Eutectic nucleation in Al-Si alloys

Stuart D. McDonald, Kazuhiro Nogita, Arne K. Dahle

Research output: Contribution to journalArticle

199 Citations (Scopus)

Abstract

In addition to a change in silicon morphology, modification of aluminium-silicon alloys with strontium or sodium increases the size of the eutectic grains. To determine the mechanism responsible, eutectic solidification in commercial purity and ultra-high purity aluminium-silicon alloys, with and without strontium additions, was examined by a quenching technique. In the commercial unmodified alloy, nucleation was prolific while in the high-purity unmodified alloy few eutectic grains nucleated. The addition of strontium to the commercial alloy reduced the number of eutectic grains that nucleated. Addition of strontium to the high-purity alloy did not significantly alter nucleation. It is concluded that commercial purity alloys contain a large number of potent nuclei that are susceptible to poisoning by impurity modification. The flake-to-fibre transition that occurs with impurity modification is shown to be independent of any change in eutectic nucleation mode and frequency.

Original languageEnglish
Pages (from-to)4273-4280
Number of pages8
JournalActa Materialia
Volume52
Issue number14
DOIs
Publication statusPublished - Aug 16 2004

All Science Journal Classification (ASJC) codes

  • Electronic, Optical and Magnetic Materials
  • Ceramics and Composites
  • Polymers and Plastics
  • Metals and Alloys

Fingerprint Dive into the research topics of 'Eutectic nucleation in Al-Si alloys'. Together they form a unique fingerprint.

  • Cite this

    McDonald, S. D., Nogita, K., & Dahle, A. K. (2004). Eutectic nucleation in Al-Si alloys. Acta Materialia, 52(14), 4273-4280. https://doi.org/10.1016/j.actamat.2004.05.043