CN103359917A - Preparation method of infrared chalcogenide glass lenses - Google Patents

Abstract

The invention discloses a method for preparing an infrared chalcogenide glass lens, which comprises the following steps: 1) putting clean block chalcogenide glass into a planetary ball mill, and sieving after ball milling to obtain chalcogenide glass with a particle size ≤ 6.5 μm Glass powder; 2) Transfer the chalcogenide glass powder into the mold, cool to room temperature naturally after molding, and then remove the mold to obtain the chalcogenide glass lens; 3) Put the chalcogenide glass lens into a precision annealing furnace with a protective atmosphere and keep it warm Then slowly lower the temperature to 80-100°C, and finally turn off the power of the annealing furnace, and cool down to room temperature with the furnace to obtain a uniform chalcogenide glass lens. The infrared chalcogenide glass lens prepared by the method has high uniformity, is suitable for preparing various infrared lenses, and is especially suitable for preparing various lens elements required by infrared night vision systems such as vehicles and security systems.

Description

A kind of preparation method of infrared chalcogenide glass lens

technical field

The invention relates to a method for preparing a glass lens, in particular to a method for preparing an infrared chalcogenide glass lens.

Background technique

Chalcogenide glass is a glass formed by combining sulfur, selenium or tellurium elements in Group VIA elements of the periodic table except oxygen and polonium, or a combination of sulfur, selenium or tellurium elements and other elements. As early as 1870, S. Sellack and others had discovered that sulfur could form glass alone, and found that arsenic sulfide and arsenic selenide could also form stable glass. However, it was not until the 1950s that chalcogenide glasses began to receive widespread attention due to their excellent infrared-transmitting optical properties. In 1950, R. Frerichs and others in the United States re-studied As ₂ S ₃ glass and concluded that this optical material could be used in infrared systems.

At present, there are several types of glass systems such as Ge-As-Se, As-Se, Ge-Sb-Se, and As-S in commercial chalcogenide glasses at home and abroad. Foreign chalcogenide glass manufacturers mainly include Amorphous Materials in the United States, Vitron Gmbh in Germany, and Umicore in France. In China, there are companies such as Ningbo Sunny Infrared, Beijing Guojinghui, and Hubei Xinhuaguang. In addition, Ningbo University’s infrared materials and The device laboratory also has the ability to provide pilot products in batches.

As a new type of infrared optical material, chalcogenide glass has the following advantages and disadvantages compared with germanium single crystal and zinc selenide (ZnSe) crystal: ① In terms of the transmission range, Ge single crystal is the widest, followed by ZnSe crystal. ② As far as the temperature coefficient of refractive index dn/dT is concerned, ZnSe is the lowest, followed by chalcogenide glass, and the highest is Ge single crystal. The dn/dT of chalcogenide glass is 1/9 to 1/5 of that of Ge single crystal material, and heat dissipation Poor performance clearly predominates. ③ In terms of resource utilization and manufacturing and processing costs, chalcogenide glass is the most dominant, mainly because the consumption of Ge sparse resources is low, and as an amorphous material, precision molding technology can be used to manufacture lenses in batches, while ZnSe and Ge single crystals often It requires single-point diamond turning process, which has low production efficiency and high cost. In general, chalcogenide glasses have the advantages of low dn/dT coefficient, low cost of large-scale preparation and processing, and less consumption of Ge resources. Ge single crystal material is still the most commonly used lens material for the front-end optical system of infrared thermal imaging cameras. However, under the circumstances that the rapid growth of the civilian market has led to a sharp increase in the demand for low-cost infrared lens components, especially from the perspective of the future development of civilian night vision systems such as vehicles and security, chalcogenide glass has become a substitute for or used in infrared thermal imaging camera systems. An excellent candidate material to partially replace traditional Ge single crystal lenses.

The manufacture of chalcogenide glass lenses mainly includes the preparation and processing of chalcogenide glass. The preparation of chalcogenide glass needs to be carried out in an oxygen-free and water-free atmosphere due to the particularity of its raw materials. Generally, chalcogenide glass raw materials (such as Ge, Sb or As and Se or S, etc.) are put into a quartz ampoule, vacuumed to <10 ^-3 Pa with a vacuum pump, and then the quartz tube is fused and sealed with acetylene or oxyhydrogen flame , and then put the sealed quartz ampoule into a swing furnace for swing melting, and finally take it out of the furnace for water quenching or air quenching. After annealing, smash the quartz ampoule to obtain a chalcogenide glass sample.

The processing of chalcogenide glass lenses has two types: cold processing and precision molding. The cold processing method of chalcogenide glass is basically the same as that of germanium single crystal and ZnSe crystal. Compared with these traditional infrared crystal materials, the biggest advantage of chalcogenide glass is that it can be precision molded. The precision molding of chalcogenide glass mainly involves the processing and production of precision molds, the design and production of molded separation membranes, the parameters of molding processes, and the precision annealing process after molding, etc.

In the above technology, after the chalcogenide glass is prepared, it is sliced and polished into preforms, and the preforms with good quality (no internal stripes, stones, crystallization, etc.) are selected through optical inspection, and after molding treatment, the final product is obtained Sophisticated infrared optics. In the process of cutting, polishing and selecting, not only need to consume a lot of manpower and material resources, but also cause a lot of resource waste of glass frit. In addition, in order to prepare infrared chalcogenide glass with high uniformity, many equipment and process improvements have been made for the above-mentioned chalcogenide glass preparation process. However, the transformation of equipment and the improvement of process technology are complex processes, which require a large amount of human and financial resources, and the cost is relatively high. It is necessary to study the preparation method of chalcogenide glass and lens with simple process, low cost and high uniformity.

Contents of the invention

The technical problem to be solved by the present invention is to provide a method for preparing infrared chalcogenide glass lenses with low cost and simple process in view of the deficiencies in the prior art. The infrared chalcogenide glass lenses prepared by this method have high uniformity and are suitable for It is suitable for the preparation of various infrared lenses, especially for the preparation of various lens elements required by infrared night vision systems such as vehicles and security systems.

The technical scheme adopted by the present invention to solve the above-mentioned technical problems is: a preparation method of infrared chalcogenide glass lens, comprising the following steps:

1) Preparation of chalcogenide glass powder: put the clean block chalcogenide glass into a planetary ball mill, the weight ratio of the grinding body to the block chalcogenide glass is 5-8:1, at the speed of 200-1000r/min Ball mill for 12-36 hours, and then pass through a 2000-mesh sieve to obtain chalcogenide glass powder with a particle size of ≤6.5 μm;

2) Compression molding: Transfer the above-obtained chalcogenide glass powder into a mold, then mold the glass powder at a temperature of 350-450 ° C and a mechanical pressure of 8-30 MPa for 1-5 hours under a protective atmosphere, and then cool naturally to room temperature, demoulding, to obtain the chalcogenide glass lens;

3) Annealing: put the chalcogenide glass lens obtained by molding into a precision annealing furnace with a protective atmosphere, keep it at a temperature of 270-330°C for 5-10h, and then slowly cool it down at a rate of 0.2-1.0°C/min to 80 ~ 100 ℃, and finally turn off the power of the annealing furnace, so that the chalcogenide glass lens is cooled to room temperature with the furnace, and a uniform chalcogenide glass lens is obtained.

Preferably, in step 1), the bulk chalcogenide glass is a chalcogenide glass scrap, and before use, the chalcogenide glass scrap is immersed in absolute ethanol, and then ultrasonically cleaned at a frequency of 20-50kHz 1 to 3 times, the single ultrasonic cleaning time is 10 to 30 minutes, and then dried at a temperature of 120 to 150 ° C for 30 to 60 minutes to obtain clean chalcogenide glass scraps.

Preferably, the bulk chalcogenide glass is bulk Ge-Sb-Se-like chalcogenide glass.

Compared with the prior art, the advantages of the present invention are as follows: the present invention controls the particle size of the chalcogenide glass powder and combines suitable molding and annealing processes to produce a highly uniform chalcogenide glass without streaks and defects Lenses: chalcogenide glass powder is prepared by using a planetary ball mill before molding, so when preparing chalcogenide glass lenses, it is not limited by the shape and size of chalcogenide glass raw materials, and the flexibility of raw material selection is large during preparation. At the same time, the present invention The method has simple process, the utilization rate of raw materials can reach 100%, no waste of raw materials, and low cost. The method of the invention is suitable for preparing various infrared lenses, and is especially suitable for preparing various lens elements required by infrared night vision systems such as vehicle-mounted and security systems.

Description of drawings

Fig. 1 is a schematic diagram of compression molding for preparing infrared chalcogenide glass lenses by the method of the present invention.

Detailed ways

Below in conjunction with embodiment the present invention is described in further detail.

Example 1: First, immerse the scraps of Ge ₂₈ Sb ₁₂ Se ₆₀ chalcogenide glass in absolute ethanol, and then ultrasonically clean them three times at a frequency of 30 kHz. The time for a single ultrasonic cleaning is 20 minutes, and then dry at 140°C for 60 minutes. , to obtain clean Ge ₂₈ Sb ₁₂ Se ₆₀ chalcogenide glass scraps; then put the above-mentioned clean scraps into a planetary ball mill, the weight ratio of the grinding body to the block chalcogenide glass is 6:1, at a speed of 400r/min Ball mill for 16 hours under the same conditions, and then pass through a 2000-mesh sieve to obtain chalcogenide glass powder with a particle size ≤ 6.5 μm; transfer the chalcogenide glass powder to a cylindrical mold, and then at 380 ° C, under protective atmosphere conditions, under 12 MPa The mechanical pressure of the glass powder is molded for 1.5h, and then naturally cooled to room temperature, and the chalcogenide glass lens is obtained; the chalcogenide glass lens is put into a precision annealing furnace with a protective atmosphere, and kept at 300°C for 6h, and then Slowly lower the temperature to 80°C at a rate of 0.3°C/min, and finally turn off the power of the annealing furnace, and let the chalcogenide glass lens cool down to room temperature with the furnace, and obtain a uniform chalcogenide glass lens.

Example 2: First, immerse the scraps of Ge ₂₀ Sb ₁₅ Se ₆₅ chalcogenide glass in absolute ethanol, and then ultrasonically clean them three times at a frequency of 30 kHz. The time for a single ultrasonic cleaning is 20 minutes, and then dry at 130°C for 50 minutes. , to obtain clean Ge ₂₀ Sb ₁₅ Se ₆₅ chalcogenide glass scraps; then put the above-mentioned clean scraps into a planetary ball mill, the weight ratio of the grinding body to the block chalcogenide glass is 7:1, at a speed of 600r/min Ball mill for 20 hours under the same conditions, and then pass through a 2000-mesh sieve to obtain chalcogenide glass powder with a particle size of ≤6.5 μm; transfer the chalcogenide glass powder to a cylindrical mold, and then heat it at 390°C under a protective atmosphere at 10MPa The mechanical pressure of the glass powder is molded for 2 hours, then naturally cooled to room temperature, and the mold is removed to obtain a chalcogenide glass lens; the chalcogenide glass lens is placed in a precision annealing furnace with a protective atmosphere, kept at 280 ° C for 8 hours, and then Slowly lower the temperature to 95°C at a rate of 0.5°C/min, and finally turn off the power of the annealing furnace to allow the chalcogenide glass lens to cool down to room temperature with the furnace, and obtain a uniform chalcogenide glass lens.

Example 3: First, immerse the scraps of Ge ₃₀ Sb ₁₀ Se ₆₀ chalcogenide glass in absolute ethanol, and then ultrasonically clean them three times at a frequency of 30 kHz. The time for a single ultrasonic cleaning is 20 minutes, and then dry at 140°C for 60 minutes. , to obtain clean Ge ₃₀ Sb ₁₀ Se ₆₀ chalcogenide glass scraps; then put the above-mentioned clean scraps into a planetary ball mill, the weight ratio of the grinding body to the block chalcogenide glass is 7.5:1, at a speed of 900r/min Ball mill for 12 hours under the same conditions, and then pass through a 2000-mesh sieve to obtain chalcogenide glass powder with a particle size of ≤6.5 μm; transfer the chalcogenide glass powder to an aspherical mold, and then at 380°C, under protective atmosphere conditions, under 14MPa The mechanical pressure of the glass powder is molded for 5 hours, then naturally cooled to room temperature, and the mold is removed to obtain a chalcogenide glass lens; the chalcogenide glass lens is placed in a precision annealing furnace with a protective atmosphere, and kept at 300 ° C for 6 hours, and then Slowly cool down to 100°C at a rate of 0.7°C/min, and finally turn off the power of the annealing furnace, and let the chalcogenide glass lens cool down to room temperature with the furnace, and then obtain a uniform chalcogenide glass lens.

Example 4: First, immerse the scraps of Ge ₁₅ Sb ₂₀ Se ₆₅ chalcogenide glass in absolute ethanol, and then ultrasonically clean them three times at a frequency of 30 kHz. The time for a single ultrasonic cleaning is 20 minutes, and then dry at 130°C for 50 minutes. , to obtain clean Ge ₁₅ Sb ₂₀ Se ₆₅ chalcogenide glass scraps; then put the above-mentioned clean scraps into a planetary ball mill, the weight ratio of the grinding body to the block chalcogenide glass is 8:1, at a speed of 1000r/min Ball mill for 33 hours under the same conditions, and then pass through a 2000-mesh sieve to obtain chalcogenide glass powder with a particle size of ≤6.5 μm; transfer the chalcogenide glass powder to an aspherical mold, and then at 410°C, under protective atmosphere conditions, under 30MPa The mechanical pressure of the glass powder is molded for 1 hour, then naturally cooled to room temperature, and the mold is removed to obtain a chalcogenide glass lens; the chalcogenide glass lens is placed in a precision annealing furnace with a protective atmosphere, and kept at 320 ° C for 9 hours, and then Slowly lower the temperature to 80°C at a rate of 1.0°C/min, and finally turn off the power of the annealing furnace to allow the chalcogenide glass lens to cool down to room temperature along with the furnace to obtain a uniform chalcogenide glass lens.

Claims (3)

1. the preparation method of an infrared chalcogenide glass eyeglass is characterized in that may further comprise the steps:

1) preparation chalcogenide glass powder: clean block chalcogenide glass is put into planetary ball mill, the weight ratio of grinding element and block chalcogenide glass is 5～8:1, ball milling 12～36h under the speed conditions of 200～1000r/min, then cross 2000 mesh sieves, obtain the chalcogenide glass powder of particle diameter≤6.5 μ m;

2) compression molding: chalcogenide glass powder obtained above is transferred in the mould, then under 350～450 ℃ of temperature, under the protective atmosphere condition with the mechanical pressure of 8～30MPa to glass powder mold pressing 1～5h, then naturally cool to room temperature, move back mould, obtain the chalcogenide glass eyeglass;

3) annealing: the chalcogenide glass eyeglass that will obtain through mold pressing; put into the fine annealing stove of protective atmosphere; under 270～330 ℃ of temperature, be incubated 5～10h; then with the speed slow cooling to 80 of 0.2～1.0 ℃/min～100 ℃; close at last the power supply of annealing furnace; make the chalcogenide glass eyeglass cool to room temperature with the furnace, namely obtain uniform chalcogenide glass eyeglass.

2. the preparation method of a kind of infrared chalcogenide glass eyeglass according to claim 1, it is characterized in that in the step 1), described block chalcogenide glass is the chalcogenide glass scrap stock, first described chalcogenide glass scrap stock are immersed in the dehydrated alcohol before the use, be ultrasonic cleaning 1～3 time under 20～50kHz condition in frequency again, the single ultrasonic cleaning time is 10～30min, and then dry 30～60min under 120～150 ℃ of temperature obtains clean chalcogenide glass scrap stock.

3. the preparation method of a kind of infrared chalcogenide glass eyeglass according to claim 1 and 2 is characterized in that described block chalcogenide glass is block Ge-Sb-Se class chalcogenide glass.

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