Journal of Applied Sciences1812-56541812-5662Asian Network for Scientific Information10.3923/jas.2008.3727.3732KhosroshahiR.A. AhmadiN.P. SamadzadehS. 122008820With the aim of studying the effect of Si on Mechanical Alloying (MA)
process of TiAl (γ) intermetallic compound, two compositional powder
blends of Ti-50Al(at%) and Ti-48Al-2.4Si(at%) were mechanically alloyed
in a planetary ball mill. The structural evaluation in these powders was
done by X-Ray Diffraction (XRD) technique and Scanning Electron Microscopy
(SEM). It was found that elemental powders were progressively transformed
into nanocrystalline Ti solid solution and amorphous phases during MA
process. The time required for Ti solid solution or amorphous phase formation
was longer in Si containing powders. While annealing of the mechanically
alloyed Ti-50Al powders at 900°C for 10 min leads to the nanocrystalline
phase of TiAl(γ), nanocrystalline phases of mainly TiAl(γ) together
with some silicides and Ti3Al(α2) phase were
formed in Si containing powders. Annealing at higher temperature of 1150°C
leads unstable silicides to be transformed into more stable ζ-Ti5Si3
phase.]]>Chau-Jie, Z. et al.,2006435-436698704Fanta, G. et al.,200194549Froes, F.H.S., O.N. Senkov and E.G. Baburaj,20013014453Imayev, R.M. et al.,19993Al in the temperature range of 20-600°C.]]>4718091821Koch, C.C.,19982443948Kumaran, S. et al.,2008185124130Lu, L., M.O. Lai and F.H. Froes,2002546264Polmer, I.J.,20054th Edn.,Soni, P.R.,19991st Edn.,pp: 40-51pp: 40-51Suryanarayana, C.,2001461184Szewczak, E. et al.,1997226-228115118Takasaki, A. and Y. Furuya,19991112051217Westbrook, J.H. and R.L. Fleischer,19951995