SU1400868A1 - Method of producing abrasive tool - Google Patents

Abstract

The invention relates to the manufacture of a diamond-bonded diamond tool and improves the durability of the diamond tool, reduces the roughness of the treated surface and eliminates burns on it when grinding without the use of a lubricant-coolant. B1 is composed of an abrasive powder, a phenol-formaldehyde resin, fillers and a pore former, which is hydrated sodium pyrophosphate. Additionally, the mixture is treated with a composition containing sulfur, synthetic divinipny rubber with a mole, m. 1000-3000 and stearin in the following ratio, wt.%: Sulfur 5-12, synthetic-. Comical divinyl rubber (mol.m. 1000-3000) 20-60, stearin the rest. As a result of this preparation of the charge on the abrasive grains, a coating is formed in the form of a durable polymer film that plays the role of a lubricant, and the sodium stearate formed during the heat treatment of the mixture is a surfactant with respect to metals. 1 tab. i (Л С

Description

The invention relates to the manufacture of diamond-bonded diamond tools.

The purpose of the invention is to improve the quality of the treated surface and the durability of HHCTpy ieHTa.,

The proposed method of making diamond tools includes preparing a mixture consisting of an abrasive powder, a phenol-formaldehyde resin, fillers and a pore-forming agent. Sodium pyrophosphate hydrate is used as a pore-forming agent. m. 1000-3000 and stearin in the following ratio, wt.%:

Sulfur 5-12

Synthetic divinyl .ny rubber mol.m.

1000-3000 20-60

Stearin

The method is carried out as follows.

In accordance with the recipe, weighed weights of phenol-formaldehyde resin (24.5-25.5) copper powder (20.0-23.0%), molybdenum disulfide powder (3.5%), rosin (0.5%) of AFM micropowder 40/28 (18 wt.%), Electrocorundum powder M5 (18.0%) and sodium pyrophosphate hydrate (3.5-5.8%). The weights are placed in a planetary type mixer and mixed until the components are evenly distributed.

Separately, a lubricant composition is prepared. Technical sulfur (0.3-1.5 wt.%) Is heated to 65-70 ° C, mol.m. 1,100 units (1.1–4.5 wt.%) And stearin (4.4–6.0 wt.%); the components are mixed, the mixture is cooled to room temperature, the composition is ground to obtain a powder with a particle size less than 0.5 mm. The resulting powder is treated with previously mixed components of the mixture, adding to them a powder of a lubricating composition (5.8-12.0 wt.% Of the total mass of the mixture) and thoroughly mixing with them in a planetary mixer.

The prepared mixture is placed in the mold, pressed and thermally processed according to known conditions.

Sodium pyrophosphate hydrate inlet (water.

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five

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five

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five

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evaporating, during the manufacture of the charge, the circle forms pores in it. In contrast to the well-known pore-forming agent, aluminum potassium alum, sodium pyrophosphate hydrate makes it possible to increase the strength of the wheel and increase its durability (when grinding in the above conditions, the bond of the wheel does not plasticize). In addition, during the decomposition of sodium pyrophosphate hydrate, phosphoric anhydride is released, which phosphates the surface of a viscous heat-resistant alloy (under the influence of pressure and high temperatures that occur in the cutting zone during grinding conditions), and embrittles it. This reduces cutting effort, eliminates clogging of the wheel and increases its durability. The sodium released, interacting with the lubricant stearin, forms sodium stearate, which reduces the roughness of the treated surface.

The treatment of the charge (composition: sulfur - rubber - stearin) is achieved as a reduction of the roughness of the treated surface, and the elimination of prizhogi on it. In the process of preparing the mixture, when mixing it in the mixer, the diamond and abrasive grains are enveloped with sulfur and rubber in the presence of stearin, i.e. a coating is formed on the grains. When sintering the tool, this coating polymerizes, as a result of which a durable polymer film is created on the grains. In the process of grinding, this film plays the role of a lubricant, which contributes to reducing the roughness of the treated surface, as well as eliminating burns (when processing at elevated conditions without the use of coolant) by reducing the temperatures in the contact zone diamond - the material to be processed. The stearin introduced into the lubricant composition interacts during sintering of the tool. sodium pyrophosphate to form sodium stearate, which in the finished tool is located in the pores of the circle. Stearate, in comparison with stearin, is a stronger surfactant in relation to metals, and this leads to a decrease in the wear of the tool (its strength) of its Resistance) and to an improvement in the quality of the treated surface by reducing friction and reducing

temperatures at elevated grinding conditions.

The introduction of each component of the lubricant composition to the charge separately does not lead to the desired result, since abrasive, charge materials do not form a sufficiently uniform polymer coating (individual abrasive particles are covered with only one component). The ratio of the components of the composition is determined by the polymerization conditions of the coating.

From the mixture according to the proposed method, diamond wheels 1A1 200x20x5 AFM 40/28 are made. Circles are tested when machining a heat-resistant alloy when machined. Grinding modes: speed of a circle of 37 m / s, feed transverse 0.04 mm / two-stroke.

The test results are shown in the table.

During the tests, the durability of the wheel (specific consumption in mg / cm), the roughness of the treated surface and the presence of prizhog on the treated surface are monitored. Grinding without coolant.

As a result of the tests, it was established that the proposed method provides

Claims (1)

Increases the durability of diamond wheels by 37-45%, reducing the roughness of the treated surface by an average of 1 class and eliminating burns on it when grinding without coolant. Invention Formula A method of making an abrasive tool, in which a mixture containing an abrasive powder, phenol-formaldehyde resin and fillers, is mixed with a pore forming material, is thermally pressed, and is characterized by the fact that, in order to control the quality of the surface and durability of the tool, it is taken hydrate of sodium pyrophosphate, and after mixing, after addition, the mixture is treated with a powdery composition containing sulfur; synthetic divinyl rubber with mol.m. and stearin in the following ratio, May.%: Sulfur 5-12 Synthetic divinyl rubber mol.m. 1000-300020-60 Stearin