Lithium aluminosilicate glass with surface crack repairing capability, and preparation method thereof

Abstract

The invention discloses a tempered lithium aluminate glass product with surface crack repairing capability, and a preparation method thereof. The composition in the glass product comprises 57-63% of SiO2, 17-21 wt% of Al2O3, 0.5-4 wt% of B2O3, 3.5-5 wt% of Li2O, 8-12 wt% of Na2O, 0.2-3% of MgO and 0.1-4 wt% of ZrO2, the ratio of (Al2O3+RO) to (B2O3+R2O) is 1.0-2.0, and the ratio of (R2O+RO-ZrO2) to Al2O3 is 0.5-1.0. According to the preparation method, the molten salt in the first tempering is a NaNO3 and KNO3 mixed salt contains at least 40 wt% of NaNO3, the molten salt in the middle tempering is a NaNO3 and KNO3 mixed salt containing at most 50% of NaNO3, and the molten salt in the last tempering is a NaNO3 and KNO3 mixed salt containing at most 10 wt% of NaNO3. In the disclosed embodiment, the compressive stress layer is at least 30 MPa when the surface of the tempered lithium aluminosilicate glass extends to 50 [mu]m, the distance between the internal tensile stress area and the surface of the glass is at least 0.1 t, and the ring crush strength of the tempered lithium aluminosilicate glass is at least 1 GPa.

Description

technical field [0001] The invention belongs to the technical field of glass materials, and in particular relates to a lithium aluminate glass with good surface crack repair ability and a preparation method thereof. Background technique [0002] The process of rapid cooling of glass from high-temperature melt to room temperature and the process of glass processing will produce a large number of micro-cracks and other defects on the surface and sub-surface of the glass. When the glass is in use, it is often subjected to different external forces, resulting in stress concentration near the micro-cracks. When the stress value exceeds the ultimate strength of the glass, the micro-cracks begin to expand and cause glass fracture failure. Therefore, the repair of micro-cracks on the glass surface is very important to improve the strength and durability of the glass. [0003] When there are cracks on the glass surface, when the glass is reheated to the glass strain point or above, ...

AI Technical Summary

Problems solved by technology

However, the heat treatment of thin glass below 1.5mm above the strain point causes problems such as surface deformation and warping of the glass, which limits the use of this crack repair method.

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