Mechanochemical synthesis and characterization of TiB2 and VB2 nanopowders

A novel method for the synthesis of transition-metal boride nanopowder has been developed using a mechanochemical reaction between LiBH4, LiH and transition-metal chloride (TiCl3 and VCl3) by high energy ball milling. This method successfully produces TiB2 and VB2 particles dispersed within a soluble LiCl matrix. Subsequent washing with distilled water, ethanol and acetone to remove the LiCl matrix phase yields TiB2 and VB2 nanopowders of 15–60 nm particle size. From the X-ray diffraction patterns and high resolution transmission electron microscopy image, it is found that each particle is polycrystalline consisting of 3–5 nm crystallites. Neither particle nor crystallite size are increased significantly after heating at 680 °C.