In situ synchrotron investigation of the microstructural heterogeneity induced on alloy 718 by laser melting

Volpato GM, Fredel MC, Pereira AS, Nicolodelli G, Göken M, Neumeier S, Tetzlaff U (2026)

Publication Type: Journal article

Publication year: 2026

Journal

Materials and Design Elsevier

Book Volume: 271

Article Number: 117026

DOI: 10.1016/j.matdes.2026.117026

Abstract

Laser processing of high-temperature Ni-base alloys offers high precision, reliability, and design flexibility, but can significantly affect microstructural stability and thus the overall reliability of components. In this context, this study evaluates the microstructural evolution of Inconel Alloy 718 during laser melting, focusing on the formation of microstructural gradients and the effects of laser reheating and remelting. An experimental synchrotron setup enabling parallel laser melting and in situ high-energy X-ray diffraction was developed. Combined with ex situ analyses, this setup allowed the evolution of the main phases to be tracked during processing, together with oxidation mechanisms and lattice distortion. Laser incidence caused the dissolution of γ′, γ″, and δ phases, while reheating promoted reprecipitation of γ′ and γ″. Reheating also increased the fraction of MC carbides and the Laves phase. Oxidation in air was dominated by Cr2O3, TiO2, and NiCr2O4, with a shell-like morphology observed for the former two oxides. Significant γ lattice distortion was detected, showing a transition from expansion to contraction when a given region experienced reheating and/or partial remelting.

Authors with CRIS profile

Mathias Göken Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften) Steffen Neumeier Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften)

Involved external institutions

Federal University of Santa Catarina / Universidade Federal de Santa Catarina (UFSC) BR Brazil (BR) Technische Hochschule Ingolstadt DE Germany (DE)

How to cite

APA:

Volpato, G.M., Fredel, M.C., Pereira, A.S., Nicolodelli, G., Göken, M., Neumeier, S., & Tetzlaff, U. (2026). In situ synchrotron investigation of the microstructural heterogeneity induced on alloy 718 by laser melting. Materials and Design, 271. https://doi.org/10.1016/j.matdes.2026.117026

MLA:

Volpato, G. M., et al. "In situ synchrotron investigation of the microstructural heterogeneity induced on alloy 718 by laser melting." Materials and Design 271 (2026).

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