The affection of annealing process on the Ti_(50.2)Ni_(29.8)Cu_(20) shape memory alloy ribbons

In the paper the Ti50.2Ni29.8Cu20 alloy ribbons were prepared by single-roll melt spinning technique and the affection of annealing process on the martensite transformation of the Ti50.2Ni29.8Cu20 alloy ribbons was studied by DSC(using differential scanning calorimetry),XRD(X-ray energy-dispersive spectroscopy system) and TEM(Transmission Electron Microscope).The results showed that,the phase in room temperature mostly was B19 martensite with some Ti2Ni precipitates in the Ti50.2Ni29.8Cu20 alloy ribbons after annealing,and there was only the one-stage B2-B19 martensite transformation during cooling and heating process;the Martensite Temperature(Ms) increased firstly and then decreased slightly with the increase of the anneal temperature,and the transformation hysteresis decreased slowly which was from13.4 K decreased to 8.7 K with the increase of the anneal temperature;the Martensite Temperature(Ms) increased with the increase of the anneal temperature and the thermal hysteresis is not sensitive to the anneal time.