|About this Abstract
||MS&T22: Materials Science & Technology
||High Entropy Materials: Concentrated Solid Solutions, Intermetallics, Ceramics, Functional Materials and Beyond III
||3D Ink-extrusion Printing of CoCr(Cu)FeNi High-entropy
||Dingchang Zhang, Christoph Kenel, David C. Dunand
|On-Site Speaker (Planned)
3D ink extrusion printing is an additive manufacturing (AM) method where a powder-loaded liquid ink is extruded layer by layer to form complex shaped 3D objects; the green material is then isothermally sintered into a densified part. Here, we fabricate micro-lattices of two high-entropy alloys (equiatomic CoCrFeNi and CoCrCuFeNi) by extrusion printing of ink containing a blend of binary oxides, followed by reduction in hydrogen and sintering. This method avoids the problems of residual stress (inducing cracks) and textured microstructure that occur in laser/electron-based AM methods; it also offers the use of submicron metal oxide powders which achieve very high surface quality after sintering. We focus on (i) measuring the kinetics of co-reduction of oxides and alloy interdiffusion by in-situ X-ray diffraction, (ii) understanding the microstructural evolution after solid and liquid sintering, and (iii) studying the compressive properties of micro-lattices, via experimental measurements and numerical finite element modeling.