In situ and ex situ studies of anomalous eutectic formation in undercooled Ni–Sn alloys. (15th September 2020)

• Record Type: Journal Article
• Authors: Zhao, Rijie; Wang, Yeqing; Gao, Jianrong; Baker, Evan B.; Matson, Douglas M.; Kolbe, Matthias; Chuang, Andrew Chih-Pin; Ren, Yang
• Is Part Of: Acta materialia. Volume 197(2020)
• Page Start: 198
• Page End: 211
• Publication Date: 2020-09-15
• Subjects: Eutectic -- Undercooling -- X-ray diffraction -- Crystal growth -- Solidification microstructure; Materials -- Periodicals; Materials science -- Periodicals; Materials -- Mechanical properties -- Periodicals; Metallurgy -- Periodicals; Chemistry, Inorganic -- Periodicals; 620.112
• DOI: 10.1016/j.actamat.2020.07.048
• Languages: English
• ISSNs: 1359-6454

Abstract

Abstract: Anomalous eutectic formation in undercooled Ni–Sn alloys was investigated by in situ X-ray diffraction and ex situ remelting and annealing experiments. Dynamic recrystallization and partial remelting of primary solids followed by repeated nucleation and growth of eutectic grains in the mushy zone were revealed by time-resolved X-ray diffraction. Ex situ experiments demonstrated that partial remelting of near-equilibrium solidified alloys of eutectic or near-eutectic composition can convert regular lamellar eutectic into anomalous eutectic, whereas high-temperature annealing of splat-quenched alloys of similar composition can convert eutectic or two-phase dendrites into anomalous eutectic. It is concluded that compared to ripening in solid-states, partial remelting of eutectic or two-phase dendrites in a mushy zone provides a more realistic mechanism for anomalous eutectic formation in undercooled solidification of Ni–Sn eutectic alloys. Graphical abstract: Image, graphical abstract