|About this Abstract
||2017 TMS Annual Meeting & Exhibition
||Phase Transformations and Microstructural Evolution
||Martensitic Transformation near Grain Boundaries and PhaseBboundaries in Dual-phase Shape Memory Alloys
||Ying Chen, Rebecca Dar
|On-Site Speaker (Planned)
Many polycrystalline Shape Memory Alloys (SMAs) are limited by their inherent intergranular brittleness during martensitic transformation. We focus on a dual-phase SMA in which a ductile non-transforming second phase is precipitated along grain boundaries to plastically accommodate transformation strain in its adjacent volume and alleviate stress concentration. We study strain recovery at austenite/precipitate interfaces as well as at bare grain boundaries using nanoindentation and resolve orientation influence using EBSD mapping. Austenite volume adjacent to its interface with precipitate has the highest strain recovery of all regions tested, while bare grain boundaries exhibit the lowest shape recovery. These preliminary results suggest transformation-interface interactions depend on the interface type, and optimizing austenite/precipitate morphology is promising to enable applications of polycrystalline SMAs with high superelastic recovery and enhanced transformation ductility.
||Planned: Supplemental Proceedings volume