In situ observation of the specific nucleation behavior of grains during the solidification of Al alloy inoculated by Sc

The specific behavior of grains nucleation on primary Al3Sc particles and its effects on subsequent nucleation events have not been uncovered by previous ex situ analysis. Here, the real-time grains nucleation during the solidification of Al-10Cu alloy inoculated by Sc is first observed via synchrotron radiography. The results show that grains can nucleate on one face and grow along other faces of relatively large cuboid Al3Sc particles, leading to the incomplete engulfment of particles. Hence, two or more grains can nucleate on the same Al3Sc particle and grains can easily detach from particles, both of which promote grains nucleation during solidification. The discoveries modify the previous common view on the role of particles between grain boundaries and enlighten the better application of flow-induced technologies to the refinement of Al alloys inoculated by Sc.

Automated summary

The specific behavior of grains nucleation on primary Al3Sc particles and its effects on subsequent nucleation events were observed for the first time by synchrotron radiography. It was found that grains can nucleate on one face and grow along other faces of relatively large cuboid Al3Sc particles, which leads to incomplete engulfment of particles. This discovery modifies the previous common view on the role of particles between grain boundaries and enlightens the better application of flow-induced technologies to the refinement of Sc-inoculated Al alloys.