Developed a new method of electrolytic-plasma nitriding, which enable to carry out surface modification of high-speed steels and provide the high kinetic energy efficiency of diffusion saturation process. . Implementation of electrolytic-plasma nitriding of high-speed steel R6M5 in the optimal mode was determined, which leads to a significant increase in hardness and wear-resistance of the high-speed steel surface layer. It is experimentally established, that after nitriding of electrolytic-plasma heating on the surface of high-speed steel R6M5 formed the modified layer, which has high abrasive wear resistance as compared with the source material.

In the present work, the effect of the detonation-spraying mode on the tribological properties of Al2O3 coating was studied. It was found that a decrease in the delay time between shots is leading to an increase in the hardness and elastic module of Al2O3 coatings. The obtained values of the coefficient of friction showed that a decrease in the delay time between shots leads to a slight reduction in the coefficient of friction. It is determined that reducing the delay time between shots to 0.25 seconds leads to an increase in the resistance of coatings to abrasive wear. It was found that the main reason for the increase in hardness and wear resistance with a decrease in the delay time between shots to 0.25 s is associated with an increase in the volume fraction of the α-Al2O3 phase. It was found that increase in the volume fraction of the α-Al2O3 phase is caused by the secondary recrystallization γ → α, which occurs due to the heating of particles during coating formation, i.e. due to increase in temperature above 1100 °C in single spots of the coating when they are put each other.

In this work the influence of electrolytic-plasma nitriding on the abrasive wear-resistance of R6M5 high-speed steel were under research. We registered that after electrolytic-plasma nitriding on R6M5 steel surface modified layer is formed with 20-40 μm thickness and with increased microhardness of 9000-12200 MPa. Testing mode for the nitrided samples high-speed steel on abrasive wear developed. It is established, that electrolyte-plasma nitriding allows to increase wear-resistance of R6M5 steel surface layer comparing to original. It was determined that abrasive wear-resistance of R6M5 steel surface layer is increased to 25% as a result of electrolytic plasma nitriding. Thus, studies have demonstrated the feasibility and applicability of electrolytic-plasma nitriding in order to improve cutting tools work resource, working under friction and wear conditions.

The article presents the results of studying the process of electrolytic-plasma hardening of 0.34Cr-1Ni-Mo-Fe steel by surface hardening, as well as the results of the current-voltage characteristics of the cathodic electrolytic-plasma process depending on the composition of the electrolyte. Temperature-time and special modes of electrolytic-plasma hardening of steel 0.34Cr-1Ni-Mo-Fe were determined. The optimal composition of the electrolyte for electrolytic-plasma hardening has been determined, providing a relatively high heating rate and high hardness of the steel surface. It has been determined that after the electrolytic-plasma hardening, the microhardness of 34KhN1M steel increases 2.9 times due to the formation of fine martensite. In this case, the basis of the material does not change, it consists of a ferrite-pearlite structure.

This work were studied the effect of technological parameters of detonation spraying on the phase composition and tribological characteristics on the bases of NiCr and Al2O3 coatings. As well as there was obtained and investigated multilayer coating on the bases of NiCr/NiCr- Al2O3/Al2O3 . It was determined that during detonation spraying the phase composition of Al2O3 coatings strongly depends on the degree of filling the borehole with a gas mixture. The a - Al2O3 -phase content in the coatings increases when the degree of filling is 63% and 54%. Only one CrNi3 phase is observed on the diffractograms and only increase of reflex intensity (020) at barrel filling by 58% is observed by sputtering on the bases of NiCr coatings in different degrees of barrel filling. The results of the coating nanohardness study showed that the hardness of the Al2O3 coating increases depending on the content of a- Al2O3 in it. Al2O3 coating has the maximum nanohardness values and is 16.42 GPa at the borehole is filled to 63%. The nanohardness of NiCr coating has the maximum values at barrel filling by 58% and consisting of 8.02 GPa.