TiN-TiB2 composite coatings reactively produced by electrothermally exploded powder spray

Composite coatings composed of titanium nitride, TiN, and diboride, TiB2, were reactively produced by the electrothermally exploded powder spray technique, in which feedstock powder was prepared from titanium and boron nitride particles. The microstructure of the coating was composed of titanium-ceramic particles the size of which were on the order of several nanometers to a few hundred nanometers. Such reactive thermal spraying brought base-metal saturation into a coating layer at the early stages of coating formation. The ceramic composite spray using feedstock of TiN and TiB2 particles preferentially brought a new phase of cubic titanium boronitride together with TiN and TiB2 into a coating. On comparing such a coating to one produced by the conventional method, the reactive thermal spray coating was richer in TiN and TiB2 due to the excess nitrogen in the feedstock.