| About this Abstract |
| Meeting |
MS&T22: Materials Science & Technology
|
| Symposium
|
Additive Manufacturing of High and Ultra-high Temperature Ceramics and Composites: Processing, Characterization and Testing
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| Presentation Title |
Optimizing Functionally Graded ZrB2-Mo Components by Ceramic On-Demand Extrusion (CODE) |
| Author(s) |
Austin J. Martin, Clare Sabata, Jeremy L. Watts, Gregory E. Hilmas, Ming C. Leu, Tieshu Huang |
| On-Site Speaker (Planned) |
Austin J. Martin |
| Abstract Scope |
Functionally graded materials (FGMs) involve the spatial variation of chemical composition or structure to achieve an optimization of material properties. Ultra-high temperature ceramics (UHTCs) are classified as materials which have melting points above 3000°C, and although UHTCs can retain high strengths and oxidation resistance at high temperatures (>1500°C), these materials are typically brittle and therefore may benefit from underlying ductile or higher fracture toughness substructures. Molybdenum (Mo) alloys, such as Mo-Si-B or Ti-Zr-Mo (TZM), are high temperature (~1000°C), creep resistant alloys which have improved fracture toughness (RT ~10 MPa∙√m) or greater) compared to pure zirconium diboride (ZrB2). Using ceramic on-demand extrusion (CODE), eleven-layer ZrB2-Mo FGMs bars were produced with nominally 10% grading between layers. These baseline gradings warped an average of 20° after sintering due to a mismatch in sintering kinetics. Chemical and physical modifications to the ZrB2 and Mo pastes, respectively, were evaluated to alleviate the camber from co-firing. |