Structural and microstructural characterization of SiB_(0.5)C_(1.5)N_(0.8)Al_(0.3) powders prepared by mechanical alloying using aluminum nitride as aluminum source

摘要

SiB_(0.5)C_(1.5)N_(0.8)Al_(0.3) powders were fabricated by mechanical alloying using crystalline silicon (c-Si), hexagonal boron nitride (h-BN), graphite (C) and aluminum nitride (A1N) powders as starting materials. The microstructure of the synthesized SiB_(0.5)C_(1.5)N_(0.8)Al_(0.3) powders is predominantly amorphous with a very small volume fraction of A1N nano-crystalline phase. The SiB_(0.5)C_(1.5)N_(0.8)Al_(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.~(29)Si and ~(27)Al 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_(0.5)C_(1.5)N_(0.8)Al_(0.3) powders, respectively.