摘要
The characteristics of the strains induced by transformation and magnetic field in ascast Ni-Mn-Ga alloy were systematically investigated.It is found that internal stress and texture introduced during casting bring the anisotropy of temperature-induced strains.However,no anisotropy of field-induced strains is induced,and the internal stress and the texture modulate only the temperature dependence of field-induced strains.Large retardance of field-induced strains was observed,which indicates the rearrangement of martensitic variants as a competition process between the stress energy and Zeeman energy.The non-continuous field dependence of strain indicates the unstable microstructure during martensitic transformation.
The characteristics of the strains induced by transformation and magnetic field in ascast Ni-Mn-Ga alloy were systematically investigated.It is found that internal stress and texture introduced during casting bring the anisotropy of temperature-induced strains.However,no anisotropy of field-induced strains is induced,and the internal stress and the texture modulate only the temperature dependence of field-induced strains.Large retardance of field-induced strains was observed,which indicates the rearrangement of martensitic variants as a competition process between the stress energy and Zeeman energy.The non-continuous field dependence of strain indicates the unstable microstructure during martensitic transformation.
基金
Sponsored by National Natural Science Foundation of China(50001010)
National High Technology Research Plan of China(AA200132722)
