Heterogeneous Nucleation and Solidification Prediction ofSn-5wt.%Pb Droplets

Abstract

We develop a model for heterogeneous nucleation catalyzed by oxidationon the droplet surface and the internal nucleation similar to surfaceoxidation. The fraction covered by oxide on the surface of the dropletis calculated as a function of time and temperature based on thechemical reaction dynamic and transition state theory, which is areasonable expression for the oxidation behaviour of Sn-5 wt.%Pbdroplets. The continuous-cooling-transformation curves were computedusing the above experimental results under the heterogeneous surfacenucleation and the internal nucleation of droplets. Also, we predict thesolidification behaviour of the droplet in gas-atomized spraying processusing this model. The same model can be applied to predict thenucleation behaviour for any type of cooling schedule.