| Abstract Scope |
Materials for extreme environments require accurate temperature-dependent properties and mechanistic insight to enable reliable performance. This work highlights recently developed high-temperature experimental approaches that enable efficient, mechanism-resolved understanding in both ultra-high temperature ceramics and refractory alloys. For TaC, a customized Gleeble-based methodology enables extraction of thermal expansion and elastic modulus from a single specimen up to 1700°C. Subsequent tensile loading to failure reveals signatures consistent with grain-boundary sliding at relatively low temperatures for a ceramic. Ongoing electron microscopy aims to resolve the underlying mechanisms. Complementary studies on Mo-47.5Re employ strain-rate jump testing during high-temperature tension to extract strain-rate sensitivity and activation volume within a single specimen. These mechanistic fingerprints provide insight into transitions between thermally activated screw dislocation motion, solute pinning, deformation twinning, and diffusion-assisted processes. Together, these results demonstrate how advanced high-temperature testing enables a unified, mechanism-based understanding across material classes. |