About this Abstract |
Meeting |
MS&T21: Materials Science & Technology
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Symposium
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High Entropy Materials: Concentrated Solid Solutions, Intermetallics, Ceramics, Functional Materials and Beyond II
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Presentation Title |
High-throughput Design and Processing of MPEAs Using Additive Manufacturing |
Author(s) |
Dan J. Thoma, Michael Niezgoda, Phalgun Nelaturu, Zahabul Islam, Michael Moorehead, Adrien Couet |
On-Site Speaker (Planned) |
Dan J. Thoma |
Abstract Scope |
The large number of possible compositional variations with multi-principal-element alloys (MPEAs) requires bulk combinatorial processing methodologies to validate alloy design strategies. In this study, directed energy deposition (DED) is used for high-throughput additive manufacturing of bulk MPEAs, including refractory-based alloys and iron-based alloys. With four powder hoppers containing elemental powders, 25 bulk samples (1 x 1 x 1 cm), each with different compositions, can be processed within 4 hours. Actual vs. nominal compositions within 5% can be achieved. Test coupons exhibit less than 1% unmelted material and roughly 1% porosity. Moreover, owing to the high cooling rates in DED (~1000 K/s), secondary dendrite arm spacings are reduced by a factor of four as compared to arc-cast samples, permitting less homogenization times. Thermodynamic calculations and a new dimensionless number help predict process parameters, and examples of high-throughput characterization and property assessment of the 25 sample combinatorial plates will be introduced. |