Effect of partial substitution of Cu in Al₆₅Cu₃₅ by transition metal in mechanical alloying of Al₆₅Cu₂₀TM₁₅

Abstract

Mechanical alloying (MA) of Al-Cu yields a single-phase disordered bcc solid solution in a wide composition range (35-65 at.% Al). In the present work, a systematic effort is made to investigate the effect of partial substitution of Cu with a transition metal (TM) on the identity and sequence of phase evolution in MA in a high-energy ball mill. The ternary elements (Zn, Fe, Cr, Ti, Nb, and Zr) were added maintaining an initial composition of Al₆₅Cu₂₀TM₁₅. While addition of Zn yields nanocrystalline solid solution phases, ternary addition of Fe and Cr, in accordance with the earlier reported studies, leads to formation of quasicrystalline (QC) phases. On the other hand, MA of Al₆₅Cu₂₀TM₁₅ with TM=Ti, Nb, and Zr for an appropriate time develops a completely amorphous product under the present set of milling conditions. Thus, the present results indicate that MA of Al₆₅Cu₂₀TM₁₅ with Ti, Nb, and Zr is a potential route of synthesizing Al-rich amorphous alloys or nanocrystal dispersed amorphous matrix composite.