Thermal stability of Al3BC3 powders under a nitrogen atmosphere

Abstract

Abstract The thermal stability of Al3BC3 powders under nitrogen was studied. AlN–BN composites were generated during the nitridation of Al3BC3. Possible reaction mechanisms responsible for the thermal decomposition of Al3BC3 powders were discussed. The relatively weaker Al–C bonds in Al3BC3 promoted the fast diffusion of Al and the generation of AlN–BN layers inhibited the deeper nitridation, thus the thermal decomposition was governed by surface reaction. The formed nitrides resulted in a volume change and cracked the resulting layers as the reactions progressed, facilitating the diffusion of N2 and enhanced the decomposition of Al3BC3. The intensive reaction involving Al3BC3 and N2 could be attributed to the prolonged reaction time at high temperature and continued escape of vaporized Al and B. This result contributes to a theoretical basis of high-temperature application of Al3BC3 under nitrogen.