Aluminosilicate glass with excellent mechanical properties

Abstract

The invention discloses aluminosilicate glass with excellent mechanical properties, which belongs to the field of glass and comprises the following oxides: 42 to 45 mol.% of SiO2, 16 to 18 mol.% of Al2O3, 8 to 9 mol.% of B2O3, 14 to 16 mol.% of MgO, 13 to 15 mol.% of CaO, 2 to 4 mol.% of SrO and 2 to 4 mol.% of BaO. The elastic modulus of the aluminosilicate glass is 90 to 94 GPa, the Vickers hardness is 650 to 660 kg / mm < 2 >, the fracture toughness is 0.9 to 1.0 MPa * m < 1 / 2 >, the three-point breaking strength is 130 to 140 MPa, and the strain point is 640 to 660 DEG C. The glass can be used as cover plate glass in the field of electronic information display.

Description

Technical Field

[0001] The invention belongs to the field of glass, and in particular relates to aluminosilicate glass with excellent mechanical properties. Background Art

[0002] Glasses with high hardness, high Young's modulus, and high fracture toughness are widely used in electronic display screen protective covers for smartphones, laptops, tablets, and wearable devices because they are highly resistant to scratches and sharp contact damage. The cover glass is the outermost layer of the electronic display and is also the most vulnerable part of the wearable device to external environments. Higher hardness, Young's modulus, and fracture toughness can reduce the thickness of the glass while maintaining sufficient durability. In order to enhance the strength of traditional cover glass, such as soda-lime silicate (Na2O-CaO-SiO2) glass and alkali-aluminum silicate (R2O-Al2O3-SiO2) glass, chemical strengthening methods are widely used to improve their mechanical properties through an ion exchange process. However, once the glass is chemically strengthened, it is difficult to reprocess and the shape design is limited; more importantly, chemical strengthening only changes the surface stress distribution, not the internal structure. Therefore, it is of great significance to design and prepare glass with excellent mechanical properties that does not require tempering and has high hardness, high Young's modulus, and high fracture toughness. Summary of the invention

[0003] In order to obtain a cover glass for electronic information display which does not require tempering and has high hardness, high Young's modulus and high fracture toughness, the present invention provides an aluminosilicate glass with excellent mechanical properties.

[0004] The purpose of the present invention can be achieved through the following technical solutions:

[0005] The invention discloses an aluminosilicate glass with excellent mechanical properties, comprising the following oxide composition: 42-45 mol% SiO2, 16-18 mol% Al2O3, 8-9 mol% B2O3, 14-16 mol% MgO, 13-15 mol% CaO, 2-4 mol% SrO and 2-4 mol% BaO.

[0006] Wherein, the total amount of (MgO+CaO+SrO+BaO) is 30-35 mol.%; the molar ratio of (MgO+CaO) / (SrO+BaO) is 4-8.

[0007] Preferably, the aluminosilicate glass contains the following oxide composition: 43-44 mol.% SiO2, 16-17 mol.% Al2O3, 8-8.5 mol.% B2O3, 14-15 mol.% MgO, 13-14 mol.% CaO, 2-3 mol.% SrO, 2-3 mol.% BaO. The total amount of (MgO+CaO+SrO+BaO) is 31-34 mol.%; the molar ratio of (MgO+CaO) / (SrO+BaO) is 4.5-7.5.

[0008] The glass component does not contain alkali metal oxides, such as Li2O, Na2O, K2O, etc. This effectively avoids the diffusion process of alkali metal ions in the glass to the film layer to which it is attached when the glass is used under high temperature conditions, thereby avoiding the film layer short circuit problem caused by alkali metal ions and improving the stability of the glass and its components.

[0009] The elastic modulus of the aluminosilicate glass is 90-94 GPa, and the Vickers hardness is 650-660 kg / mm 2 , fracture toughness is 0.9-1.0MPa*m 1 / 2 , the three-point flexural strength is 130-140MPa, and the strain point is 640-660℃.

[0010] The method for preparing aluminosilicate glass comprises the following steps:

[0011] (1) Mix the components according to the above ratio; (2) First, raise the temperature from room temperature to 1200°C at a rate of 3°C / min and keep it warm for 2 hours; then raise the temperature from 1200°C to 1500°C at a rate of 2°C / min and keep it warm for 3 hours; (3) Pour the completely melted glass liquid onto a copper plate for shaping, and place it in an annealing furnace for annealing at a temperature of 700°C for 1 hour. Finally, the sample is cooled to room temperature in the furnace to obtain the aluminosilicate glass.

[0012] Beneficial effects of the present invention:

[0013] The biggest difference between the glass oxide composition provided by the present invention and the traditional silicate glass is the increase in the number of main components of the system and the increase in mixing entropy. Traditional oxide glass is usually dominated by one or two components, and the type of coordinated atoms is relatively single. Once the initial crack is formed under the action of external force, due to the structural similarity, the crack tip is more likely to extend rapidly in a direction close to a straight line. However, the glass composition provided by the present invention has a relatively close content of each component in the system, which increases the diversity of coordinated atoms and makes the interaction between atoms more complex. The complex interaction between atoms will increase the resistance of the crack tip to linear expansion, resulting in the bending growth of the crack. The bending expansion of the crack can slow down the linear release of stress, so that the glass has excellent mechanical properties without the need for tempering. DETAILED DESCRIPTION

[0014] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0015] Aluminosilicate glass with excellent mechanical properties, the specific implementation steps are as follows:

[0016] (1) According to the glass composition in Table 1, various raw materials are fully and uniformly mixed; (2) First, the temperature is raised from room temperature to 1200°C at a rate of 3°C / min and kept at this temperature for 2 hours; then, the temperature is raised from 1200°C to 1500°C at a rate of 2°C / min and kept at this temperature for 3 hours; (3) The completely melted glass liquid is poured onto a copper plate for forming, and is placed in an annealing furnace for annealing at a temperature of 700°C for 1 hour. Finally, the sample is cooled to room temperature in the furnace to obtain an aluminosilicate glass with excellent mechanical properties.

[0017] In the following embodiments and comparative examples: the elastic modulus of glass was measured using a glass elastic modulus tester in accordance with ASTM C-623, and the unit was GPa; the flexural strength of glass was measured using a test method for bending strength of glass material in accordance with JC / T 676-1997, and the unit was MPa; the strain point of glass was measured using a three-point tester in accordance with ASTM C-336, and the unit was ℃.

[0018] Table 1 Comparison of specific composition and performance indicators of the embodiments and comparative examples

[0019]

[0020]

[0021] From the data in Table 1, it can be seen that the glass composition of the present invention has an elastic modulus of 90 to 94 GPa and a Vickers hardness of 650 to 660 kg / mm 2 , fracture toughness is 0.9-1.0MPa*m 1 / 2 , the three-point flexural strength is 130-140MPa, and the strain point is 640-660℃.

[0022] The above contents are merely examples and explanations of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. An aluminosilicate glass with excellent mechanical properties, characterized in that: It contains the following oxide composition: 42-45 mol.% SiO2, 16-18 mol.% Al2O3, 8-9 mol.% B2O3, 14-16 mol.% MgO, 13-15 mol.% CaO, 2-4 mol.% SrO, and 2-4 mol.% BaO.

2. The aluminosilicate glass with excellent mechanical properties according to claim 1, characterized in that: The total amount of (MgO+CaO+SrO+BaO) is 30-35 mol.%; the molar ratio of (MgO+CaO) / (SrO+BaO) is 4-8.

3. The aluminosilicate glass with excellent mechanical properties according to claim 1, characterized in that: It contains the following oxide composition: 43-44 mol.% SiO2, 16-17 mol.% Al2O3, 8-8.5 mol.% B2O3, 14-15 mol.% MgO, 13-14 mol.% CaO, 2-3 mol.% SrO, and 2-3 mol.% BaO.

4. The aluminosilicate glass with excellent mechanical properties according to claim 3, characterized in that: The total amount of (MgO+CaO+SrO+BaO) is 31-34 mol.%; the molar ratio of (MgO+CaO) / (SrO+BaO) is 4.5-7.

5.

5. The aluminosilicate glass with excellent mechanical properties according to any one of claims 1 to 4, characterized in that: The steps include: (1) mixing the components according to the above ratio; (2) raising the temperature to melt the glass at a constant temperature; (3) pouring the completely melted glass onto a copper plate to form the glass, and placing the glass in an annealing furnace for annealing. Finally, the sample is cooled to room temperature in the furnace to obtain the aluminosilicate glass.

6. The aluminosilicate glass with excellent mechanical properties according to claim 5, characterized in that: Step (2) is specifically as follows: first, the temperature is raised from room temperature to 1200°C at a rate of 3°C / min, and kept warm for 2 hours; then, the temperature is raised from 1200°C to 1500°C at a rate of 2°C / min, and kept warm for 3 hours.

7. The aluminosilicate glass with excellent mechanical properties according to claim 5, characterized in that: Annealing parameters in step (3): annealing temperature is 700° C. and time is 1 hour.

Images