摘要
Nucleation of dendritic primaryα（Al） phase with addition of element Ce and Sr in hypoeutectic Al-7%Si-Mg cast alloy was investigated by using differential scanning calorimetry （DSC） and scanning electron microscopy. DSC results were used to calculate the activation energy and nucleation work of primaryα（Al） phase. The results show that the values of activation energy and nucleation work are decreased and the nucleation frequency is increased with the additions of Ce and Sr to the alloys. Moreover, the grain size of dendriticα（Al） phase is well refined, and the nucleation temperatures of primaryα（Al） dendrites are decreased with the additions of Ce and Sr. The effects of elements Ce and Sr additions on kinetic nucleation of primary α（Al） phases were also discussed in hypoeutectic Al-7%Si-Mg cast alloy.
利用差示量热法(DSC)和扫描电镜研究Al-7%Si-Mg亚共晶铸造铝合金添加Ce与Sr元素后初生α(Al)枝晶的动力学形核。根据DSC结果计算初生α(Al)相的激活能和形核功。结果表明,合金中添加Ce与Sr元素后,激活能和形核功降低,形核率增加;同时,初生α(Al)晶粒细化,其形核温度降低。讨论添加Ce与Sr元素对Al-7%Si-Mg亚共晶铸造铝合金初生α(Al)枝晶动力学形核的影响。
基金
Project (42-QP-009) support by Research Fund of the State Key Laboratory of Solidification Processing,China
Project (B08040) supported by the Program of Introducing Talents of Discipline to Universities ("111"Project),China
