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METALWORKING EQUIPMENT AND TOOLS

Based on the measurement results, it can be noted that the lubricant test has a more
beneficial effect on improving surface quality. The surface quality of the copper coating decreases
after the test of a pair in industrial oil from 11 - 10 to 10 - 9 grade of purity (Table 2). Evaluating
the surface by additional parameters Rz and R t, it can be noted that the average value of ten
protrusions and depressions increases significantly - from 0.767 x 10-6 m to 2.770 x 10-6 m,
and the sum of the maximum protrusion and maximum depression increases more significantly
- from 1.153 x 10-6 m to 4.120 x 10-6

heated gas inlet to m. After testing the pair in the Litol-24
coating supersonic the nozzle - heated gas inlet to lubricant, the class of copper coating
nozzle gas inlet to the the heater
nozzle surface cleanliness remains at the same,
very high, level (Table 2). The value of the
parameters Rz and Rt does not change
so significantly - from 0.930 x 10-6 m to
1.317 x 10-6 m and from 1.287 x 10 -6 m
powder
feed to 2.400 x 10 -6 m.
In general, it can be noted that the
obtained results of measuring the surface
microrelief after testing samples with
coatings applied at 270 °C and 450 °C, and counterbodies confirm the conclusions drawn from
the results of wear analysis, namely: copper coating after sputtering at low temperatures is
advisable use in liquid lubrication conditions. And to increase the durability of the friction pair,
where a copper coating applied at a high temperature is used, a grease should be used.
It should be especially emphasized that according to the data of tribotechnical tests
for friction pairs, ShKh15 steel with copper coating obtained by the method of gas-dynamic
spraying, it can be concluded that the coatings are highly wear-resistant, commensurate with
its indicators during friction in the selective transfer mode [7], when losses wear is extremely
small. The coating obtained by the method of gas-dynamic spraying has high performance
when tested under friction and wear conditions: Ih (coatings) ≈ (1.1 - 1.5) x 10-10 and Ih
(counterbody) ≈ (0.3 - 0.4 ) x 10-11 with friction in mineral oil I-20A and Ih (coatings) ≈ (2 -
5) x 10-10 and Ih (counterbody) ≈ 0.2 x 10-11 in Litol-24 grease .
This gives grounds to believe that the gas-dynamic spraying method is a very promising
tool for solving problems of increasing the reliability, durability and safety of operation of
friction units of various designs. In addition, the features of the wear of the coating indicate the
dependence of the level of surface destruction during friction of the coating against steel both
on the external test conditions (which is characteristic of the processes of friction and wear) and
on the technological parameters of the process. The latter opens up prospects and directions
of technological research for solving technical problems and ensuring the required performance
characteristics of products. Friction pairs "steel - steel" have been extensively studied when
assessing the effect on surface properties using methods of thermal and chemical-thermal
treatment [8]. For example, tribotechnical tests of a pair of ShKh15 steel (after quenching and
ion implantation of nitrogen, 65 HRC) - ShKh15
steel (after quenching 60-65 HRC) were carried
out in the medium of a grease C grease at sliding
speeds of 0.1 - 0.2 m / s and pressures at the
contact 0 - 40 MPa. For these test conditions, the
amount of wear is practically independent of the
pressure at the contact and in the steady-state
friction mode is Ih = 0.09 x 10-9 for a nitrided
sample and Ih = 0.04 x 10-9 for a conjugated
one.
Considering a number of circumstances:
different lubricants, standard deviation σ = 0.19
x 10-10, general high level of wear resistance
of ShKh15 steel with coatings (nitrided layer,
copper film), different equipment recording weight loss, it can be assumed that the achieved
level of the performance of the copper coating obtained by gas-dynamic spraying corresponds
to the well-known more expensive methods of ensuring the performance of steel-steel friction
pairs. It should be emphasized that the studied method of gas-dynamic spraying of copper (and

14 Stanochniy park