An aluminosilicate glass having excellent mechanical properties

Abstract

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

Description

Technical Field

[0001] This invention belongs to the field of glass, and specifically relates to an aluminosilicate glass with excellent mechanical properties. Background Technology

[0002] Glasses with high hardness, high Young's modulus, and high fracture toughness are widely used in protective covers for electronic displays of smartphones, laptops, tablets, and wearable devices because of their excellent resistance to scratches and sharp contact damage. Cover glass is the outermost layer of an electronic display and the most vulnerable part of a wearable device to external damage. Higher hardness, Young's modulus, and fracture toughness allow for reduced glass thickness while maintaining sufficient durability. To improve the strength of traditional cover glass, such as soda-lime silicate (Na2O-CaO-SiO2) and alkali aluminosilicate (R2O-Al2O3-SiO2) glass, chemical strengthening methods are widely used, improving their mechanical properties through ion exchange processes. However, once glass has undergone chemical strengthening, it becomes difficult to reprocess, and shape design is limited; more importantly, chemical strengthening only alters the surface stress distribution, not the internal structure. Therefore, designing and fabricating glass with excellent mechanical properties—high hardness, high Young's modulus, and high fracture toughness—without the need for tempering is of great significance. Summary of the Invention

[0003] To obtain cover glass for electronic information displays that 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 objective of this invention can be achieved through the following technical solutions:

[0005] An aluminosilicate glass with excellent mechanical properties 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.

[0006] 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, and 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 composition does not contain alkali metal oxides such as Li₂O, Na₂O, and K₂O. This effectively avoids the diffusion of alkali metal ions into the attached thin film layer when the glass is used under high-temperature conditions, thereby preventing short circuits caused by alkali metal ions and improving the stability of the glass and its components.

[0009] The aluminosilicate glass has an elastic modulus of 90–94 GPa and a Vickers hardness of 650–660 kg / mm². 2 The fracture toughness is 0.9-1.0 MPa*m. 1 / 2 The three-point flexural strength is 130-140 MPa, and the strain point is 640-660℃.

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

[0011] (1) Mix the components according to the above proportions; (2) First, raise the temperature from room temperature to 1200℃ at a rate of 3℃ / min and keep it at that temperature for 2 hours; then raise the temperature from 1200℃ to 1500℃ at a rate of 2℃ / min and keep it at that temperature for 3 hours; (3) Pour the fully melted glass onto a copper plate for shaping and place it in an annealing furnace for annealing at a temperature of 700℃ for 1 hour. Finally, cool the sample with the furnace to room temperature to obtain the aluminosilicate glass.

[0012] The beneficial effects of this invention are:

[0013] The glass oxide composition provided by this invention differs significantly from traditional silicate glass in that it increases the number of principal components and the mixing entropy. Traditional oxide glasses are typically dominated by one or two components, with a relatively homogeneous type of coordinating atoms. Once an initial crack forms under external force, the crack tip tends to extend rapidly in a near-linear direction due to structural similarity. In contrast, the glass composition provided by this invention features a more similar content of each component, which increases the diversity of coordinating atoms and makes the interactions between atoms more complex. These complex interactions increase the resistance to near-linear crack tip propagation, leading to flexural crack growth. This flexural crack propagation can slow down the linear release of stress, thus enabling the glass to possess excellent mechanical properties without the need for tempering. Detailed Implementation

[0014] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0015] An aluminosilicate glass with excellent mechanical properties is described in the following steps:

[0016] (1) Mix all raw materials thoroughly and evenly according to the glass composition in Table 1; (2) First, raise the temperature from room temperature to 1200℃ at a rate of 3℃ / min and keep it at that temperature for 2 hours; then raise the temperature from 1200℃ to 1500℃ at a rate of 2℃ / min and keep it at that temperature for 3 hours; (3) Pour the fully melted glass onto a copper plate for shaping and place it in an annealing furnace for annealing at a temperature of 700℃ for 1 hour. Finally, cool the sample with the furnace to room temperature to obtain aluminosilicate glass with excellent mechanical properties.

[0017] In the following examples and comparative examples: the elastic modulus of glass was determined using a glass modulus tester according to ASTM C-623, with the unit being GPa; the flexural strength of glass was determined according to JC / T 676-1997 Test Method for Bending Strength of Glass Materials, with the unit being MPa; and the strain point of glass was determined using a three-point tester according to ASTM C-336, with the unit being ℃.

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

[0019]

[0020]

[0021] As shown in Table 1, the glass composition of the present invention has an elastic modulus of 90–94 GPa and a Vickers hardness of 650–660 kg / mm². 2 The fracture toughness is 0.9-1.0 MPa*m. 1 / 2 The three-point flexural strength is 130-140 MPa, and the strain point is 640-660℃.

[0022] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. An aluminosilicate glass with excellent mechanical properties, characterized in that, It is composed of the following oxides: 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; 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.

2. The aluminosilicate glass with excellent mechanical properties according to claim 1, characterized in that, Includes the following steps: (1) Mix the components according to the above proportions; (2) Heat the glass to maintain the temperature and melt it; (3) Pour the melted glass onto a copper plate to form it and place it in an annealing furnace for annealing. Finally, cool the sample with the furnace to room temperature to obtain the aluminosilicate glass.

3. The aluminosilicate glass with excellent mechanical properties according to claim 2, characterized in that, Step (2) is as follows: First, raise the temperature from room temperature to 1200℃ at a rate of 3℃ / min and keep it warm for 2 hours; then raise the temperature from 1200℃ to 1500℃ at a rate of 2℃ / min and keep it warm for 3 hours.

4. The aluminosilicate glass with excellent mechanical properties according to claim 2, characterized in that, The annealing parameters in step (3) are: annealing temperature of 700℃ and time of 1 hour.

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