Effects of thermal cycling on the temperature memory effect of TiNiNb alloys

The temperature memory effect (TME) in Ti₅₀Ni₁₅Nb₃₅ and Ti₄₈Ni₁₇Nb₃₅ alloys was investigated by using differential scanning calorimeter (DSC). After several incomplete thermal cycles upon heating to the arrest temperature, the TME appeared in the next 30 complete thermal cycles. This is contradictive to the previous understanding, that is, TME could be erased totally by one complete thermal cycle. In our research, we also found that the numbers of the incomplete thermal cycle plays an important role in inducing this repeatable TME. However, with increasing of heating rate, the memory effect became weaker and disappeared within fewer cycling numbers. These were considered closely relating to the existence of a large number of interfaces between the TiNiNb and (Nb, Ti) phases.