The Possibility of Dense Materials Based on Obtaining an AlN–SiC Solid Solution by Self-Propagating High-Temperature Synthesis Gasostating

Russian Journal of Non-Ferrous Metals - The synthesis and sintering of the (AlN)x(SiC)1 – x solid solution have been studied under conditions of self-propagating high-temperature synthesis...     

Aluminum oxynitride by SHS under high pressure of nitrogen gas

Aluminum oxynitride (γ-AlON) powders were prepared from low-caloric Al–Al₂O₃ mixtures by SHS under high pressure of nitrogen gas in the presence of heat-generating agent, Mg(ClO₄)₂, as a booster. The preparation procedure was characterized and optimized with respect to Al/Al₂O₃ ratio, amount of heatgenerating additive, and nitrogen gas pressure. The morphology of synthesized γ-AlON powders was found to depend on Al powder brand. Compared to γ-AlON powders obtained in chemical furnace, we managed to prepare less sintered arenaceous cakes that could be easily disintegrated into target γ-AlON powder. SHSproduced powders may find their application in production of optical ceramics.     

AlON powders by SHS under nitrogen pressure with KClO<Subscript>4</Subscript> as a booster

AlON powders were prepared by SHS under nitrogen pressure using KClO₄ as a booster and characterized by XRD and SEM. The combustion product obtained under optimized conditions represented pure AlON powder that contained minimal amount of byproducts.     

Structure and phase formation of combustion products during the synthesis of γ-AlON in self-propagating high-temperature synthesis

Synthesis of aluminum oxynitride (γ-AlON) in conditions of self-propagating high-temperature synthesis (SHS) gas-statting under high pressures (10–100 MPa) of gaseous nitrogen, including the mode of so-called coupled combustion reactions (chemical furnaces) is investigated. It is shown that chemical and phase compositions of combustion products, as well as their structure and morphology of powder particles, depend on the reagent ratio in Al–Al₂O₃ initial mixture, as well as on nitrogen pressure, combustion temperature of highly exothermic components of chemical furnaces, and grade of initial reagents. The structure of γ-AlON powder particles are determind and its relation with operation conditions of SHS. Optimal SHS parameters for Al₅O₆N (γ-AlON) formation are established.     

Self-Propagating High-Temperature Synthesis of Silicon Carbide Nanofibers

Russian Journal of Non-Ferrous Metals - The results of investigations into the organization of the synthesis of silicon carbide fibers in the gas phase using silicon powder, an energy additive of...     

Nanostructured particles of boron,aluminum, and silicon nitrides by thermally coupled SHS reactions of nitriding

The paper shows the investigation results of structure and phase formation of boron, aluminum and silicon nitride particles in gaseous nitrogen of high pressure (10–40 MPa) under the terms of thermocoupled high- and low-exothermic reactions (so-called chemical furnaces). In this case the high-exothermic reaction is an additional heat source for the low-exothermic one. The reactions are separated in space and chemically independent. The nitriding terms which are close to extreme ones (high burning temperatures of aluminum, boron and silicon, high heating rates, etc.) provide the reagent evaporation and promote gastransport reactions with the combustion mechanism transition from the solid-phase to gas-phase or vaporliquid due to volatile intermediate products of nitriding and impurities. As a result, the SHS products contain not only well-known forms of nitride particles (nano-fibers, nano-filaments, nano-plates, nano-whiskers, etc.) but such structures as BN nano-tubes with various types of morphology and cubic modifications of BN and AlN as well. It is to be studied additionally.