2002年7月
Microstructure and shape memory behavior of Ti51.2(Pd27.0Ni21.8) and Ti49.5(Pd28.5Ni22.0) thin films
Materials Science and Engineering A
- ,
- ,
- 巻
- 332
- 号
- 1-2
- 開始ページ
- 47
- 終了ページ
- 55
- 記述言語
- 英語
- 掲載種別
- DOI
- 10.1016/S0921-5093(01)01714-2
The shape memory characteristics of Ti-rich Ti(Pd,Ni) thin films annealed from the amorphous state has been clarified based on the microstructural observations compared with those of the near-equiatmic ones. The films with the compositions of Ti51.2(Pd27.0Ni21.8) and Ti49.5(Pd28.5Ni22.0) were crystallized at 773, 873 and 973 K for 1 h. The low-temperature crystallizations at <
973 K from the amorphous state are effective for grain refinement without an additional element or thermo-mechanical treatment. The Ti51.2(Pd27.0Ni21.8) film annealed at 773 K shows fine plate-like Ti2Pd-type precipitates with a diameter <
100 nm inside the B2 grain. These precipitates have the habit plane parallel to a {100) plane of the B2 matrix and with the orientation relationship of {100}B2∥{001}Ti2Pd and <
010>
B2∥<
001>
Ti2Pd. It was found that the shape memory characteristics could be improved by the precipitation hardening of the Ti2Pd-type precipitates, probably because of the internal strain field produced along the {001} planes of the precipitates. The film shows the Ms temperature of 485 K, the recoverable strain of 2.53% and the residual strain of 0.14% under the constant stress of 440 MPa. © 2002 Elsevier Science B.V. All rights reserved.
973 K from the amorphous state are effective for grain refinement without an additional element or thermo-mechanical treatment. The Ti51.2(Pd27.0Ni21.8) film annealed at 773 K shows fine plate-like Ti2Pd-type precipitates with a diameter <
100 nm inside the B2 grain. These precipitates have the habit plane parallel to a {100) plane of the B2 matrix and with the orientation relationship of {100}B2∥{001}Ti2Pd and <
010>
B2∥<
001>
Ti2Pd. It was found that the shape memory characteristics could be improved by the precipitation hardening of the Ti2Pd-type precipitates, probably because of the internal strain field produced along the {001} planes of the precipitates. The film shows the Ms temperature of 485 K, the recoverable strain of 2.53% and the residual strain of 0.14% under the constant stress of 440 MPa. © 2002 Elsevier Science B.V. All rights reserved.
- ID情報
-
- DOI : 10.1016/S0921-5093(01)01714-2
- ISSN : 0921-5093
- SCOPUS ID : 0036645510