Preparation and Characterization of Nano-Crystalline Ti-2 at%Fe-10 at%Si Alloy by Mechanical Alloying and Pulsed Current Sintering Process

Abstract

Ti-2 at%Fe-10 at%Si amorphous powder was synthesized by mechanical alloying (MA) of elementary Ti, Fe and Si powders using planetary ball milling for 1440 ks. Crystallization temperature of the obtained amorphous powder was ca. 830 K. Ti-2 at%Fe-10 at%Si amorphous powder was consolidated using a pulsed current sintering (PCS) process at a die temperature of 773 K under a pressure of 372 MPa. Then the compact was densified at a die temperature between 743 K and 763 K, which is around the crystallization temperature of the amorphous phase. The obtained Ti-2 at%Fe-10 at%Si alloy consists mainly of nanocrystalline α-Ti phase. The compressive strength of the nanocrystalline compact at room temperature was more than 1.7 GPa, much higher than that of a commercial Ti-6 mass%Al-4 mass%V alloy.