Tadashi Nishihara1 and Nobuhiro Iguchi2
1Graduate School, Waseda University, Tokyo
In this paper the abnormal behavior of shape recovery appeared on the transformation superplastic deformation of Ti-6Al-4V was examined, with particular emphasis on the recovery during (α+β)→β transformation.
The main results obtained were as follows:
(1) The material after the superplastic deformation exhibited an irreversible shape-memory effect during (α+β)→β transformation under stress free heating.
(2) The shape recovery depended on the factors affecting the transformation superplastic deformation such as the maximum temperature of thermal cycle, heating rate and applied stress. The perfect shape recovery trended to be appeared under the intensive superplastic deformation defined by the strain rate sensitivity exponent, m=1.
(3) The relation between the transformation superplasticity and the shape memory effect could be expressed using 4-parameters-Rheology-Model.
Please do not copy without permission.