Self-propagating High-temperature Synthesis of Ti₅Si₃/TiAl₃ Intermetallics

Abstract

The products with designed volume ratio of Ti₅Si₃ : TiAl₃=1 : 0, 3 : 1, 1 : 1, 1 : 3 and 0 : 1 prepared by self-propagating high-temperature synthesis (SHS) were investigated in the present study. The differential thermal analysis (DTA) results suggested that the Si in reactants had a significant influence not only on the melting of Al, but also on the subsequently exothermic reaction between Ti and Al. Also, the presence of Al altered the reaction process of Ti₅Si₃. The phase composition of SHS reaction product agreed well with the designed volume ratio of Ti₅Si₃ : TiAl₃. Compared with those apparently coarse ones in monolithic Ti₅Si₃ or TiAl₃, the grains were considerably refined and microcracks gradually disappeared in products with coexistence of Ti₅Si₃ and TiAl₃.