Local Structures of Mechanically Alloyed Al70Cu20Fe10 Nanocomposites Studied by XRD and XAFS

Ternary Al70Cu20Fe10 alloy nano-composites prepared by mechanical alloying are characterized by X-ray diffraction (XRD) and X-ray absorption fine structure (XAFS). The results indicate that after milled for 10 hours, the coordination environment around Cu atoms is changed largely and becomes disordered, but the local structure of Fe atoms still remains as that of α-Fe. This indicates the forming of inter-metallic compound Al2Cu with body center cubic structure. Even if the milling time is extended to 40 hours, only small amount of α-Fe can be alloyed to produce Al-FeCu alloy. However, the annealing treatment at 700 °C can drive the α-Fe to incorporate into the Al2Cu compound to form an icosahedral alloy phase.