Single-layer bullet-proof glass and preparation method thereof

Abstract

The invention discloses single-layer bullet-proof glass and a preparation method thereof.The single-layer bullet-proof glass comprises a base material and graphene nanoplatelets, and the base material comprises, by mass, 55%-65% of quartz sand, 8%-15% of aluminum borate whiskers, 6%-12% of alumina powder, 3%-8% of magnesium oxide and 2%-5% of yttrium oxide; 1-3% of lanthanum oxide, 0.5-2% of zirconium oxide, 1.5-4% of sodium carbonate, 0.5-1% of potassium carbonate and 0.2-0.8% of a clarifying agent, and the addition mass of the graphene nanoplatelets is 0.5-1% of that of the base material. According to the present invention, through the multi-scale collaborative design of the high modulus whisker, the rare earth-zirconium synergistic reinforcement, the graphene nanometer reinforcement and the chemical tempering, the density is reduced while the bulletproof performance and the optical quality are significantly improved, such that the broad industrialization prospect is provided.

Description

Technical Field

[0001] This invention relates to the field of special glass technology, and in particular to a single-layer bulletproof glass and its preparation method. Background Technology

[0002] With the increasing frequency of public safety incidents, the demand for bulletproof glass in military, police, finance, and transportation sectors has grown dramatically. Traditional bulletproof glass often uses multiple layers of soda-lime-silica glass laminated with PVB film, resulting in significant thickness, weight, severe optical distortion, and insufficient protection against high-energy rifle bullets. Existing technologies attempt to replace some glass layers with high-hardness oxide ceramics such as alumina and zirconium oxide, but ceramics are brittle, have weak interfacial bonding, and are prone to secondary injuries from breakage; alternatively, adding metal mesh can improve toughness, but this sacrifices light transmittance. Therefore, developing a lightweight, highly transparent, highly tough, and single-piece bulletproof glass capable of protecting against pistol and even rifle bullets has become an urgent technical challenge. Summary of the Invention

[0003] The purpose of this invention is to provide a single-layer bulletproof glass and its preparation method. Through multi-scale synergistic design of high-modulus whiskers, rare earth-zirconium synergistic strengthening, graphene nano-reinforcement and chemical tempering, the bulletproof performance and optical quality are significantly improved while reducing density, which has broad industrialization prospects.

[0004] The above-mentioned technical objective of the present invention is achieved through the following technical solution: A single-layer bulletproof glass, characterized in that it comprises a base material and graphene microflakes, wherein the base material comprises the following components by mass percentage: 55-65% quartz sand, 8-15% aluminum borate whiskers, 6-12% alumina powder, 3-8% magnesium oxide, 2-5% yttrium oxide; 1-3% lanthanum oxide, 0.5-2% zirconium oxide, 1.5-4% sodium carbonate, 0.5-1% potassium carbonate, and 0.2-0.8% clarifying agent; wherein the graphene microflakes are added at 0.5-1% of the mass of the base material.

[0005] Preferably, the aluminum borate whiskers have an aspect ratio of 10 to 50 and an average diameter of 0.5 to 2 μm.

[0006] Preferably, the graphene microsheets have an average thickness of 1–5 nm and a diameter of 1–10 μm.

[0007] Preferably, the thickness of the single-layer bulletproof glass is 8 to 25 mm.

[0008] Preferably, the clarifying agent is a composite system of CeO2 and Sb2O3 mixed in a mass ratio of 1:1 to 3:1.

[0009] A method for preparing single-layer bulletproof glass, characterized by comprising the following steps: S1, Quartz sand, alumina powder, magnesium oxide, yttrium oxide, lanthanum oxide, zirconium oxide, sodium carbonate, potassium carbonate and clarifying agent are mixed, a mixed solvent of ethanol and water and graphene microsheets are added, and wet ball milling is performed to obtain a uniform slurry; S2, the obtained uniform slurry is spray-granulated to obtain granulated powder with good flowability; S3, the granulated powder is loaded into the mold and cold isostatically pressed to obtain the green body; S4, the green blank is sintered in two steps and cooled in the furnace to obtain the glass matrix; S5, Chemical Tempering: The sintered glass substrate is immersed in a molten KNO3 salt bath at 400–450°C for 4–8 hours to perform K... + / Na + Ion exchange forms a compressive stress layer with a surface thickness ≥40μm.

[0010] Preferably, in the S1 mixture of ethanol and water, the volume ratio of ethanol to water is 1:1 to 2:1, the wet ball milling time is 4 to 8 hours, and the ball milling speed is 200 to 400 r / min.

[0011] Preferably, the inlet temperature of the spray granulation in S2 is 180-220°C, the outlet temperature is 80-100°C, and the atomization pressure is 0.2-0.5 MPa.

[0012] Preferably, the pressure for cold isostatic pressing in S3 is 150-250 MPa, and the holding time is 2-5 min.

[0013] Preferably, the two-step sintering in S4 specifically comprises: the first step of heating to 600-800°C at a heating rate of 5-10°C / min and holding for 1-2 hours to remove organic matter; and the second step of heating to 1250-1350°C at a heating rate of 3-5°C / min and holding for 2-4 hours.

[0014] In summary, the present invention has the following beneficial effects: The bulletproof glass of the present invention has a single integral structure. Through the above-described formula and preparation method, a glass body with high hardness, high toughness, and excellent optical properties is directly formed. Its microstructure is a multi-scale composite system: aluminum borate whiskers and graphene microflakes are uniformly distributed in the glass matrix, forming a three-dimensional reinforcing network; rare earth oxides and zirconium oxide work synergistically to refine the grains and improve the interfacial bonding strength; after chemical tempering, a compressive stress layer is formed on the surface, further enhancing the impact resistance. Therefore, this bulletproof glass can be used alone without being combined with other glass layers or polymer layers to effectively resist the penetration of handgun bullets. Detailed Implementation

[0015] The specific embodiments of the present invention will be further described below. These embodiments do not constitute a limitation on the present invention.

[0016] A single-layer bulletproof glass comprises a base material and graphene microflakes. The base material, by mass percentage, comprises the following components: 55-65% quartz sand, 8-15% aluminum borate whiskers, 6-12% alumina powder, 3-8% magnesium oxide, 2-5% yttrium oxide; 1-3% lanthanum oxide, 0.5-2% zirconium oxide, 1.5-4% sodium carbonate, 0.5-1% potassium carbonate, 0.2-0.8% clarifying agent, and graphene microflakes added at 0.5-1% of the base material.

[0017] The aspect ratio of aluminum borate whiskers is 10–50, and the average diameter is 0.5–2 μm.

[0018] The graphene microsheets have an average thickness of 1–5 nm and a diameter of 1–10 μm.

[0019] The thickness of single-layer bulletproof glass is 8-25mm.

[0020] The clarifying agent is a composite system of CeO2 and Sb2O3 mixed in a mass ratio of 1:1 to 3:1.

[0021] A method for preparing single-layer bulletproof glass, characterized by comprising the following steps: S1, Quartz sand, alumina powder, magnesium oxide, yttrium oxide, lanthanum oxide, zirconium oxide, sodium carbonate, potassium carbonate and clarifying agent are mixed, and graphene microsheets are added for pre-dispersion to avoid agglomeration. The volume ratio of ethanol to water in the mixed solvent is 1:1 to 2:1. Wet ball milling is performed for 4 to 8 hours at a speed of 200 to 400 r / min to obtain a uniform slurry. S2, the obtained uniform slurry is spray granulated with an inlet temperature of 180-220℃, an outlet temperature of 80-100℃, and an atomization pressure of 0.2-0.5MPa to obtain granulated powder with good flowability; S3, the granulated powder is loaded into the mold and subjected to cold isostatic pressing at a pressure of 150-250 MPa and a holding time of 2-5 min to obtain the green body; S4. The green body is sintered in two steps. In the first step, the temperature is raised to 600-800℃ at a rate of 5-10℃ / min and held for 1-2 hours to remove organic matter. In the second step, the temperature is raised to 1250-1350℃ at a rate of 3-5℃ / min and held for 2-4 hours. After cooling in the furnace, the glass matrix is ​​obtained. S5, Chemical Tempering: The sintered glass substrate is immersed in a molten KNO3 salt bath at 400–450°C for 4–8 hours to perform K... + / Na + Ion exchange forms a compressive stress layer with a surface thickness of ≥40μm, increasing surface hardness by more than 35%.

[0022] Quartz sand provides the SiO2 network framework; aluminum borate whiskers (9Al2O3·2B2O3) combine high modulus (E≈400GPa) and high-temperature stability, acting as fiber toughening agents; alumina and zirconium oxide improve surface hardness and ballistic penetration resistance; yttrium oxide and lanthanum oxide rare earth oxides refine grains and improve fracture toughness; graphene microflakes can form "bridging" and "pull-out" effects at crack tips, absorbing impact energy; CeO2 / Sb2O3 composite clarifying agent effectively eliminates bubbles, ensuring optical quality.

[0023] Example 1 The ingredients are formulated according to the following mass percentages: 62.7% quartz sand, 12% aluminum borate whiskers, 10% alumina powder, 5% magnesium oxide, 3% yttrium oxide, 2% lanthanum oxide, 1% zirconium oxide, 3% sodium carbonate, 0.8% potassium carbonate, 0.5% clarifying agent (CeO2:Sb2O3=2:1), and 0.8% graphene micro-flakes.

[0024] Preparation steps: (1) Ingredient preparation and wet ball milling: Mix the above components (except graphene microsheets), add ethanol-water co-solvent (volume ratio 1:1) and graphene microsheets, and ball mill in a ball mill for 6 hours at a speed of 300 r / min to obtain a uniform slurry; (2) Spray granulation: The slurry is granulated in a spray drying tower with an inlet temperature of 200℃, an outlet temperature of 90℃, and an atomization pressure of 0.3MPa to obtain granulated powder; (3) Cold isostatic pressing: Granulated powder is loaded into a mold and cold isostatically pressed at 200MPa pressure for 3 minutes to obtain a green blank. (4) Two-step sintering: The green blank is first heated to 700℃ at 8℃ / min and held for 1.5h; then heated to 1300℃ at 4℃ / min and held for 3h, and then cooled with the furnace. (5) Chemical tempering: The sintered glass is immersed in KNO3 molten salt at 420℃ for 6 hours to form a surface compressive stress layer.

[0025] The final product was 25mm thick bulletproof glass. The actual performance was as follows: light transmittance 87%, haze 0.18%, surface density 42kg / m². It was tested with Type 54 7.62mm pistol bullets according to the GA165-2016 standard. The bullet velocity was 450m / s, and it did not penetrate. There were no flying fragments on the back of the bullet.

[0026] Example 2: The amount of graphene microsheets used in Example 1 was increased to 1%, while the rest remained the same as in Example 1, except that the thickness was reduced to 20 mm and the areal density was reduced to 34 kg / m³. 2 It can still stop the same type of bullets.

[0027] Comparative Example 1: Based on the traditional soda-lime-silicon glass formula of 63% SiO2, 15% Na2O, 10% CaO, and 12% Al2O3, three 10mm glass layers and two 0.76mm PVB films were laminated, resulting in a total thickness of 32mm and a surface density of 78kg / m³. 2 Under the same conditions, it was penetrated.

[0028] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art can make various modifications or equivalent substitutions to the present invention within the scope of its essence and protection. Such modifications or equivalent substitutions should also be considered to fall within the protection scope of the present invention.

Claims

1. A single-layer bulletproof glass, characterized in that, The product comprises a base material and graphene microflakes. The base material, by mass percentage, includes the following components: 55-65% quartz sand, 8-15% aluminum borate whiskers, 6-12% alumina powder, 3-8% magnesium oxide, 2-5% yttrium oxide; 1-3% lanthanum oxide, 0.5-2% zirconium oxide, 1.5-4% sodium carbonate, 0.5-1% potassium carbonate, and 0.2-0.8% clarifying agent. The graphene microflakes are added at 0.5-1% of the mass of the base material.

2. The single-layer bulletproof glass according to claim 1, characterized in that: The aluminum borate whiskers have an aspect ratio of 10 to 50 and an average diameter of 0.5 to 2 μm.

3. The single-layer bulletproof glass according to claim 1, characterized in that: The graphene microsheets have an average thickness of 1–5 nm and a diameter of 1–10 μm.

4. The single-layer bulletproof glass according to claim 1, characterized in that: The thickness of the single-layer bulletproof glass is 8-25mm.

5. The single-layer bulletproof glass according to claim 1, characterized in that: The clarifying agent is a composite system of CeO2 and Sb2O3 mixed in a mass ratio of 1:1 to 3:

1.

6. A method for preparing a single-layer bulletproof glass according to any one of claims 1 to 5, characterized in that: Includes the following steps: S1, Quartz sand, alumina powder, magnesium oxide, yttrium oxide, lanthanum oxide, zirconium oxide, sodium carbonate, potassium carbonate and clarifying agent are mixed, a mixed solvent of ethanol and water and graphene microsheets are added, and wet ball milling is performed to obtain a uniform slurry; S2, the obtained uniform slurry is spray-granulated to obtain granulated powder with good flowability; S3, the granulated powder is loaded into the mold and cold isostatically pressed to obtain the green body; S4, the green blank is sintered in two steps and cooled in the furnace to obtain the glass matrix; S5, Chemical Tempering: The sintered glass substrate is immersed in a molten KNO3 salt bath at 400–450°C for 4–8 hours to perform K... + / Na + Ion exchange forms a compressive stress layer with a surface thickness ≥40μm.

7. The method for preparing a single-layer bulletproof glass according to claim 6, characterized in that: In S1, the volume ratio of ethanol to water in the mixed solvent is 1:1 to 2:1, the wet ball milling time is 4 to 8 hours, and the ball milling speed is 200 to 400 r / min.

8. The method for preparing a single-layer bulletproof glass according to claim 1, characterized in that: The inlet temperature of the spray granulation in S2 is 180-220℃, the outlet temperature is 80-100℃, and the atomization pressure is 0.2-0.5MPa.

9. The method for preparing a single-layer bulletproof glass according to claim 1, characterized in that: The pressure for cold isostatic pressing in S3 is 150-250 MPa, and the holding time is 2-5 min.

10. The method for preparing a single-layer bulletproof glass according to claim 1, characterized in that: The two-step sintering process in S4 is as follows: the first step is to raise the temperature to 600-800℃ at a heating rate of 5-10℃ / min and hold it for 1-2 hours to remove organic matter; the second step is to raise the temperature to 1250-1350℃ at a heating rate of 3-5℃ / min and hold it for 2-4 hours.