SU1661156A1 - Method of producing nitrided phosphate glass - Google Patents

Abstract

This invention relates to the field of producing phosphate glasses with a low refractive index, which can be used in the optoelectronic industry. The goal is to increase the microhardness, decrease the linear thermal expansion coefficient of the glass by increasing the content of chemically bound nitrogen in the glass. The method includes the following operations. A mixture consisting of zinc and magnesium phosphates, into which boron and aluminum nitrides are introduced, is made up in such a quantity that the content of bound nitrogen in glass in terms of nitrides is 10-50 mol%. The mixture is placed in a crucible, the material of which does not contain cations that make up nitrides, and glass is synthesized under oxidizing conditions at temperatures between 100 and 200 ° C above the melting point of the initial phosphate mixture, but not above 1300 ° C. After synthesis, the glass is rapidly cooled to room temperature. Chemical resistance of glass to water is 0.08–0.170 mg / cm ² , microhardness 300–900 kg / mm ² , thermal expansion coefficient (CLP) (30–62) ^. 10 ^-7 1 / K. 1 TABLE

Description

This invention relates to a process for producing nitrated phosphate glass with improved performance properties that can be used in optoelectronics.

The purpose of the invention is to increase the microhardness, decrease the coefficient of linear thermal expansion of glass by increasing the content of chemically bound nitrogen in the glass.

The method is carried out as follows. In a mixture consisting of zinc and magnesium phosphates, boron and aluminum nitrides are introduced so that the glass is chemically bound

nitrogen was 10-50 mol.%, a corundum or platinum crucible, covered with a lid of the same material, and placed in an electric resistance furnace. The oven temperature is raised to a temperature of 100-200 ° C above the melting point of the initial phosphates and kept at this temperature for 30-45 minutes, then cooled rapidly. Oxidizing conditions are provided by cooking in an electric furnace in an oxidizing atmosphere (air) in a crucible made of substances that do not contain reducing agents, and also by the absence of reducing agents in the mixture.

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If boron nitride and magnesium are introduced into the mixture, the synthesis is carried out in corundum crucibles, if aluminum nitride is introduced into platinum crucibles. Carrying out the process in an oxidizing atmosphere prevents not only the reduction of phosphorus within the specified temperature limits, but also provides a more complete incorporation of nitrides into phosphate glasses.

The original glass has a composition, mol.%: ZnO 25; MgO 0.25; P20s 50.

Example 1. A mixture containing, g: Zn (H2Pp4} zx2H20 5.9; Md (PO3) 2 3.6; BN 0.26, mixed, placed in a corundum crucible and tightly closed with a corundum lid. Then the crucible is placed in an electric resistance furnace with initial temperature of 900 ° C, then the temperature in the furnace is raised to 1200 ° C and maintained at this temperature for 45 minutes Then the crucible is removed from the furnace, the molten glass is poured onto the steel substrate. The finished glass is annealed at 600 ° C for 30 minutes. the glass is stable, transparent and has a low refractive index. glass sample of 8.6 g. The content of chemically bound nitrogen in terms of BN is 20 mol.%.

PRI mme R 2. A mixture containing, g: Zn (H2P04) 2 -2H20 5.9; Md (POH) 2 3.6; BN 0.2; AIN 0.11, mix, fall asleep in a platinum crucible and close it with a lid. The crucible with the charge is placed in an electric furnace at 950 ° C, the temperature is raised to 1250 ° C and maintained at this temperature for 50 minutes, after which the crucible is removed from the furnace. The finished glass is stable, transparent, has a low refractive index. The mass of the obtained sample of 8.7 g

The content of chemically bound nitrogen in terms of BN is 15 mol.% + AIN - 5 mol.%.

Example 3. A mixture of Zn (POa) 2, MD (ROS and AIN mixed, poured into a platinum crucible, which is closed with a lid, the crucible with the mixture is placed in an electric furnace at 900 ° C, raise the temperature to 1300 ° C and incubated for 45 min, after the crucible is removed. The finished glass is annealed at 600 ° C for 30 minutes, the resulting glass is stable, transparent, and has a low refractive index.

The glass contains nitrogen in terms of AIN 15 mol.%.

The dependence of the operational properties of nitrated phosphate glasses on the synthesis conditions and the molecular content of nitrogen in glass in terms of boron nitride and aluminum nitride in glass is presented in the table.

As can be seen from the table, an increase in nitrogen content in nitrated phosphate glass in terms of nitrides in the range of 10-50 mol.%, When carrying out synthesis under oxidizing conditions and corresponding temperatures, allows, in comparison with the known glass obtained in reducing conditions, to increase microhardness three times, to reduce the coefficient of linear thermal expansion by 3-4 times.

Claims (1)

Invention Formula A method of producing low refractive index nitrated phosphate glass, including preparing the charge, introducing nitrides into it, and cooking, characterized in that, in order to increase the microhardness, decrease the linear thermal expansion coefficient by increasing the content of chemically bound nitrogen in the glass, in an oxidizing environment at a temperature above the melting point of the mixture of initial phosphates by 100–200 ° C, but not higher than 1300 ° C. Chemically resilience to NlO, mg / cm 0.35 + 0.02 0.13 + 0.01 0.12 + 0.01 0.17 + 0.01 0.1 + 0.01 0.08 + 0.01 0, 12 + 0.02 Micro Vickers Hardness, kg / mm2 250 + 30 550 + 50 850 + 50 900 + 50 600 + 50 650 + 50 560 + 50 Coefficient linear thermal extensions x 1 (H deg-1 68 + 542 + 330 + 335 + 445 + 5 Tendency to crystallization, intensity of exothermic effect, 25 50 + 5 38 + 5 sixteen ten ten 20 23 25 50 + 5 38 + 5 ten 20 23 25