About this Abstract |
| Meeting |
MS&T25: Materials Science & Technology
|
| Symposium
|
Advances in Refractory High Entropy Alloys and Ceramics
|
| Presentation Title |
Multiphase Design Strategies in Nb–Ti Refractory Alloys with Interstitial Alloying |
| Author(s) |
Ravit Silverstein, Nicoló Maria della Ventura, Florent Mignerot, Julia Pürstl, Tresa M. Pollock , Daniel S. Gianola |
| On-Site Speaker (Planned) |
Ravit Silverstein |
| Abstract Scope |
BCC-based refractory multi-principal element alloys are promising for high-temperature applications due to their high melting points and strength retention. To optimize strength, ductility, and oxidation resistance, recent efforts have shifted toward designing multiphase alloys rather than single-phase solid solutions. One emerging approach involves the addition of dilute interstitials addition, which has shown to significantly enhance strength.
This study investigates Nb–Ti alloys as a model system to understand interstitial-driven phase evolution and mechanical behavior. Our results show that interstitials promote two interrelated pathways: spinodal decomposition and the formation of a lamellar two-phase structure. Site-specific nanoindentation and in situ micro-tensile testing reveal tensile strengths up to 3 GPa, while breaking the strength-toughness dichotomy. Phase evolution is examined using diffraction simulation tools and 4D-STEM, which uncover intermediate structures along the Burgers path and a competing de-Fontaine pathway. These findings are correlated with wavelength-based strengthening models, offering insight into designing multi-component refractory alloys. |