Mechanochemical synthesis of TiN/TiB2/Ti-silicide nanocomposite powders and their thermal stability

Extremely fine and homogeneous TiN/TiB2/Ti-silicide composite powders have been synthesized from mixtures of Ti, BN and Si3N4 powders by high-energy ball milling through a mechanically activated self-sustaining reaction. They have a microstructure consisting of TiN and TiB2 crystallites of less than 15 nm embedded in amorphous TiSi2 or Ti5Si3 matrix. When these nanocomposite powders were annealed at high temperatures, the microstructure did not change significantly and TiN and TiB2 mutually suppressed the grain growth of both phases effectively.