title: Three-dimensional reconstruction of anomalous eutectic in laser remelted Ni-30 wt.% Sn alloy.
abstract: Laser remelting has been performed on Ni-30 wt.% Sn hypoeutectic alloy. An anomalous eutectic formed at the bottom of the molten pool when the sample was remelted thoroughly. 3D morphologies of theα-Ni and Ni3Sn phases in the anomalous eutectic region were obtained and investigated using serial sectioning reconstruction technology. It is found that the Ni3Sn phase has a continuous interconnected network structure and theα-Ni phase is distributed as separate particles in the anomalous eutectic, which is consistent with the electron backscatter diffraction pattern examinations. Theα-Ni particles in the anomalous eutectic are supersaturated with Sn element as compared with the equilibrium phase diagram. Meanwhile, small wavy lamella eutectics coexist with anomalous eutectics. The Trivedi-Magnin-Kurz model was used to estimate undercooling with lamellar spacing. The results suggest that the critical undercooling found in undercooling solidification is not a sufficient condition for anomalous eutectic formation. Besides,α-Ni particles in the anomalous eutectic do not exhibit a completely random misorientation and some neighboringα-Ni particles have the same orientation. It is shown that both the coupled and decoupled growth of the eutectic two phases can generate theα-Ni + Ni3Sn anomalous eutectic structure.
authors.affiliation: State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an, Shaanxi 710072, People's Republic of China.
authors.forename: Yong-Qing
authors.initials: YQ
authors.lastname: Cao
authors.affiliation: State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an, Shaanxi 710072, People's Republic of China.
authors.forename: Xin
authors.initials: X
authors.lastname: Lin
authors.affiliation: State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an, Shaanxi 710072, People's Republic of China.
authors.forename: Zhi-Tai
authors.initials: ZT
authors.lastname: Wang
authors.affiliation: School of Materials Science and Engineering, Xi'an University of Technology, 5 South Jinhua Road, Xi'an, Shaanxi 710048, People's Republic of China.
authors.forename: Li-Lin
authors.initials: LL
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an, Shaanxi 710072, People's Republic of China.
authors.forename: Meng-Hua
authors.initials: MH
authors.lastname: Song
authors.affiliation: State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an, Shaanxi 710072, People's Republic of China.
authors.forename: Hai-Ou
authors.initials: HO
authors.lastname: Yang
authors.affiliation: State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, 127 West Youyi Road, Xi'an, Shaanxi 710072, People's Republic of China.
authors.forename: Wei-Dong
authors.initials: WD
authors.lastname: Huang
keywords: 3D reconstruction; Ni–Sn alloy; anomalous eutectic; laser remelting