退火工艺对Ti_(50.2)Ni_(29.8)Cu_(20)合金薄带中马氏体相变的影响

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

通过快速凝固法制备Ti50.2Ni29.8Cu20合金薄带,并利用XRD(X射线衍射仪)、DSC(差示扫描量热仪)、TEM(透射电子显微镜)等手段研究退火温度和退火时间对Ti50.2Ni29.8Cu20合金薄带马氏体相变的影响。结果表明,退火处理后Ti50.2Ni29.8Cu20合金薄带的室温相主要是B19马氏体和少量的Ti2Ni析出相,在冷却和加热过程中只发生B2-B19单步马氏体相变;Ti50.2Ni29.8Cu20合金薄带的马氏体相变温度随退火温度的升高先升高,但当退火温度升高到700℃时又略有降低,薄带的相变热滞随退火温度的升高而减小,从13.4℃减小到8.7℃;Ti50.2Ni29.8Cu20合金薄带的马氏体相变温度随退火时间的增加而增加,而薄带的相变热滞对退火时间不敏感。

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 Ti2 Ni 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.