TY - BOOK
T1 - Shape Memory Behaviour in NiTi
AU - Liu, Yinong
N1 - This thesis has been made available in the UWA Profiles and Research Repository as part of a UWA Library project to digitise and make available theses completed before 2003. If you are the author of this thesis and would like it removed from the UWA Profiles and Research Repository, please contact [email protected]
PY - 1990
Y1 - 1990
N2 - [Truncated] This thesis reports on a study of the shape memory behaviour in a Ti-50.2%Ni alloy. The study consists of mainly three parts, (i) transformation behaviour, (ii) mechanical behaviour and (iii) two-way memory training. The transformation behaviour was studied with respect to the effect of heat treatment after cold work. Experiments were carried out using D S C and T E M methods. It is found that a NiTi alloy m a y exhibit two different transformation sequences, P <-> M or P —» R —> M -» P, according to the annealing temperature being above or below a critical temperature. The critical temperature is closely related to recrystallisation. Insitu observation of the transformations was carried out on a Philips 430 T E M. Structures such as polygonal grains of parent phase with twin-like parallel streaks, martensite with stripe patterns and plate martensite, and order-disorder domains were examined. The 1/3(110) and 1/3(111) diffraction spots, the characteristic reflections of the R phase, were found in specimens annealed even at temperatures above the critical annealing temperature, indicating the thin film effect on transformation behaviour. The 1/3 spots were observed to intensify with decreasing temperature.
AB - [Truncated] This thesis reports on a study of the shape memory behaviour in a Ti-50.2%Ni alloy. The study consists of mainly three parts, (i) transformation behaviour, (ii) mechanical behaviour and (iii) two-way memory training. The transformation behaviour was studied with respect to the effect of heat treatment after cold work. Experiments were carried out using D S C and T E M methods. It is found that a NiTi alloy m a y exhibit two different transformation sequences, P <-> M or P —» R —> M -» P, according to the annealing temperature being above or below a critical temperature. The critical temperature is closely related to recrystallisation. Insitu observation of the transformations was carried out on a Philips 430 T E M. Structures such as polygonal grains of parent phase with twin-like parallel streaks, martensite with stripe patterns and plate martensite, and order-disorder domains were examined. The 1/3(110) and 1/3(111) diffraction spots, the characteristic reflections of the R phase, were found in specimens annealed even at temperatures above the critical annealing temperature, indicating the thin film effect on transformation behaviour. The 1/3 spots were observed to intensify with decreasing temperature.
U2 - 10.26182/5c5d097074819
DO - 10.26182/5c5d097074819
M3 - Doctoral Thesis
ER -