Solidification behaviour of rapidly quenched Cu-Sn alloys

A series of solidification experiments using DTA furnace were performed on different Cu-Sn alloys. The undercooling, cooling rates of the liquid and the solid states, solidification times and temperatures were evaluated from the curves. The cooling curves for different samples and alloys were simulated using a FEM solidification program. The heat transfer coefficient and the heat of fusion were evaluated. The calculated fraction of solid formed before quenching has been compared with the experimental result. It was found that the calculated values of the heat of fusion were much lower than the tabulated ones. The fraction of solid was also found to be much higher than those calculated theoretically. It is proposed that a large number of vacancies form during rapid solidification and that they condense during and after the solidification. The influence of these defects on the thermodynamics and solidification of the alloys has been evaluated.