Method for preparing bismuth-doped yttrium aluminum silicate glass through sol-gel method and secondary melting method

Abstract

The invention relates to the field of preparation of doped glass, and discloses a method for preparing bismuth-doped yttrium aluminosilicate glass by a sol-gel method and a secondary melting method, which mainly comprises the following steps: mixing all components in a liquid environment by using a sol precursor, and quickly drying at high temperature to prepare a dry gel block. And carrying out heat preservation and heat treatment on the xerogel at a low temperature through subsequent two melting processes to prepare uniform bubble-free bismuth ion doped yttrium aluminosilicate glass, crushing the glass, carrying out ball milling, carrying out second high-temperature heat treatment, taking out the glass at a high temperature, and pouring the glass into a mold. In the process, the xerogel prepared in advance by adopting a sol-gel method improves the doping uniformity and reduces the melting point of the glass; gas is completely removed through the first-time pre-sintering treatment, holes are closed through sintering, and the defects of bubbles, stripes and the like of the glass are eliminated, so that the transmittance and the luminescence property are improved; ball-milled powder instead of cullet is adopted for secondary melting, so that the uniformity of the glass is improved, and the melting point is further reduced.

Description

Technical Field

[0001] The present invention relates to a process for preparing doped glass, and in particular to a method for preparing bismuth-doped yttrium aluminosilicate glass via a sol-gel method and a secondary melting method. Background Art

[0002] Bismuth-doped yttrium aluminum silicate glass is a core component of fiber lasers, fiber amplifiers, etc. It can be used to manufacture infrared windows, sensor lenses, etc., and is suitable for military (such as night vision goggles) and medical (infrared imaging) fields.

[0003] The most common glassmaking process currently involves melting and sintering all the raw materials at high temperature. However, this method is prone to bubbles and streaks, poor doping uniformity, limited purity, and the introduction of impurities. Furthermore, the presence of agglomeration results in low doping concentrations.

[0004] Glass production based on the sol-gel method typically begins with the preparation of a xerogel, which is then heat-treated to produce glass. However, due to the shrinkage of pores and the release of gases during the heat treatment, the glass is prone to cracking, making it difficult to obtain large, intact pieces of glass.

[0005] To address the above issues, the present invention proposes a method for preparing bismuth-doped yttrium aluminosilicate glass via a sol-gel method and a secondary melting method to solve the above-mentioned problems of doping concentration, low purity, bubbles, streaks, poor uniformity, and easy breakage of glass during heat treatment. Summary of the Invention

[0006] The technical solution of the present invention is as follows: A method for preparing rare earth-doped glass by a sol-gel method and a secondary melting method comprises the following steps:

[0007] (1) heating the precursor in a water bath and mixing it uniformly to prepare a sol;

[0008] (2) The prepared sol is placed in an oven and dried at high temperature to form a dry gel block.

[0009] (3) The dry gel block is pre-sintered in a box furnace. First, the temperature is slowly increased at a temperature of 200°C to 500°C at a heating rate of 20°C / h to 30°C / h to remove moisture and most organic matter; then the temperature is increased to 900°C to 1100°C at a heating rate of 100°C / h to 200°C / h and kept at this temperature for 1h to 4h. The glass is densified by high-temperature viscous flow to remove all residual organic matter.

[0010] (4) After the glass is crushed, it is subjected to a ball milling process to further reduce the melting point. After passing through a sieve, it is subjected to a second ball milling process to ball mill the raw material into particles with a size of 100nm to 5μm.

[0011] (5) The glass powder is subjected to secondary heat treatment in a box furnace, with a heating rate of 3°C / min to 5°C / min before 1000°C and a heating rate of 1°C / min to 3°C / min above 1000°C to 1600°C to 1750°C, and kept warm for 1h to 4h before being taken out at high temperature and poured into a mold.

[0012] Furthermore, the precursor is tetraethyl silicate, aluminum sec-butoxide, aluminum nitrate, yttrium nitrate and anhydrous ethanol.

[0013] Furthermore, the first ball milling time is 1 h to 4 h, and the second ball milling time is 5 h to 10 h.

[0014] The key to this invention is to first prepare a highly uniform rare earth-doped xerogel through a sol-gel process, then pre-sinter it to produce cullet. This glass is then ball-milled twice to obtain a uniformly doped core glass powder, which is then melted again to produce bulk glass. Compared to traditional glass production methods that involve a single high-temperature melting and sintering of all the raw materials, this method avoids problems such as poor uniformity, impurity defects caused by limited purity, and bubbles and streaks. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the specific implementation of the present invention or the technical solutions in the prior art, the drawings required for describing the specific implementation or the prior art will be briefly introduced below. Obviously, the drawings described below are only one implementation of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0016] Figure 1 This is a process flow chart of an embodiment of the present invention;

[0017] Figure 2 This is a sol picture of an embodiment of the present invention;

[0018] Figure 3 Picture of wet gel from an embodiment of the present invention;

[0019] Figure 4 Picture of xerogel according to the embodiment of the present invention;

[0020] Figure 5 Pictures of broken glass from an embodiment of the present invention;

[0021] Figure 6 Picture of glass powder according to the embodiment of the present invention;

[0022] Figure 7 Image of bismuth-doped yttrium aluminosilicate glass according to an embodiment of the present invention;

[0023] Figure 8 These are the emission spectrum and transmission spectrum of bismuth-doped yttrium aluminosilicate glass according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the technical solutions in the specific implementation methods of the present invention are clearly and completely described below to further illustrate the present invention. Obviously, the specific implementation methods described are only part of the implementation methods of the present invention, rather than all styles.

[0025] Example 1: This example is a method for preparing rare earth doped glass by sol-gel method and secondary melting method. Figure 1 As shown, the following steps are included:

[0026] (1) According to the designed glass composition SiO2-Y2O3-Al2O3, the raw materials are tetraethyl silicate, aluminum sec-butoxide, aluminum nitrate, yttrium nitrate, and anhydrous ethanol. Weigh the precursor raw materials according to the raw material composition. In this case, the total amount of oxides is 30g. Mix them evenly by heating in a water bath to prepare the following Figure 2 The sol shown;

[0027] (2) Figure 3 As shown, the prepared sol was placed in an oven and dried at 75°C for 2 days and then taken out as shown in FIG. Figure 4 The xerogel block shown.

[0028] (3) The dry gel block is subjected to the first heat treatment in a box furnace, heating the temperature from 200°C to 500°C at a rate of 15°C / h, then heating to 900°C at a rate of 150°C / h, and keeping the temperature for 1 hour to obtain block glass.

[0029] (4) Crush the glass in an agate mortar. Figure 5 As shown, the ball milling was then performed once for 2 h, followed by sieving with a sieve and then ball milling for a second time for 8 h. Figure 6 As shown, the raw materials are ball-milled into glass powders less than 500 nm.

[0030] (5) The glass powder is subjected to a second heat treatment, with a heating rate of 5°C / min before 1000°C and a heating rate of 3°C / min after 1000°C to 1600°C, kept at this temperature for 2 hours, and then poured into a mold to obtain the desired shape of glass, such as Figure 7 shown.

[0031] (6) The glass is ground and optically polished, and then characterized. The characterization results are as follows: Figure 8 As shown, the characteristic emission peak of divalent bismuth ions is observed around 765nm under excitation at 380nm, 590nm, and 609nm wavelengths. The transmission spectra show that the transmittance of the samples is above 88%, with a UV absorption cutoff at the right side of 325nm.

[0032] The above describes the main technical features and basic principles of the present invention and the related advantages. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments and that the present invention can be implemented in other specific forms without departing from the concept or essential characteristics of the present invention. Therefore, from all perspectives, the above-mentioned specific embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the foregoing description, and it is intended that all changes that come within the meaning and range of equivalents of the claims be included within the present invention.

[0033] In addition, it should be understood that although this specification is described according to various implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each implementation method can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A method for preparing bismuth-doped yttrium aluminosilicate glass via a sol-gel method and a secondary melting method, characterized in that: Using the sol-gel method, the precursor is made to achieve molecular uniformity and high purity under liquid conditions. The organic matter is initially removed by oven drying, and the organic matter is further removed by a heat treatment. Then, two ball millings are performed to obtain glass powder. The organic matter is completely removed by a second heat treatment and melted into glass liquid at high temperature. The glass is poured into a mold to obtain the desired shape of glass.

2. The method for preparing bismuth-doped yttrium aluminosilicate glass via a sol-gel method and a secondary melting method according to claim 1, wherein: The primary heat treatment temperature is slowly increased at a heating rate of 20°C / h to 30°C / h from 200°C to 500°C, then increased to 900°C to 1100°C at a heating rate of 100°C / h to 200°C / h, and kept warm for 1h to 4h.

3. The method for preparing bismuth-doped yttrium aluminosilicate glass via a sol-gel method and a secondary melting method according to claim 1, wherein: The secondary heat treatment adopts a heating rate of 3℃ / min~5℃ / min before 1000℃, and adopts a heating rate of 1℃ / min~3℃ / min after 1000℃ to increase the temperature to 1600℃~1750℃, and takes it out at high temperature after keeping it for 1h~4h.

4. The method for preparing bismuth-doped yttrium aluminosilicate glass via a sol-gel method and a secondary melting method according to claim 1, wherein: The particle size of the glass powder after the first ball milling is between 0.5 μm and 5 μm; the particle size of the glass powder after the second ball milling is between 100 nm and 1500 nm.

5. The method for preparing bismuth-doped yttrium aluminosilicate glass via a sol-gel method and a secondary melting method according to claim 1, wherein: The precursors are tetraethyl silicate, aluminum sec-butoxide, aluminum nitrate, yttrium nitrate and anhydrous ethanol.

6. The method for preparing bismuth-doped yttrium aluminosilicate glass via a sol-gel method and a secondary melting method according to claim 1, wherein: The first ball milling time is 1h~4h, and the second ball milling time is 5h~10h.

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