Abstract
The use of Ni-rich TiNiHf alloys as high temperature shape memory alloys (SMAs) through aging has been presented. For Ni-rich Ti80-xNixHf20 alloys, their phase transformation temperatures are averagely increased more than 100 K by aging at 823 K for 2 h. Especially for the alloys with Ni-content of 50.4 at. pct and 50.6 at. pct, their martensitic transformation start temperatures (Ms) are more than 473 K after aging. TEM observation confirmed that some fine particles precipitate from the matrix during aging. The aged Ni-rich TiNiHf SMAs show the better thermal stability of phase transformation temperatures than the solution-treated TiNiHf alloys. The fine particles precipitated during aging should be responsible for the increase of phase transformation temperatures and its high stability.
Original language | English |
---|---|
Pages (from-to) | 691-695 |
Number of pages | 5 |
Journal | Journal of Materials Science and Technology |
Volume | 22 |
Issue number | 5 |
Publication status | Published - 1 Sept 2006 |
Keywords
- Aging
- High temperature shape memory alloy
- Phase transformation
- TiNiHf alloy
ASJC Scopus subject areas
- Ceramics and Composites
- Mechanics of Materials
- Mechanical Engineering
- Polymers and Plastics
- Metals and Alloys
- Materials Chemistry