Phase formation in rapidly quenched Cu-based alloys

Abstract

In the present investigation, we report the formation of γ-brass type phase in the rapidly quenched Cu50Ga30Mg 5Ti15 and Cu50Al30Mg 5Ti15 alloys. Rapid solidification of Cu 50Ga30Mg5Ti15 alloy shows the formation of simple cubic γ-brass type phase (a = 0.863 nm), which on annealing at 1,023 K for 60 h transforms to disordered type γ-brass phase (a = 0.879 nm). It has been observed that intensity modulation of electron diffraction spots corresponding to simple cubic γ-brass phase is similar to the intensity modulation observed in the mirror orientation of icosahedral quasicrystalline phase. Contrary to the crystalline phase formation in Cu-Ga-Mg-Ti alloy, rapid solidification of Cu50Al30Mg 5Ti15 shows the formation of amorphous and nanocrystalline bcc γ-brass type phase (a = 0.870 nm), which on annealing transforms to ordered γ-brass type phase (a = 0.872 nm). The structural and microstructural characterization was done through X-ray diffraction and transmission electron microscopy. © 2009 Springer Science+Business Media, LLC.