Influence of Nb Addition on Phase Transformation of TiNiFe Shape Memory Alloy

摘要

The influence of Nb addition on phase transformation, especially the intermediate R phase transformation and microstructure of TiNiFe shape memory alloys were investigated by means of electrical resistivity, optical microscope, energy dispersive spectroscopy and X-ray diffraction. The results showed that the R phase transformation was inhibited with the increase of Nb content. The martensite start transformation temperature decreased from 227K to 158K when the Nb content increased from 0.5 at.% to 2 at.%. The microstructure of the alloys were mainly characterized by TiNi matrix phase in which Fe and Nb resolved.