Influence of Pre-Deformation Strain on Recovery Performance of Ni47Ti44Nb9 Alloy Φ8mm Pipe Joint

Abstract

Using the method of expanding diameter in low temperature and water bath heating, this paper studied the effect of pre-deformation strain on shape memory recovery characteristics of Ni47Ti44Nb9 alloy Φ8 mm pipe joint. The results showed that the transformation hysteresis was relative stable along with the pre-deformation strain more than 12.1%, which was 130°C. And the radial recoverable strain got maximum value 8.4% when the pre-deformation strain was in 10.8%~12.5%. But the radial recovery rate of inside diameter declined smoothly with the pre-deformation strain. Systems considering the three parameters of transformation hysteresis, recoverable strain and strain recovery rate, it seemed the excellent predeformed strain for Ni47Ti44Nb9 alloy Φ8 mm pipe joint was just in 12%~17%.