Titanium alloys are widely used in the aerospace, defensive and shipbuilding industry due to their low weight, high specific strength and corrosion resistance. Recently, the need for increased durability and tribological characteristics of simultaneous weight loss of heavy unmanned aerial vehicles (drones), both military and civilian purposes. Replacing steel parts with titanium will reduce the weight of heavy unmanned aircraft by tens of kilograms. However, titanium alloys have low durability and are grasped during friction with mounting elements. Therefore, the elements of attachment from titanium alloys can only be used with durable coatings. Which determined the purpose of the work - to increase the tribological characteristics of the titanium alloy of VT6 by the formation of layers on its surface, diffusely modified by interstitial elements. For the formation of strengthened layers, samples were subjected to thermochemical treatment (TCT) in the vacuum oven according to the following modes: 1) Oxidation mode. The samples were heated in an electric furnace in a vacuum (P = 0.6 mPa) to 750 °C, kept 5 h in a vacuum 0.1 Pa, cooled to 350 °C and put atmospheric air, and then cooled the stove with samples to room temperature. 2) Nitriding mode. The samples were heated in vacuum (P = 0.6 mp) to 850 °C, technical nitrogen to P = 105 Pa, kept 3 h, cooled in nitrogen to 250 °C, vacuum removed nitrogen and cooled the oven with samples to room temperature. 3) Oxynitriding mode. The samples in the electric furnace were heated in vacuum (P = 0.6 mPa) to 650 °C, the nitrogen oxygen mixture (80% N2 + 20% O2) was allowed to pressure P = 0.01 Pa, heated to 850° C and kept 3 h, afte cooling in vacuum to room temperature. Microhardness from surface and in the sections of the surface layers was determined on the PMT- 3M device for the load on the indentor 0.49 N. The work studied the effect of modification of the Titanium alloy surface with the interstitial elements (nitrogen, oxygen) to increase its tribological characteristics paired with a countertil of X18H10T in conditions of dry friction with sliding with a specific load of 1.0 MPa for 600 s. By the thermochemical treatment of titanium samples was formed diffusion surface-strengthened layers. Their phase composition was determined, which after nitriding corresponded to TiN1,83, afte oxidation – titanium oxide TiO2, and after oxynitriding – titanium oxyinitride type TiN0,46O0,54. The friction coefficient in the pair of nitrided VT6 alloy – steel X18H10T increases during the test time and reached a high value (f = 0.6). Acute projections on the nitrided surface was cuted the layers of stainless steel. The friction coefficient in the pair of oxided and oxinitrided VT6 alloy – steel X18H10T10T decreased over time and reached low values (f = 0.15-0.20), which was due to the grind in of the surfaces of these elements of friction.

VT6 titanium alloy, thermochemical treatment, phase composition, friction coefficient