RU2069619C1 - Material "neopol" for manufacturing hard polishing instrument - Google Patents

Abstract

FIELD: production of polishing materials. SUBSTANCE: solid polishing material "Neopol" useful in suspensionlessly polishing parts made of optical glasses and various-type sitals is based on low-cost inorganic binder. Novelty consists in that material contains abrasive and ceramic binder composed, wt. - %: boron oxide 1.2-10.0, silica 0.5-6.0, alumina 0.6-1.0, potassium carbonate 0.07-1.30, magnesium trioxide 0.08-1.30, calcium oxide 0.04-0.20, sodium carbonate 0.05-0.20. Ratio of abrasive (cerite) to binder is (80-98):(2-20). EFFECT: enhanced performance. 2 cl, 2 tbl

Description

 The invention relates to the production of a solid polishing tool on an inorganic binder for the non-suspension polishing of parts from optical glasses and glass plates of various grades.

 Known materials for non-suspension polishing of optical parts based on various polishing resins. A method of manufacturing a polishing pad is described, which consists in introducing 50 weight into the molten polishing resin. polishing powder, stir and mold the polishing pad.

 An abrasive mass is also used, containing an abrasive, a filler (metal, alloy, metal carbide, metal oxide, etc.) an alkali metal salt and an organic binder (various resins). The polishing pad is characterized by high wear resistance due to the introduction of alkali metal salts and carbonic acid.

 The main disadvantage of these materials is the dependence of the surface shape of the tool on temperature changes during polishing and, as a result, low accuracy in the shaping of optical surfaces.

This disadvantage is absent in the so-called solid polishing pad. A known material for a solid abrasive tool containing an organic binder in the following ratio of components (wt.) / 3 /:
abrasive 90 95
pitch 4.5 8.5
pulverbakelite 0.5 1.5
The use of solid polishers allows you to automate the polishing process and significantly reduce the consumption of scarce and expensive polishing powder, which will ultimately lead to a significant improvement in the entire technological process for processing optical parts.

 However, with all the obvious advantages of these materials (high productivity, accuracy of forming), they have a number of significant drawbacks, namely, the instability of polishing properties due to the inconsistency of the structural formula of the organic binder, the need to use intensive polishing modes and, as a consequence, the impossibility of their use for polishing large-sized parts, as well as the toxicity of the binder.

 The proposed technical solution allows to increase the stability of polishing properties, the performance of the polishing process, reduce toxicity, and expand the field of application (from micro-optics to large-sized parts made of optical glass and glass materials of various grades, crystals, and other solid materials).

The essence of the invention lies in the fact that an inorganic binder of the following composition (wt.) Is introduced into the abrasive powder (cerite): B ₂ O ₃ 1.20-10.00, SiO ₂ 0.50-6.00, Al ₂ O ₃ 0 , 60-1.00, K ₂ CO ₃ 0.07-1.30, MgO 0.08-1.30, CaO 0.04 -0.20, Na ₂ CO ₃ 0.05-0.20, with the ratio of abrasive and ligament (wt.): abrasive 80.00-98.00, ligament 2.00 -20.00. It is this combination of oxides in the binder that ensures the continuous supply of grains of polishing material and their constant renewal on the treated surface.

 The binder material gives high manufacturability to the materials made on its basis, namely plasticity during molding of products, strength during drying and preservation of these properties during further heat treatment of the finished material. Such characteristics of the material as strength, hardness, porosity, wear resistance can be varied over a wide range, changing the heat treatment mode.

For the manufacture of polishing elements, a mixture of the abrasive with the indicated oxides is thoroughly mixed in ethanol, dried, pressed into tablets of size d 15 mm, h 7 -8 mm, which are then calcined in air at temperatures of 760 880 ^o C for 5 hours. The compositions of the tested elements are shown in table 1.

 From the obtained elements (tablets) in the amount of 24 pieces, a polishing tool is prepared by attaching them with shellac to an AC-59 brass faceplate with a diameter of d 100 mm. Before measurements, the polishing tool is ground with an AFM 125/100 M1 diamond plan washer to ΔΗ≈0 (spread at the height of the elements). Measurement of tool wear is carried out on flat parts made of CO-115M ceramic, with a diameter of 130 mm, pre-polished to N 3, ΔN 0.3 and P111 purity, sequentially every 60 minutes of polishing by direct measurements at 4 points on its surface. The measurement results are compared with those for the prototype (table 2).

Tests are carried out on the 6ShP-150M machine under various modes:
pressure P 100 330 g / cm ²
spindle speed ω 90 180 rpm
upper link vibration frequency v 40 63 dv.hod. / min
span 30 mm
EXAMPLE 1 (composition 1): A tool for polishing optical parts is manufactured.

A mass of 100 g for a polishing tool is prepared as follows. Prepare samples of abrasive (cerite) and ligaments in the following quantities, g:
CeO ₂ 90.0 (TU 48-4-467-85)
B _2> O ₃ 4.0 (TU 6-09-1853-77)
SiO ₂ 3.0 (GOST 9428-73)
Al ₂ O ₃ 0.7 (TU 6-09-426-75)
K ₂ CO ₃ 1,0 (TU 6-09-2831-78)
MgO 1,0 (GOST 4526-75)
CaO 0.1 (TU 6-09-3587-79)
Na ₂ CO ₃ 0.2 (GOST 83-79)
They are mixed in an agate mortar for 1 hour in ethanol (GOST 17299-78), dried, pressed 24 tablets with a diameter of 15 mm, a height of 7-8 mm under a pressure of 500 kg / cm ² and burn in air at temperatures of 760, 800 , 820 or 850 ^o C for 5 hours in an electric furnace brand SNOL-1,6.2.5.1 / 11-43. A polishing tool is made from the obtained elements and tested for polishing ability when polishing for 120 minutes the СО-115М metal on the 6ШП-150М machine under the following conditions:
P 144 g / cm ²
v 63 d.p./min
w 180 rpm
The test results are shown in the table.

EXAMPLE 2 (composition II): Take a sample of abrasive (cerite) and ligaments in the following quantities, g: CeO ₂ 92.00; B ₂ O ₃ 3,50; SiO ₂ 2.50; Al ₂ O ₃ 0.40; K ₂ CO ₃ 0.07; MgO 0.08; CaO 0.10; Na ₂ CO ₃ 0.10.

The manufacture of elements (tablets) is carried out by the method described in example 1, and calcined at a temperature of 830 ^o C for 5 hours. Polishing tools are also made and tested in the same way. The test results are shown in the table.

EXAMPLE 3 (composition III): Take samples of abrasive (cerite) and ligaments in the following quantities, g: CeO ₂ 95.00; B ₂ O ₃ 3.00; SiO ₂ 1.50; Al ₂ O ₃ 0.10; K ₂ CO ₃ 0.15; MgO 0.15; CaO 0.05; Na ₂ CO ₃ 0.05.

The manufacture of tablets and testing them is carried out by the method described in example 1, with the difference that the tablets are fired at a temperature of 860 ^o C for 5 hours. The test results are shown in the table. The selected interval (80 98%) of cerite is due to the following considerations. The concentration of the binder is more than 20 wt. reduces polishing performance (composition V).

 The decrease in the concentration of the binder is less than 2 wt. leads to the destruction of the material during polishing (composition VI).

Tests showed that the proposed composition of the solid polishing material has improved operational properties compared to the prototype with the same quality of the polished surface according to the following indicators:
1. Polishing performance increases from 8 to 40 times.

 2. The wear resistance of the tool increases by 2-33 times.

 Due to the fact that the claimed material will be further introduced into production, we consider it appropriate to assign it the name "Neopol".

Claims (1)

 1. A material for the manufacture of a solid polishing tool containing an abrasive and a binder, characterized in that as the last material contains a ceramic binder of the following composition, wt. B ₂ O ₃ 1.2 10.0
SiO ₂ 0.5 6.0
Al ₂ O ₃ 0.6 1.0
K ₂ CO ₃ 0.07 1.30
MgO 0.08 1.30
CaO 0.04 0.20
Na ₂ CO ₃ 0.05 0.20
while the abrasive and the bond are in the following ratio, wt. Abrasive 80 98
Bundle 2 20
2. The material according to claim 1, characterized in that it contains cerite as an abrasive.

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