Shandong Univ, Minist Educ, Key Lab Liquid Struct & Hered Mat, Jinan 250061, Peoples R China
; Chinese Acad Sci, Inst High Energy Phys, Beijing Synchtotron Radiat Lab, Beijing 100039, Peoples R China
Viscosities and liquid structure of alloys Cu75Al25, Cu87Sn13 and Al-12.5%Si and pure metals Cu and Sn are investigated by using torsional oscillation viscometry and high temperature x-ray diffractometry. The viscosities of pure metals and eutectic alloy melts along with the short-range order structure are found to follow the Arrhenius law in a wide range of temperature above the liquidus. The breakpoints in Arrhenius plots emerge when the structures of alloy melts are transformed from the medium-range order structure to the short-range order structure. It has been found that the change of the viscosity of the metallic alloys is a characteristic of microstructure transformation in the related melts.