Post-melting anomaly of Pb-Bi alloys observed by internal friction technique

With the help of an improved internal friction method, it was found that a peak could appear, as the temperature increased, above the liquidus in each of the internal friction curves of Pb-Bi alloys. The features of this kind of peak are similar to those found during the solid-liquid transition in the same experiments, and in accordance with the characteristics from solid-solid transitions verified by previous investigators. The results suggest that structural changes take place to some extent in the molten alloys as a function of temperature, which have been confirmed by the corresponding calorific peak in a differential scanning calorimeter. This phenomenon might help in understanding the nature of molten alloys and their melting mechanism as well. In addition, the internal friction technique proved to be quite sensitive to liquid structures and effective for studying liquid materials.