Impurity effects on the solidification of primary Al3(Sc,Zr) phase in Al alloys

4th International Conference on Advances in Solidification Processes

材料科学;物理学

Li, J.H.^1 ; Schumacher, P.^1,2

Drpartment of Casting Research, Montanuniversitat Leoben, Leoben

A8700, Austria^1

Austrian Foundry Research Institute, Leoben

A8700, Austria^2

关键词: Al-based alloys;    Al3Sc particles;    Commercial purity;    Heterogeneous nucleation;    Impurity effect;    Layer-by-layer growth;    Nucleation and growth;    Solidification fronts;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/117/1/012020/pdf
DOI  :  10.1088/1757-899X/117/1/012020

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

The nucleation and growth of primary Al3Sc phase has been investigated in high purity Al alloys and commercial purity Al alloys, with a special focus on the impurity effects. In the case of high purity Al alloys, most primary Al3Sc phases were pushed to grain boundaries during moving solidification front. Such type of primary Al3Sc phase does not contribute to the heterogeneous nucleation and thereby no significant grain refinement of Al alloys was observed, although some Al3Sc particles remain the same orientation with the Al matrix. In the case of commercial purity Al alloy, the presence of impurities, e.g. Ti, Fe and Si, enhances the heterogeneous nucleation of primary Al3Sc phase. Most primary Al3Sc phases are located within the Al matrix, and keep the same orientation with the Al matrix. Furthermore, the presence of impurities also changes the growth mode of primary Al3Sc phase. In the case of commercial purity Al alloy, a layer by layer growth was observed. This investigation demonstrates that impurities have important effects on the nucleation and growth of primary Al3Sc phases in Al based alloys.