The growth behavior of Al2Cu phase in confined spaces constituted by γ–Al2O3 particle clusters

• The γ–Al 2 O 3 particle clusters in Al–Cu melt form confined spaces for phase growth. • The morphology of Al 2 Cu eutectics inside the confined space differs from those in the matrix. • This work may bring insights for the interaction behavior between solid phase and melt. The growth behavior of intermetallic compounds in confined spaces is an interesting research topic as it may differ from conventional growth models. In this work, an Al–15Al 2 O 3 master alloy rod was inserted into an Al–33.2Cu melt. After holding at the selected temperature 640 °C, the rod keeps still in the melt, while Cu atoms diffuse inwards the rod. During the cooling process, wormlike coarse Al 2 Cu particles were achieved inside the rod. It is regarded that due to the restriction effect of γ–Al 2 O 3 particle clusters the as–constituted confined spaces act as barriers for the growth of Al 2 Cu.