Self-Consolidation Mechanism of Nanostructured Ti(5)Si(3) Compact Induced by Electrical Discharge

Electrical discharge using a capacitance of 450 μF at 7.0 and 8.0 kJ input energies was applied to mechanical alloyed Ti(5)Si(3) powder without applying any external pressure. A solid bulk of nanostructured Ti(5)Si(3) with no compositional deviation was obtained in times as short as 159 μsec by the discharge. During an electrical discharge, the heat generated is the required parameter possibly to melt the Ti(5)Si(3) particles and the pinch force can pressurize the melted powder without allowing the formation of pores. Followed rapid cooling preserved the nanostructure of consolidated Ti(5)Si(3) compact. Three stepped processes during an electrical discharge for the formation of nanostructured Ti(5)Si(3) compact are proposed: (a) a physical breakdown of the surface oxide of Ti(5)Si(3) powder particles, (b) melting and condensation of Ti(5)Si(3) powder by the heat and pinch pressure, respectively, and (c) rapid cooling for the preservation of nanostructure. Complete conversion yielding a single phase Ti(5)Si(3) is primarily dominated by the solid-liquid mechanism.