Explosive Reaction Pressing of Intermetallic Compounds from Stoichiometric Powder Mixtures

Intermetallic NiAl, TiAl and TiAl3 were synthesized by shock compression experiments from stoichiometric powder mixtures of nickel and aluminium as well as of titanium and aluminium. Good consolidation and complete intermetallic reaction were achieved by the direct method of explosive compaction. For each powder mixture, a certain individual threshold pressure has to be exceeded in order to initiate intermetallic reaction. The reacting compounds melted completely with subsequent rapid solidification during the passage of the shock wave. The new material shows high hardness. Pores are formed by gaseous reaction products in the NiAl and TiAl3 compacts. The TiAl structure is fully-dense and dendritic.