Vol 25, No 3 (2016)

Suggested was a mathematical model for a two-stage mechanochemical synthesis of TiC in a mode of thermal explosion. Preliminary mechanical activation of green Ti–C mixtures was found to markedly accelerate the process. Calculated results well agreed with the available experimental data on mechanically activated Ti–4 wt % C mixtures. Using the method of reverse problem and relevant experimental data, we evaluated some kinetic and thermophysical characteristics of mechanochemical synthesis in the Ti–С system.

Combustion of 2Zr–Al–C powders in a mode of frontal combustion (mode I) or thermal explosion (mode II) was studied by time-resolved XRD. Reaction route in the above SHS reactions was found to be different. No formation of ternary MAX phases was observed. In mode I, leading is the reaction yielding ZrC and the final product contains zirconium intermetallics. The SHS reaction in mode II involves the interaction of Al melt with Zr particles via consecutive formation of solid solution Zr[Al], ZrAlC_1.77, and intermetallics ZrAl₃, ZrAl₂, Zr₂Al₃. The Zr–C reaction does not occur because of its low caloricity.

We report on the synthesis of superconducting Nb₃Al intermetallic with a critical temperature of 18 K. Nb–3Al powder compacts were used to fabricate Nb₃Al intermetallic by Mechanically Activated SHS (MA-SHS) and Mechanically Activated ElectroThermal Explosion (MA-ETE). Phase composition of the obtained samples was characterized by XRD, SEM, optical microscopy, EDX, and atomic emission spectroscopy (AES).

Cobalt oxide nanoparticles were deposited on the surface of glass cloth by solution-combustion synthesis and used as a catalyst for the growth of carbon nanotubes via the CVD process. The structure and morphology of thus prepared smart glass cloth were characterized by XRD, TEM, and SEM. Thus prepared carbon nanotubes 23–26 nm in diameter exhibited good current–voltage characteristics. The heating efficiency of the flexible heating element at low temperature was tested on a soldier model. The smart glass cloth showed good electroconductive and effective Joule heating from external current source. The conductive glass cloth can be recommended for use in various functional applications.

Influence of calcium peroxide (CaO₂) additives on the characteristics and properties of composite coatings deposited by centrifugal SHS was investigated. Microstructure and composition of deposited coatings were characterized by SEM, EDX, XRD, and mechanical testing. The additives of CaO₂ and Al were found to markedly improve the properties of deposited composite coatings. Under optimized conditions, the deposited coatings exhibited rather smooth surface, good adhesive strength, and reasonable micro-hardness.