CN104211303A - Microcrystalline glass having good optical transmittance and containing large-size microcrystalline phases and preparation method of microcrystalline glass - Google Patents

Abstract

The invention discloses microcrystalline glass having a good optical transmittance and containing large-size microcrystalline phases and a preparation method of the microcrystalline glass. The microcrystalline glass comprises the following chemical components in parts by weight: 35-50 percent of SiO2, 10-20 percent of Al2O3, 15-25 percent of BaO and 10-25 percent of LaF3. The preparation method comprises the following steps: grinding the raw materials SiO2, Al2O3, BaCO3 and LaF3 in proportion, evenly mixing, fusing, quenching and pressing to form glass; and then carrying out heat treatment on the glass so as to obtain the microcrystalline glass. The microcrystalline glass can be used for separating out discoid monocrystal microcrystalline phases with large size while maintaining good optical transmittance at the same time; the transmissivity of the microcrystalline glass is more than 95% higher than that of the glass. The prepared microcrystalline glass has the optical transmittance and contains the large-size microcrystalline phases, so that the optical performance of a luminescent material can be improved. The preparation method is simple in production process, easily controllable in condition and low in cost.

Description

Glass-ceramics with good optical transparency and large-sized crystallite phase and preparation method thereof

technical field

The invention relates to a glass-ceramic and a preparation method thereof, in particular to a glass-ceramic with good optical transparency and a large-sized crystallite phase and a preparation method thereof.

Background technique

Glass-ceramics is generally a composite material with uniform distribution of crystal and glass phases obtained by controlled crystallization of glass with a specific chemical composition, also known as glass ceramics. As a composite material, glass-ceramics has both the excellent properties of glass and crystal, as well as a series of excellent properties that traditional glass and ceramics do not have. It is often superior in thermal, optical, chemical, biological, mechanical and electromagnetic properties. For metal and organic polymer materials, it has attracted extensive attention of researchers.

In terms of optical applications, it is generally desirable to obtain transparent glass-ceramic materials, such as light sources and optical gain media, which need to reduce their own absorption and scattering of light. According to the Rayleigh scattering theory, the smaller the size of the microcrystalline phase, the smaller the scattering effect on light, so the size of the microcrystalline phase is generally required to be at the nanometer level. At present, most researches focus on optically transparent glass-ceramics with small size at the nanometer scale, but due to the abundance of interface defects in the nanoscale crystallite phase, it is very unfavorable for the luminescence of luminescent centers such as rare earth/transition metal ions. , greatly reducing its quantum efficiency. However, when the size of the microcrystalline phase increases slightly, it is easy to become translucent or even devitrified due to enhanced scattering, and the transparency decreases quickly.

Contents of the invention

The object of the present invention is to provide a kind of glass-ceramics containing large-size crystallite phase with good optical transparency and its preparation method, to obtain the glass-ceramic with good optical transparency and to contain large-size crystallite phase, which is beneficial to Improve the optical properties of luminescent materials.

Technical scheme of the present invention is:

1. A glass-ceramic containing a large-sized crystallite phase with good optical transparency, the chemical composition of which is as follows:

The crystallite phase of the glass-ceramic is BaAl ₂ Si ₂ O ₈ .

The crystallite phase size of the glass-ceramics is at least 80 μm.

The crystallite phase of the glass-ceramic is disc-shaped.

The microcrystalline phase of the glass-ceramic is single crystal.

The optical transmittance of the glass-ceramics is above 95% of that of glass.

Two, a kind of preparation method of the glass-ceramics that contains the large-scale microcrystalline phase of good optical transparency, comprises the following steps:

1) Grind and mix SiO ₂ , Al ₂ O ₃ , BaCO ₃ , and LaF ₃ raw materials in proportion to the glass composition;

2) putting the mixed raw materials into a corundum crucible and melting them to obtain molten glass;

3) Pour the glass melt onto a stainless steel plate, and then flatten it with another stainless steel plate at room temperature to obtain transparent glass;

4) heat-treating the obtained glass in a muffle furnace, then cooling to room temperature and taking it out to obtain the glass-ceramics.

The molar percentages of SiO ₂ , Al ₂ O ₃ , BaCO ₃ , and LaF ₃ in the step 1) are 35-50:10-20:15-25:10-25.

The melting temperature in the corundum crucible in the step 2) is 1450-1550° C., and the melting time is 30 minutes.

The heat treatment temperature of the muffle furnace in the step 3) is 750-900° C., and the heat treatment time is 0.5-10 hours.

The beneficial effects of the present invention are:

1. A glass-ceramic in which disc-shaped single crystal BaAl ₂ Si ₂ O ₈ with a size of at least 80 μm is precipitated in a glass matrix can be obtained, and the transmittance of the glass-ceramic is more than 95% of that of glass.

2. Compared with the nano-sized crystallite phase, the micron-scale large-size crystallite phase greatly reduces the interface effect, and it is expected to be further doped with rare earth/transition metal ions to achieve higher efficiency luminescence.

3. Micron-scale single crystal microcrystals can provide a good research carrier for studying the optical or other properties of bulk single crystals.

4. The production process is simple, the conditions are easy to control, and the cost is low.

Description of drawings

FIG. 1 is the XRD spectrum of the glass-ceramic corresponding to Example 1.

FIG. 2 is the transmission spectrum of the glass-ceramic corresponding to Example 1.

FIG. 3 is an optical micrograph of the glass-ceramic corresponding to Example 1. FIG.

Detailed ways

The chemical composition (mol percent) of glass-ceramic of the present invention is as follows:

The crystallite phase of the prepared glass-ceramics is BaAl ₂ Si ₂ O ₈ , the size of which is at least 80 μm, disc-shaped, and single crystal. The prepared glass-ceramic still maintains good optical transmittance through experimental test, and the optical transmittance is more than 95% of that of glass.

The inventive method comprises the following steps:

1) Grind and mix SiO ₂ , Al ₂ O ₃ , BaCO ₃ , and LaF ₃ raw materials in proportion to the glass composition;

The preferred molar percentages of SiO ₂ , Al ₂ O ₃ , BaCO ₃ , and LaF ₃ are 35-50:10-20:15-25:10-25.

2) putting the mixed raw materials into a corundum crucible and melting them to obtain molten glass;

The preferred melting temperature in the corundum crucible is 1450-1550°C, and the melting time is 30 minutes.

3) Pour the molten glass onto a stainless steel plate, and press it with another stainless steel plate at room temperature to obtain transparent glass.

4) heat-treating the obtained glass in a muffle furnace, then cooling to room temperature and taking it out to obtain the glass-ceramics.

The preferred heat treatment temperature of the muffle furnace is 750-900° C., and the heat treatment time is 0.5-10 hours.

The principle of the glass-ceramics of the present invention to precipitate large-sized crystallite phases and maintain good optical transparency is that the glass prepared by the melting and quenching method is in a thermodynamic non-equilibrium state, and when heat-treated at a certain temperature, the glass network structure relaxes. The local structure is adjusted to a crystal phase with low free energy, and the microcrystalline phase is obtained through nucleation and growth. Since the composition and structure of the crystal phase and the glass phase in the glass-ceramics involved in the present invention are very close, the crystallization process only needs short-range atom migration and structural adjustment, which is beneficial to obtain large-sized crystallite phases, and the volume changes The small size will not cause defects such as voids at the interface to reduce the scattering effect, and the refractive index difference between the microcrystalline phase and the glass phase is small, so the glass-ceramics of the large-sized microcrystalline phase still maintains good optical transparency.

The present invention will be further described below in conjunction with the embodiments and accompanying drawings, but the protection scope of the present invention should not be limited thereby.

Table 1 lists the chemical composition, melting temperature, heat treatment system, crystallite phase size, and transmittance (relative to glass) of 6 examples of the present invention. Accompanying drawing 1, 2, 3 are respectively the XRD spectrum, transmission spectrum, optical micrograph of the glass-ceramics corresponding to embodiment 1.

The glass-ceramics provided by Examples 1-6 of the present invention are prepared according to the following method:

Grind and mix the raw materials in proportion according to the chemical composition of the glass corresponding to Examples 1-6, put them into a corundum crucible and melt at 1450-1550°C for 30 minutes, then pour the glass melt on a stainless steel plate, and use another piece of stainless steel The steel plate is flattened, and the transparent glass is obtained after cooling to normal temperature, and finally the glass-ceramic that meets the requirements is obtained under the corresponding heat treatment system.

Table 1

The specific embodiments above are used to illustrate the present invention, rather than to limit the present invention. Within the spirit of the present invention and the protection scope of the claims, any modification and change made to the present invention will fall into the protection scope of the present invention.

Claims (10)

1. A kind of glass-ceramic containing large-sized crystallite phase with good optical permeability, it is characterized in that: the chemical composition of this glass-ceramic is as follows: Composition mol% SiO ₂ 35~50 Al ₂ O ₃ 10~20 BaO 15~25 LaF ₃ 10~25. 2. A glass-ceramic with good optical transparency and containing a large-sized crystallite phase according to claim 1, characterized in that: the crystallite phase of the glass-ceramic is BaAl ₂ Si ₂ O ₈ . 3. A kind of glass-ceramic with good optical transparency containing large-sized crystallite phase according to claim 1, characterized in that: the size of the crystallite phase of the glass-ceramic is at least 80 μm. 4. A kind of glass-ceramic with good optical transparency and containing large-sized crystallite phase according to claim 1, characterized in that: the crystallite phase of the glass-ceramic is disc-shaped. 5. A kind of glass-ceramic with good optical transparency containing large-sized crystallite phase according to claim 1, characterized in that: the crystallite phase of the glass-ceramic is a single crystal. 6. A kind of glass-ceramics with good optical transparency containing large-sized crystallite phase according to claim 1, characterized in that: the optical transmittance of the glass-ceramics is more than 95% of that of glass. 7. the method for preparing the glass-ceramic containing large-size crystallite phase of a kind of good optical transmittance for preparing the described glass-ceramics of claim 1, is characterized in that comprising the following steps: 1) Grind and mix SiO ₂ , Al ₂ O ₃ , BaCO ₃ , and LaF ₃ raw materials in proportion according to the glass composition; 2) Put the mixed raw materials into the corundum crucible and melt to obtain glass melt; 3) Pour the glass melt onto a stainless steel plate, and then flatten it with another stainless steel plate at room temperature to obtain transparent glass; 4) Put the obtained glass in a muffle furnace for heat treatment, then cool it to room temperature and take it out to obtain the glass-ceramics. 8. The preparation method of glass-ceramics with good optical transparency and large-sized crystallite phase according to claim 7, characterized in that: SiO ₂ and Al ₂ O ₃ in the step 1) , BaCO ₃ , and LaF ₃ molar ratios are 35~50:10~20:15~25:10~25. 9. A method for preparing a glass-ceramic with good optical transparency and containing a large-sized crystallite phase according to claim 7, characterized in that: the melting temperature in the corundum crucible in the step 2) is 1450 ~1550℃, melting time is 30min. 10. A method for preparing a glass-ceramic with good optical transparency and containing a large-sized crystallite phase according to claim 7, characterized in that: the heat treatment temperature of the muffle furnace in the step 3) is 750 ~900℃, heat treatment time is 0.5~10 hours.