Spatial control of microstructure and material hardness in functionally graded stainless steels by DED-LB/M and in-situ alloying
Maier A, Tangermann-Gerk K, Nikas D, Rühr M, Chechik L, Roth S, Krakhmalev P, Schmidt M (2025)
Publication Language: English
Publication Type: Journal article, Original article
Publication year: 2025
Journal
Book Volume: 340
Article Number: 118867
DOI: 10.1016/j.jmatprotec.2025.118867
Open Access Link: https://www.sciencedirect.com/science/article/pii/S0924013625001578?via=ihub
Abstract
Duplex stainless steels (DSS) are characterized by a two-phased microstructure (δ-ferrite and γ-austenite) with equal phase fractions, providing an exceptional combination of high strength, toughness, and corrosion resistance. This duplex microstructure is conventionally achieved by a precise thermo-mechanical process (e.g., hot rolling) followed by multiple post-processing steps (coating, joining, assembly) to meet the requirements in high-performance applications (e.g., advanced wear and corrosion resistance). Laser directed energy deposition of metals (DED-LB/M) enables simultaneous processing of multiple materials in a single component, allowing for the customization of the functionality while reducing the number of process steps required. In this study, a 1.4462 DSS was manufactured by DED-LB/M and compositionally modified (in-situ alloyed) with increasing proportions of elemental Cr and/or Mo powder to control both the phase formation and material hardness. Subsequent solution annealing (1050 °C; 2 h) and quenching homogenized the as-built microstructure within each grading increment. Microstructure analysis (phase fraction, morphology, and grain size using electron backscattered diffraction) was correlated with the local chemical composition by energy dispersive X-ray spectroscopy. Hardness profiles along the grading direction indicated a gradual increase in material hardness due to the stabilization of δ-ferrite (+ 69 HV10) or σ-phase (+ 683 HV10) with the addition of Cr and/or Mo. This approach demonstrates that in-situ alloying in DED-LB/M facilitates the spatial control of phase structures and the customization of functional properties. Components can now be manufactured in a single process with smooth compositional transitions and locally enhanced material properties, e.g. ductile core with wear and corrosion resistant shell.
Authors with CRIS profile
Andreas Maier
Lev Chechik Lehrstuhl für Photonische Technologien (LPT) Michael Schmidt Lehrstuhl für Photonische Technologien (LPT)
Lev Chechik Lehrstuhl für Photonische Technologien (LPT) Michael Schmidt Lehrstuhl für Photonische Technologien (LPT)
Involved external institutions
Bayerisches Laserzentrum gemeinnützige Forschungsgesellschaft mbH (BLZ)
Germany (DE)
Karlstad University / Karlstads universitet
Sweden (SE)
KSB SE & Co. KGaA
Germany (DE)
Germany (DE)
Karlstad University / Karlstads universitet
Sweden (SE)
KSB SE & Co. KGaA
Germany (DE)
How to cite
APA:
Maier, A., Tangermann-Gerk, K., Nikas, D., Rühr, M., Chechik, L., Roth, S.,... Schmidt, M. (2025). Spatial control of microstructure and material hardness in functionally graded stainless steels by DED-LB/M and in-situ alloying. Journal of Materials Processing Technology, 340. https://doi.org/10.1016/j.jmatprotec.2025.118867
MLA:
Maier, Andreas, et al. "Spatial control of microstructure and material hardness in functionally graded stainless steels by DED-LB/M and in-situ alloying." Journal of Materials Processing Technology 340 (2025).
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