Parameters of martensite transformation and structural state in rapidly quenched Ti35Ni15Cu shape memory alloys

Abstract

Influence of the quenching rate on the martensite transformation parameters (transformation temperatures and hysteresis) of 50Ti35Ni15Co shape memory ribbons obtained by meltspinning technique has been studied. Increase of quenching rate results in decrease of the B2⇔B19 and B19⇔B19′ martensite transformations temperatures, broadening of direct and reverse transformation intervals, decrease of hysteresis. The B2-type ordering takes place during rapid solidification. Rapid solidification of 50Ti35Ni15Cu alloy results in fine β-phase grain size structure with relative large size scattering. Two types of martensite morphology, plate-like and triangular shapes, have been observed in ribbons.