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.

A mathematical model was developed to determine the order of failure of layers in a two-layer ceramics composite and to determine the conditions for achieving the maximum limit load under three-point loading. The model was set in the space of three “bilayer parameters”: the ratio of the thickness of the lower layer to the whole thickness of the beam, the ratio of Young’s moduli of the lower layer to the upper layer, and the ratio of flexural strengths of the materials of the lower layer to the upper layer. The adequacy of the model obtained was confirmed by experimental results on the three-point bending of the experimental specimens. The experimental samples were two-layer composites consisting of a cermet layer TiB/Ti and a layer of α-Ti. The samples were obtained by free self-propagating high-temperature synthesis (SHS) compression and with varying their thickness. The results obtained make it possible to predict in advance which layer, based on the specific bilayer parameters, will trigger the brittle fracture mechanism as well as to set the maximum destructive load of bilayer composites.

This study investigates TNM-type titanium aluminide alloys, representing the third generation of β-stabilized γ-TiAl heat-resistant materials. The aim of this work is to study the combustion characteristics and to produce compact materials via the free SHS compaction method from initial powder reagents taken in the following ratio (wt%): 51.85Ti–43Al–4Nb–1Mo–0.15B, as well as to determine the effect of high-temperature isothermal annealing at 1000 °C on the structure and properties of the obtained materials. Using free SHS compression (self-propagating high-temperature synthesis), we synthesized compact materials from a 51.85Ti–43Al–4Nb–1Mo–0.15B (wt%) powder blend. Key combustion parameters were optimized to maximize the synthesis temperature, employing a chemical ignition system. The as-fabricated materials exhibit a layered macrostructure with wavy interfaces, aligned parallel to material flow during compression. Post-synthesis isothermal annealing at 1000 °C for 3 h promoted further phase transformations, enhancing mechanical properties including microhardness (up to 7.4 GPa), Young’s modulus (up to 200 GPa) and elastic recovery (up to 31.8%). X-ray powder diffraction, SEM, and EDS analyses confirmed solid-state diffusion as the primary mechanism for element interaction during synthesis and annealing. The developed materials show promise as PVD targets for depositing heat-resistant coatings.

In the fabrication of finished articles with as low porosity as possible by compaction methods, it is necessary to assess the formability of the material. Characteristically, metal–ceramic materials, especially refractory ones, have a very narrow temperature–time range where they are capable of plastic deformation. In this paper, we report our results on the high-temperature forming of TiC-based metal-matrix metal–ceramic composite materials. The metallic matrix was produced from PKh18N15M high-alloy steel powder (10–70 wt %). In the synthesis of the metal–ceramic composites, we used powder materials (titanium and carbon black) which react exothermically to form titanium carbide. The formability of the synthesized material was evaluated using the unrestricted self-propagating high-temperature synthesis (SHS) compression method. As a criterion, we used strain: the ratio of the difference in cross-sectional area between the deformed sample and starting compact to the area of the deformed sample. It has been shown that increasing the fraction of the metallic binder from 10 to 60 wt % causes the combustion temperature and speed to decrease by a factor of 1.6 and 23, respectively. At a metallic binder content of 70 wt %, synthesis is impossible. The structure and phase composition of the material have been shown to undergo no qualitative changes, independent of the content of the metallic matrix. The results obtained in this study can be helpful in improving the technique for the fabrication of compact TiC-based composite materials with a PKh18N15M metallic matrix in order to minimize their porosity.

Intermetallic materials based on titanium aluminides (TiAl and Ti₃Al) were produced from initial powder components of titanium and aluminum by the method of free SHS-compression, which combines combustion processes in the self-propagating high-temperature synthesis (SHS) mode and high-temperature shear deformation of the combustion products. To elucidate the mechanism of phase formation, the temperature and combustion velocity of the studied compositions were measured. It was established that under free SHS-compression conditions these parameters decrease with increasing fraction of free titanium and decreasing fraction of aluminum in the starting charge. It was shown that, owing to the early contact of the synthesized material with the press plunger during free SHS-compression, the phase-formation processes are completed. The regularities of the effect of the ratio of the powder reagents (titanium and aluminum) in the starting powder mixture on the phase composition, structure and mechanical properties (microhardness, elastic modulus, elastic recovery) are presented. It was found that the highest values of microhardness and elastic recovery correspond to a composition consisting of 74 wt % Ti₃Al and 26 wt % TiAl, whereas the maximum elastic modulus corresponds to a composition of 86 wt % TiAl and 14 wt % Ti₃Al.