CN111056749A

CN111056749A - Chemical strengthening method for high-alumina glass

Info

Publication number: CN111056749A
Application number: CN201911401764.0A
Authority: CN
Inventors: 彭寿; 马立云; 高强; 仲召进; 石丽芬; 王萍萍; 王巍巍; 赵凤阳; 李金威; 柯震坤; 韩娜; 倪嘉; 单传丽; 李常青; 周刚; 曹欣; 崔介东
Original assignee: CNBM Bengbu Design and Research Institute for Glass Industry Co Ltd
Current assignee: CNBM Bengbu Design and Research Institute for Glass Industry Co Ltd
Priority date: 2019-12-31
Filing date: 2019-12-31
Publication date: 2020-04-24

Abstract

The invention relates to a chemical strengthening method of high-alumina glass, which comprises the following steps: 1. adding potassium nitrate into a tempering furnace to be melted into molten salt; 2. heating the glass sample to 380-450 ℃, immersing the glass sample into molten salt, preserving heat for 4-6 hours, and then putting the glass sample into hot water at 90 ℃ for quenching; 3. placing the glass sample in a muffle furnace, preserving heat for 0.5-1 h at 500-550 ℃, and then cooling to below 100 ℃; 5. and heating the glass sample to 380-450 ℃, immersing the glass sample into the potassium nitrate molten salt, keeping the temperature for 4-6 h, taking out the glass sample, and putting the glass sample into hot water at 90 ℃ for quenching. The invention has the beneficial effects that: the chemically strengthened glass of the present invention has a higher value of the depth of compressive stress layer by lowering the CS on the glass surface than in the prior art, and has a higher value of the CS at a deep position from the glass surface, and therefore has excellent scratch resistance and is less likely to crack. As a measure for reducing the breakage, it is effective to increase the stress depth of the end face so that the crack existing on the end face does not progress.

Description

Chemical strengthening method for high-alumina glass

Technical Field

The invention relates to chemically strengthened glass, in particular to chemically strengthened glass suitable for high-aluminum cover plate glass.

Background

In recent years, devices such as mobile phones (particularly smart phones), digital cameras, PDAs, touch panel displays, and large-sized televisions have been becoming increasingly popular.

Cover glass in these applications is mainly made of high alumina glass, which is chemically strengthened by ion exchange to improve strength. Such as: JP 2006-. In recent years, there have been increasing cases where chemically strengthened glass is used for exterior parts of digital signage, mice, smartphones, and the like, and in particular, chemically strengthened glass is used for cover glass of smartphones. However, there is no better solution for improving the impact resistance.

Disclosure of Invention

The invention aims to solve the problem that high-alumina glass in the prior art has insufficient impact resistance and is easy to damage, and provides a high-alumina glass chemical strengthening method.

The technical scheme provided by the invention for solving the technical problems is as follows:

the chemical strengthening method of the high-alumina glass is characterized by comprising the following steps:

(1) processing a glass sample into a preset size, edging, cleaning and drying;

(2) adding potassium nitrate with the purity of more than 95 percent into a tempering furnace, heating and melting into molten salt, and clarifying;

(3) heating the glass sample to 380-450 ℃ for preheating treatment;

(4) immersing the glass sample into the molten salt at 450-490 ℃, taking out after the heat preservation time is 4-6 h, and putting into water for quenching;

(5) putting the glass sample into a muffle furnace, preserving heat for 0.5-1 h at 500-550 ℃, and then cooling along with the furnace;

(6) heating the glass sample to 380-450 ℃ again for preheating treatment;

(7) and (3) immersing the glass sample into the potassium nitrate molten salt at the temperature of 400-490 ℃, keeping the temperature for 4-6 h, taking out, and placing into water for quenching.

The invention has the beneficial effects that:

the chemically strengthened glass of the present invention has a higher value of the depth of compressive stress layer by lowering the CS on the glass surface than in the prior art, and has a higher value of the CS at a deep position from the glass surface, and therefore has excellent scratch resistance and is less likely to crack. As a measure for reducing the breakage, it is effective to increase the stress depth of the end face so that the crack existing on the end face does not progress.

Detailed Description

In order to better understand the present invention, the following examples are further provided to illustrate the present invention, but the present invention is not limited to the following examples

Example 1

Selecting high-alumina glass with the thickness of 0.7mm, cutting and edging the glass sheet, cleaning, putting the glass sheet into a preheating furnace for preheating treatment, wherein the preheating temperature is 380 ℃, heating along with the furnace and preserving heat for half an hour, then quickly transferring the glass sheet into molten salt, the molten salt comprises potassium nitrate with the purity of more than 95%, the molten salt temperature is 480 ℃, the ion exchange time is 4 hours, taking out the glass sheet after the exchange is finished, and testing the stress and stress layer depth value of the glass by using a stress tester.

And (3) putting the glass sheet into a muffle furnace for heat treatment at 490 ℃, preserving the heat for 0.5 hour, cooling along with the furnace, and testing the stress and the stress layer depth value of the glass by using a stress tester.

And cutting and edging the glass sheet, cleaning, placing the glass sheet into a preheating furnace for preheating treatment, wherein the preheating temperature is 380 ℃, the temperature is increased along with the furnace, the temperature is kept for half an hour, then the glass sheet is quickly transferred into molten salt, the temperature of the molten salt is 450 ℃, the ion exchange time is 3 hours, the glass sheet is taken out for quenching and cooling after the exchange is finished, and a stress tester is used for testing the stress and stress layer depth value of the glass. The molten salt component is potassium nitrate with purity of more than 95%.

Example 2

The present embodiment is different from embodiment 1 in that: the third step is ion exchange temperature and time of 420 ℃ for 4 h.

Example 3

The present embodiment is different from embodiment 1 in that: the third step is ion exchange temperature and time of 390 ℃ for 5h

Example 4

The present embodiment is different from embodiment 1 in that: the ion exchange temperature and time of the first step are 480 ℃ for 5h, and the heat treatment temperature and time of the second step are 500 ℃ for 1h

Example 5

The present embodiment is different from embodiment 1 in that: the ion exchange temperature and time of the first step are 480 ℃, 5h, the second heat treatment temperature and time are 500 ℃, 1h, the ion exchange temperature and time of the third step are 420 ℃ and 4h

Example 6

The present embodiment is different from embodiment 1 in that: the ion exchange temperature and time of the first step are 480 ℃ for 5h, the heat treatment temperature and time of the second step are 500 ℃ for 1h, and the ion exchange temperature and time of the third step are 390 ℃ for 5h

Comparative example 1

Substantially the same as in example 1, the difference from example 1 is that: the ion exchange temperature and time of the first step are 400 ℃ for 6h, the heat treatment temperature and time of the second step are 510 ℃ for 1h, and the ion exchange temperature and time of the third step are 420 ℃ for 3 h.

Comparative example 2

Substantially the same as in example 1, the difference from example 1 is that: the ion exchange temperature and time of the first step are 400 ℃ for 6h, the heat treatment temperature and time of the second step are 510 ℃ for 1h, and the ion exchange temperature and time of the third step are 420 ℃ for 4 h.

The comparison of the properties of the examples is shown in the attached Table 1.

TABLE 1 comparison of Properties of various glass samples

	At one step temperature/time Workshop	One step stress CS Mpa	One step depth Dol. mu. m	Two step temperature/time Workshop	Two-step stress CS Mpa	Two step depth Dol. mu. m	Three step temperature/time Workshop	Three step stress CS Mpa	Three step depth Dol. mu m
										Comparative example 1	400℃ 6h	934.71	33.3786	510℃ 1h	196.251	72.2522	420℃ 3h	782.9136	55.6944
Comparative example 2	400℃ 6h	939.4104	34.7788	510℃ 1h	184.8512	73.5812	420℃ 4h	789.0116	57.6808
										Examples 1	480℃ 4h	738.5286	69.021	490℃ 0.5h	385.4504	89.5144	450℃ 3h	648.2046	82.5548
Examples 2	480℃ 4h	728.778	69.2546	490℃ 0.5h	391.1516	89.2224	420℃ 4h	629.1698	84.1654
										Examples 3	480℃ 4h	734.572	69.4968	490℃ 0.5h	389.1134	88.5078	390℃ 5h	611.1502	82.0116
Examples 4	480℃ 5h	736.791	67.1542	500℃ 1h	360.1022	97.8078	450℃ 3h	667.7944	82.8482
										Examples 5	480℃ 5h	747.7482	71.2564	500℃ 1h	371.7828	96.8458	420℃ 4h	655.9436	90.209
Examples 6	480℃ 5h	743.0982	71.7422	500℃ 1h	382.5098	95.2252	390℃ 5h	633.0788	86.4556

Although the preferred embodiments and examples have been described in detail above, the present invention is not limited to the embodiments and examples described above, and various modifications and substitutions may be made thereto without departing from the scope of the claims. The above embodiments can be combined as appropriate.

Claims

1. The chemical strengthening method of the high-alumina glass is characterized by comprising the following steps:

(1) processing a glass sample into a preset size, edging, cleaning and drying;

(2) adding potassium nitrate with the purity of more than 95 percent into a tempering furnace, heating to 400 ℃, melting into molten salt, clarifying and keeping the temperature;

(3) heating the glass sample to 380-450 ℃ for preheating treatment;

(4) heating the molten salt to 450-490 ℃ and keeping the temperature;

(5) immersing the glass sample into the molten salt at 450-490 ℃, keeping the temperature for 4-6 h, taking out, and putting into hot water at 90 ℃ for quenching;

(6) putting the glass sample into a muffle furnace, preserving heat for 0.5-1 h at 500-550 ℃, and then cooling to below 100 ℃ along with the furnace;

(7) heating the glass sample to 380-450 ℃ again for preheating treatment;

(8) adjusting the temperature of the molten salt to 400-490 ℃ and keeping the temperature;

(9) and (3) immersing the glass sample into the potassium nitrate molten salt again, keeping the temperature for 4-6 h, taking out, and putting into hot water at 90 ℃ for quenching.