weight of P 2 O 5 And 0-2% by weight of TiO 2 (ii) a The ZrO 2 Crystal phase zirconia is formed. The microcrystalline glass composition has high light transmittance, good fracture toughness and good scratch resistance and drop resistance.)

1. Crystal toughening lithium aluminosilicate microcrystalThe glass composition is characterized in that the microcrystalline glass contains 50-68 wt% of SiO based on the total weight of the microcrystalline glass composition₂8-25% by weight of Al₂O₃3-8% of Na₂O, 5-10% by weight of Li₂O, 0-2% of MgO, 3-5% of CaO, 0-5% of SrO and 1-4% of ZrO₂0-5% by weight of P₂O₅And 0-2% by weight of TiO₂(ii) a The ZrO₂Crystal phase zirconia is formed.

2. The composition of claim 1, wherein the crystalline phase zirconia is at least one of cubic, monoclinic, and tetragonal phase zirconia.

3. The glass-ceramic composition according to claim 1, wherein the glass-ceramic preferably contains 54-66% by weight of SiO based on the total weight of the glass-ceramic composition₂10-22% by weight of Al₂O₃4-7% of Na₂O, 6-9% by weight of Li₂O, 0.1-1.8% MgO, 3.2-4.6% CaO, 1-4% SrO, 1.2-3.8% ZrO₂1-4% by weight of P₂O₅And 0.2 to 1.5 weight percent of TiO₂。

4. The microcrystalline glass composition of claim 1, wherein the ZrO₂The crystal is a nano crystal, and the size of the crystal is below 10 nm.

5. The microcrystalline glass composition of claim 1, wherein the microcrystalline glass composition further comprises a fining agent, wherein the fining agent comprises at least one of salt cake, tin oxide, stannous oxide, cerium oxide, and sodium oxide.

6. The microcrystalline glass composition of claim 1, whereinAl mentioned above₂O₃、Li₂O、Na₂The O component is such that₂O₃-Li₂O-Na₂O is between-2% and 16%; ZrO (ZrO)₂/Al₂O₃Between 4 and 45%; ZrO (ZrO)₂/(Na₂O+Li₂O) is between 12 and 45%.

7. The method for producing a microcrystalline glass composition according to claim 1, wherein said production method comprises the steps of:

s1, adding SiO₂、Al₂O₃、Na₂O、Li₂O、MgO、CaO、SrO、ZrO₂、P₂O₅And TiO₂Mixing the raw materials, and heating and melting to obtain a first material;

s2, pouring the first material to form a blocky glass product to obtain a second material;

s3, annealing the second material in an annealing furnace to obtain a third material;

s4, carrying out heat treatment on the third material to obtain a fourth material containing crystal phase zirconium oxide;

and S5, performing chemical strengthening treatment on the fourth material containing the crystal phase zirconium oxide.

8. The production method according to claim 7, wherein the heating and melting conditions in step 1 include: the temperature is 1550-1650 ℃, and the time is 6-8 h; the annealing treatment conditions in the step 3 comprise: the temperature is 450-650 ℃, and the time is 1-3 h; the heat treatment conditions in step 4 include: the temperature is 550-900 ℃ and the time is 1-24 h.

9. The method of claim 7, wherein the chemical strengthening treatment comprises a one-step ion exchange process and a two-step ion exchange process, the one-step ion exchange process comprising: carrying out first soaking on the fourth material in first molten salt; the first molten salt is 100% KNO₃Molten salt, the condition of the first soaking is at 460 DEG CSoaking for 4 h; the two-step ion exchange process comprises the following steps: performing second soaking on the fourth material in second molten salt, and then performing third soaking in third molten salt; the second molten salt is 75% KNO₃+25％NaNO₃(wt%) solution, the second soaking condition is soaking for 8h at 480 ℃;

the third molten salt is 30% KNO₃+20％K₂CO₃+ 25% KCl + 25% KOH (wt%) solution, said third soaking condition being soaking at 440 ℃ for 2 h.

10. Use of the microcrystalline glass composition according to any one of claims 1-6 or the microcrystalline glass composition prepared by the preparation method according to any one of claims 7-9 for preparing electronic equipment, buildings and/or vehicles.

Technical Field

The disclosure relates to the field of glass ceramic composite materials, in particular to a seed type toughened lithium aluminum silicate glass ceramic composite material and a preparation method thereof.

Background

With the increasing approach of 5G communication, the whole mobile phone appearance industry is undergoing a great revolution. At present, the traditional mobile phone appearance piece is mainly made of metal materials, but the metal materials have a shielding effect on mobile phone signals and conflict with 5G communication, meanwhile, the requirements of the market on the appearance, the texture and the like of the mobile phone appearance piece are higher and higher, and glass and ceramic materials stand out under a series of development trends. Compared with ceramic materials, glass has the advantages of wide raw material source, low hardness, easy surface treatment, richer colors and the like, and has great market potential. However, conventional glass is highly brittle and susceptible to microcracking, which can reduce the actual mechanical strength by 2 to 3 orders of magnitude from the theoretical mechanical strength.

Glass ceramics are a material consisting of a microcrystalline phase and a glassy phase and having a uniform and dense structure. Generally, a microcrystalline glass can be obtained by uniformly eluting a large number of fine crystals from a certain nucleating substance in a glass by means of heat treatment or the like to form a dense multiphase complex of a microcrystalline phase and a glass phase. The mechanical property of the glass is intervened between the glass and the ceramic, the average hardness, the breaking strength and the fracture toughness of the glass are improved, the generated microcrystal can also block or deflect a microcrack expansion path, and the falling resistance of the glass is improved. Meanwhile, aiming at the requirement of the electronic product on the transparency of the cover glass, the selected microcrystalline glass must have higher optical transmittance. However, general microcrystalline glass with high light transmittance is difficult to further perform ion exchange, and has low fracture toughness, so that the performances of scratch resistance, drop resistance and the like are difficult to further improve. Therefore, it is an urgent problem to be solved by those skilled in the art to provide a microcrystalline glass having high light transmittance and good fracture toughness.

Disclosure of Invention

The invention provides a seed toughened lithium aluminosilicate microcrystalline glass composition and a preparation method thereof.

In order to achieve the above object, the first aspect of the present disclosure provides a seed toughened lithium aluminosilicate microcrystalline glass composition, wherein the microcrystalline glass contains 50-68 wt% of SiO based on the total weight of the microcrystalline glass composition₂8-25% by weight of Al₂O₃3-8% of Na₂O, 5-10% by weight of Li₂O, 0-2% of MgO, 3-5% of CaO, 0-5% of SrO and 1-4% of ZrO₂0-5% by weight of P₂O₅And 0-2% by weight of TiO₂(ii) a The ZrO₂Crystal phase zirconia is formed.

A second aspect of the present disclosure provides a method for preparing the microcrystalline glass composition according to the first aspect, wherein the method comprises the following steps:

s1, adding SiO₂、Al₂O₃、Na₂O、Li₂O、MgO、CaO、SrO、ZrO₂、P₂O₅And TiO₂Mixing the raw materials, and heating and melting to obtain a first material;

s2, pouring the first material to form a blocky glass product to obtain a second material;

s3, annealing the second material in an annealing furnace to obtain a third material;

s4, carrying out heat treatment on the third material to obtain a fourth material containing crystal phase zirconium oxide;

and S5, performing chemical strengthening treatment on the fourth material containing the crystal phase zirconium oxide.

The third aspect of the present disclosure provides a use of the microcrystalline glass composition according to the first aspect or the microcrystalline glass composition prepared by the preparation method according to the second aspect in preparing electronic devices, buildings and/or vehicles.

Through the technical scheme, the chemically-strengthened and zirconia-toughened glass ceramic is good in hardness, breaking strength, fracture toughness and the like, and has good scratch resistance and drop resistance. Moreover, the microcrystalline glass can be chemically strengthened, so that the chemically strengthened glass with better scratch resistance and drop resistance can be obtained, and can be used as a microcrystalline glass material with high strength and hardness for the front cover of the mobile phone and also can be used as a microcrystalline glass material with high strength for the rear cover of the mobile phone.

Additional features and advantages of the disclosure will be set forth in the detailed description which follows.

Detailed Description

The following describes in detail specific embodiments of the present disclosure. It should be understood that the detailed description and specific examples, while indicating the present disclosure, are given by way of illustration and explanation only, not limitation.

In one aspect, the present disclosure provides a seed toughened lithium aluminosilicate microcrystalline glass composition, wherein the microcrystalline glass contains 50-68% by weight of the total weight of the microcrystalline glass composition% by weight of SiO₂8-25% by weight of Al₂O₃3-8% of Na₂O, 5-10% by weight of Li₂O, 0-2% of MgO, 3-5% of CaO, 0-5% of SrO and 1-4% of ZrO₂0-5% by weight of P₂O₅And 0-2% by weight of TiO₂(ii) a The ZrO₂Crystal phase zirconia is formed.

According to the present disclosure, wherein the crystalline phase zirconia is at least one of cubic crystalline phase zirconia, monoclinic crystalline phase zirconia, and tetragonal crystalline phase zirconia.

ZrO₂There are three crystalline forms in the glass, namely cubic (c-ZrO)₂) Monoclinic type (m-ZrO)₂) Square type (t-ZrO)₂) A monoclinic (m-ZrO) form with a crystal form change when heated to 1170 DEG C₂) Converted into square (t-ZrO)₂) The volume is contracted; square type (t-ZrO) when cooling₂) Transformation into monoclinic form (m-ZrO)₂) The volume expands. Usually ZrO₂During the heat treatment of the microcrystalline glass, tetragonal form (t-ZrO) is firstly precipitated₂)。ZrO₂The toughening mode of the microcrystalline glass mainly comprises the following steps: stress induced phase change toughening, phase change induced micro-crack toughening and micro-crack deflection toughening. This depends to a large extent on the degree of transformation and the location where the transformation occurs. Using ZrO₂The transformation of the crystal phase causes micro-cracks in the matrix, thereby absorbing the energy of crack propagation, weakening or preventing the crack propagation, achieving the effect of toughening, and simultaneously improving the strength of the glass. 1-4% ZrO in this disclosure₂The fracture toughness of the toughened microcrystalline glass can reach 3.8 MPa.m^1/23-4 times higher than the same material without zirconia.

According to the disclosure, the microcrystalline glass preferably contains 54-66% by weight of SiO based on the total weight of the microcrystalline glass composition₂10-22% by weight of Al₂O₃4-7% of Na₂O, 6-9% by weight of Li₂O, 0.1-1.8% of MgO, 3.2-4.6% of CaO, 1-4% of SrO and 1.2-3.8% ofZrO₂1-4% by weight of P₂O₅And 0.2 to 1.5 weight percent of TiO₂。

According to the disclosure, wherein the ZrO₂The crystal is a nano crystal, and the size of the crystal is below 10 nm.

According to the disclosure, the microcrystalline glass composition further contains a fining agent, and the fining agent can be decomposed at high temperature in the glass melting process, gasified to generate gas or reduce the viscosity of glass, so that bubbles in molten glass are eliminated, and a better melting effect is achieved. The clarifying agent is a clarifying agent conventional in the art, such as mirabilite, stannic oxide, stannous oxide, cerium oxide, sodium oxide, and the like, and is not further limited.

According to the present disclosure, wherein the Al₂O₃、Li₂O、Na₂The O component is such that₂O₃-Li₂O-Na₂O is between-2% and 16%; ZrO (ZrO)₂/Al₂O₃Between 4 and 45%; ZrO (ZrO)₂/(Na₂O+Li₂O) is between 12 and 45%.

＝Al₂O₃-Li₂O-Na₂O is between-2% and 16%, so that the melting temperature of the glass can be effectively reduced, the solubility of the zirconia in the base glass is improved, and the zirconia is crystal-phase zirconia;

by controlling Al in the microcrystalline glass₂O₃、ZrO₂、Li₂O、Na₂Correlation between O so that ZrO₂/Al₂O₃Between 4 and 45% ZrO₂/(Na₂O+Li₂O) is between 12 and 45 percent, and the network intermediate and the network modifier in the system can be adjusted, thereby adjusting Li⁺、Na⁺The ion existing state in the glass effectively controls ZrO₂Is crystallized to prepare the ZrO₂The glass is microcrystalline glass with a crystalline phase, so that the performance of the glass is improved.

In another aspect, the present disclosure provides a method for preparing the microcrystalline glass composition according to the first aspect, wherein the method comprises the following steps:

s1, adding SiO₂、Al₂O₃、Na₂O、Li₂O、MgO、CaO、SrO、ZrO₂、P₂O₅And TiO₂Mixing the raw materials, and heating and melting to obtain a first material;

s2, pouring the first material to form a blocky glass product to obtain a second material;

s3, annealing the second material in an annealing furnace to obtain a third material;

s4, carrying out heat treatment on the third material to obtain a fourth material containing crystal phase zirconium oxide;

and S5, performing chemical strengthening treatment on the fourth material containing the crystal phase zirconium oxide.

According to the present disclosure, the conditions of the heating and melting in step 1 include: the temperature is 1550-1650 ℃, and the time is 6-8 h; the specific melting temperature and melting time can be determined by those skilled in the art according to practical situations, which are well known to those skilled in the art and will not be described herein.

The annealing treatment conditions in the step 3 comprise: the temperature is 450-650 ℃, and the time is 1-3 h; the specific annealing temperature and annealing time can be determined by those skilled in the art according to practical situations, which are well known to those skilled in the art and will not be described herein.

The heat treatment conditions in step 4 include: the temperature is 550-900 ℃ and the time is 1-24 h. The specific heat treatment temperature and time can be determined by those skilled in the art according to practical situations, which are well known to those skilled in the art and will not be described herein.

According to the present disclosure, the chemical strengthening treatment includes a one-step ion exchange process and a two-step ion exchange process, the one-step ion exchange process including: carrying out first soaking on the fourth material in first molten salt; the first molten salt is 100% KNO₃Fused salt, wherein the first soaking condition is soaking for 4 hours at 460 ℃; the two-step ion exchange process comprises the following steps: second soaking the fourth material in second molten salt, and then carrying out third soakingPerforming third soaking in molten salt; the second molten salt is 75% KNO₃+25％NaNO₃(wt%) solution, the second soaking condition is soaking for 8h at 480 ℃;

the third molten salt is 30% KNO₃+20％K₂CO₃+ 25% KCl + 25% KOH (wt%) solution, said third soaking condition being soaking at 440 ℃ for 2 h.

As described above, since the main crystal in the microcrystalline glass is ZrO₂Crystals, free of ions participating in ion exchange. Therefore, the content of alkali metal ions in the glass phase is high, and ion exchange can be efficiently performed. And due to ZrO of the microcrystalline glass₂During the precipitation of crystals, the [ ZrO ] is transferred along with alkali metal ions₆]Na around octahedron⁺Ions will be transferred to [ ZrO ]₄]Around the tetrahedron, the ion exchange layer depth can be increased.

In another aspect, the present disclosure provides a use of the microcrystalline glass composition according to the first aspect or the microcrystalline glass composition prepared by the preparation method according to the second aspect in preparing electronic devices, buildings and/or vehicles.

The present disclosure is further illustrated by the following examples, but is not to be construed as being limited thereby.

Examples 1 to 5 and comparative examples 1 to 2

The components in examples and comparative examples were weighed according to the glass compositions shown in tables 1-2, mixed well, and the mixture was poured into a platinum crucible, and then heated for 7 hours in a high temperature furnace at 1620 ℃ and stirred using a platinum rod to discharge bubbles. Pouring the molten glass into a stainless steel cast iron mold, forming into a specified block-shaped glass product, then annealing the glass product in an annealing furnace at 610 ℃ for 1h, and turning off a power supply to cool the glass product to 25 ℃ along with the furnace. The glass article was cut, ground, polished and the polished glass intermediate sample 50X 0.7 mm.

The glass intermediate sample of 50X 0.7mm was heat-treated at 640 deg.C/10 h and 680 deg.C/10 h, respectively. The other preparation processes in the respective examples are the same except for the heat treatment process and the components.

The one-step ion exchange process comprises the following steps: at 100% KNO₃Fused salt, soaking for 4h at 460 ℃; the two-step ion exchange process comprises the following steps: first, at 75% KNO₃+25％NaNO₃(wt%) soaking the solution at 480 ℃ for 8 h; second, at 30% KNO₃+20％K₂CO₃+ 25% KCl + 25% KOH (wt%) solution, soaking at 440 deg.C for 2 h. Except for the above process, other chemical strengthening preparation processes in the respective embodiments are the same.

The AP in each example of table 1 represents the original sample. AP1 is a lithium aluminosilicate glass produced with the composition of the corresponding example, which was not heat treated and did not contain ZrO₂And (4) crystals. AP2 is the chemically strengthened glass obtained after chemically strengthening (ion exchanging) the lithium aluminosilicate glass AP1 of the corresponding example.

The obtained glass-ceramic (before ion exchange) is tested for vickers hardness and fracture toughness by a conventional testing instrument, and the chemically strengthened lithium aluminosilicate glass, as well as the chemically strengthened glass (after ion exchange) for vickers hardness, fracture toughness, surface tensile stress and stress depth of layer are tested.

TABLE 1

From the test results in table 1, it is understood that the microcrystalline glass of the present invention has higher vickers hardness and better fracture toughness than the lithium aluminosilicate glass AP1 by any of the treatment processes. The Vickers hardness of the lithium aluminosilicate glass AP1 is 571 and 582Kgf/mm²The Vickers hardness of the glass ceramics can reach 610-²The Vickers hardness is obviously improved compared with AP 1. The fracture toughness of AP1 is 1.01-1.09 MPa.m^1/2In the embodiments of the present disclosure, the microcrystalline glassThe fracture toughness of the glass can reach 1.26-1.39 MPa.m^1/2The fracture toughness is obviously improved compared with AP 1.

The chemically strengthened glass ceramics of the present disclosure have a higher vickers hardness than the lithium aluminosilicate glass AP2, regardless of the ion exchange process employed. The Vickers hardness of the lithium aluminosilicate glass after one-step chemical strengthening is 650-679Kgf/mm²The Vickers hardness of the chemically strengthened glass can reach 740-788Kgf/mm²(ii) a The Vickers hardness of the AP2 is 730-²The Vickers hardness of the chemically strengthened glass can reach 770-812Kgf/mm². Therefore, the Vickers hardness of the AP2 is further improved than that of the chemically strengthened AP2 in the previous examples.

Compared with the lithium aluminosilicate glass AP2, no matter which ion exchange process is adopted, the chemically strengthened glass ceramics disclosed by the invention have higher fracture toughness, and the fracture toughness of AP2 after one-step chemical strengthening is 1.19-1.45 MPa.m^1/2In the embodiment of the disclosure, the fracture toughness of the chemically strengthened microcrystalline glass can reach 1.82-2.66MPa · m^1/2(ii) a The fracture toughness of the AP2 is 1.29-1.88 MPa.m after the two-step chemical strengthening^1/2In the embodiment of the disclosure, the fracture toughness of the chemically strengthened microcrystalline glass can reach 1.42-2.66 MPa.m^1/2. Therefore, the fracture toughness of the chemically strengthened glass AP2 in the foregoing examples is higher than that of the glass-ceramic AP 1.

Compared with the lithium aluminosilicate glass AP2, no matter which ion exchange process is adopted, the surface stress value of the chemically strengthened glass-ceramic disclosed by the invention is higher, the surface stress of the AP2 after one-step chemical strengthening is 802-925 MPa, and the surface stress of the chemically strengthened glass-ceramic in the embodiment disclosed by the invention can reach 848-925 MPa; the surface stress of the AP2 after the two-step chemical strengthening is 968-1013MPa, and the surface stress of the microcrystalline glass after the chemical strengthening in the embodiment of the disclosure can reach 987-1025 MPa;

compared with the lithium aluminosilicate glass AP2, the chemically strengthened glass of the chemically strengthened glass-ceramic disclosed by the invention has deeper stress depth which can reach 77 mu m at most no matter which ion exchange process is adopted.

Compared with the conventional lithium aluminosilicate glass, the crystalline phase zirconia toughened microcrystalline glass provided by the disclosure has better performances such as breaking strength, fracture toughness and hardness. Secondly, due to ZrO₂The size of the crystals is much lower than the visible wavelength range, and ZrO₂The crystal is colorless and transparent, the refractive index is close to that of glass, and the degree of reflection, refraction, birefringence and absorption of light is controllable when the light passes through the glass, so that the microcrystalline glass has higher transmittance in a visible light wave band, which can reach more than 85 percent, and further can reach more than 88 percent. The glass ceramics are characterized in that the strength of the glass can be further enhanced by chemically strengthening by ion exchange, as compared with the characteristic that general glass ceramics are difficult to ion exchange. In addition, the microcrystalline glass has a large depth of a tensile stress layer formed in the subsequent chemical strengthening process, so that the mechanical properties such as surface hardness, breaking strength and fracture toughness are further improved.

The microcrystalline glass or the microcrystalline glass prepared by the preparation method provided by the disclosure has higher light transmittance, good fracture toughness and obviously improved Vickers hardness and surface compressive stress.

The preferred embodiments of the present disclosure have been described in detail above, however, the present disclosure is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present disclosure within the technical idea of the present disclosure, and these simple modifications all fall within the protection scope of the present disclosure.

It should be noted that, in the foregoing embodiments, various features described in the above embodiments may be combined in any suitable manner, and in order to avoid unnecessary repetition, various combinations that are possible in the present disclosure are not described again.

In addition, any combination of various embodiments of the present disclosure may be made, and the same should be considered as the disclosure of the present disclosure, as long as it does not depart from the spirit of the present disclosure.