Effect of structure transition on solidification: 'sn-50wt%sb' visited

摘要

D.C. four-probe method was used to investigate the temperature dependence of electrical resistivity of Sn-50wt%Sb melt. Anomalous changes observed on resistivity-temperature curves (ρ-T) suggest that temperature induced liquid-liquid structure transition (L-LST) might occur in Sn-50wt%Sb melt at hundreds of degrees above its liquidus, and the transition is reversible after the first heating cycle. An isothermal experiment based on ρ-T curve was conducted to further probe the effect of the L-LST on solidification morphologies. Results show that the size of the primary phase decreases and that the microstructure becomes finer when solidified from the melt experienced the irreversible L-LST.