Article ID Journal Published Year Pages File Type
5435831 Acta Materialia 2017 10 Pages PDF
Abstract

The formation of the twin nucleus is an important phenomenon during the solidification of multi-crystalline silicon. However, the available model by Duffar and Nadri [Scripta Mater. 62(12) (2010) 955] was unable to predict a critical undercooling for twinning that was comparable with the experiments. Through the detailed analysis of the grain structures in the multi-crystalline silicon sheets grown by directional solidification, we find that the grain boundary plays a crucial role. By taking this into account, we revise the previous model. The free energy change (per unit length) when one or two facets anchor to the groove tri-junction and the critical undercooling for twinning are derived and compared with experiments. The predicted undercooling and the probability of forming a twinned nucleus at the groove based on the revised model are consistent with the experimental observations.

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Related Topics
Physical Sciences and Engineering Materials Science Ceramics and Composites
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