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METALWORKING EQUIPMENT AND TOOLS

The surface quality of counterbodies, which work in conjunction with
the coating sprayed at 450 °C, belongs to the 10-11 cleanliness classes. For
counterbodies working in tandem with a copper coating applied at 270 °C,
the surface quality corresponds to 9 - 10 grade of cleanliness. The tests
were carried out in two types of lubricants: liquid - industrial oil I-20A
and plastic Litol-24 lubricant.
Industrial oil I-20A is intended for use in hydraulic systems of
machine tools and automatic lines of presses. It is also used for
construction and road construction machines in the open air, in gears,
sliding and rolling guides of machine tools and other mechanisms.
I-20A oil is produced in accordance with GOST 20799-88 and is made
on the basis of mineral distillate and residual base oils. It corresponds
to group 32 according to the JSO classification.
Litol-24 lubricant is a mineral oil thickened with lithium soap with
the addition of an additive package. It is designed for the lubrication
of a variety of joints operating in a wide temperature range, from -40
to +120 °C. These are sliding pairs, units of cars, ships, construction and
machine-tool equipment, gears, friction surfaces of wheeled and tracked
vehicles, electric machines. Litol-24 lubricant meets the requirements of
DIN51 K 3K - 40 specification. After testing, the sample and counterbody
were cleaned of excess lubricant with a cloth and washed in a solvent.
Then, the surface of the objects under study was treated with alcohol and
dried in a thermal cabinet at a temperature of 70 °C for 30 min. After that,
the sample and counterbody were weighed on an electronic balance with
an accuracy of 0.0001 g.

Test results
Analyzing the data on the total wear of coatings applied at different spraying temperatures,
it can be noted that when a friction pair is operating in industrial oil I-20A, the coating applied
at 450 °C has a higher wear resistance (Fig. 1). When used in a pair of Litol-24 lubricant, the
coating applied at 270 °C resists wear more effectively (Fig. 1).
The total wear rate of counterbodies (0.3 x 10-11) is lower when working in pairs with a
coating applied at 450 °C when tested in industrial oil I-20A than with a copper coating applied
at 270 °C (0.4 x 10-11) (Fig. 2). The use of Litol-24 lubricant in a friction pair is accompanied by
the same counterbody wear 0.2 x 10-11. As can be seen from the experimental data, the effect
of mass transfer of the copper coating to the mating surface is expressed in a twofold decrease
in the level of wear of ShKh15 steel without coating, which is a counterbody in a friction pair.
Analyzing the results of the total wear of coated specimens and counterbodies, it can
be argued that when using industrial oil I-20A as a lubricant, the coating should be applied
at a temperature of 450 °C. To increase the efficiency of the friction unit when using Litol-24
lubricant, it is advisable to spray a copper coating at an airflow temperature of 270 °C.
The obtained result can be due to the difference in hardness (138.5 and 113.6 HV 0.025
/ 10) and cohesive strength (100 MPa and 88 MPa) of the coating metal applied at low and high
temperatures.
The results of measurements of the microgeometry of the surface of the counterbodies
and specimens with a copper coating applied at a temperature of 450 °C, carried out before and
after the test, are shown in Table 1.
Analysis of the state of the surface of the samples after testing shows that when the
mating of the samples of ShKh15 steel with a coating applied at a temperature of 450 °C
works, the surface quality of the counterbodies improves (Table 1). If we consider additional
parameters for assessing the quality of the surface, namely the average value for 10 ridges and
valleys (Rz) and the sum of the maximum projection and depression (Rt), then the following
can be noted.
When tested in industrial oil, the value (Rz) decreases by an order of magnitude - from
0.785 x 10-6 m to 0.080 x 10-6 m, and the parameter (Rt) - from 1.270 x 10-6 m to 0.10 x

12 Stanochniy park