SU1713788A1 - Mass for production of high-porous abrasive tool - Google Patents

Abstract

The invention relates to the manufacture of an abrasive tool on a bakelite bond and can be used in the manufacture of porous circles. The abrasive mass contains a grinding material, a pore-forming organic binder. The ratio of the total volume content of the grinding material and the binder to the volume content of the binder is within 1:

Description

31 This is V,: U 1,0: (3-5,7). With an increase in the content of the bulk mixture, it is quickly clenched and compressed, which makes it non-technological. This is due to the fact that TFP, as a dry fine component, takes a significant amount of moisture and dehydrated BZ more intensively builds phenolic bonds, which causes its cleavage. With a lower content of free-flowing moisture contained in liquid bakelite, it strongly moistens the mixture, and it naturally evaporates very medno. The mixture remains mobile for a long time and is excessively wet. When pressed, such a mixture adheres to mold parts, which increases the labor intensity of making abrasive products. Therefore, an experimentally determined range of TFP content at which the mixture does not set and does not have excess moisture. If the specified ratios of the components of the mass are observed, there is no complete separation of the mixture when mixing the mass, even when the ratio of liquid and powder binder is at least to the maximum. The ratio of material, coater and binder allows you to extend the bakelite bond tool nomenclature in order to reduce hardness by five degrees by applying the manufacturing method known for manufacturing the tool on other types of links, which is heat-treating the molded product in a mold . This method became possible due to the reduced content of superconductors, therefore, the reduced release of volatile components during the heat treatment process, namely, volatilization, accumulating under the upper plate of the mold during the curing period, deform the product. The volatiles that appear during the heat treatment, in the mixture according to the proposed ratio, are insignificant and are not accumulated through the gaps of the mold, keeping the product geometry unchanged. Using the method of heat treatment of the product in the mold will significantly increase the scope of the existence of formulations. This method of making circles ensures the stability of the geometry. 84 allows you to expand the gamut of bakelite bond tool characteristics: the minimum bulk density of the abrasive mass sniffs from 1.8 to 1.3 g / cm. Abrasive masses are prepared according to the recipes given in Table 1, the number of samples for each recipe. The starting materials for the production of abrasive masses are: abrasive material - electrocorundum normal 14A 25-H, spherocorundum 125, potassium chloride, liquid binder - bakelite liquid BZ, powdered sv euytsey - TFP, cryolite brand KP. In the examples. 1-12, 21 and 22, 26, and 27 are formulations of abrasive masses containing sphero- corund as a pore-forming agent; in examples 13, 20, 23, 24, 2B to 29, abrasive masses with potassium chloride as a pore-forming agent are given. In this case, recipes are given with a minimum, optimal, maximum, and out of the limits of the claimed ratios ... In parallel, a known abrasive mass is produced (Example 25) with potassium chloride and cryolite. Compliance with certain limits of the ratio between the bulk components of the mixture and the binder, as well as between the components of the binder, will make it possible to manufacture an abrasive mass that is technologically advanced with a uniformly distributed blowing agent. In examples 1-3, 6, 7, 10, 17, and 18, the maximum binder content is required to wet the bulk components of the mixture and to form evenly strong bridges of the binder throughout the product. In examples 10 and 18, with a maximum binder content, the ratio of the V binder components is 1: 2, i.e. one third of the binder is a phenolic binder powder, with this ratio the uniformity of the blowing agent distribution is significantly reduced, as the mass is not humidified and the blowing agent , not moistened with liquid bakelite, has the ability to migrate into the mixture. The areas bound by the bond set to form phenolic bonds that are destroyed when trying to restore uniformity to the mix, which ultimately reduces the strength of eating

517

example 17 with a maximum content of the ligament ratio, the ratio of components is such that the BZ is much larger than the TFP (Vca, n.) therefore the mass is sufficiently well moistened, but the TFP is very small for dusting the mixture and the wet mass creates additional difficulties the manufacture of samples - sticking mass on the parts of the mold and the spreading of the sample with free heat treatment without a mold.

In examples 12-20, the exorbitant maximum binder content, which is excessive, the mass is very wet and the product is deformed during the heat treatment process.

In examples 5, 8, 9, and 13, the minimum content of the binder required to wet the bulk components of the mixture and the formation of bridges of the binder uniformly distributed throughout the structure of the product.

The lower content of the binder (examples 11 and 19) is not enough to hold the grinding material and after heat treatment, areas devoid of the binder are shed from the product.

In Example 9, with a minimum binder content, almost all of it consists of liquid bakelite. V..p sV, 1; 6,7 The mixture is very wet and low-tech - unsuitable for further processing.

In examples 26 and 29 - the minimum content of the grinding material, which provides few cutting edges and, as a result, low cutting properties, i.e. low grinding ratio; tool life is also reduced.

In examples 27 and 28 - the minimum content of the blowing agent, as a result of which, during the grinding process, grinding defects, such as burns, may occur on the treated surface.

The order of introduction of the components and the duration of mixing are as follows: mixing the grinding material and a porous agent (0.5–10 min), wetting the grinding material and the porogen with liquid bakelite (2–2.5 min), introducing the powder components of the phenol powder binder and cryolite (1.5-2 min).

Preparation according to the recipes given in table. 1, abrasive mass

86

Estimated primarily by technological properties (uniform and sufficient moisture content of the mass). Of abrasive masses possessing

satisfactory technological properties, make experienced circles PP 200x20 76, the number of samples for each option 2-3.

Samples are made by cold pressing and heat treated in a mode with a gradual rise in temperature to.

At a given bulk density

samples from 1.3 to 1.8 g / cm, the pressing force is sufficient to obtain the required density, is the force that creates the upper plate of the mold with its mass (this

about 0.03-0.06 kg / cm).

With a bulk density of 1.8 to 2.1, pressing is carried out with a press.

Heat treatment of samples is carried out in a mold (with a bulk density of 1.3-1.8 g / cm) and in the free state (with a bulk density of more than 1.8 g / cm).

The manufactured samples are controlled according to the following parameters: actual bulk density, hardness of the wheels and breaking speed.

The bulk density of the circles is determined by the formula

R

35

If the contract

v

where P is the sample mass, g, V is the sample volume, see

The hardness of the wheels is determined from the depth of the well using the readings of a Model 910 sandblaster at a pressure of 0.15 MPa in the device chamber.

The bursting speed of the wheels is determined

rotation on the testing machine LT 6 and calculated by the formula

V.% p m / s

1000-600

where dr is the outer diameter of the circle; - the number of revolutions on the sensor of the machine at which the circle broke.

The uniformity of the blowing agent distribution is determined as follows. The uniformity of the distribution of the pore former separately of the upper, lower ends and each of the

halves of the cylindrical peripheral surface of the circle, as well as the identity of the distribution of the blowing agent between pairs of different surfaces of the circle.

The uniformity of the distribution of the blowing agent is defined as the ratio of the accumulated amount of points to the maximum possible amount of points, in percent.

The results of the tests are given in Table. 2

The performance characteristics of samples made according to examples j21-29 are determined by face processing of cylindrical samples with a diameter of 30 mm from steel ShKh 15, and are listed in Table. 3

 As can be seen from the table. 2, in cases where the proposed ratios of the bulk components to the binder and the binder components to each other are met, the uniformity of the blowing agent distribution in the finished products is about 100%. In those cases where the content of the bond is less than the recommended (examples 11 and 19), the strength of the manufactured products drops sharply. This is due to the fact that the areas of the abrasive mixture that are not reinforced with a bond and perform a function similar to cracks in a circle provoke a rupture of the circles. The uniform distribution of the blowing agent is also significantly reduced.

In cases where the content of the binder is more than the recommended, while respecting the ratio of components in the binder, the mixture becomes excessively wet, raw-plastic and preforms made with great difficulty fall apart during the heat treatment process (examples 12 and 20).

In examples 9 and 17, the amount of binder per quantity of bulk materials in the mixture is within the recommended limits, but the content within the binder is

88 phenol powder binder crust, only slightly, that, in general, the abrasive mixture is non-technological due to excessive humidity, therefore, the samples could not be made.

In examples 10 and 18, with enough liquid bakelite, there are so many

binder, that all moisture contained in liquid bakelite is neutralized by TFP, which, interacting with the BZ, builds phenolic bonds, forming lumps in the mass. The mixture was non-technological and samples were not made. i.

As can be seen from the above examples, it is possible to manufacture products of hardness from VM to T1 with the same technology without using baking powder or hardeners, using only traditional materials. At the same time, the speed of the circles in the

In most cases, it is possible to draw conclusions about the suitability of wheels on operations of flat buttresses or machine parts.

Claims (1)

Invention Formula. The mass for the manufacture of highly porous abrasive tools containing grinding material is the former, a liquid and powdered organic binder, characterized in that, in order to improve the quality of the tool, the ratio of the total volume content of the grinding material and the blowing agent to the volume content of the binder is within 1: (0.07-0.09), when the ratio of the volume content of the grinding material to the blowing agent is within 1: (O, 37-4.0) and the powder and liquid phenol binder is within 1: (3-5.7). Table I 1: 0.92 ", 93 1: 0.09 1: 3 4.95 1iO, 37 1: 0.09 1: 3 6.30 1: 2.5 1: 0.09 1: 3. 5.36 1: 0.08 1: 1.23 1: 4 1: 0.07 3.15 1: 0.5 1: 5.7 6.75 1: 4.0 1: 0.09 1: 3 1: 2.47 4.68 1: 0.09 1: 3 2.4S 1: 1.33 1: 0.07 1: 5.7 4.69 1: 1.23 1: 0.07 1: 6.7 6.03 1: 2 1: 0.09 1: 1.23 4.02 1: 4 1: 0.06 t: 1.23 6.70 1: 4 1: 0.10 1: 1.23 3.01 1: 0.07 1: 1.53 1: 5.7 4.16 1: 4 1: 0.40 1: 0.08 4.40 1: 0.96 1: 4 1: 0.08 4.40 1: 0.08 1: 3 1: 0.96 1i6,7 1: 0.73 5.76 1: 0.09 1: 0.64 4.86 1: 2 1: 0.09 1: 0.64 1: 0.06 1: 4 3.24 1j4. 1: 0.64 5, “0 1: 0.10 1: 6.07 1: 4 3.99 1: 0.54 1: 0.54 4.86 1: 4 1: 0.09 1: 0.54 1: 4 1: 0.07 3.99 1: 4 1: 0.54 4.86 1: 0.09 17.00 1: 0.32 1: 0.61 , 85 1: 0.6: 0.8 4.70 1: 4,8 1: 0.07 1: 3.27 1:40 1: 0.07 3.5 1: 0.25 1: 0.30 1: 0.08 3.8 1,3,8 1: 4.2 1: 0: 3.5 4.5 1: 0.09 Table 2 Excessive moisture Samples Not production mixture Non-technological mixture is unevenly moistened, wet areas The same are observed Technological, there is under-moisture of the mixture Technological, there is excessive redundancy in moisture processing Technological Low-tech, the mass contains a large amount of excess BZ Samples are not Tehnological, and there is no . fine samples not manufactured potassium Technologically, insufficient moisture is observed Fabricated samples Technological mixture processing wet Technological, moist 12.0 15.2% hce VM1 decayed during thermoextraxe VM1 collapsed as the compound was injected, pore-forming potassium chloride 14A 25-Н С2 - В Вод 7П Continuation of r & bl 2 0.53 Prizhog 13.7 7% grinding material, maximum spherocorund 14A25-H VM1 II B water 4.5 7Maximum content of grinding material, low content of pore-forming spherocorundum 14A25-NM2 - | B Water 7.0 8Maximum content of grinding material, insignificant content of pore-forming agent - potassium chloride 14A25-N VM1 B Water 7.1 l 9 Minimum content of the grinding material, maximum content of the pore-forming agent - potassium chloride 14A25-H 10.0 B Water 3.2 Continuation of table 3 0.47 Not 12.8 0.60 Burnout 18.0 3 10% 0.51 Burnout 12.0 0.40 Not 2.0