Revealing heterogeneous nucleation of primary Si and eutectic Si by AlP in hypereutectic Al-Si alloys

Li, J., Hage, F. S., Liu, X., Ramasse, Q. and Schumacher, P. (2016) Revealing heterogeneous nucleation of primary Si and eutectic Si by AlP in hypereutectic Al-Si alloys. Scientific Reports, 6, 25244. (doi: 10.1038/srep25244) (PMID:27120994) (PMCID:PMC4848514)

Abstract

The heterogeneous nucleation of primary Si and eutectic Si can be attributed to the presence of AlP. Although P, in the form of AlP particles, is usually observed in the centre of primary Si, there is still a lack of detailed investigations on the distribution of P within primary Si and eutectic Si in hypereutectic Al-Si alloys at the atomic scale. Here, we report an atomic-scale experimental investigation on the distribution of P in hypereutectic Al-Si alloys. P, in the form of AlP particles, was observed in the centre of primary Si. However, no significant amount of P was detected within primary Si, eutectic Si and the Al matrix. Instead, P was observed at the interface between the Al matrix and eutectic Si, strongly indicating that P, in the form of AlP particles (or AlP ‘patch’ dependent on the P concentration), may have nucleated on the surface of the Al matrix and thereby enhanced the heterogeneous nucleation of eutectic Si. The present investigation reveals some novel insights into heterogeneous nucleation of primary Si and eutectic Si by AlP in hypereutectic Al-Si alloys and can be used to further develop heterogeneous nucleation mechanisms based on adsorption.

• Item Type: Articles
• Additional Information: J.L. gratefully acknowledges the access to TEM at the Erich Schmid Institute of Materials Science of the Austrian Academy of Sciences and the financial support from the Major International (Regional) Joint Research Project (No. 51420105005) from China. The SuperSTEM Laboratory is the U.K. National Facility for Aberration- Corrected Scanning Transmission Electron Microscopy, supported by the Engineering and Physical Sciences Research Council (EPSRC).
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Hage, Dr Fredrik Sydow
• Authors: Li, J., Hage, F. S., Liu, X., Ramasse, Q., and Schumacher, P.
• College/School: College of Science and Engineering > School of Physics and Astronomy
• Journal Name: Scientific Reports
• Publisher: Nature Publishing Group
• ISSN: 2045-2322
• ISSN (Online): 2045-2322
• Copyright Holders: Copyright © 2016 The Authors
• First Published: First published in Scientific Reports 6: 25244
• Publisher Policy: Reproduced under a Creative Commons License