Effect of NiTi content and test temperature on mechanical behaviors of NiTi–PU composites

For purpose of developing damping materials with increased damping capacity over a wide band, NiTi–PU composites were fabricated by vacuum molding polyether polyurethane melt with NiTi alloy chips additive. The composites were tested using three-point bending at various testing temperatures. Appreciable improvements were observed in bending modulus and load-deflection hysteresis loops of PU matrix. The bending modulus and hysteresis loop area of a composite with 70% NiTi volume content reach a maximum, which are 5.4 times and 5.6 times higher than those of PU matrix, respectively. The mechanism of bending modulus enhancement of NiTi additive was discussed. Keywords: Nitinol, Polyurethane, Composites, Bending modulus, Hysteresis loop