Additive Manufacturing of Functional, Energy, and Magnetic Materials: Advanced Manufacturing of Other Functional Materials
Sponsored by: TMS Functional Materials Division, TMS: Additive Manufacturing Committee, TMS: Magnetic Materials Committee
Program Organizers: Markus Chmielus, University of Pittsburgh; Sneha Prabha Narra, Carnegie Mellon University; Mohammad Elahinia, University of Toledo; Reginald Hamilton, Pennsylvania State University; Iver Anderson, Iowa State University Ames Laboratory
Thursday 2:00 PM
March 18, 2021
Room: RM 2
Location: TMS2021 Virtual
2:00 PM
Inconel-steel Multi-metal-material by Liquid dispersed Metal Powder Bed Fusion: Microstructure, Stress and Property Gradients: Sabine Bodner1; L.T.G. van de Vorst2; Jakub Zalesak3; Juraj Todt3; Julius Keckes3; Verena Maier-Kiener1; Bernhard Sartory4; Norbert Schell5; Jaap Hooijmans6; Jaco Saurwalt6; Jozef Keckes1; 1Montanuniversität Leoben; 2TNO; 3Austrian Academy of Sciences; 4Materials Center Leoben GmbH; 5Helmholtz-Zentrum Geesthacht ; 6Admatec Europe BV
Synthesis of functional multi-material hybrid structures represents a serious scientific and technological challenge. In this contribution, liquid dispersed metal powder bed fusion is used to fabricate a multi-metal structure based on alternating 316L stainless steel and Inconel 625 alloy layers. Gradients of phases, residual strains, microstructure, mechanical properties and chemical composition were determined at different length scales within the build-up by the use of cross-sectional synchrotron X-ay diffraction, nanoindentation and transmission electron microscopy. The advanced correlative characterization revealed nano-scaled spherical chromium-metal oxide dispersoids that were formed due to reactive additive manufacturing process. Morphologically sharp stainless steel-Inconel interfaces as well as regions with intermixed alloy’s elements could be realized by adapting the layer stack. Finally, this study shows that liquid dispersed metal powder bed fusion offers the possibility for the synthesis of complex microstructures based on dissimilar metal alloys.
2:20 PM
Meltpool Oxidation and Reduction and Inclusion Evolution during the PBF Type Additive Manufacturing: Durim Eo1; Seong Gyu Chung1; Jungwook Cho1; 1Pohang University of Science and Technology
Oxide dispersion strengthened material can be fabricated via AM process by mixing oxide dispersion with alloy powder directly or control oxide inclusion evolution during the solidification. To optimize the strengthening effect by oxide inclusion, oxygen content and inclusion size should be optimized with the knowledge about the meltpool oxidation and reduction and inclusion evolution kinetics. To comprehend these subjects, stainless steel 316L blocks were fabricated with the powder bed fusion type AM process under different process parameters including basic parameters (P, V, h, and gas flow) as well as directional relationship between the shielding gas flow and laser scanning. It was found that in 316L alloy system, meltpool reduction and oxidation occurred simultaneously during the process involving CO and CO2 gas formation with vapor jet formation and dissolution back to the meltpool. Also it is found that the nucleation and growth kinetic of oxide inclusion is strongly dependent on process parameters.
2:40 PM
Engineered Interconnected Porosity for Enhanced Functional Devices: Scott Roberts1; Ben Furst1; Eric Sunada1; 1Jet Propulsion Laboratory
In general, porosity is seen as a failure in additive manufacturing processes. However, in some instances, controlled porosity can be used as a positive. Through careful control of various machine parameters in a powder bed fusion machine, we have been able to crate tunable interconnected open porosity structures in SS316L, Ti-6-4, AlSi10Mg, and Inconel 625. Pore sizes can range from sub-micron to 250 μm. Porosities span 0 to 60%. Additionally, structures with multiple porosities (or fully solid) regions can be created, enabling greater design freedom than previously available. By combining our porous settings with previously demonstrated scan strategies we can create pores of arbitrary geometry. Characterization of the properties of our porous structures (e.g., electrical conductivity, tensile/compressive strength, elastic moduli) will also be discussed. We have also demonstrated our ability to integrate local porosity control as a method for fabricating devices such as integrated heat pipes, filters, and more.