Process of Obtaining Chromium Nitride in the Combustion Mode under Conditions of Co-Flow Filtration

Abstract

In this work, the combustion process of chromium powder in the co-flow filtration mode was studied. The effect of nitrogen-containing gas flow rate on the nitridation of combustion products is shown. The effect of the amount of argon in the nitrogen–argon mixture on the burning rate and the burning temperature of the chromium powder is shown. It was found that an increase in the percentage of argon in the nitrogen–argon mixture can lead to the formation of an inverse combustion wave. The actual burning temperature is higher than adiabatic burning temperature in the co-flow filtration mode, thus the phenomenon of superadiabatic heating is observed. The phase composition of the obtained combustion products was studied. It was shown that the forced filtration mode allows for synthesizing non-stoichiometric Cr2N nitride.

AlN Production in Co-Flow Filtration Mode at Low Pressures

“…Obviously, this was due to the larger amount of fuel entering the reaction zone. At the same time, a more rapid cooling of the reaction products was observed: the “quenching” process [ 24 , 25 ]. Such quenching fixes the composition of the products formed in the high-temperature region [ 25 ].…”

“…Combustion in the co-flow filtration mode was carried out in a SHS reactor, which consisted of a reaction chamber (inner diameter of 1.6 cm), a gas supply unit, and a unit for recording operating parameters. The experimental procedure on the combustion of the raw components in the co-flow filtration mode is similar to the experimental procedure on the combustion of chromium powder in the co-current gas flow, which was described in detail in our work [ 24 ].…”

“…It is known that the co-flow filtration mode is very sensitive to the purity of the filtering reagent [19]. Previous experiments [24,25] confirmed that the addition of inert argon to nitrogen significantly affects the combustion process. The more cold ballast gas (argon) enters the reaction zone, the more energy will be spent on heating it and the more intensively the heat will be redistributed.…”