SU1202836A2 - Abrasive compound - Google Patents

Description

The invention relates to the abrasive industry, can be used in the manufacture of tools, mainly cutting wheels on a bakelite bond, intended for cutting hot metals, is an improvement of the invention according to the author. No. 406715.

The purpose of the invention is to increase the operational capabilities of the abrasive tool by increasing

2Ae (OH) s250 With APgOz, DegOz NgO De.Oz

In the process of heating, a three-stage dehydration of A1 (OH) 2 occurs with three endothermic effects at 250, 330 and, which is confirmed by the result of thermographic analysis.

The drawing shows a thermogram of alumina hydrate.

On the A1 (OH) 3 thermogram heated to 600 ° C, curve T shows the rate of temperature change, the DTA curve shows the change in the heat content of the substance, and the TE and DTG curves show the change in the mass of the substance.

With an increase in temperature, the alumina hydrate has three endothermic effects and is accompanied by a decrease in mass.

The total endothermic effect is 2565 kJ / mol.

Components

The content of components, wt.% In the abrasive mass for example

The estimated amount of grain normal electrocorundum brand 1.4A grain 63 is loaded into the blade. wet the mixer with a liquid ba

of the bakelite bond in the grinding process.

The abrasive mass contains abrasive grains, a bond, and alumina hydrate as a filler.

The crystal structure is A1 (OR is layered and is represented by cations A and OH anions. Aluminum oxide hydrate is not soluble in water, and when heated to the temperature of the uppermost it decomposes according to the following scheme:

The decomposition products of A1 (OH) d are water. The introduction of abrasive mass of aluminum oxide hydrate allows to increase the endothermic effect and strengthen the bonds.

The introduction of aluminum oxide hydrate less than 1 wt.% Does not allow to obtain the specified positive effect, and the introduction of more than 5 wt.% Adversely affects the performance due to the possible clogging of the working surface of the abrasive tool, which leads to an increase in power consumption of the machine.

Make an abrasive mass for pieces of circles according to the formulations given in table. one.

Table 1

55 kelite BZh-3 and stirred for two minutes.

In a separate paddle mixer serve pulverbakelit brand

SPP-011A, cryolite and hydrate of alumina and stirred for four minutes. Thereafter, the prepared binder is fed to the first mixer with a moistened sander and mixed for 4 minutes. Abrasive mass wipe

Estimated amount of heat

- absorbed 100 g mass, kJ

Discharge speed m / s Grinding factor

Maximum power consumption of the machine, kW

Calculated from the heat of formation of A1 (OH) 3 and its content in abrasive masses.

. Calculation example (as in example 1): 1 mole of AKON) or 78 g (based on molecular weight) during dehydration 2565 kJ of heat is absorbed, 1 g of substance is 32.9 kJ. 100 g of the mass contains 1 g of AKOH), so the amount of heat absorbed is 32.9 kJ.

From the data table. 2 it follows that the abrasive mass of the proposed composition have a higher endothermic effect.

The use of the proposed abrasive mass in the cutting tool allows increasing the breaking rate by 8.3-12.5%, and the grinding coefficient when cutting metal heated to 700-800 ° C - by 15-55%.

Cutting discs made of abrasive mass with a content of A1 (OH) 3 below the lower limit (Example 4) have strength. Also there are several Editors A. Sabo

Compiled by T.Nikonorova Tehred O.Netse

Order 8363/18 Circulation 768 Subscription

VNIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushská yab., 4/5

Branch PPP Patent, .g. Uzhgorod, st. Project, 4

1202836

through a 2.5 × 2.5 mm sieve to remove aggregate formations.

Made from abrasive mass 5 according to examples 1-5 circles have operational performance given in table. 2

table 2

32.9 98.6 164.4 16.4 197.3 130 132 135 125 135 4.6 4.6 6.2 5.3 3.8 4.0

eleven

12

ten

15

9

five

0

five

to Bbmie, but inferior in grinding properties due to low endothermic effect.

Increasing the content of А1 (ОН) in the abrasive mass over the upper limit (Example 5) gives the cutting wheels high strength, and a very high endothermic effect worsens the renewal of the working surface, as evidenced by an increase in maximum consumed Power due to the surface of the wheel .

Thus, the introduction into the composition of the abrasive mass of gvdrat alumina as a substance with an endothermic effect. Allows more significantly reduce the temperature in the working layer of the bond to increase the duration of its working capacity without noticeable destruction and, thereby, to improve the performance of the circle.

Corrector S.Cherni,

Claims (1)

ABRASIVE MASS by ed. St. No. 406715, distinguishing with the fact that, in order to increase the operational performance of the tool, abrasives and grindings were introduced into it as a substance giving an endothermic effect (72) A.P. Kurnosov, N.A. Karpova, L.G. Pitsyna, I.Ya. Zhabin, S.I. Khatsko, N.I. Fomkin and V.I. Dudin (53) 621.922.079 (088.8) (56) USSR Copyright Certificate No. 406715, cl. In 24 D 3/34, 1971. aluminum oxide hydrate in an amount of May 1–5 ·%.