| About this Abstract |
| Meeting |
2020 TMS Annual Meeting & Exhibition
|
| Symposium
|
Phase Transformations and Microstructural Evolution
|
| Presentation Title |
Effect of Precipitates on Martensitic Transformation in NiTiHf Shape Memory Alloys |
| Author(s) |
Taiwu Yu, Yipeng Gao, Peter Anderson, Michael Mills, Yunzhi Wang |
| On-Site Speaker (Planned) |
Taiwu Yu |
| Abstract Scope |
Nanoscale coherent H-phase precipitates have strong effects on the B2 (cubic) to B19’ (monoclinic) martensitic transformation (MT) behavior in NiTiHf high-temperature shape memory alloys (SMAs). Two typical patterns of martensite coexisting with the H-phase precipitates are predicted by phase field simulations, i.e., plate-shaped precipitates of 70-250 nm limit the growth of martensites within the space between precipitates, leading to an inter-precipitate growth, while precipitates of size below 40 nm are imbedded in the growing martensitic plates, leading to an intra-precipitate growth. These predictions agree well with the experimental observations. Furthermore, the effects shape, size, spatial distribution, and volume fraction of the H-phase precipitates on various characteristics of the MT are quantified. The work is supported by DOE BES under Grant No. DE-SC0001258. |
| Proceedings Inclusion? |
Planned: Supplemental Proceedings volume |