CN107601901A - A kind of glass ceramics and preparation method thereof and the application as material of infrared window - Google Patents

Abstract

Application the present invention relates to a kind of glass ceramics and preparation method thereof and as material of infrared window, the chemical composition of described glass ceramics is Ga_x+yGe_28‑xSb_12‑ySe₆₀, wherein x ∈ [2,5], y ∈ [1,3].With Ge₂₈Sb₁₂Se₆₀Parent glass is compared, and glass ceramics provided by the invention remains the high transmittance of original basis glass and wide transmission window, and is improved a lot in terms of intensity, and its Vickers hardness has more than 1.2 times of raising compared to parent glass highest.

Description

A kind of glass ceramics and its preparation method and application as infrared window material

technical field

The invention relates to the technical field of inorganic materials, in particular to a glass ceramic, a preparation method thereof and an application as an infrared window material.

Background technique

It is well known that controllable microcrystallization is a great challenge in the field of glass ceramics. A major research goal in glass-ceramics in the past decade has been the formation of submicron-sized grains. This material with uniform distribution of microcrystals and glass phases combines the superior properties of glass and ceramics, such as high mechanical strength, corrosion resistance, wear resistance, and good thermal stability. Especially in terms of light transmission, when the grain size is small enough, optical losses such as light scattering can be avoided. According to the light scattering theory, if we want to avoid light scattering, the grain size must be smaller than the wavelength of the incident light, which is also for us to design Glass ceramics that transmit specific light bands provide the theoretical basis.

Thermal imaging systems were originally used in military applications, but now they are increasingly used in civilian equipment, and their market potential is huge. In the thermal imaging system, the infrared lens is the key optical device. Existing infrared lenses such as Ge single crystals are expensive, difficult to polish and shape, and difficult to prepare large-scale objects. As its substitute, infrared transparent glass has a large high-temperature thermal expansion coefficient, and its hardness needs to be improved. Although the crystallization of chalcogenide glasses has been studied, few attempts have been made to obtain infrared-transmitting glass ceramics through controllable crystallization.

Among the existing commercialized infrared-transmitting chalcogenide glasses, the grade 205 chalcogenide glass has been widely used, and its chemical composition is Ge ₂₈ Sb ₁₂ Se ₆₀ . This glass has a wide transmission window and a high Infrared transmittance, but due to its high brittleness and poor mechanical properties, the glass has poor processability, so the yield is low in the actual production process. This is a technical problem that needs to be solved urgently. If you want to solve the above problems by directly microcrystallizing Ge ₂₈ Sb ₁₂ Se ₆₀ glass to obtain its crystallized glass, this method is difficult to realize, because the crystallization process of Ge ₂₈ Sb ₁₂ Se ₆₀ is surface crystallization, and the crystallization Crystals are uncontrollable and will eventually lead to devitrification of the glass. Therefore, it is very important to find a material with high mechanical properties and good infrared transmission properties.

Contents of the invention

The technical problem to be solved by the present invention is to provide a glass-ceramic and its preparation method for the above-mentioned deficiencies in the prior art. The prepared glass-ceramic improves the transmission window of the base glass without changing the transmission window strength.

In order to solve the problems of the technologies described above, the technical solution provided by the invention is:

A glass ceramic is provided, the chemical composition of the glass ceramic is Ga _x+y Ge _28-x Sb _12-y Se ₆₀ , where x∈[2,5], y∈[1,3].

Preferably, said x=4, y=2.

The present invention also provides the preparation method of above-mentioned glass ceramics, and its steps are as follows:

1) Weighing raw materials: according to the equivalent ratio of elements Ga, Ge, Sb and Se in Ga _x+y Ge _28-x Sb _12-y Se ₆₀ , weigh the amount of elemental Ga, Ge, Sb and Se for future use;

2) Preparation of basic glass: in an inert atmosphere, mix the raw materials weighed in step 1), grind them into batches, place them in a container and evacuate them to a degree of 10 ^-3 -10 ^-6 Pa, and then Melt the container and heat it, slowly heat up to 850-950°C at a rate of 3°C/min, keep warm for 8-20h, then cool down to 600-650°C with the furnace, keep warm for 1-3h, take it out, and place it in the air or Quenched in water, then kept at 280-340°C for 2 hours for annealing, and finally sliced and polished to obtain basic glass;

3) Preparation of glass ceramics: the basic glass obtained in step 2) is placed in a vacuum-sealed tube furnace for microcrystallization treatment, and after the microcrystallization treatment is completed, it is naturally cooled with the furnace to obtain glass ceramics.

According to the above scheme, the purity of the simple substances Ga, Ge, Sb and Se in step 1) is all above 99.999%.

According to the above scheme, the microcrystallization treatment process conditions in step 3) are as follows: the temperature is raised to 300-360° C. at room temperature and kept for 120-360 hours.

The present invention also provides the application of the above-mentioned glass-ceramic as an infrared window material. The glass-ceramic has good light transmittance at λ=1-16 μm, and the transmittance is greater than 60%.

The present invention is based on Ge ₂₈ Sb ₁₂ Se ₆₀ , adding a small amount of Ga element into the glass, Ga element replaces part of Ge and Sb to form Ga _x+y Ge _28-x Sb _12-y Se ₆₀ glass, and then glass crystallite into glass ceramics.

Ga, as a crystal nucleating agent, can improve the nucleation ability of glass, and can change the crystallization process from surface crystallization to bulk crystallization, and after a large number of experimental attempts, the applicant found that the glass can be realized by adjusting the appropriate composition. Controllable crystallization of ceramics, the Ga _x+y Ge _28-x Sb _12-y Se ₆₀ glass is made into glass ceramics, and its mechanical properties will be greatly improved under the condition that its transmission properties remain unchanged.

The beneficial effect of the present invention is that: compared with Ge ₂₈ Sb ₁₂ Se ₆₀ base glass, the glass-ceramic provided by the present invention retains the high transmittance and wide transmission window of the original base glass, and has a greater improvement in strength , its Vickers hardness is up to 1.2 times higher than that of the base glass.

Description of drawings

Fig. 1 is the transmittance collection of illustrative plates of the glass ceramics that embodiment of the present invention 1,2,3 gains;

Fig. 2 is the micro Vickers hardness photo of the glass-ceramic obtained in embodiment 2;

3 is an optical micrograph of the glass ceramic obtained in Example 3.

detailed description

In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings.

Example 1

A glass ceramic whose chemical composition is Ga ₃ Ge ₂₆ Sb ₁₁ Se ₆₀ .

The specific preparation method is as follows:

1) Weigh raw materials: according to the molar percentage of each raw material: Ga3%, Ge26%, Sb11%, Se60%, select elemental Ga, Ge, Sb and Se, the purity is 99.999%, and set aside;

2) Preparation of basic glass: In an environment full of inert gas, mix Ga, Ge, Sb and Se raw materials, grind and mix them to make batches, put them in a container and vacuumize, the vacuum degree is 10 ^-3 -10 ^-6 Pa, then melt the container and put it in the heating equipment for heating, slowly raise the temperature to 900°C at a rate of 3°C/min, and keep it at this temperature for 20h, then cool it down to 650°C with the furnace, keep it for 3h and then take it out , quenched in air, and then annealed at 320°C for 2 hours, then sliced and polished to obtain the basic glass. During the preparation process, shake or shake the container to achieve homogenization;

3) Preparation of glass ceramics: place the basic glass obtained in step 2) in a vacuum-sealed tube furnace for microcrystallization treatment. After the end, it was naturally cooled with the furnace to obtain glass ceramics (denoted as Y1).

The transmittance curve of the prepared glass ceramics is shown in Figure 1-Y1, which has a transmittance of more than 60% in the wavelength range of 1-16 μm; at the same time, the Vickers hardness of this example was measured with a microhardness tester, and the Take the average value of 30 points, the average value of Hv is 135kgf/mm ^-2 , the same method is used to measure the hardness of the basic glass, the average value is 120kgf/mm ^-2 , the hardness is 0.125 times higher than that of the basic glass.

Example 2

A glass ceramic whose chemical composition is Ga ₆ Ge ₂₄ Sb ₁₀ Se ₆₀ .

The specific preparation method is as follows:

1) Weigh raw materials: according to the molar percentage of each raw material: Ga6%, Ge24%, Sb10%, Se60%, select elemental Ga, Ge, Sb and Se, the purity is 99.999%, and set aside;

2) Preparation of basic glass: In an environment full of inert gas, mix Ga, Ge, Sb and Se raw materials, grind and mix them to make batches, put them in a container and vacuumize, the vacuum degree is 10 ^-3 -10 ^-6 Pa, then melt the container and place it in the heating equipment for heating, slowly raise the temperature to 930°C at a speed of 3°C/min, and keep it at this temperature for 20h, then cool it down to 650°C with the furnace, keep it for 3h and then take it out , quenched in air or water at room temperature, and then annealed at 320°C for 2 hours, then sliced and polished to obtain the basic glass;

3) Preparation of glass ceramics: place the basic glass obtained in step 2) in a vacuum-sealed tube furnace for microcrystallization treatment. After the end, it was naturally cooled with the furnace to obtain glass ceramics (denoted as Y2).

The transmittance curve of the prepared glass-ceramic is shown in accompanying drawing 1-Y2, there is more than 60% transmittance in 1-16 μ m wavelength range; The photo of the micro Vickers hardness of the prepared glass ceramics is shown in Fig. 2), and 30 points were made, and the average value was taken, and the average value of Hv was 152kgf/mm ^-2 . 120kgf/mm ^-2 , the hardness is 0.26 times higher than that of basic glass.

Example 3

A glass ceramic whose chemical composition is Ga ₈ Ge ₂₃ Sb ₉ Se ₆₀ .

The specific preparation method is as follows:

1) Weigh raw materials: according to the molar percentage of each raw material: Ga8%, Ge23%, Sb9%, Se60%, select elemental Ga, Ge, Sb and Se, the purity is 99.999%, and set aside;

2) Preparation of basic glass: In an environment full of inert gas, mix Ga, Ge, Sb and Se raw materials, grind and mix them to make batches, put them in a container and vacuumize, the vacuum degree is 10 ^-3 -10 ^-6 Pa, then melt the container and place it in the heating equipment for heating, slowly raise the temperature to 930°C at a speed of 3°C/min, and keep it at this temperature for 20h, then cool it down to 650°C with the furnace, keep it for 3h and then take it out , quenched in air or water at room temperature, and then annealed at 320°C for 2 hours, then sliced and polished to obtain the basic glass;

4) Preparation of glass ceramics: place the basic glass obtained in step 2) in a vacuum-sealed tube furnace for microcrystallization treatment. After the end, it was naturally cooled with the furnace to obtain glass ceramics (denoted as Y3).

The transmittance curve of the prepared glass ceramics is shown in Figure 1-Y3, which has a transmittance of more than 60% in the wavelength range of 1-16 μm. The thermal expansion coefficients of the original basic glasses of Y1, Y2, and Y3 are 146×10 ^-7 K ^-1 , 143×10 ^-7 K ^-1 and 145×10 ^-7 K ^-1 , respectively, and the thermal expansion coefficients of the prepared glass ceramics are 113 ×10 ^-7 K ^-1 , 105×10 ^-7 K ^-1 and 108×10 ^-7 K ^-1 , compared with the base glass, the glass-ceramic The coefficient of thermal expansion is significantly reduced.

The Vickers hardness of this example was measured with a microhardness tester, 30 points were scored, and the average value was taken. The average value of Hv was 143kgf/mm ^-2 . The same method was used to measure the hardness of the basic glass, and the average value was 120kgf/mm ^-2 , the hardness is 0.2 times higher than that of the base glass. The optical micrograph of the glass ceramics obtained in this embodiment is shown in FIG. 3 . It can be seen that the crystal grains of the glass ceramics are fine and evenly distributed, and the grain size is less than 10 nanometers.

Claims (6)

1. A glass-ceramic, characterized in that the chemical composition of the glass-ceramic is Ga _x+y Ge _28-x Sb _12-y Se ₆₀ , wherein x∈[2,5], y∈[1,3 ]. 2. The glass ceramic according to claim 1, characterized in that: said x=4, y=2. 3. A preparation method of the glass-ceramic according to claim 1 or 2, characterized in that the steps are as follows: 1) Weighing raw materials: according to the equivalent ratio of elements Ga, Ge, Sb and Se in Ga _x+y Ge _28-x Sb _12-y Se ₆₀ , weigh the amount of elemental Ga, Ge, Sb and Se for future use; 2) Preparation of basic glass: in an inert atmosphere, mix the raw materials weighed in step 1), grind them into batches, place them in a container and evacuate them to a degree of 10 ^-3 -10 ^-6 Pa, and then Melt the container and heat it, slowly heat up to 850-950°C at a rate of 3°C/min, keep warm for 8-20h, then cool down to 600-650°C with the furnace, keep warm for 1-3h, take it out, and place it in the air or Quenched in water, then kept at 280-340°C for 2 hours for annealing, and finally sliced and polished to obtain basic glass; 3) Preparation of glass ceramics: the basic glass obtained in step 2) is placed in a vacuum-sealed tube furnace for microcrystallization treatment, and after the microcrystallization treatment is completed, it is naturally cooled with the furnace to obtain glass ceramics. 4. The preparation method according to claim 3, characterized in that the purity of the elemental Ga, Ge, Sb and Se in step 1) is above 99.999%. 5 . The preparation method according to claim 3 , characterized in that the microcrystallization treatment process conditions in step 3) are: heating to 300-360° C. at room temperature and keeping the temperature for 120-360 hours. 6. An application of the glass-ceramic according to claim 1 or 2 as an infrared window material, characterized in that the transmittance of the glass-ceramic at λ=1-16 μm is greater than 60%.