Self-propagating high temperature synthesis process involving addition of varying amounts of NaCl. Milling assisted Self-propagating high temperature synthesis (MA-SHS). Solvothermal reaction in benzene of metallic sodium with amorphous boron powder and TiCl4 at 400 °C: TiCl4 + 2 B + 4 Na → TiB2 + 4 NaCl Many TiB2 applications are inhibited by economic factors, particularly the costs of densifying a high melting point material - the melting point is about 2970 °C, and, thanks to a layer of titanium dioxide that forms on the surface of the particles of a powder, it is very resistant to sintering. Admixture of about 10% silicon nitride facilitates the sintering, though sintering without silicon nitride has been demonstrated as well. Thin films of TiB2 can be produced by several techniques. The electroplating of TiB2 layers possess two main advantages compared with physical vapor deposition or chemical vapor deposition: the growing rate of the layer is 200 times higher (up to 5 μm/s) and the inconveniences of covering complex shaped products are dramatically reduced. Potential applications Current use of TiB2 appears to be limited to specialized applications in such areas as impact resistant armor, cutting tools, crucibles, neutron absorbers and wear resistant coatings. TiB2 is extensively used for evaporation boats for vapour coating of aluminium. It is an attractive material for the aluminium industry as an inoculant to refine the grain size when casting aluminium alloys, because of its wettability by and low solubility in molten aluminium and good electrical conductivity. Thin films of TiB2 can be used to provide wear and corrosion resistance to a cheap and/or tough substrate. References Compare Magnesium diboride See also Boride Titanium carbide Cermet Sintering Hot pressing Borides Titanium(IV) compounds Superhard materials