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[Display omitted] • Develop a modularity data-driven scheme with high efficiency and accuracy to quantitatively describe microstructural evolution. • Practical application of the scheme on a simulated eutectic patterns evolution by the phase-field method. • Uncovering the dynamic variation of eutectic patterns under different interface energy and initial lamellar spacing conditions. Solid-liquid interface dynamics plays a crucial role in microstructure evolution during solidification. However, it is difficult to extract sufficient spatial information to describe the variation in the irregular and non-periodic solid-liquid interface domains, resulting in a challenge remaining in quantifying analysis by a quick and low-dimensionally visualized way. We proposed an interface-oriented two-point statistics method to solve the unbiassed statistics of the spatial information in these irregular and non-periodic interfaces. The challenge was successfully overcome by a carefully designed data-driven scheme, which has the advantages of easy to operate, high accuracy and efficiency. Taking the eutectic microstructure evolution simulated by phase-field method as an example, we also obtained novel insights on tailoring eutectic patterns, that is, the transformation of four patterns (lamellar elimination, regular lamellae, oscillatory eutectics and branching lamellae) depends on initial lamella spacing whether the interface energy is isotropic or anisotropic. Additionally, interfacial energy anisotropy, compared to the isotropic case, not only prolongs the time of patterns transformation, but also narrows the spacing range between elimination and creation of lamellae. Our proposed scheme is also able to be applied into more occasions about microstructure evolution in different materials systems. [ABSTRACT FROM AUTHOR]

The dissolution behavior of γ/Laves eutectic within a typical Ni-based superalloy (Inconel 718) was investigated by in-situ and conventional transmission electron microscopy (TEM) techniques. The results show that the Laves phase dissolved firstly at 700°C, but a new Ni 7 Nb 2 phase possessing similar composition with δ-Ni 3 Nb phase precipitated near Laves phase did not dissolve at temperatures up to 950°C. The new Ni 7 Nb 2 phase with lattice parameters: a =0.473 nm, b =0.794 nm, c =1.21 nm and β =91.3°, shows a C2/m space group symmetry. The crystal structure of the new Ni 7 Nb 2 phase can be understood by "triple layers" as the Ni 7 Zr 2 -type structure does, stacking perpendicular to the (001) planes. Instead of stacking with one single shift vector s corresponding to the Ni 7 Zr 2 -type structure, the stacking sequences of the new Ni 7 Nb 2 can be characterized by alternate occurrence of + s and - s. Moreover, the structural change of γ/Laves eutectic constituent before and after heat treatment was investigated. The Ni 7 Nb 2 could remain after heat treatment. Since the experimental Ni 7 Nb 2 structure was shown to be unstable in the Ni-Nb binary system by calculation, it is suggested that Zr, Si and Co promote the formation of Ni 7 Nb 2 phase in superalloys according to the segregation behaviors of elements. Moreover, as Ni 7 Zr 2 is considered to be detrimental to the mechanical properties, Ni 7 Nb 2 phase should also have negative influences and should be eliminated through possible approaches. The finding of the new phase should shed light on the microstructural controlling and heat treatment process formulating of superalloys. [Display omitted] [ABSTRACT FROM AUTHOR]