SU1316803A1 - Glass/ceramic binder for abrasive tool - Google Patents

Abstract

The invention relates to the field of machine tool and aviation industry, in particular to the links and technology of making abrasive tools, mainly containing cubic boron nitride or diamond, used for sharpening metal cutting tools from hardened steels without using coolants, and improves grinding performance and tool wear resistance. The binding contains, in wt%: lead zinc borosilicate glass 35–70, borosilicate glass 3–35, chromium 3–20, and silicon nitride 5–13. As a solid lubricant, the binder contains graphite 5-11 wt.%. 1 tab. (€ (L with O) ac

Description

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This invention relates to bindings. and technologies for the manufacture of abrasive tools, mainly containing cubic boron nitride (CBF) or diamond, used for sharpening metal tools from hardened steels without. use of coolant.

The aim of the invention is to create a bond for a tool with CBN providing a high cutting ability: this leads to an increase in productivity and wear resistance.

The proposed lead containing lead zincborosilicate: glass, borosilicate glass and solid lubricant additionally contains chromium and silicon nitride, and the components are selected in the following ratio, wt.%: Lead zincborosilicate glass 35-70 Borosilicate glass 3-35 Graphite (solid lubricant) 5- eleven

Chrome 3-20

Silicon Nitride 5-13

At the same time, leadzincborosilicate glass has the following composition, wt%:

Pb72,6-76,6

ZnO 1.0--13.0

B.OZ 7.8-9.8

SiO; 1.6-2.6

WAO.1.2-2.2

 0.5-1.6

and borosilicate glass has a composition, wt.%:

SiO ,, 45,0-55,0

10.0-20.0

2.0-6.0 5.0-10.0 4.5-10.0 41.0-12.0 5., 5-12.0 0.5-1.5

The chromium introduced into the bond, together with all its components, provides a high cutting ability, since it does not oxidize in the glass melt and remains in the bond in the metallic state and does not allow it to grip the steel during its grinding. When the chromium content is less than 3%, the cutting capacity does not increase. With an increase in the content of chromium over the maximum, i.e., above 20%, the wear resistance of the bond decreases (see table).

WAO Lip

Na ,, 0

Ab oh

Fe, 0,

8032

Silicon nitride is well wetted by a melt of a mixture of glasses, and in combination of chromium with silicon nitride and graphite in a melt of glasses, 5 forms a wear-resistant composition that has the properties of a solid lubricant and provides a high cutting ability of the tool. With the introduction of silicon nitride in the amount of less than 5%, the wear resistance of the bond does not increase. With the introduction of its more than the maximum content, i.e. more than 13%, tool wear resistance is reduced

15 Example, Circle form 12A245

125 5 C 32 prepared from binder components in the following ratio, wt%:

Lead zincborosilicate glass (№) 35 0 Borosilicate glass (№ 2) 35 Graphite. 5 Chromium - 20 Silicon Nitride 5 5 Glass composition No. 1, wt%: PHO 74.8; ZnO 12.0; 8.3; SiOj 1.3; BAO 2.0; 1.1

The composition of glass number 2, May ,,: SiO 30.02; Li ,, 0 5.37; Na ,, 0 7.75; , 30 9.27; Q.0 3.38; BAO 7.78; , 4.50; 0.6.

Impurities of oxides CaO, MgO, TiO, - the rest.

For the preparation of the charge, the components of the binder are glasses No. 1 and No. 2, graphite. chromium, silicon nitride, sifted through a 63 μm sieve, is mixed for

2h To the mixture add cubic brand K 125/100 grit and mix

0 it with the charge. Cubonite circles

forms 12A245 125x5x3x32 - К17-1-КР 125 / 100-100-24.9 are briquetted under a pressure of 1500 kg / cm, they are sintered at 520 ° С for 60 minutes, then i; hot pressing is performed at a pressure of 200 kg / cm.

PRI me R 2, According to the technology indicated in example 1, circles of form 12A245 - 50 K17-2-KP 125 / 100-100-24,9 are made.

SampleZ, According to the technology indicated in the example, circles of form 12A245 125x5x3 32 K17-3-KP 125 / 100-100-24.9 are made of a trace of lean composition, wt.%: Glass No. 1 56; glass number 2 17; graphite 8; chrome 10; silicon nitride 9.

The chemical composition of glasses is given in Example 1. Composition of the binder, wt%:

31316803

No. 1 70; glass number 2 3; graphite

bo on ve

eleven; chromium 3jO; silica nitride 13.0.

npHN; ep4. According to the technology indicated in Example 1, circles of the form 125x5x3 32 - K-17-4-KP 125 / 100-100-24.9 of the following composition are made, wt%: glass No. 1 61; glass number 2 19; graphite 9; chromium. eleven.

The chemical composition of the glass is shown in example 1.

Example5. According to the technology, similarly to example I, circles are made of the form 12А245 ° 125x5x3x32 - К-17-5-КР 125 / 100-100-24,9, of the following composition, wt.%: Glass № 1.63; glass number 2 18; graphite 9; silicon nitride 10. The chemical composition of the glass is given in example 1.

Example 6. According to the technology described in example 1, the circles are made of the form 12A245 125x5x3X32 - K-17-6-KP 125 400-24.9 of the following composition, wt.%: Glass No. 1 54; glass number 2 11; graphite 8; chrome 8; silicon nitride 19, the chemical composition of the glass is shown in example 1.

Example7. According to the technology specified in Example I, circles of form 12A245 125x5x3x32 - K-17-KP 125 / SHO-100-24.9 of the following composition are made, in wt.%: Glass 1 50; glass number 2 12; graphite 7; chromium 25; silicon nitride 6. The chemical composition of glasses is given in example 1.

Dp of comparative tests in examples 1-4 were made on 3 terms of the following characteristics: 12A245 ° 1 25x3 5 x32 - K-1 7-l-K 1 25 / 100-100-24.9; 12A245 125x3, 5x32 K-17-2-KP 125 / 100-100-24.9; 12A245 ° 125 5хЗ 32 - К-17-3-КР 125 / 100-100- 24.9; 12A245 3x-32 - K-17-4-KP 125 / 100-100-24.9; 12A245 ° 125 5x3x32 K-17-5-КР 125 / 100-100-24.9; -12А245 ° 125х5 3 О2 - К-17-6-КР 125 / 100-100- 24.9; 12А245 125х5хЗ 32 - К-17-7-КР 125 / 100-100-24,9, and three cubonite circles made according to the prototype, with the following characteristics: 12А245 125А5ЛЗХ32 - К16-КР 125 / 100-100-24,9

Comparative tests were carried out without the use of coolant during grinding of steel R6M5 in the following modes:

Circle speed, m / s. Longitudinal feed, m / min

Transverse feed mm / dv. move

The performance indicators of the 2A-45 cubit grinding wheels on the K17 ceramic bonds are given in the table,

As a result of the tests, it was established that the cubonite circles on the proposed K17 bond (npimep 3) have a specific consumption of cubonite by 30–35% lower, and the productivity of pinch is 1.5 times as compared with the circles on the same bond,

From the test results it follows that the highest wear resistance and cutting ability showed circles of the following composition, wt,%:

0

Glass number 1

Glass number 2

Graphite

Chromium

Silicon nitride

56

17

eight

ten

9

The cubonite circles of examples 1 and 2 show better results than the prototype, while the circles of examples 4, 5 and 7 are at the same level as the prototype and are slightly worse, while example 3 has wear resistance 30-35% higher.

thirty

Q

five

0

five

five

Claims (1)

Invention Formula Glass-ceramic bond of abrasive tool for machining steels, containing borosilicate glass of composition, wt.%: SiO 45.0-55.0 10.0-20.0 4.5-10.0 4.0-12.0 2.0-6.0 BaO5.0-10.0 5.5-12.0 0.5-1.5, Leadzincborne silicate glass composition, wt.%: PCO B, 0h Na ,, 0 K.2,0 Fe, 0, Zno Sio BaO , Al.O72, 6-76.6 11.0-13.0 1.6-2.6 1.2-2.2 7.8-9.8 0.5-i, 6 about tl and h a --2.3 and solid lubricant, I differ from the fact that, in order to increase the productivity and wear resistance of the tool, the bond additionally contains chromium and silicon nitride in the following ratio and components, wt%: