Dynamic properties of Ti51Pd30Ni19 high-temperature shape memory alloy under different heat treatment conditions

Ti-51 Pd-30 Ni-19 alloy was prepared in a different heat treatment state for retaining different dynamic mechanical properties. It has been found that specimens annealed at 1273 K followed by furnace cooling or by quenching exhibit different phase transformation behaviour. Subsequent annealing at lower temperature (after rolling) does not change the transformation sequence. DMTA (dynamic mechanical thermal analysis) measurement results reveal that the variation of the elastic modulus is different for the two kinds of transformation, which show elasticity softening and elastic step, respectively. The elastic modulus of low-temperature martensite differs as well. It has been found that damping of the peaks occurs on both heating and cooling the alloy across the phase transformation temperatures. The damping properties, tan delta, of the new phase possess higher values than those of the parent phase.