Synthesis of Ti-Al alloy by mechanical alloying and its microstructure

Abstract

This study aims to discuss the morphology of TiAl alloys prepared by mechanical alloying (MA) techinique. The alloy composition varied from 45 to 75 at.% of Ti with MA time from 0 to 60 hours under Ar atmoshere. The vial and the balls were stainless steel. From the SEM observation, the diameter of MA particle is becoming smaller with increasing MA time. The diameter of Ti50Al50 powder indicates a size of 15 μm after 40 hours of ball milling. From the XRD measurements, the microstructure of MA alloy indicates an amorphous structure in the case of 20 hours of MA. We tried to synthesis TiAl or Ti3Al intermetallic alloy phase by heat treatment. DSC measurements shows crystallization started around 600°C for each alloy, Although we could not synthesis the single phase, from the TEM bright image observation, we have confirmed that the alloy is composed by nano-size particles more and less 10 nm of diameter of crystalline particles. © 2008 The Japan Institute of Metals.