In the present study, pulsed laser post-processing was applied to improve the properties of the thermally sprayed NiCrCoFeCBSi/40 wt.% WC coatings. The powder mix was deposited onto a mild steel substrate by flame spray method and then the as-sprayed coatings were processed by Nd:YAG laser. The peak power density applied was between 4.00 × 106 and 5.71 × 106 W/cm2, and the laser operating speed ranged between 100 and 400 mm/min, providing processing in a melting mode. Scanning electron microscopy, energy dispersive spectroscopy, Knop hardness measurements, and “ball-on-disc” dry friction tests were applied to study the effect of the processing parameters on the geometry of laser pass and microstructure, hardness, and tribology of the processed layers. The results obtained revealed that pulsed laser processing provides a monolithic remelted coating layer with the microstructure of ultrafine, W-rich dendrites in Ni-based matrix, where size and distribution of W-rich dendrites periodically vary across remelted layer depth. The composition of W-rich dendrites can be attributed to a carbide of type (W, Cr, Ni, Fe)C. The cracks sensitivity of coatings was visibly reduced with the reduction of power density applied. The hardness of coatings was between ~1070 and ~1140 HK0.2 and correlated with microstructure size, being dependent on the processing parameters. The friction coefficient and wear rate of coatings during dry sliding were reduced by up to ~30% and up to ~2.4 times, respectively, after laser processing.

The possibility of using polymer concrete for metal cutting machine beds is analyzed. A comparison of the structures of the machine beds made of polymer concrete and cast iron is made. The frequency of the body of the machine beds made of polymer concrete and cast iron is determined. An analysis of the stress–strain state under static loads is carried out. To increase resistance to wear, it is proposed to spray polymer concrete frames are proposed by the gas–thermal method. The installation of thermal spraying for guide machine beds is given. The optimal parameters for spraying the guides of the machine beds made of polymer concrete are established calculated using the finite element method for the guide beds of metal cutting machine tools using polymer concrete with gaseous coating. The manufacture of the foundation bed from polymer concrete increases the vibration resistance of the machine by 1.4 times. At the same time, the metal consumption of metal cutting machines will decrease by 60%. To increase the wear resistance of the frame guides, it is proposed to use thermal spraying with certain modes typical for polymer concrete. The installation of thermal spraying for bed guides is given. Calculating using the finite element method for the guide beds of metal cutting machines showed that the use of polymer concrete with a wear-resistant coating is justified.

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Preliminary cleaning of the surface of hydraulic cylinder rods is of great importance for subsequent coating. The most widely used surface preparation for thermal spraying is jet-abrasive treatment. The shot blast modes provide the hardness and strength of the material being processed. The impact of the abrasive makes the surface rough, increasing the contact area. Experimental studies of jet-abrasive processing of the hydraulic cylinder rod surface, as well as its activation for the thermal spraying, were carried out. The prepared surface of the rod for thermal spraying must meet the requirements for surface roughness and the size of the hardened layer at work. The experiments made it possible to identify the optimal modes of jet-abrasive treatment, which affect surface roughness and abrasive penetration of abrasive. To obtain the desired roughness values, it is preferable to use the following: a steel shot with an abrasive particle size in the range of 0.3–1.5 mm, taking the compressed air pressure in the range of 0.4–0.7 MPa; processing time—within 3.5–5 min; counterflow angle with the surface—70–90°; consumption of abrasive particles—300–500 kg/h. A special installation for jet-abrasive processing has been designed, which makes it possible to restore the surfaces of long rods by thermal spraying directly at the site of operation of the large machines.