Structural and microstructural characterization of SiB 0.5C 1.5N 0.8Al 0.3 powders prepared by mechanical alloying using aluminum nitride as aluminum source

Abstract

SiB 0.5C 1.5N 0.8Al 0.3 powders were fabricated by mechanical alloying using crystalline silicon (c-Si), hexagonal boron nitride (h-BN), graphite (C) and aluminum nitride (AlN) powders as starting materials. The microstructure of the synthesized SiB 0.5C 1.5N 0.8Al 0.3 powders is predominantly amorphous with a very small volume fraction of AlN nano-crystalline phase. The SiB 0.5C 1.5N 0.8Al 0.3 powders appeared to possess a structure containing hybridization of several bonds such as Si–C, B–C–N, C–C, B–N and Al–N because of the solid reactions among c-Si, h-BN, graphite and AlN. 29Si and 27Al solid-state nuclear magnetic resonance spectra showed the formation of amorphous SiC structure based on SiC 4 sites and the coexistence of AlN 4 and AlN 5 units in SiB 0.5C 1.5N 0.8Al 0.3 powders, respectively.