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METALWORKING EQUIPMENT AND TOOLS

INCREASING THE RESOURCE

OF SLIDING SURFACES BY

GAS-DYNAMIC SPRAYING OF

COATINGS

The quality of products in mechanical
engineering depends on the accuracy and
reliability of machine tools, which, in terms
of their characteristics, should be one step
higher than the complexity and accuracy of the part being manufactured. The most critical
parts and assemblies of machine tools include a horizontal machining center, guides for lathes
and gear hobbing machines with CNC, etc., with minimal wear of which the surface treatment
system is disrupted, which leads to an increase in rejects in the manufacture of parts and
products.

A significant increase in the wear resistance
of units and parts is achieved by the methods of
forming coatings of different compositions and wear intensity
morphologies on products. A special place among
the common methods of coating products made of
iron-carbon alloys are occupied by the method of
gas-dynamic spraying. Gas-dynamic spraying uses a I-20 A oil Litol 24
stream of heated air moving with a supersonic speed
Fig. 1. Total intensities wear of coatings, when applied
□
into which a mechanical mixture of plastic particles at temperature: - 270 0С, □ - 450 0С.
of metals (copper, aluminum, nickel, etc.) and solid
particles of corundum is introduced. When colliding
with the surface, plastic metal particles are fixed on
it, and solid corundum particles deform them and
compact the coating [1].
The coatings applied by gas-dynamic spraying
coating to steel with a hardness of up to 45 HRC wear intensity
have high mechanical characteristics, which can
ensure reliable operation of the product when
exposed to significant normal and tangential loads.
For example, the strength of adhesion of a copper

reaches 50 MPa, and the cohesive strength of the
coating metal is within the range of 80 - 150 MPa, I-20 A oil Litol 24
depending on the technological parameters of Fig. 2. Total intensities wear of counterbodies tested
spraying [2]. Coefficient of friction of the copper with a coating applied a □ - 270 0С, □ - 450 0С.
coating in conjunction with the counterbody (ball)
made of ShKh15 steel when tested in an oil bath is in The aim of the presented work is
the range of 0.07 - 0.08 in the range of specific loads
35 - 60 MPa [3]. Taking into account the possibility of to study the influence of technological
coating local and hard-to-reach areas of the surface parameters of the spraying of a copper
coating and the used lubricants on the
of the product with minimal heating of the substrate
(≤140 °), the method can be indispensable for wear rate of the surfaces of the conjugate
sliding friction pair.
creating surfaces (bearings) of sliding friction.

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