Heterogeneous Nucleation and Solidification Prediction of Sn-5wt.%Pb Droplets
摘要
We develop a model for heterogeneous nucleation catalyzed by oxidation on the droplet surface and the internal nucleation similar to surface oxidation. The fraction covered by oxide on the surface of the droplet is calculated as a function of time and temperature based on the chemical reaction dynamic and transition state theory, which is a reasonable expression for the oxidation behaviour of Sn-5wt.%Pb droplets. The continuous-cooling-transformation curves were computed using the above experimental results under the heterogeneous surface nucleation and the internal nucleation of droplets. Also, we predict the solidification behaviour of the droplet in gas-atomized spraying process using this model. The same model can be applied to predict the nucleation behaviour for any type of cooling schedule.