In this work, intermetallic materials based on γ-TiAl in situ strengthened with the Ti₃Al phase have been obtained from the initial components of titanium and aluminum under the conditions of free SHS-compression in one technological step and in ten seconds. This method combines the process of the combustion of initial components in the mode of self-propagating high-temperature synthesis (SHS) with high-temperature shear deformation of the synthesized materials. The following initial compositions have been studied (mol): Ti–Al, 1.5 Ti–Al, and 3 Ti–Al. Thermodynamic calculations have been carried out and the actual combustion temperature of the compositions under study has been measured. To increase the exothermicity of the studied compositions, a “chemical furnace” based on a mixture of Ti–C powders has been used, which allows us to increase the combustion temperature and stabilize the combustion front. It has been found that the actual combustion temperature of the selected compositions increased from 890–1120 to 1000–1350 °C. The results of X-ray powder diffraction and SEM are presented, mechanical and tribological characteristics of the obtained materials are measured, and 3D images of wear grooves are given. It has been found that a decrease in Ti molar fraction and an increase in Al molar fraction in the initial mixture lead to an increase in the mechanical (hardness up to 10.2 GPa, modulus of elasticity up to 215 GPa) and tribological characteristics (wear up to 4.5 times, coefficient of friction up to 2.4 times) of intermetallic materials.

The effect of the delay time before applying pressure on the formability of a TiC–(5–50 wt %) NiCr–based material and on its phase composition, unit cell parameters, and microstructure was experimentally studied by free SHS compression under conditions combining combustion and high-temperature shear deformation. It was shown that, with an increase in the relative density of the initial sample, the combustion temperature first rises and then sharply decreases. The mechanism of formation of the studied materials was determined at various quantitative contents of nichrome in the mixture. It was found that the optimal nichrome content in the mixture is 20–40 wt %, at which the strain of the material is maximum. The route of the synthesis of the initial reagents (titanium, carbon black, and nichrome) under free SHS compression was identified. It was detected that the synthesized material consists of TiC particles distributed in a matrix of Cr_1.12Ni_2.88 and Cr₂Ni₃. At >30 wt % nichrome in the mixture, a small amount of the unreacted titanium is observed, which can be controlled by the synthesis conditions.

We determined the compactability regularities observed during the cold uniaxial pressing of layered powder green samples, taking into account factors such as composition, height, and number of Ti–B (TiB) and Ti–Al–Nb–Mo–B (TNM) layers. The following composition was chosen for the TNM layer at %: 51.85Ti–43Al–4Nb–1Mo–0.15B, while for the Ti-B layer we selected the composition wt %: Ti-B-(20, 30, 40) Ti. Green samples were made containing both 100 vol % TiB and TNM, and those taken in the following proportions, vol %: 70TiB/30TNM, 50TiB/50TNM, 30TiB/70TNM; multilayer green samples were studied in the following proportions, vol %: 35TiB/30TNM/35TiB, 25TiB/25TNM/25TiB/25TNM, 35TNM/30TiB/35TNM. Based on the obtained rheological data, we determined the rheological characteristics of the layered green samples, including compressibility modulus, compressibility coefficient, relaxation time, and limiting value of linear section deformation. These characteristics were found to vary depending on the composition, height, and number of layers. Our findings revealed that reducing the TNM content in the charge billet composition improves the compaction of powder materials under the given technological parameters of uniaxial cold pressing. Moreover, we observed that increasing the boron content and decreasing the amount of titanium in the Ti–B composition enhances the compactability of powder materials. We also established a relationship between the compaction pressure interval and the density of the layered powder green sample.

The paper analyzes the structure, and the mechanical and tribological properties of Ti–Cr–C–Ni–Fe coatings formed on R6M5 high-speed steel in four modes of electrospark deposition (ESD) using TiC–NiCr electrodes manufactured by extrusion in combination with self-propagating high-temperature synthesis (SHS). The analysis shows that the coatings formed in the four ESD modes at a discharge energy of 0.2, 0.3, 0.6, and 1.0 J are composed mainly of Cr–Ni–Fe–C_solid and Fe_0.7Ni_0.3 matrix phases strengthened with Ti_0.8Cr_0.2C particles the size of which decreases to less than 100 nm in going from the coating surface to the substrate. In the SHS electrode during the deposition, most carbide particles are melted. Increasing the discharge energy increases the fraction of solid grains transferred to the substrate by a factor of up to 9. The dependences of the total anode mass loss and total cathode mass gain on the ESD time in the four modes have a classical form. Also considered are the discharge energy dependences of the SHS electrode transfer coefficient, coating run-in length, and wear of the coating and counterbody. The coating hardness measures 10.6–13.5 GPa.

Distinctive features of the formation of the structure of a titanium carbide-based alloy with a nichrome binder under self-propagating high-temperature synthesis (SHS) conditions have been studied theoretically and experimentally. We have observed qualitative changes in the structure of the material due to differences in SHS process: without pressure, pressing, and extrusion. Unlike in the case of pressureless SHS, SHS extrusion involves mechanical mixing of the material, which ensures better uniformity of the structure formation process. Based on proposed models for thermal conditions of SHS extrusion and experimental data, we have examined the influence of heat removal conditions and strain on the grain size of TiC along and across extruded rods. Analysis of the results we obtained has shown that the maximum discrepancy between theoretical calculations and experimental data is within 10% and that, in the case of the minimum size of TiC grains, the discrepancy does not exceed 1–5%, which confirms good agreement between the proposed model and experimental data.

We studied how the ratio of precursor titanium and boron powders influenced the combustion temperature and combustion velocity in the high-temperature self-propagating synthesis (SHS) mode, and the microstructure, phase composition, and mechanophysical properties of rods fabricated by SHS extrusion. The subject matters of the study were materials for which the as-batch phase compositions of products were TiB–(20–40) wt % Ti. The formation of boron solid solution in titanium was considered. Scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and mechanical measurements implied the texture of the prepared materials (TiB whiskers were aligned in the direction in which the external pressure was applied). In all of the composites studied, the conductivity was close to the conductivity of undoped titanium; the electrical resistance increased slightly in response to increasing boron weight fraction. The three-point bending strength of the material increased by a factor of 1.7 at most as the weight fraction of boron solid solution in titanium increased from 20 to 40 wt %.