Characterization of high damping TiNi shape memory alloy

TiNi shape memory alloys exhibit superior shape memory effect, superelasticity, and high damping capacity. The damping behaviour of a ternary TiNiCu7 alloy were characterized by dynamic mechanical analyzer (DMA) instrument, dynamic mechanical thermal analysis (DMTA) and differential scanning calorimetry (DSC) equipment. The loss factor Tan delta, storage modulus E' and loss modulus E " of shape memory alloy aging followed by furnace cooling and air cooling were Measured. It shows that test method and cooling rate of aging have significant effect on the results of damping capacity of TiNi SMA. Internal friction values (Q(-1)) corresponding to cubic B2 parent phase to rhombohedral R phase transformation are as high as 0.14 for the TiNiCu7 alloy measured by DMA in single cantilever mode, lower than that of 0.21 measured by DMTA in three-point bending mode.