Additive Manufacturing for Energy Applications II: Qualification, Intensification and Up-scaling
Sponsored by: TMS Structural Materials Division, TMS: Nuclear Materials Committee
Program Organizers: Isabella Van Rooyen, Pacific Northwest National Laboratory; Subhashish Meher, Pacific Northwest National Laboratory; Indrajit Charit, University of Idaho; Michael Kirka, Oak Ridge National Laboratory
Tuesday 8:30 AM
February 25, 2020
Room: 9
Location: San Diego Convention Ctr
Session Chair: Isabella van Rooyen, Idaho National Laboratory; Edward Herderick, Ohio State University
8:30 AM Invited
The Intensification and Scale-up of Electric Field Assisted Sintering Techniques (FAST) for the Net-shape Production of Complex Materials and Components: Robert O'Brien1; Richard Martineau1; Troy Holland1; Derek Gaston1; David Hansinger2; Robert Aalund2; 1Idaho National Laboratory; 2Thermal Technology LLC
Electro-Magnetic Field Assisted Sintering Techniques (FAST), or Spark Plasma Sintering (SPS) are net-shape or near-net-shape powder metallurgy approaches performed within electrically conductive dies/tooling that provides for the shaping of final product Unlike conventional press and sintering techniques that are performed over a period of several hours or, FAST is highly energy-efficient due to localized heating in the die/tooling only. Deep understanding of the physics of FAST is somewhat limited but must be understood on a material by material basis in order to successfully up-scale and intensify the FAST process to be practicable by industry. Idaho National Laboratory, in partnership with industry is helping bridge the valley of death between bench scale FAST R&D, additive manufacturing methods and deployment of automated production scale FAST for complex ceramic, metallic and composite energy / general industrial materials and components by coupling advanced modeling and simulation with scale-up and intensification research and development.
9:00 AM
Process-related Cyclic Properties of Additively Manufactured Structures: Matilde Scurria1; Rainer Wagener1; Benjamin Möller1; Tobias Melz1; 1Fraunhofer Lbf
The research on the use of Additive Manufacturing for the production of components designed with structural functions ranges from tooling equipment, to the design of parts intended to automotive and aircraft industries, for example. Both the well-established materials, previously optimized for standard technologies, as well as new materials, designed on purpose for additive manufacturing processes, are used in these applications. The lack of standards or guidelines regarding the fatigue assessment of these structures causes research to start from the bottom every time a new material or part will be produced by additive manufacturing. For this reason, the cyclic stress-strain behavior of structures produced by laser powder bed fusion of different metallic materials has been analyzed and compared, in order to define the common lines linked to the process, which can be taken into account during an early design stage. Process-related cyclic properties are aspired for the purpose of characterization.
9:20 AM
A High-throughput Alloy Development Strategy for Corrosion Resistant Materials via Directed Energy Deposition: Phalgun Nelaturu1; Michael Moorehead1; Bonita Goh1; Dan Thoma1; Adrien Couet1; Kumar Sridharan1; 1University of Wisconsin
Next-generation molten salt based energy systems require materials with high corrosion resistance and thermal stability. High-entropy alloys (HEAs), alloys with multiple principal components, open up a vast composition space that might hold promising materials resistant to molten salt corrosion. This necessitates rapid alloy development (including synthesis and testing) to identify promising candidate materials. To this end, directed energy deposition was employed as a high-throughput technique to synthesize two quaternary systems – i) FeCrMnNi, based on 316SS, for nitrate salt environments, and ii) NiMoCrFe, based on Hastelloy-N, for fluoride salt environment. Grids of twenty-five samples with varying compositions were fabricated via in-situ alloying of elemental powders in a LENS system. Samples with controlled uniform compositions and dimensions were achieved by carefully manipulating processing parameters. The alloys manufactured by this high-throughput approach were characterized before and after high-temperature molten salt exposure via SEM, EDS, XRD, and profilometry to understand the corrosion behavior.
9:40 AM
In-situ Monitoring to Inform Process Optimization and Microstructure Control: Glenn Bean1; David Witkin1; Tait McLouth1; Alison Kremer1; 1The Aerospace Corporation
For material produced via additive manufacturing, there are limited post-processing and non-destructive evaluation methods to ensure defect-free geometries, which drives the need for inspecting the material during its production. Commercial solutions for in-process monitoring are typically used to discern deviations from typical processing windows, but the thermal and optical signatures captured by these tools can also be leveraged to understand the development of microstructure and porosity. Connecting in-situ monitoring signatures with porosity, microstructure, and mechanical properties is the first step towards the ultimate goal of real-time feedback for process and microstructure optimization. This work focuses on the use of Inconel 718 printed via selective laser melting to correlate sensor data and OEM-processed signal metrics with physical material quality, microstructure morphology, crystalline texture, and mechanical behavior with respect to variation in laser processing parameters.
10:00 AM Break
10:20 AM
Influence of Wire Arc Additive Manufacturing on Mechanical Properties of Ti-64 for Large Scale Aviation Parts: Daniel Elitzer1; Heinz Höppel1; Mathias Göken1; Daniel Baier2; Christina Fuchs2; Heinz Bähr3; Thomas Meyer4; Andreas Gallasch5; Markus Manger6; 1Friedrich-Alexander University Erlangen-Nürnberg; 2Technical University Munich; 3Aircraft Philipp GmbH & CO. KG; 4HEGGEMANN AG; 5Software Factory GmbH; 6Fronius International GmbH
Nowadays, structural parts for the aero industry are milled from solid blocks, which leads to a buy-to-fly-ratio of 25:1. A promising possibility to efficiently improve the ecological footprint is wire arc additive manufacturing (WAAM). By this cost-efficient technique, it is feasible to decrease the lead-time and reduce the material loss to a buy-to-fly ratio of 7:1. Test samples with different welding parameters and post-process heat-treatments were produced and mechanically tested. Subsequently, the achieved microstructure was characterized using SEM and EBSD. As-built state specimens showed similar strength compared to conventionally produced samples. Due to WAAM intrinsic heat-treatment, a stress-relieve treatment was found to be negligible. Currently, the fatigue behaviour and evolution of residual stresses with respect to the welding parameters are investigated. Hence, WAAM Ti-64 fulfils the required mechanical properties and thus opens a promising way for the efficient production of high quality titanium parts.
10:40 AM
Probabilistic Component Acceptance Method as an Additive Manufacturing Qualification Approach: George Griffith1; Isabella van Rooyen1; 1Idaho National Laboratory
Abstract:Additive manufacturing (AM) methods are complex and involve many steps. As a component transforms through design, raw materials, processing and inspection a large amount of data can potentially be collected. As modern AM qualification methods are evolving and maturing, AM qualification processes will be likely challenged by historic paradigms established for current nuclear industry fabrication processes. Modern AM processes allows for more complex component designs and acceptance of AM fabricated components will be perceived to become also more complex with the associated larger datasets. We are proposing a probabilistic component acceptance method based on performance evaluation methods. This approach will allow conservative best component characterization and understanding from the complete fabrication process to apply to the part acceptance. We provide basic examples from safety evaluations and component acceptance evaluations.