About this Abstract |
| Meeting |
MS&T25: Materials Science & Technology
|
| Symposium
|
Advances in Refractory High Entropy Alloys and Ceramics
|
| Presentation Title |
Mechanisms of spall failure in niobium subjected to high-throughput laser-driven micro-flyer impact |
| Author(s) |
Nicolo Della Ventura, Arezoo Zare, Jacob Diamond, Todd Hufnagel, K.T. Ramesh, Daniel S. Gianola |
| On-Site Speaker (Planned) |
Nicolo Della Ventura |
| Abstract Scope |
Designing BCC alloys for shock resistance requires understanding microstructural evolution and failure mechanisms under dynamic loading. However, conventional plate impact experiments are time-consuming and costly, and the deformation behavior of pure BCC metals remains poorly understood. To address this, a high-throughput laser-driven micro-flyer technique was used to study spall failure in pure niobium at strain rates of 10⁶ 1/s and peak shock stresses between 7.3 and 15.3 GPa. Post-mortem analysis of samples recovered at incipient and advanced failure states reveals ductile failure through mixed intergranular and intragranular fracture. Cavities nucleating within grains grow via dislocation emission from void surfaces until a radius of approximately 260 nm, after which cracks propagate along {101} planes. Misorientation gradients and high-angle grain boundaries at crack fronts indicate dynamic recrystallization in heavily deformed regions. The observed spall strengths and microstructural features are discussed in relation to analytical models of cavitation-driven failure. |