Characterization of MXenes at every step, from their precursors to single flakes and assembled films

A review of results of applying the powder technology of self-propagating high-temperature synthesis (SHS) for obtaining various nanomaterials that can be used according to the tribotechnical indentation is given. First, these are low-cost nanopowders of sulfides, oxides, nitrides, carbides, borides, and metals which are suitable as solid lubricants and friction modifiers for liquid and plastic lubricating materials. Second, these are solid compact nanostructured ceramic and composite materials for the fabrication of tribotechnical construction. This type of nanomaterial can be fabricated both ex situ from SHS nanopowders by sintering or introduction into the melt both in situ in one stage from initial powders reagents by gasostatic SHS technology, forced SHS compaction, SHS casting, and SHS in the melt, which considerably simplifies and cheapens the production of such materials. Third, these are SHS materials for the deposition of nanostructured coatings of various thicknesses with a high wear resistance and low friction coefficients, such as nanostructured materials for surfacing and spraying, electrospark alloying electrodes, multicomponent targets for magnetron sputtering, cathodes for vacuum-arc evaporation, and nanodispersed fillers of electrochemical and chemical coatings.

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Nanomaterials of SHS technology for tribological applications: A review

Application of SHS process for fabrication of copper-titanium silicon carbide composite (Cu-Ti 3 SiC 2 )

The paper discusses the results of studying the structure and properties of powder coatings based on Ti3SiC2/TiC, obtained by the method of detonation spraying on the surface of the tool steel N9. It is determined that the coating has a uniform structure, cracks and delaminations are not observed. The results of X-ray structural analysis of coatings showed that the coating before annealing consists of phases TiC and Ti3SiC2. After annealing, the formation of TiO2 phases and an increase in the intensity of the (103) and (108) reflections of the Ti3SiC2 phases are observed. It is established that an increase in the content of the phases of Ti3SiC2 in coatings leads to an increase in the microhardness of coatings.

Influence of Heat Treatment on the Phase Composition and Microhardness of Coatings Based on Ti3SiC2/ TiC

Structural-phase and tribo-corrosion properties of composite Ti3SiC2/TiC MAX-phase coatings: an experimental approach to strengthening by thermal annealing

In this work, we describe the synthesis of the MAX-phase of titanium silicon carbide (Ti3SiC2) received by the method of self-propagating high-temperature synthesis (SHS) with application of pressure (SHS-pressing). Compacted Ti3SiC2 was obtained from initial mixture of powders of titanium, silicon and carbon (soot) with the ratio of powder components of 3Ti+(1.2-1.25)Si+2C. Using X-ray diffraction, scanning electron microscopy and energy dispersive analysis, it was shown that the synthesized product of SHS-pressing is a dense composite material consisting of the core phase of Ti3SiC2 and side phases of TiC and TiSi2. The basic physical and mechanical properties of the new composite material: density, compressive strength, hardness, electrical conductivity were studied. This material is of interest as a promising electric contact material.

Synthesis of MAX-Phase of Titanium Silicon Carbide (Ti3SiC2) as a Promising Electric Contact Material by SHS Pressing Method

In the present work, the structure and composition of the surface layer formed during self-propagating high-temperature synthesis (SHS) of porous ternary carbide Ti 3 SiC 2 from the initial mixture of powders 3Ti+1.15Si+2C in the surrounding gas atmosphere of different compositions were investigated. Using X-ray analysis, scanning electron microscopy and energy dispersive analysis, it was shown that a porous composite material, consisting of the main phases Ti 3 SiC 2 and TiC, is synthesized under these conditions. During the synthesis in atmospheres of air and nitrogen, a film of 2-3 microns thickness consisting of TiO 2 and TiN is formed on the surface of the porous material. During the SHS process in an inert argon atmosphere and in vacuum, this film is not formed. In nitrogen atmosphere, conglomerates of TiN particles are formed on the film as well.

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The Influence of Gas Atmosphere Composition on Formation of Surface Films in Self-Propagating High-Temperature Synthesis of Porous Ti3SiC2

The phase composition, structure, and properties of self-propagating high-temperature synthesis (SHS)-compacted materials of the Ti-C-Al-Si system are investigated. It is shown that metal-like titanium compounds can be used as cathodes for vacuum-arc evaporators. The coatings fabricated from SHS cathodes are single-phase and represent cubic titanium nitride of the (Ti, Al, Si)N composition. The volume of a microdrop phase in them is smaller by a factor of 2.5–3.0 as compared with TiN, while their microstructure is not fragmented into low-strength columnar elements; the CSR size is twice smaller than that of titanium nitride. Being approximately identically hard, the (Ti, Al, Si)N coatings substantially surpass TiN coatings in elastic and plastic failure resistance due to the lower elasticity modulus. When milling the tungsten-copper alloy, the hardness of hard-alloy milling cutters with the (Ti, Al, Si)N coating is higher by a factor of 2.4 than with the TiN coating fabricated from the titanium cathode with the magnetic plasma flow separation.

D. M. Davydov

Papers

Synthesis of MAX-Phase of Titanium Silicon Carbide (Ti3SiC2) as a Promising Electric Contact Material by SHS Pressing Method

The Influence of Gas Atmosphere Composition on Formation of Surface Films in Self-Propagating High-Temperature Synthesis of Porous Ti3SiC2

Composition, structure, and properties of SHS-compacted cathodes of the Ti-C-Al-Si system and vacuum-arc coatings obtained from them