Characteristics of Ti50-Pd(50-x)-W(x) High Temperature Shape Memory Alloy

Characteristics of high temperature shape memory alloy in Ti50-Pd(50-x)-W(x) at%, x = 3 and 5 system has been examined. The prepared ingot was homogenized at 1273 K for 86.4 ks followed by water quenched. The homogenized samples were hot-rolled at 1273 K to a plate shape with thickness of 3.5 mm and 1.0 mm. Transformation temperatures were determined by 4-probe electrical resistivity measurement. The transformation behavior in the both samples exhibited similar trend. The first heating curve showed no significant step. In contrast, the first cooling curve exhibited clear step due to martensitic transformation. After second cycle, the transformation behavior was stabilized, thus the clear steps in the cooling and heating curves were seen. Stressstrain curve of hot-rolled plate with 3.5 mm was examined by compression in Ti50-Pd47-W3 at% alloys. The sample exhibited 1 % shape memory effect. By bending test, nearly perfect SME effect was observed in hot rolled Ti50-Pd45-W5 at% alloy plate with thickness of 1 mm.

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Effect of aging on transformation behavior and shape memory effect of a CuAlNb high temperature shape memory alloy

Journal of Materials Science ◽

10.1007/s10853-006-0573-y ◽

2006 ◽

Vol 41 (18) ◽

pp. 6165-6167 ◽

Cited By ~ 2

Author(s):

Z. Y. Gao ◽

Y. Wu ◽

Y. X. Tong ◽

W. Cai ◽

Y. F. Zheng ◽

...

Keyword(s):

High Temperature ◽

Shape Memory Alloy ◽

Shape Memory ◽

Shape Memory Effect ◽

Memory Effect ◽

Transformation Behavior

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Martensitic Transformation Behavior and Shape Memory Effect of an Aged Ni-rich Ti-Ni-Hf High Temperature Shape Memory Alloy

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.138.399 ◽

2008 ◽

Vol 138 ◽

pp. 399-406 ◽

Cited By ~ 3

Author(s):

Xiang Long Meng ◽

Yu Dong Fu ◽

Wei Cai ◽

J.X. Zhang ◽

Qing Fen Li ◽

...

Keyword(s):

High Temperature ◽

Martensitic Transformation ◽

Shape Memory Alloy ◽

Shape Memory ◽

Shape Memory Effect ◽

Memory Effect ◽

Aging Temperature ◽

Transformation Behavior ◽

Transformation Temperatures ◽

Solution Treated

The martensitic transformation behavior and shape memory effect (SME) have been investigated in a Ni-rich Ti29.6Ni50.4Hf20 high temperature shape memory alloy (SMA) in the present study. After aging, the transformation temperatures of Ti29.6Ni50.4Hf20 alloy increase obviously due to the precipitation of (Ti,Hf)3Ni4 particles. And the transformation sequence changes from one-step to two-step. When the experimental alloy is aged at different temperatures for 2h, the transformation temperatures increase rapidly with increasing the aging temperature and then change slightly with further increasing the aging temperature. Most of the martensite variants preferentially oriented in the aged Ti29.6Ni50.4Hf20 alloy. The aged Ti29.6Ni50.4Hf20 alloy shows the better thermal stability of transformation temperatures than the solution-treated one because the precipitates depress the introduction of defects during thermal cycling. In addition, the proper aged Ti29.6Ni50.4Hf20 alloy also shows the larger SME than the solution-treated one since the precipitates strengthen the matrix strongly.

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Effects of High Temperature ECAE Process on Microstructures and Martensitic Transformation of TiNi Shape Memory Alloy

Materials Science Forum ◽

10.4028/www.scientific.net/msf.503-504.1013 ◽

2006 ◽

Vol 503-504 ◽

pp. 1013-0 ◽

Cited By ~ 11

Author(s):

Chao Ying Xie ◽

Z.G. Fan ◽

Z.H. Li ◽

G.Q. Xiang ◽

X.H. Cheng

Keyword(s):

Phase Transformation ◽

High Temperature ◽

Martensitic Transformation ◽

Shape Memory Alloy ◽

Shape Memory ◽

Tini Alloy ◽

Behavior Changes ◽

Transformation Behavior ◽

Coarse Grains ◽

Short Annealing

Microstructures and transformation behavior of TiNi shape memory alloy after high temperature ECAE process have been investigated. It is found that the initial coarse grains were refined after high temperature ECAE processes and short annealing at 750°C. Transformation temperatures of TiNi alloy sharply decreased after two ECAE processes, rose obviously when annealed at 750°C for 5min, and quickly rose back after annealing at 500°C for 2 hours. Reasons for phase transformation behavior changes have been discussed.

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