SU1315271A1 - Compound for impregnating abrasive tool - Google Patents

Abstract

The invention relates to the field of abrasive machining, in particular to compositions for the impregnation of an abrasive tool used in grinding both with and without the use of coolant. The aim of the invention is to improve the quality of processing impregnated circle. For this purpose, chromium (III) oxide is added to the composition containing the phenol-formaldehyde binder and solvent, the ingredients of the composition are taken in the following ratio, vol.%: Phenol-formaldehyde binder 25-45, chromium (III) oxide 10-25 the solvent is the rest. 2 tab. sl with:

Description

The invention relates to abrasive machining, in particular to compositions for the impregnation of an abrasive tool used in grinding both with and without the use of coolant,

The aim of the invention is to improve the quality of processing the blanks, processed by the tool, impregnated with the proposed composition.

The composition for impregnating an abrasive tool contains phenol-formaldehyde binder, solvent, and chromium (III) oxide as an antifriction filler in the following ratio of ingredients, vol.%: Phenol-formaldehyde binder 25-45

Chromium (III) oxide 10-25 SolventExtra

An impregnator film containing chromium (III) oxide, working as a boundary lubricant, prevents the workable metal from setting to abrasive tool grains. At the same time, working as a polishing paste, it performs the smoothing of the microrelief of the workpiece surface. A decrease in the chromium (III) oxide content of less than 10% leads to both an increase in roughness due to a decrease in the polishing effect, as well as the formation of burns and tregcin due to insufficient shielding of the abrasive grains from the metal being treated. An increase in its content of more than 25% leads to an insufficiently strong retention of its phenol formaldehyde binder and, as a consequence, to the rapid destruction of the impregnator film. In addition, the effect of reducing the content of phenol-formaldehyde binder is less than 25%. Increasing it over 45% will excessively increase the strength of retention of abrasive grains in the body of the circle, which leads to the formation of large areas of wear, the appearance of burns and cracks.

Chromium (III) oxide, introduced into the grinding wheel during the impregnation process, simultaneously affects the polishing and screening action (such as boundary lubrication) and, in addition, chemically interacts with the resin. To ensure the polishing effect, the content of chromium (III) oxide in the impregnator film formed on the surface of the grain and binder should be sufficiently high (more than 10%). To ensure screening effect.

12

Chromium oxide must be firmly held in the film. The high retention of a large amount of chromium oxide is ensured by chemically modifying the phenol-formaldehyde

chromium (III) oxide itself, chromium ions in the process of heat treatment of impregnated circles are embedded in phenol-formaldehyde resin molecules,

This leads to an increase in the heat resistance of the phenol-formaldehyde binder. At high temperatures in the grinding zone, such a resin degrades much slower than

unmodified. It is this effect that provides a sufficiently strong retention of a large amount of chromium oxide with a relatively small amount of modified phenol-formaldehyde resin. An increase in the heat resistance of a resin modified with a heavy metal (chromium) is explained by the presence of highly heat-resistant chromium carbides in the polymer structure, which are formed when exposed to high grinding temperatures.

In addition to the strong retention of a large amount of chromium (III) oxide, the modified phenol-formaldehyde

the binder increases the durability of the circles. The impregnating composition is prepared as follows: In 30-65 rpm, acetone is dissolved in 25-45 parts of pulverbecite, then 10-25 rpm is added to the resulting solution, chromium (III) oxide powder, the resulting suspension Lift up soaking circles for 2-5 minutes, depending on the size and

instrument characteristics. Drying is performed at 20-25 ° for 2-4 days. Heat treatment is carried out at 180-200 0 for 2 hours.

The percentage of impregnating compositions for analysis is given

in tabl, 1.te1

Table 1

Pulver bakelite

Disulfide

,

25 35 45 50 20

24A25PSM17K5 is carried out on a KV-250 circular sewing machine.

Grinding modes: speed of a circle of 30 m / s, speed of a detail of 30 m / min, feed of 0.004 m / s. The material of the part is nitrided steel 38Х2МЮА (HRC-58- 60), coolant - 5%, Ukrinol-1M emulsion.

The test results are shown in Table 2. Table2

Editor I.Kikolaychuk

Order 2256/16 Circulation 715. Subscription

VYIIPI USSR State Committee

for inventions and discoveries 113035, Moscow, Zh-35, Raushsk nab., 4/5

Production and printing company, Uzhgorod, st. Project, 4

Claims (1)

Invention Formula An abrasive tool impregnating composition containing a phenol-formaldehyde binder, an antifriction filler and a solvent, characterized in that, in order to improve the quality of treatment with the impregnated circle, the composition as an antifriction filler contains chromium (III) oxide, with the ingredients taken as follows ratio, about. %: Phenol-formaldehyde binder Chromium oxide (HI) 10-25 Solvent Remaining Compiled by L.Sergeeva Tehred M.Hodanich Proofreader T.DSolb