RU2550681C1 - Composition for impregnating abrasive tool on ceramic binder designed to polish nickel- or iron-based plasma coatings - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention relates to compositions for impregnating an abrasive tool on a ceramic binder, used in mechanical processing of components. The composition for impregnating an abrasive tool on a ceramic binder contains an organic substance and water. The organic substance is triethanolamine and oleic acid, with the following ratio of components, wt %: triethanolamine 42-70; oleic acid 8-13; water - the balance.

EFFECT: high resistance of the abrasive tool and specific processing capacity with low roughness of the polished surface.

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Description

Technical field

The invention relates to the field of abrasive processing, in particular, when grinding hard-to-work plasma coatings on nickel and iron base without the use of cutting fluids (coolant) and can be used in the manufacture and operation of abrasive tools.

State of the art

Known compositions for the impregnation of an abrasive tool containing dissolved organic compounds followed by a drying step without additional heat treatment (Aut. St. USSR No. 1283069, class B24D 3/34, 1987, Bull. No. 2; Autost. St. USSR No. 1255412, class B24D 3/34, 1986, Bull. No. 33; Aut. St. USSR No. 1386436, CL B24D 3/34, 1988, Bull. No. 13).

However, these impregnating compositions have the following disadvantages: limited scope; a slight increase in the resistance of the abrasive tool and the specific productivity of processing (the ratio of the volume of the removed metal to the volume of the worn tool).

Closest to the proposed technical essence and the achieved result is a composition for impregnation of an abrasive tool according to Auth. USSR No. 1710324, class B24D 3/34, 1992, Bull. No. 5.

The impregnator used in this composition is an aqueous solution of urea and thiocarbamide. This impregnator has a number of significant disadvantages, such as: the amount of chemically active substances directly in the contact zone of abrasive grain and metal is insignificant; increasing the resistance of the abrasive tool and specific productivity is not significant.

The objective of the invention is to remedy the aforementioned disadvantages of known impregnators in order to increase the resistance of grinding wheels and the specific processing performance with a satisfactory roughness of the polished surface.

SUMMARY OF THE INVENTION

The problem is achieved in that in the composition for impregnation of an abrasive tool containing organic substances and water, triethanolamine and oleic acid are used as organic substances during impregnation in the following ratio of components, wt. %:

Triethanolamine 42-70 Oleic acid 8-13 Water Rest

The compositions are prepared by first dissolving in water, oleic acid, and then triethanolamine in the indicated proportions at 15-40 ° C. The abrasive tool is impregnated by free capillary lifting when immersed in a solution at 0.75 tool heights. Impregnation time 3-5 min depending on the size and shape of the abrasive tool. After impregnation, the tool is dried for 1-3 days at 15-30 ° C. In the table. 1 shows examples of impregnating compositions (compositions 2-6) and the composition of the prototype (composition 1) for conducting their comparative tests.

Technological tests of these compositions were carried out on a model 3601 surface grinding machine using the mortise grinding method using abrasive wheels of standard size 150 × 20 × 32 mm with a characteristic of 25AF60O6V35 (25A25NST16K7). Grinding modes: cutting speed - 22 m / s; table longitudinal stroke speed - 7 m / min; vertical feed - 0.01 mm / dv. move.

Grinded material - microporous plasma coatings made of PV-H85Y15 grade intermetallic powder nickel-based ¹ ( ¹ hereinafter simply PV) (HRC 25-30) and iron-based powder composition ² ( ² hereinafter simply RV), consisting of 10% by weight of the powder PV-N85Yu15 intermetallic grade, 10% self-fluxing powder alloy PR-НХ17СР4, the rest is iron powder ПЖРВ 2.200.26 (HRC 40-45). The plasma-sprayed samples of a prismatic shape with dimensions 100 × 70 × 22 mm were processed. Grinding was carried out without cooling. In similar conditions, tests were conducted circle impregnated with the composition of the prototype.

The main indicators of the grinding process were taken to be the resistance of grinding wheels, the specific productivity for the period of resistance, the roughness of the treated surface and the power of grinding.

The duration of each experiment was equal to the period of resistance of the circle, which was determined by the appearance of visible burns and other grinding defects on the treated surface. The roughness of the polished surface was monitored on a profilograph - ABRIS-PM7 profilometer. To measure the grinding power, a single-phase laboratory wattmeter D539 was used.

Three to five duplicate experiments were performed for each of these formulations in order to obtain reliable data. For each series of experiments, the average values of the indicators were determined. A summary of the selected indicators for all tested impregnating compositions (compositions 2-6), as well as for the composition of the prototype (composition 1) when grinding plasma coatings are presented in table. 2.

Analysis of the obtained data shows that the best results were achieved at a concentration of triethanolamine and oleic acid in solution of 70 and 13 wt.%, Respectively (composition No. 6). The proposed impregnating composition No. 6 provides an increase in the durability of the abrasive tool and the specific processing productivity when grinding the PV coating by 1.26 and 1.22 times, respectively, and pancreatic coatings by 1.24 and 1.20 times in comparison with the prototype composition. The impregnating composition No. 6 also provided a slight decrease (by 2-6%) in the roughness of the polished surfaces and the grinding power.

The increase in the cutting ability of the impregnated circles is explained by the formation of a boundary lubricating layer during grinding that prevents the juvenile surfaces from setting abrasive grains and processed plasma coatings. The specified lubricating layer is formed as a result of the destruction of weak chemical bonds of the surface of abrasive grains with molecules of triethanolamine and oleic acid.

The effective thickness of the lubricating layer is determined by the concentration of the components that make up the impregnator, and especially triethanolamine. When the concentration of triethanolamine in the solution is less than 40 wt.%, An insufficient thickness of the boundary lubricating layer is formed, which leads to an increase in the adhesion area of juvenile surfaces. When the concentration of triethanolamine in the solution reaches 70 wt.%, Adhesive setting of juvenile surfaces is almost completely eliminated, and a further increase in concentration does not lead to a decrease in grinding performance. At the same time, with an increase in the concentration of triethanolamine, the viscosity of the impregnating composition sharply increases, which leads, firstly, to a significant increase in the duration of the impregnation process, and, secondly, to a decrease in pore volume, and hence to worsening of the conditions for the placement of chips and increase the intensity of greasing the circle.

Claims (1)

Composition for impregnating a ceramic bonded abrasive tool for grinding nickel and iron-based plasma coatings containing organic matter and water, while it contains triethanolamine and oleic acid as an organic substance in the following ratio, wt.%:
Triethanolamine 42-70 Oleic acid 8-13 Water Rest