Internal Friction of Hydrogenated Ti (Ni,Cu) Shape Memory Alloys |
| Journal |
Key Engineering Materials (Volume 319) |
| Volume |
High Damping Materials II |
| Edited by |
N. Igata and S. Takeuchi |
| Pages |
39-44 |
| DOI |
10.4028/www.scientific.net/KEM.319.39 |
| Online since |
September, 2006 |
| Authors |
T. Ueura,
Takuya Sakaguchi,
N. Igata,
S. Takeuchi
|
| Keywords |
Hydrogenation, Internal Friction, Shape Memory Alloy (SMA), Snoek-Koester Peak, Ti-Ni-Cu Alloy |
| Abstract |
Effects of hydrogen doping on the internal friction (IF) of ternary Ti50Ni50-xCux (x=15, 20,
25) shape memory alloys, prepared by rolling and annealing laminating Ti and Ni-Cu alloy sheets,
have been measured with a damping mechanical analyzer in a forced bending oscillation mode at
temperatures from 173K to 423K at three frequencies, 0.1, 1 and 5Hz. The effects of hydrogen
doping on IF are common to the three alloys: a hydrogen IF peak appears at around 260K; the IF
peak value (tanφ) increases rapidly with increasing hydrogen concentration up to tanφ=0.03 at
0.5at% and then decreases; the peak temperature also increases rapidly and then gradually decreases.
From the frequency dependence of the peak temperature, the activation energy E and the
pre-exponential factor ω0 have been analyzed to be E=0.6-0.7eV and ω0=1013-14s-1. The origin of the
hydrogen IF is interpreted to be the Snoek-Koester effect due to interaction of twin boundary
dislocations and segregated hydrogen atoms. Effects of hydrogen on mechanical properties of the
alloys have also been studied. |
| Full Paper |
Get the full paper by clicking here
|
| Preview |
Free first page example |
