Effects of trace elements (Y and Ca) on the eutectic Ge in Al–Ge based alloys. (1st June 2016)

• Record Type: Journal Article
• Authors: Li, J.H.; Wanderka, N.; Balogh, Z.; Stender, P.; Kropf, H.; Albu, M.; Tsunekawa, Y.; Hofer, F.; Schmitz, G.; Schumacher, P.
• Is Part Of: Acta materialia. Volume 111(2016)
• Page Start: 85
• Page End: 95
• Publication Date: 2016-06-01
• Subjects: Al–Ge alloy -- Segregation -- Solute entrainment -- Eutectic solidification -- HAADF-STEM -- Atom probe tomography; Materials -- Periodicals; Materials science -- Periodicals; Materials -- Mechanical properties -- Periodicals; Metallurgy -- Periodicals; Chemistry, Inorganic -- Periodicals; 620.112
• DOI: 10.1016/j.actamat.2016.03.043
• Languages: English
• ISSNs: 1359-6454

Abstract

Abstract: 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 Al2 Ge2 Y and Al2 Ge2 Ca 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. Graphical abstract: