126 Prakt. Met. Sonderband 41 (2009) 
(4) The resulting TWSME increases with increasing number of constrained thermal cycles in Gefi 
the early stages and then decreases after reaching a maximum point, while with an 1 
increasing number of constrained thermal cycles the plastic deformation increases strongly TR 
and therefore the shape recovery ratio reduces. 
(5) After several hundred free thermal cycles (not constrained) the two-way effect became o- Ma 
larger with higher shape recovery and finally stabilized. 
(6) The microstructure of melt-spun ribbons after thermomechanical training consists of two 
phases, martensite B19" and a NiTi, precipitates. 1 Eir 
(7) The height of the austenitic peak (endothermic behaviour) increases and the transformation 
temperatures decrease slightly with an increase in the number of cycles. The exothermic Der fi 
behaviour of the transformation shows that an intermediate phase (NiTiz) appears during sche ( 
thermal cycles, which is stabilized probably by the accumulation of defects introduced by TRIP- 
thermal cycles. miert. 
(8) After training, many fine NiTi, spherical particles were observed by TEM and therefore, the mung 
trained ribbons show higher strength than ribbons without training. Since these ribbons have zeichr 
good mechanical properties (strength and ductility) they seem very suitable for future zentri 
microactuator applications. 
Die A 
verfor 
5 References rons 
EBSL 
[1] Y. Liu, J. Laeng, T.V. Chin, T.H. Nam, Mater. Sci. Eng. A 435-436 (2006) 251-257. aufklz 
[2] P. Ochin, V. Kolomytsev, A. Pasko, P. Vermaut, F. Prima, R. Portier, Mater. Sci. Eng. A 438- (Taylı 
440 (2006) 630-633. schlus 
[4] X. M. Zhang, J. Fernandez, J.M. Guilemany, Mater. Sci. Eng. A 438-440 (2006) 431-435. grobk 
[5] K. Wada, Y. Liu, Mater. Sci. Eng. A 481-482 (2008) 166-169. 
[6] Ch. Y. Chang, D. Vokoun, Ch. T. Hu, Metall. Mater. Trans. A 32 (2001) 1629. 
[7] Y. Motemani, M. Nili-Ahmadabadi. M.J. Tan, M. Bornapour. Sh. Rayagan, J. Alloys Compd. 2W 
469 (2009) 164-168. 
[8] H. Matsumoto, J. Alloys Compd. 350 (2003) 213-217. 21M 
[9] L. Contardo, G. Guenin: Acta Metall. Mater. 38 (1990) 1267. 
[10] Y. Liu, P.G. McCormick: Acta Metall. Mater. 38 (1990) 1321. Der 
[11] L.J. Chiang, C.H. Li, Y.F. Hsu, W.H. Wang, J. Alloys Compd. 462 (2008) 47-51. chung 
[12] RD. Jean, J.C. Tsai: Scripta Metall. Mater. 30 (1994) 1027. VErwe 
[13] Y. Liu, P.G. McCormick: Proc. ICOMAT-92, Monterrey Inst. of Advanced Studies (1993) ung 
923. von 
[14] Y. Liu, J. Humbeeck, R. Stalmans, L. Delaey: J. Alloys Compd. 247 (1997) 115. Dehn 
[15] K. Mehrabi, M. Bruncko, B. J. McKay, D. Uhlenhaut, A. C. Kneissl: Prakt. Met. Sonderband runge 
40 (2008) 209-214. Abb. 
[16] S. Turenne, S. Prokoshkin, V. Brailovski and N. Sacepe, Can. Metall. Q. 39 (2000), pp. 217- Temp 
224. Bildu 
Zur U 
stands 
The support of the Erich Schmid Institute of Materials Science (Austrian Academy of Sciences. bzw. 
Leoben) for the TEM investigations is gratefully acknowledged. 
* e-ma 
"Der 
Berga