Structure of medium-range order in
molten Al-Fe alloy
molten Al-Fe alloy
(1. Key Laboratory of Liquid Structure and Heredity of Materials,
Ministry of Education, Shandong University, Ji′nan 250061, China;
2. State Key Laboratory of Microstructure of Solid,
Nanjing University, Nanjing 210093, China)
Ministry of Education, Shandong University, Ji′nan 250061, China;
2. State Key Laboratory of Microstructure of Solid,
Nanjing University, Nanjing 210093, China)
Abstract: The molecular-dynamics (MD) simulation was carried out to investigate the structure of medium-range order (MRO) of a liquid Al5Fe2 alloy. Prepeak is observed in the structure factor S(Q), which is considered as the signature of MRO. Results from MD simulation and experiment agree well with each other, which proves reliability of the simulation. It is found from the calculated Ashcroft-Langreth structure factors that there exists strong interactional force between atom Al and Fe, which results in the great concentration fluctuation, i.e. the chemical order, in the liquid Al5Fe2. Both the chemical order parameter, α , and the Bhatis-Thornton（BT）structure factors indicate the preference for unlike-neighbor bonds. It is seen from the low-Q domain of S(Q) and the concentration-concentration structure factor SCC(Q) that the prepeak mai, nly comes from the first peak of SCC(Q). The structural model, which reflects the characteristic of MRO, is also constructed .
Key words: Al-Fe alloy; MD simulation; medium-range order; structure factor; prepeak