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

The thermodynamic properties of the melts of the Fe–Mn(Ti)–Si, Fe–Mn–Ti, and Mn–Si–Ti ternary systems at 1873 K were studied using the “geometric” and “analytical” Redlich-Kister-Mujian models from reliable analogous data for binary boundary subsystems. Special attention is paid to the precise thermodynamic properties of melts of the Fe-Mn, Fe-Si, and Mn-Si systems, with analysis of new data for the Si-Ti, Fe-Ti, and Mn-Ti systems. Very negative deviations from ideal solutions were established for the activities of the components in melts of the Fe-Mn-Si system. In the melts of the Fe–Mn(Ti)–Si, Fe–Mn–Ti, and Mn–Si–Ti ternary systems, the minimum mixing enthalpies are observed in binary melts, and in the Fe–Mn–Si system, the minimum occurs in the Fe0.4Mn0.2Si ternary melt 0.4, because the double Fe(Mn)– Si subsystems make the largest contribution to the interaction energy between different atoms. This study demonstrates the ability to predict the thermodynamic behavior of ternary systems, allowing for optimization of alloy compositions and improvement of industrial processes. Calculations based on the Redlich-Kister-Mujianu model with a triple contribution of -200 kJ/mol for melts of the Fe–Mn–Si system agree with experimental data, which confirms sufficiently high accuracy predicted parameters.

The phase and structure formation of aluminum-matrix composite materials reinforced with titanium carbide during their synthesis and consolidation using the forging were investigated. The influence of copper additives on the structure formation, density, porosity, and hardness of aluminum-matrix composites was determined. The research results revealed the presence of Al+Cu+TiC phases in copperalloyed samples. Studies of density and porosity showed that the samples without copper additives were maximally densified after hot stamping and had minimal porosity, unlike the copper-alloyed composites.

Mechanical tests of 5- and 6-component high-entropy alloys, which were obtained for the first time by the method of hot forging, were carried out. The test results showed a fairly high hardness and strength of the obtained alloys. The TiCrFeNiC alloy (without annealing) has the highest mechanical properties. Its high strength is due to solid-solution hardening, as well as the formation of carbides in situ. Fractographic studies showed mostly quasi-brittle destruction of alloy samples.

The electrochemical corrosion properties in a 3% NaCl solution of the titanium-based multicomponent composite of the 65TiH2–30FeSiMn–B4C system were investigated. The kinetics and the mechanism of anode dissolution of metals and oxidation of specimens have been studied by using polarization curves, chemical and x-ray phase analyses. It was found a decrease in the titanium carbide peaks on the X-Ray defractions also the titanium silicon carbide almost disappears after immersing the sample in a 3% NaCl solution. Formation of silicon and boride phases of titanium in the synthesis process leads to an increase in corrosion resistance due to the inhibition of the velocities of both the anode and cathode processes.

Using fast Fourier transform the frequency spectra of sound vibrations of sound obtained by impacting a suspended material sample were obtained and analyzed. For this, the corresponding short sound files were recorded, which were then subjected to computer analysis. It was found that the frequency spectra of sound vibrations for cast silumin and for those after deformation-heat treatment have a different character. So in these spectra obtained for samples that have passed the deformation-heat treatment, a set of narrow, clearly peaks at certain frequencies have been observed. In the spectra obtained for cast samples, such clear, narrow peaks are not observed. The position of the characteristic peaks in the frequency spectra of sound vibrations was used to estimate the elastic modulus for samples that have passed various regimes of deformation-heat treatment.

The peculiarities of the structure and phase composition of the high-entropy alloy of the TiCrFeMnSiC system obtained from the powder mixture of ferrotitanium, ferrochrome and ferrosilicon-manganese ferroalloys are considered in the work. The technological scheme of alloy production included joint grinding of the mixture in a planetary mill, consolidation of the blanks, their heating to 1100 0C, hot forging on the arc press and subsequent annealing of hot-forged samples at 1200 0C. According to the results of X-ray analysis of the obtained alloy, it was found that the main phase of the alloy is the BCC phase with the parameter of the cubic lattice a = 0.2868 nm, which is a solid solution based on alloying components of the original charge. The phase composition of the composite also recorded ti tanium carbide TiC with FCC lattice with the parameter a = 0.4319 nm, which corresponds to a stoichiometric composition of about TiC0.6 and a small amount of FCC phase of iron-chromium carbide (Cr, Fe)23C6 with lattice parameter a = 1.0645 nm. The material has a high hardness (up to 60-61 HRC), which can provide high resistance of this multicomponent alloy.

The influence of high-carbon ferrochrome on the features of structure formation and properties of chromium carbide steels based on the Fe-FKh800 system was investigated. It was shown that the optimal combination of hardness and tensile strength with sufficient crack resistance has a carbide base of 65% Fe – 35% (wt.) FKh800. A typical microstructure of sintered carbide is a metal matrix composite consisting of chromium steel of composition close to Kh17 and double carbide (Cr0.799Fe0,201) 7C3. The effect of TiB2 additive on the structure, phase composition, mechanical and tribotechnical properties of materials based on the Fe- 35 (%,wt.) FKh800 system was also investigated. Additions of titanium borides in the amount of 0.38-1.48 (% wt.) leads to some increase in hardness, noticeable increase in the flexural strength and leads to increase wear resistance of carbidosteels.