SHOCK REACTIVE SYNTHESIS OF TIAL

The shock reactive synthesis (SRS) processing was developed to yield b ulk solid titanium aluminides in a non-equilibrium phase structure. Fr om blended element powder compacts with a composition of Ti50-Al50, Ti Al is directly synthesized without porosities. The shock-induced react ions can be macroscopically described by SRS-diagram, and the effect o f the detonation condition and the green compact porosity on the const ituent phases and microstructure of synthesized materials are also dis cussed on this diagram. In the reactive zone of this diagram, the abun dance ratio of alpha(2) to gamma in the alpha(2)/gamma two-phase synth esized materials can be controlled from the equilibrium ratio to the a lpha(2) single phase by increasing the detonation velocity and/or the porosity of compact. By using multi-layered samples with a sandwich st ructure of Ti and Al porous discs, the fundamental mechanism of shock- induced reactions can be investigated to clarify the role of high spee d mixing and homogenization of titanium and aluminum in the reaction p rocess at the passage of shock wave.