Inconel-Steel Multilayers by Liquid Dispersed Metal Powder Bed Fusion: Microstructure, Residual Stress and Property Gradients

Sabine C. Bodner, L.T.G. van de Vorst, Jakub Zalesak, Juraj Todt, Julius Keckes, Verena Maier-Kiener, Bernhard Sartory, Norbert Schell, J.W. Hooijmans, J.J. Saurwalt, Jozef Keckes

Publikation: Beitrag in FachzeitschriftArtikelForschungBegutachtung

10 Zitate (Scopus)

Abstract

Synthesis of multi-metal hybrid structures with narrow heat affected zones, limited residual stresses and secondary phase occurrence represents a serious scientific and technological challenge. In this work, liquid dispersed metal powder bed fusion was used to additively manufacture a multilayered structure based on alternating Inconel 625 alloy (IN625) and 316 L stainless steel (316 L) layers on a 316 L base plate. Analytical scanning and transmission electron microscopies, high-energy synchrotron X-ray diffraction and nanoindentation analysis reveal sharp compositional, structural and microstructural boundaries between alternating 60 µm thick alloys’ sub-regions and unique microstructures at macro-, micro- and nano-scales. The periodic occurrence of IN625 and 316 L sub-regions is correlated with a cross-sectional hardness increase and decrease and compressive stress decrease and increase, respectively. The laser scanning strategy induced a growth of elongated grains separated by zig-zag low-angle grain boundaries, which correlate with the occurrence of zig-zag cracks propagating in the growth direction. A sharp <110> fiber texture within the 316 L regions turns gradually into a <100> fiber texture in the IN625 regions. The occurrence of the C-like stress gradient with a pronounced surface tensile stress of about 500 MPa is interpreted by the temperature gradient mechanism model. Chemical analysis indicates a formation of reinforcing spherical chromium-metal-oxide nano-dispersoids and demonstrates a possibility for reactive additive manufacturing and microstructural design at the nanoscale, as a remarkable attribute of the deposition process. Finally, the study shows that the novel approach represents an effective tool to combine dissimilar metallic alloys into unique bionic hierarchical microstructures with possible synergetic properties.
OriginalspracheEnglisch
Aufsatznummer101027
FachzeitschriftAdditive Manufacturing
Jahrgang32.2020
AusgabenummerMarch
Frühes Online-Datum31 Dez. 2019
DOIs
PublikationsstatusVeröffentlicht - März 2020

Bibliographische Notiz

Funding Information:
A part of this work was supported by Österreichische Forschungsförderungsgesellschaft mbH (FFG) , Project No. 861496, “CrossSurfaceMech”. Financial support by the Austrian Federal Government (in particular from Bundesministerium für Verkehr, Innovation und Technologie and Bundesministerium für Wissenschaft, Forschung und Wirtschaft) represented by Österreichische Forschungsförderungsgesellschaft mbH and the Styrian and the Tyrolean Provincial Government, represented by Steirische Wirtschaftsförderungsgesellschaft mbH and Standortagentur Tirol , within the framework of the COMET Funding Programme is gratefully acknowledged. Part of the research leading to this result has been supported by the project CALIPSOplus under the Grant Agreement 730872 from the EU Framework Programme for Research and Innovation HORIZON 2020 . Another part of this work was carried out with the support of CEITEC Nano Research Infrastructure ( ID LM2015041, MEYS CR, 2016-2019 ), CEITEC Brno University of Technology. Appendix A

Publisher Copyright:
© 2020 Elsevier B.V.

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