SU726046A1 - Method of strengthening glass articles - Google Patents

Description

This invention relates to a method of strengthening glass products by replacing sodium and / or potassium ions contained in reinforced products with lithium ions contained in pairs.

There is a method of hardening glassware by ion exchange in lithium salt C.

The closest to the present invention is a method of hardening glass products by ion exchange, which is characterized by the fact that glass products containing, wt.%: N32О + К2О 7.0-25.0; SiOj 45.0-80.0; VgOz 0-5.0, as well as soda-lime glass containing, wt.%: SiO 65.0-74.0; NajO 14.0-17.0; MgO + CaO 7.0-12.0; is heated in air to a temperature corresponding to the viscosity of the glass from 10 to 10 -P. Then it is kept for at least 1 hour in pairs of at least one of the following lithium compounds: lithium iodide, lithium fluoride, lithium bromide, lithium chloride, lithium sulphate, and lithium sulfate with a view to; Parts of sodium and / or potassium ion are replaced by lithium ions released from the vapors of these compounds. After this product is cooled in air atmosphere, not subject to vapor 2.

However, the lithium compounds used can be used only for refractory glasses, the softening temperature of which is higher than the melting point of individual lithium compounds or a mixture of them.

The purpose of the invention is to improve the quality of hardening of products from fusible glasses.

The goal is achieved by the fact that in the method of hardening products from a glass ;; and by ion exchange, including heating products to a temperature of 10–20 ° C below the glass softening temperature, treating them with vapors containing lithium ions, and subsequent cooling in air, processing products are carried out in pairs containing,%: ioride lithium 50-80 and at least one salt from the group: lithium nitrate, sour sour, lithium fluorosulfonic acid, lithium perchloric acid 20-50.

Processing of glass products in pairs of lithium compounds is carried out over time. required to obtain the desired degree of hardening. Example 1. Annealed discs with a mechanically polished surface with a diameter of 80 mm and a thickness of 2.0 + 0.2 mm from an electrovacuum glass composition, weight,%: SiOj 60.0 ± 2.0; AlzO., 3.0 ± 1.0; BAO 12.0 ± 1.0; N3.0 6.0 ± 1.0; KjO 8.6 ± 1.0; CrO3 i ,, 5- MpO 8.5 ± 1.5; CoO 0.5 + 0.2 and LiaO}, 0 t 0.5, with an initial mechanical flexural strength of 5.3 kg / mm with a coefficient of variation of 11, are placed on special supports preventing the samples from touching each other and ensuring free the access of vapors to the glass surface is placed in the working space of the electric furnace and heated in air to 510 ° C. Then from the second chamber of the same furnace vapor of a mixture of lithium compounds of the composition, wt.%: 70.0 lithium chloride; 15.0 lithium perchloric acid and 15.0 lithium fluorosulfonic acid. The duration of exposure of the samples in the vapor mixture of lithium compounds is 30 minutes. Cooling of the strengthened glass samples is carried out in air at a rate of 2.5 ° C / min. In the processed glass disks, no changes (shape and surface) were observed by visual inspection. The average strength of the samples, determined by the method of central bending, obtained on the basis of 48 measurements, 11.7 kg / mm with a variation coefficient of .12.3%, i.e. it increases about 2.2 times. The feed rate of the load for both the initial and vapor-treated lithium compounds of the samples is 5 kg / mm, s. Example 2. Annealed rods with a diameter of 3.5 ± 0.2 mm and a length of 120 mm made of glass intended for the manufacture of parts for an electrovacuum technology of composition, weight,%: SiOz 74.0 ± 1.0; MDO 3.9 + 0.3; CaO 5.5 + 0.5; NaaO 16.6 ± 1.0 with initial average bending strength, determined by the four-point transverse bending method, 7.4 kg / mm with a variation coefficient of 10.6% is placed in special containers, which exclude the contact of the samples with each other and provide free vapor access to the surface of the samples. The containers with the samples are placed in the first chamber of the working space of the electric furnace and heated to 530 ° C, i.e. 20 ° C below the glass softening point. Then from the second chamber of the same furnace vapors of a mixture of lithium compounds of composition, wt.%: 75.0 lithium chloride; 10.0 lithium fluorosulfonic; 10.0 liter perchloric acid and 5.0 lithium sulfite. The duration of the sample holding in pairs of lithium compounds is 45 minutes. Cooling; Hardening of the samples is carried out in air at a rate of 2.5 C / min. In the treated shtabikov, no deformation was observed. The average strength of the samples, determined by a transverse four-point bend, obtained on the basis of 52 measurements, 193 kg / mm with a variation coefficient of 13.0%, i.e. increases by more than 2.5 times. When testing the strength of both the original and the processed shtabikov, the distance between the fixed supports is 100 + 0.2 mm, the distance between the moving and fixed prisms is 30 + 0.2 mm, and the feed rate (load) is 30 mm / min. Example 3. Heads with a diameter of 3.5 + 0.1 mm and a length of 120 mm made of glass intended for the electrovacuum production of the composition, wt.%: SiO2 67.5 J 0.5; ABOz 5 ± 0,5; BAO 12.0 ± 0.6; KjO 7.0 + i 0.5; NaaO ± 0.5; LiiO t 0.15; F 0.7 + 0.2 with an initial strength of 7.7 kg / mm with a coefficient of variation of 11.2%, placed in special stainless steel containers, placed in a working space of an electric furnace, and heated in air to 490 ° C. Then, from the second chamber of the same furnace, a mixture of lithium vapors of the composition, wt.%: 80.0 lithium chloride; 10.0 lithium nitrate and 10.0 lithium sulphite. The duration of exposure shtabikov in a mixture of vapors of lithium compounds 45 min. The hardened blades are cooled in air at a rate of 3.5 ° C / min. The average strength of the staffs is 21.1 kg / mm with a variation coefficient of 13.8%, i.e. increases by more than 2.5 times. Example 4. The non-reinforced shells of 23LK-type kinescopes made of glass of the composition shown in example 3 and withstanding an external overpressure of 1 MPa are heated in electric furnaces on special hangers at a rate of 2.5 ° C / min to 480 ° C and then subjected exposure to vapors of a mixture of lithium compounds of the composition, wt.%: 70.0 lithium chloride; 20.0 lithium fluorosulfonic; 5.0 lithium nitrate and 5.0 lithium perchloric acid. The time of the shells of kinescopes in pairs of lithium compounds I h. Then the shells of the kinescopes are cooled in an air atmosphere at a rate of 2.5 ° C / min. When visual inspection of the shells of kinescopes changes in appearance are not detected. Strengthened shells of kinescopes are subjected to excess pressure up to 5 MPa. Destruction during testing does not occur.

5 7260466

Formula and .h gain pax containing,%: lithium chloride 50-80

The method of hardening glass products by lithium nitrate, lithium sulphate, ion exchange, including heating lithium fluorosulfonic acid products, perchloric acid to a temperature 10-20 ° below the temperature of lithium 20-50. glass softening, processing them with vapors containing lithium ions, and subsequent cooling of sources of information, airborne conditions, which are distinguished into account when examining u and in order to improve the quality of chemical methods of strengthening the management of products from low-melting glass. M., TsNIIPI, 1967, p. 7-8. glass processing products carried out in pa-2. US patent No. 3615319, cl. 65-30, 1971.

and, at least, one salt from the group:

Claims (1)

Claim The method of hardening glass products by ion exchange, including heating the products to a temperature of 10-20 ° below the softening temperature of the glass, treating them with vapors containing lithium ions, and subsequent cooling in air, characterized in that, in order to improve the quality of hardening of products from fusible glasses, processing of products is carried out in steam