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

The combustion synthesis (CS) is an autogenous and strongly exothermic chemical reaction in a powdered mixture of a strong reducer and oxidizer. Such processes, due to short duration and fast quench, can be a source of novel nanomaterials. Here we present (i) the CS synthesis of SiC nanowires (SiCNWs) and (ii) the magnesiothermic reduction of the asbestos waste. The resulting raw and purified products were analyzed with different chemical and physicochemical techniques (XRD, SEM, TGA and Raman spectroscopy) to verify its composition and morphology.

Natural abundant, cheap and widely used raw materials like calcite, magnesite and dolomite contain elemental carbon up to several wt percent. Such rocks have been chemically processed here using combustion synthesis route to yield novel nanocarbons including two-dimensional graphene-like structures. The fast and efficient reduction of powdered minerals with strong reducer (Mg) produces, after chemical wet purification, carbon nanomaterial which was analyzed using different techniques like XRD and SEM. This ‘combustion’ process was followed on-line to evaluate reaction duration (usually within 1 sec).

Combustion synthesis (CS) is a technique for the synthesis of various nanopowders and complex compounds. This manuscript describes principles, some recent developments in CS and its exemplary applications: formation of silicon carbide nanofibers (SiCNFs) and transformation of synthetic and natural (Nepali dolomite) carbonates into graphene-related carbon nanostructures.

Investigated was the spark plasma sintering (SPS) of β-SiAlON/0–30 wt % BN ceramic composites. The raw materials (β- Si₅AlON₇ and BN powders) were prepared by infiltration-mediated combustion synthesis (CS). Experimentally established were the following process parameters for SPS of composites with high relative density (>95 %) and flexural strength of 250–300 MPa: (a) heating rate 50 deg/min, (b) maximum temperature 1650–1750°C, (c) and holding time 5 min.

Combustion synthesis was applied as a novel approach to produce carbon-related nanostructures. Redox reactions in the systems Mg/Si/GO/SiFx yielded interesting products like silicon carbide nanowires (SiCNWs) and graphene-related nanostructures.

In this study, Mo-Ni-B alloy system which can be a new hard alloy alternative to tungsten base cemented carbides, was investigated by means of thermochemical calculations and experimental trials. Thermochemical calculations were carried out to estimate the adiabatic temperatures and possible product compositions in the alloys by using FactSage 7.0 thermochemical software. The combustion synthesis process was performed under normal gravity and air in Cu copper crucibles by using metal oxides (MoO₃ and NiO), boron oxide (B₂O₃) as a boron source and aluminum (Al) as a metallic reductant. Alumina, (Al₂O₃) as a functional additive (diluent), were also added in order to reduce the adiabatic temperature of the reaction. Since the attained reaction temperatures for this system during the exothermic SHS process is so high (above 2000 °C), the reaction is self-sustaining and the melt consists of insoluble mixture of metallic compound and oxide phase which can be segregated under normal gravity force.

Graphene (GR), a single-atom-thick sheet of hexagonally arrayed sp2-bonded carbon atoms, is close to become the next disruptive technology, replacing some of the currently used materials and leading to new markets. The contribution will focus on the production, characteristics, and current and prospective applications of this new carbon nanomaterial. Combustion synthesis (CS) is proposed as a novel approach to produce GR-related nanomaterial.