International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The work is dedicated to the study of the properties of detonation coatings AlB12-30 wt.% Al (AB70) applied to Steel 45 using the DNEPR-5M installation. The coatings have the following characteristics: thickness h ~ 170-200 μm, Hμ = 27-29 GPa, HV = 4.35 GPa. Changes in the tribological characteristics of the composite depending on the friction mode are analyzed. The AB70 coating is found to have stable tribological characteristics: f = 0.21-0.38, wear rate I = 3.3-8.6 μm/km. Samples with coatings exceed uncoated Steel 45 in wear resistance. Changes in the surface structure after friction depending on the sliding speed and load are shown. Two wear mechanisms – oxidative and adhesive-abrasive – are established. A conclusion was drawn regarding the possibility of using the AlB12-Al system to apply detonation coatings.

This work was aimed to smelt high-entropy alloys (HEAs) based on inexpensive and common metallic elements using iron-based alloys, ligatures, commercially pure metals and study HEAs’ phase structure. High-entropy alloys of the FeNiCrCuAl system were smelted in air using induction furnace in a crucible with a rammed neutral lining made of aluminum and magnesium oxides. Elements of Fe, Ni, Cr, Cu, Al were added by way of high-alloyed cast iron or stainless-steel grade X10CrNiTi18-10 (EN 1.4541), low-carbon ferrochrome of industrial grade FeCr70C1, binary Cu-33Al ligature, tough-pitch copper and semi-finished nickel. The investigated alloys were prepared by lost foam and sand mold casting methods. A study of the microstructure showed the presence of rounded shape branches of dendrites, copper-rich interdendritic space and high-chromium carbides in the structure of samples. The phase composition of the as-cast FeNiCrCuAl alloys was represented by several phases: ordered solid solution with primitive cubic lattice of type B2, solid solutions with BCC and FCC lattices and complex carbides (FeCr)₇C₃.

The formation features of transition metals borides at high temperatures and low pressures were investigated and discussed the conditions of formation, structure and wear properties of boride layers on the surface, formed in electron beam processing in a vacuum.

The saturation of the surface layers of metals and alloys boron is conducted with the purpose of increase of their surface hardness, wear resistance, etc. Multicomponent layers containing in its composition borides of refractory metals, as a rule, formed by the methods of chemical-thermal processing in the interaction boriding component with refractory or by saturation boron refractory impurities metal or alloy.

In this work, we studied the features of formation of vanadium and iron borides on the surface of instrumental steels U8A and R18 under the influence of intense electron beams in continuous and pulse modes.