Heusler Type CoNiGa Alloys with High Martensitic Transformation Temperature
A strong need exists to develop new kinds of high-temperature shape-memory alloys. In this study, two series of CoNiGa alloys with different compositions have been studied to investigate their potentials as high-temperature shape-memory alloys, with regard to their microstructure, crystal structure, and martensitic transformation behavior. Optical observations and X-ray diffractions confirmed that single martensite phase was present for low cobalt samples, and dual phases containing martensite and γ phase were present for high cobalt samples. It was also found that CoNiGa alloys in this study exhibit austenitic transformation temperatures higher than 340°C, showing their great potentials for developing as high-temperature shape-memory alloys.
Yafang Han et al.
Y. Q. Ma et al., "Heusler Type CoNiGa Alloys with High Martensitic Transformation Temperature", Materials Science Forum, Vols. 546-549, pp. 2241-2244, 2007