Mechanochemical synthesis and SHS of diborides of titanium and zirconium

Some properties of titanium diboride (TiB2) obtained by explosive mechanochemical synthesis and self-propagated high-temperature synthesis (SHS) have been investigated. The properties of zirconium diboride (ZrB2) obtained by SHS have also been studied. There is a general opinion that explosive mechanochemical synthesis proceeds by a SHS mechanism. For that reason, it is of interest to compare the properties of a product synthesized from the same reagents, by both mechanochemical synthesis and SHS. In order to elucidate the peculiarities of mechanochemical synthesis, the changes in shape and size of the titanium particles occurring during their mechanical treatment up to the moment of synthesis have been examined. Titanium and zirconium powders with particles differing drastically in shape and size have been used for the synthesis of TiB2 and ZrB2 by SHS. It has been shown that irrespective of the difference in properties of the reagents, the products obtained have some common properties characteristic of the synthesis method and important with respect to the practical applications of the borides of titanium and zirconium.