SU1260390A1 - Coolant for machining metals - Google Patents

Abstract

The invention relates to a lubricant-coolant (coolant) used in the abrasive grinding of tungsten-free hard alloys and cutting ceramics. The aim of the invention is to increase the wear resistance of the diamond tool and the quality of the surface to be treated. Water-based coolant containing, in wt.%, 0.05-0.2 sodium nitrite and 1.0-2.5 sodium disodium phosphate, is additionally added with 0.05-0.25 ammonium sulfate. Coolant provides diamond consumption of 2.8-3.8 mg / g and surface roughness of 0.14-0.19 microns. 1 tab. g ko to Od O with QD O

Description

11260390

The invention relates to process fluids, in particular to lubricating coolants (lubricating fluids) used in abrasive grinding, and can be used in machining operations of tungsten-free hard alloys and cutting ceramics.

The purpose of the invention is to increase the wear resistance of the diamond tool and the quality of the surface to be treated. . The sodium phosphate sodium bismuth contained in the coolant dissociates into the sodium cation and the phosphoric acid anion, which, due to electrostatic attraction, envelop the surface of the diamond grains and the binder of the circle. Then, during the grinding process, thermal movement occurs and grinding products adhere to the formed activated surface of the diamond grains and binder. This process is observed at a sodium phosphate concentration of disubstituted in excess of 1 wt.%. ..

Studies have shown that when ammonium sulfate is introduced into the coolant at a concentration of over 0.05 wt.%, The grinding surface of grinding products (particles of grinded material) is observed 5–8 times less on the working surface of the diamond wheel than before the introduction of ammonium sulfate. This is due to the fact that with the introduction of ammonium sulphate, the activity of the resulting film is reduced due to the formation of a stronger electrolyte and the adhesion of grinding products. Thus, the introduction of ammonium sulfate prevents brining the circle, t, e. n; the ability to edit disappears, the film formed on the surface of the circle plays the role of a solid lubricant, reducing cutting forces and surface roughness.

At. an increase in ammonium sulfate concentration of over 0.25 wt.% in the solution increases the strength of the interionic coating and repulsion, and the effect of the ammonium sulfate salt on the surface of the formed film decreases, therefore the effect of solid lubricant is absent, which leads to an increase in cutting, wear and tear circle and surface roughness.

When the sodium phosphate dibasic is over 2.5 May.

 N

Sh

15

20

25

thirty

35

40

45

50

the activity of the ions in the solution decreases and the sticking of the grinding products onto the circle (salting it up) increases. Increasing the ammonium sulphate concentration in excess of 0.25 wt.% Does not eliminate this process.

Sodium nitrite in the composition of the proposed coolant serves as a corrosion inhibitor. Therefore, its content below 0.05 wt.% Is not enough to protect machine parts from the effects of corrosion. Its content is above 0.2 wt.% Impractical, since the effect of protection exists, and the increased concentration of sodium nitrite in the coolant worsens the sanitary and hygienic working conditions.

The offered COM is obtained by simple mixing of its constituent components in water at room temperature with continuous stirring for 5–19 minutes in the following sequence: sodium nitrite, sodium phosphoric acid disubstituted, ammonium sulfate.

Specific examples of coolant compositions and their test data for grinding of a tungsten-free hard alloy TN50 are presented in the table.

The grinding of samples with a size of 7x15x100 mm was carried out on a ZB642 model machine with a diamond circle of form 12Л2-45 ° 150х10хЗх32-АС4М100 / 80-Б11- -2-4 on modes: speed of a circle 15 m / s, longitudinal feed 0.3 m / min, transverse feed 0.15 mm / two stroke.

The same conditions were used to test known coolant (prototype) - composition 1.

From the test results it can be seen that the proposed SAL {ensures a reduction in the relative consumption of diamonds and roughness of the surface being treated. This is due to the fact that ions of dissociated sodium phosphate disubstituted and ammonium sulphate envelop the circle surface in the form of a solid lubricant, which significantly reduces the cutting forces, the roughness of the machined surface, eliminates clogging of the cutting surface of the circle and the need for editing.

Claims (1)

-55 claims Cutting fluid for metal machining, with five 0 five 0 five 0 five 0 the activity of the ions in the solution decreases and the sticking of the grinding products onto the circle (salting it up) increases. Increasing the ammonium sulphate concentration in excess of 0.25 wt.% Does not eliminate this process. Sodium nitrite in the composition of the proposed coolant serves as a corrosion inhibitor. Therefore, its content below 0.05 wt.% Is not enough to protect machine parts from the effects of corrosion. Its content is above 0.2 wt.% Impractical, since the effect of protection exists, and the increased concentration of sodium nitrite in the coolant worsens the sanitary and hygienic working conditions. The offered COM is obtained by simple mixing of its constituent components in water at room temperature with continuous stirring for 5–19 minutes in the following sequence: sodium nitrite, sodium phosphoric acid disubstituted, ammonium sulfate. Specific examples of coolant compositions and their test data for grinding of a tungsten-free hard alloy TN50 are presented in the table. The grinding of samples with a size of 7x15x100 mm was carried out on a ZB642 model machine with a diamond circle of form 12Л2-45 ° 150х10хЗх32-АС4М100 / 80-Б11- -2-4 on modes: speed of a circle 15 m / s, longitudinal feed 0.3 m / min, transverse feed 0.15 mm / two stroke. The same conditions were used to test known coolant (prototype) - composition 1. From the test results it can be seen that the proposed SAL {ensures a reduction in the relative consumption of diamonds and roughness of the surface being treated. This is due to the fact that ions of dissociated sodium phosphate disubstituted and ammonium sulphate envelop the circle surface in the form of a solid lubricant, which significantly reduces the cutting forces, the roughness of the machined surface, eliminates clogging of the cutting surface of the circle and the need for editing. containing water, sodium nitrite and sodium phosphate disubstituted, characterized in that, in order to improve the wear resistance of the diamond tool and the quality of the surface to be treated, the liquid is additionally 0.05-0-0.2 1.0-2.5