Effects of trace elements (Y and Ca) on the eutectic Ge in Al e Ge based alloys

Jiehua Li*, N. Wanderka, Z. Balogh, P. Stender, H. Kropf, M. Albu, Y. Tsunekawa, Ferdinand Hofer, G. Schmitz, P. Schumacher

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review


Effects of trace elements (0.2Y and 0.2Ca (wt%) on the eutectic Ge in high purity Al–20Ge (wt%) alloys were investigated by multi-scale microstructure characterization techniques. Particularly, the distribution of trace elements (Y and Ca) within the eutectic Ge and/or at the interface between eutectic Ge and eutectic Al was investigated by atomic resolution high angle annular dark field scanning transmission electron microscopy (HAADF-STEM) imaging and atom probe tomography (APT). The combined investigations indicate Al–Y and Al–Ca co-segregations. Such co-segregations change significant morphology and growth of the eutectic Ge. In addition, large Al2Ge2Y and Al2Ge2Ca phases were also measured. The modification of eutectic Ge is discussed in terms of previously postulated modification mechanisms: twin plane re-entrant edge growth mechanism, impurity-induced twinning, and growth restriction of eutectic Ge.
Original languageEnglish
Pages (from-to)85-95
JournalActa Materialia
Publication statusPublished - 2016


  • Al-Ge alloy
  • Segregation
  • Solute entrainment
  • Eutectic solidification
  • Atom probe tomography

ASJC Scopus subject areas

  • Materials Science(all)

Fields of Expertise

  • Advanced Materials Science

Treatment code (Nähere Zuordnung)

  • Application

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