Modelling of solidification for copper-base alloys during rapid solidification processing

A series of solidification experiments with different cooling rate for copper alloys were performed. The cooling rates and solidification under-cooling temperatures were evaluated from the cooling curves. The heat transfer coefficient and heat of fusion were calculated. It was observed that the heats of fusion are much lower than tabulated values. It was assumed that this was a result of the number of vacancies formed during the solidification process. Consequently, the effects of vacancies formed during solidification for different cooling rates were analysed. It was found that the classical solidification model should be modified in order to explain the results properly. Therefore the present solidification model, considering the effect of formation of vacancies on the solidification behavior and the thermodynamic properties, is proposed.