|About this Abstract
||2018 TMS Annual Meeting & Exhibition
||Ultrafine-grained Materials X
||Microstructural Evolution and Thermal Stability of Accumulatively Roll-bonded Cu-Nb Nanolaminates
||Jaclyn Avallone, Thomas J. Nizolek, Irene J. Beyerlein, Nathan A. Mara, Tresa M. Pollock
|On-Site Speaker (Planned)
CuNb nanolaminates are highly stable at elevated temperatures when compared to many ultrafine-grain materials. Microstructural evolution is constrained by interfaces between the immiscible metal components. Over time, these materials break down by layer pinch-off permitting grain coarsening. In this study, extended anneals were performed at high temperatures for copper (.5Tm), but at which niobium diffusivity is limited (.25Tm). Despite the high rate of diffusion rate in Cu, after 30 days the laminates remain nanostructured with no significant coarsening. Void formation at bi-metal interfaces, a phenomena that has not been reported in these systems, is observed. These voids grow larger and more frequent with time, yet they are not the primary mode of deformation or cause of failure during high temperature mechanical testing. Analysis of these structural evolution mechanisms and system stability will be discussed in relation to diffusion, thermal mismatch stresses, and the driving force for copper recrystallization.
||Planned: Supplemental Proceedings volume