SU1283069A1 - Composition for impregnating abrasive tool - Google Patents

Abstract

The invention relates to the field of abrasive treatment, in particular to compositions for the impregnation of abrasive tools used in grinding without the use of g of coolant. The aim of the invention is to improve the working conditions during the impregnation and increase the productivity of grinding. To achieve this goal, the composition for impregnating an abrasive tool contains urea in the form of a 5-15% by weight aqueous solution. Urea is non-toxic, fire- and explosion-proof. The presence of the amide group ensures the retention of carbamide molecules on the surface of the binder grains and adhered metal due to chemisorption. At low temperatures (below melting point 132,) urea is an effective solid lubricant. At Bbmie temperatures, the melting point urea decomposes to form active ammonia. Ammonia, reacting with the juvenile surfaces of the metal adhering to the surface of the grains and binder, forms solid nitrides tightly bound to the metal. Nitrides are effective high-temperature lubricants and workable up to temperatures around. Thus, when using circles impregnated with an aqueous solution of urea, protective films are formed that work both at low and at high temperatures. 2 tab. i WITH

Description

yo

00 with

Od sb

1128

The invention relates to abrasive machining, in particular to compositions for impregnating an abrasive tool used in grinding without the use of coolant.

The aim of the invention is to improve the working conditions during the impregnation and increase the productivity of grinding, as well as improve the processing quality at high cutting temperatures.

The composition for impregnating the abrasive tool contains urea in the form of a 5-15% by weight aqueous solution.

Urea is non-toxic, fire and explosion proof. This provides improved working conditions in the impregnation process. Not being readily evaporating liquid (vapor pressure 17.527 mm Hg at 20 ° C), water ensures the preparation of non-saturated solutions of a certain concentration and their long-term storage. This increases the stability of the impregnation process.

Urea is a carbonic acid amide and at temperatures below the melting point of 132, it provides lubrication for the contacting surfaces of the tool and the metal to be treated. At temperatures above the melting point, urea decomposes to form ammonia. Ammonia interacts with the treated metal to form nitrides, which play the role of boundary lubrication, preventing seizure of the juvenile surfaces of the grain and the metal being edged. Nitrides are resistant at high temperatures.

Nitrides are effective high-temperature lubricants that work up to temperatures around 100 ° C

Thus, when using wheels impregnated with an aqueous solution of urea, protective films are produced that are operable at both low and high temperatures, firmly bound to the base metal.

For comparative tests of the feed compositions, the grinding wheels 25A25PSM27K6 were impregnated in the compositions given in Table. one.

The compositions are prepared by dissolving carbamide in water in the indicated ratios.

five

five

one

0

35

40

45

50

55

and

x at 15-4 () C. The impregnation of the abrasive tool is made by the method of free capillary lifting at. immersion in the solution at 0.8 instrument height. The impregnation time is 30-120 С depending on the size and shape of the abrasive tool. After impregnation, the tool is dried for 1-3 days at 15-30 ° C. After drying, the amount of urea in circles with a CM2 hardness is 0.40-1.25% of the mass of the wheel at a solution concentration of 5-15 wt.%. Tests of the impregnated circles were carried out on the machine ZM642E. Grinding modes: wheel speed of 19 m / s, manual feed rate of the part about 0.05 m / s, grinding depth of 0.02 mm dv, stroke. Grinded material - high-speed steel Р9М4К8.

The test results of the impregnated wheels are given in table. 2

Analysis of the results shows that the proposed impregnating composition (5-15% aqueous solution of urea) provides an increase in grinding performance up to 1.25 times. The best results were obtained when the concentration of urea in the solution was 10% by weight.

When the concentration of urea in the solution is less than 5 wt.%, An insufficient amount of ammonia is formed, which leads to an intensive setting of the juvenile surfaces of the grain and the metal to be treated. When the concentration of urea in the solution is more than 15% by weight, the pore volume decreases to such an extent that this leads to a deterioration of the conditions for placing chips and clogging up the circle.

Claims (1)

Invention Formula The composition for impregnating an abrasive tool, containing a solvent and organic matter, is characterized by the fact that, in order to increase the processing performance of an abrasive tool, it contains urea as organic matter and water in the quality of solvent in the following ratio of ingredients, wt.% : Urea 5-15 WaterEverything 1283069 Table Components Content of components, May.%, In the composition. LIIi-I-IlZlLlj- I Stearin5-Urea-251015J8 Acetone95. Water-9895908582 Table 2 Circles, impregnated burn, round grinding, wheel,. % um 1.0 1.60 1.55 1.80 1.95 1.85 1.55 0.35 0.15 0.40 0.85 1.25 1.50