Microstructure–property relationships in a high-strength 51Ni–29Ti–20Hf shape memory alloy
- Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
- The Ohio State Univ., Columbus, OH (United States)
- Glenn Research Center, Cleveland, OH (United States)
NiTiHf alloys exhibit remarkable shape memory and pseudoelastic properties that are of fundamental interest to a growing number of industries. In this study, differential scanning calorimetry and isothermal compression tests have revealed that the 51Ni–29Ti–20Hf alloy has useful shape memory properties that include a wide range of transformation temperatures as well as highly stable pseudoelastic behavior. These properties are governed by short-term aging conditions, which may be tailored to control transformation temperatures while giving rise to exceptionally high austenite yield strengths which aid transformation stability. The yield strength of the austenite phase can reach 2.1 GPa by aging for 3hrs at 500°C, while aging for 3hrs at 700°C produced an alloy with an austenite finish temperature (A f ) of 146°C. High-resolution scanning transmission electron microscopy has revealed a new precipitate phase, H-phase, under the homogenized and extruded condition and the aged 3 hrs at 500°C condition, but only the previously identified H-phase precipitate was observed after aging at temperatures of 600°C and 700°C for 3 hrs. Finally, dislocation analysis indicated that plastic deformation of the austenite phase occurred by <100> type slip, similar to that observed in binary NiTi.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE
- Grant/Contract Number:
- SC0001258; AC52-06NA25396
- OSTI ID:
- 1221618
- Report Number(s):
- LA-UR-15-26868; PII: 9400
- Journal Information:
- Journal of Materials Science, Journal Name: Journal of Materials Science; ISSN 0022-2461
- Publisher:
- SpringerCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Web of Science
Recent Development of TiNi‐Based Shape Memory Alloys with High Cycle Stability and High Transformation Temperature
|
journal | February 2020 |
Similar Records
High-energy synchrotron radiation X-ray diffraction measurements during in situ aging of a NiTi-15 at. % Hf high temperature shape memory alloy
Role of microstructure on the actuation fatigue performance of Ni-Rich NiTiHf high temperature shape memory alloys