The structure and dynamic viscosity of
In 80 Cu 20 alloy melt in the temperature range from 600 ℃ to 1 000 ℃ were
investigated by using a high temperature X ray diffractometer and a torsional oscillation viscometer. The experiments show that there exist medium range order (MRO) structures in
In 80 Cu 20 alloy melt in a low temperature range above liquidus. The MRO structures are weakened with increasing temperature and disappear when the temperature surpasses 800 ℃. The nearest interatomic distance r 1 and the coordination number N s of In 80 Cu 20 alloy melt decrease as temperature increases from 650 ℃ to 1 000 ℃. Thermal contraction of
atom clusters can be found in the heating process. The viscosity of In 80 Cu 20 alloy melt drops as temperature increases and meets with the exponential relation. No sudden change in structure occurs in the measured temperature range. DSC curve of In 80 Cu 20 alloy during cooling process was measured. It is found that there is no noticeable variation of heat during cooling from 1 000 ℃ to 600 ℃, which testifies further that there is no sudden change in structure of In 80 Cu 20 alloy melt.