Microstructure Evolution of Co38Ni34Al28-Xsix (x=1, 3, 5, 7, 9) Magnetic Shape Memory Alloys

The effects of adding Si to Co
₃₈
Ni
₃₄
Al
₂₈
alloys on microstructure is investigated using optical microscopy (OM). Results show that the substitution Si for Al helps to reduce the volume fraction of γ precipitation and increase the martensitic transformation temperature. The increase of heat treatment temperature enhances solid solubility of γ phase in β phase matrix. The appropriate heat treatment results in homogenizing microstructure and enhancing the shape memory effect.